Fulltext search in archive



« advanced mode »

 previous    ...   3   4   5   6   7  8   9   10   11   12   ...    next 

Results 181 to 210 of 416:

Effect of ewes entry order into milking parlour on milkability and milk compositionOriginal Paper

Lucia Mačuhová, Vladimír Tančin, Juliana Mačuhová, Michal Uhrinča», Lucie Hasoňová, Jana Margetínová

Czech J. Anim. Sci., 2017, 62(9):392-402 | DOI: 10.17221/11/2016-CJAS

The aim of the present investigation was to evaluate how the order in which the ewes in a milking group enter the milking parlour affects their milkability and milk composition. Therefore, the order of entry into the milking parlour was evaluated in ewes of one flock (n = 353) during six evening milkings. In all, the sheep were milked in 15 milking groups. The sheep entering the milking parlour in the first milking group achieved 15 points and the sheep of each next milking group one point less, i.e. the sheep of the last group achieved 1 point. In the analysis, only the ewes with the highest and the lowest average number of points were included and assigned to the first (FG, n = 19) and the last group (LG, n = 29), respectively. After the last milking, the individual milk samples were collected from the jar to analyze the composition and somatic cell count. Machine milk yield in 30 s (0.15 ± 0.09 and 0.11 ± 0.05 l) and 60 s (0.26 ± 0.16 and 0.19 ± 0.10 l), peak flow rate (1.04 ± 0.39 and 0.77 ± 0.29 l/min), and latency time (14 ± 3 and 20 ± 13 s) significantly differed (P < 0.05) between FG and LG, respectively. Total milk yield (0.41 ± 0.17 and 0.35 ± 0.14 l) and machine milk yield (0.27 ± 0.15 and 0.22 ± 0.10 l) tended to be higher (P = 0.05 and P = 0.09) in FG than in LG, respectively. No significant differences were observed in milk composition between FG and LG. It seems that ewes which enter the milking parlour in early milking groups have better parameters of milkability than those milked in later groups.

Genetic relationship between type traits, number of lactations initiated, and lifetime milk performance in Czech Fleckvieh cattleOriginal Paper

Luboą Novotný, Jan Frelich, Jan Beran, Ludmila Zavadilová

Czech J. Anim. Sci., 2017, 62(12):501-510 | DOI: 10.17221/60/2017-CJAS

Genetic relationship was analyzed between type traits and longevity measures in dual-purpose cattle. Data from 91 486 Czech Fleckvieh cows first calved between 2003 and 2009 were used. Longevity was defined as the actual number of lactations initiated per cow and also as functional longevity, which incorporated an adjustment to account for variation in voluntary culling based upon milk production. Lifetime performance was defined as cumulative milk production through the 6th parity. All cows were scored for conformation traits during their first lactation. Genetic correlations between these traits and longevity measures were estimated by bivariate analysis using the DMU variance component program package. Type trait heritabilities ranged from 0.30 to 0.59, while heritabilities for longevity and functional longevity were 0.06 and 0.05, respectively. Heritability of lifetime performance was 0.08. Genetic correlations between type traits and longevity measures ranged from low to intermediate values. Genetic correlations of the measured body size traits to the real and functional longevity ranged from -0.06 to -0.29, for udder traits from -0.02 to 0.33, and for foot and leg traits from -0.03 to 0.17. Genetic correlations between the measured body size traits and lifetime performance ranged from -0.03 to -0.30, for udder traits from 0.05 to 0.47, for foot and leg traits from -0.07 to 0.15. Genetic correlations of composite trait scores for frame, muscularity, feet and legs, and udder with longevity traits ranged from -0.20 to 0.41 and for lifetime performance -0.14 to 0.51. The highest genetic correlations between a type trait and functional longevity were for composite udder score (0.25), feet and legs (0.26), and udder depth (0.33), suggesting that these traits could serve as indicators of functional longevity. We conclude that selection based upon easily and inexpensively measured type traits could improve functional longevity of cows as well as lifetime milk production.

Effect of dietary lupin (Lupinus albus) on the gastrointestinal microbiota composition in broiler chickens and ducksOriginal Paper

Martina Geigerová, Roman ©vejstil, Eva Skřivanová, Eva Straková, Pavel Suchý

Czech J. Anim. Sci., 2017, 62(9):369-376 | DOI: 10.17221/42/2017-CJAS

The purpose of the study was to evaluate the amount of raffinose-series oligosaccharides (RSO) in soybean meal (SBM), whole white lupin seed meal (WLM), sunflower meal (SFM), and rapeseed oil meal (ROM) and to determine whether partial or complete dietary WLM replacement affected the numbers of bacteria in selected groups in the microbiota of broiler chickens and ducks without inducing any weight loss. Total counts of anaerobes, lactobacilli, bifidobacteria, and Escherichia coli in caecal samples from both ducks and broiler chickens, as well as in a crop chyme, in broiler chickens, were determined. Live weights before slaughter were determined. Both broiler chickens and ducks were fed a control diet with SBM (L0) or diet containing 50% or 100% WLM as a substitute for SBM (groups L50 and L100, respectively). In comparison with SBM, WLM contained significantly higher amounts of RSO, and the amounts of oligosaccharides in SFM (1.73 ± 0.26 g/100 g) and ROM (1.79 ± 0.14 g/100 g) were negligible compared to those in WLM (8.26 ± 0.14 g/100 g) and SBM (6.96 ± 0.21 g/100 g). The inclusion of lupin in chicken diets did not significantly affect the monitored bacterial groups in crop chyme, but a complete replacement of SBM with WLM (L100 group) in chicken diets significantly (P ≤ 0.05) increased the counts of lactobacilli in caecal samples. Partial (L50 group) and complete (L100 group) lupin supplementation in the duck diet significantly (P ≤ 0.05) increased counts of lactobacilli and bifidobacteria by at least one order of magnitude. E. coli counts in poultry were not affected by changes in diet. The results of our study indicate that partial dietary replacement of SBM with WLM did not significantly affect the live weight of broiler chickens and ducks, but that complete replacement of SBM with WLM may lead to weight loss.

Response of three laying hen genotypes to two feed calcium levelsOriginal Paper

Mohamed Ketta, Eva Tumova, Darina Chodova

Czech J. Anim. Sci., 2019, 64(12):504-510 | DOI: 10.17221/228/2019-CJAS

The present study aimed to evaluate the effect of two dietary Ca levels (3.00% vs 3.50%) in three hen genotypes (ISA Brown, Bovans Brown and Moravia BSL) on their laying performance and quality of their eggs. In order to evaluate the response to dietary Ca, an experiment was conducted with 300 laying hens. One hundred birds from each genotype were divided into 10 replicates (10 birds/cage/Ca level). To reveal the differences, the following characteristics were measured: hen-day egg production percentage, daily feed intake, egg weight, albumen and yolk weights, Haugh unit, eggshell colour, eggshell weight, eggshell thickness, eggshell strength, egg shape index and eggshell index. A higher Ca level significantly increased the hen-day egg production percentage of Bovans Brown and Moravia BSL, while ISA Brown laying hens had the higher egg production percentage at a lower dietary Ca level (85.97% vs 82.41%). No significant effect of dietary Ca level was observed on any internal egg quality measurements except the Haugh unit. However, the dietary Ca level significantly affected some of external egg quality measurements, namely eggshell colour (P < 0.001), eggshell weight (P = 0.003) and eggshell strength (P = 0.012). The results of the present study show that laying performance and egg quality parameters responded differently according to hen genotype and dietary Ca level. Bovans Brown and Moravia BSL laying hens required higher levels of Ca to keep egg production high, while the eggshell quality measurements were better at the lower dietary Ca level. Thus, it is recommended to adjust the Ca levels in feed to the nutritional requirements of laying hens.

Comparison of different semen extenders and cryoprotectant agents to enhance cryopreservation of rabbit spermatozoaOriginal Paper

Paula Domingo, Maite Olaciregui, Noelia González, Ignacio De Blas, Lydia Gil

Czech J. Anim. Sci., 2019, 64(2):59-66 | DOI: 10.17221/53/2018-CJAS

The purpose of this research was to find a suitable protocol to enhance frozen rabbit sperm preservation analysing the role that seminal plasma (SP) plays and the effect of different cryoprotectant agents on sperm quality 0 and 2 h after thawing. Sperm samples were pooled and divided in eight fractions. Four of them were diluted with BotuCrio® (extender A), INRA 96® plus 6% glycerol (extender B), 6% N, N-dimethylformamide (extender C) and 6% N-methyl-2-pyrrolidone (extender D), respectively. The other four fractions were centrifuged and the supernatant was discarded in order to eliminate SP. Each sample was then resuspended with extender A, B, C and D. Samples were cooled progressively, loaded into 0.5 ml freezing straws and frozen with liquid nitrogen vapour. Thawing was performed by placing the straws into a bain-marie at 37°C for 21 s. Straws were dried and sperm samples placed into Eppendorf tubes to be analyzed by ISAS software, vitality test, HOS test and acrosome integrity test. The best motility and velocity parameters were obtained by extender A (P < 0.050) even when the motility parameter was compared with previous studies using other diluents. Additionally, sperm quality decreased over incubation time (P < 0.050) and no differences were found in samples processed with or without SP. This research revealed that BotuCrio® could be used for rabbit sperm cryopreservation and moreover the improvement of the cryopreservation process of rabbit sperm due to the demonstration that SP removing is not required.

Laying performance, immune response and antioxidant properties of hens segregating for naked neck and frizzle genes under low ambient temperatureOriginal Paper

Moataz Fathi, Ibrahim Al-Homidan, Gamal Rayan, Salah El-Safty, Tarek Ebeid, Osama Abou-Emera

Czech J. Anim. Sci., 2019, 64(5):216-225 | DOI: 10.17221/221/2018-CJAS

Major genes could be introgressed into laying hens to attenuate heat stress. However, under cold and/or moderate ambient temperature, these genes might possess different behaviour. The main objective of this study was to evaluate laying performance, immune response, and antioxidant status of native laying hens segregating for naked neck (Na) and frizzle (F) genes under low ambient temperature. Five genotypes were studied: homozygous naked neck (NaNaff), heterozygous naked neck (Nanaff), homozygous frizzle (nanaFF), heterozygous frizzle (nanaFf), and normally feathered (nanaff). The hens were raised under temperature range 22.2-16.7°C. No adverse effect due to ambient temperature was detected in laying performance for naked neck genotypes. Significant decrease in egg weight was recorded in nanaFF genotype compared to the other genotypes leading to significant decrease in egg mass. Significant improvement in shell thickness was associated with Na and F genes. NaNaff genotype had a significantly higher eggshell strength compared to nanaff. Furthermore, Na and F genes improved cellular mediated immune responsiveness, whereas this improvement did not extend to humoral immunity. Birds carrying F gene in homozygous state had a higher total antioxidant activity compared to the remaining genotypes. It could be concluded that the presence of Na and F genes in laying hens raised under low ambient temperature significantly increased shell thickness and, in turn, improved shell strength. Moreover, they greatly enhanced cellular immunity, particularly in heterozygous naked neck status.

Effect of the composition of starter diet fed in the rearing phase on the performance and certain physiological parameters of Holstein calvesOriginal Paper

Szandra Tóth, Melinda Kovács, Brigitta Bóta, Judit Szabó-Fodor, Gábor Bakos, Hedvig Fébel

Czech J. Anim. Sci., 2019, 64(9):367-376 | DOI: 10.17221/34/2019-CJAS

The objective of this study was to compare the effects of calf starters of different starch and fibre content on the growth, blood and rumen parameters of Holstein female calves during the pre-weaning period. A total of 60 calves were divided into two groups. Group A/B was fed according to a two-phase calf nutrition system: the calves received calf starter "A" (28.5% starch content, 16% neutral detergent fibre (NDF), 9.2% acid detergent fibre (ADF)) in days 7-45 and then calf starter "B" (14.2% starch content, 32.4% NDF, 14.3% ADF) in days 46-70. Calves of group B received calf starter "B" throughout the experimental period. The calves were weaned between 52 and 61 days of life. The data on body weight, weight gain, starter feed intake, blood metabolites and rumen fermentation parameters were collected individually. In the first phase of experiment, the starter feed consumption of A/B group was higher than that of B group (P < 0.05), but it did not manifest in differences in body weight at weaning time. At some of the sampling times, the different composition of starter diets significantly (P < 0.05) influenced the plasma urea, albumin, glucose and triglyceride concentrations. The consumption of diet with different starch and NDF content had no significant effect either on the composition of the rumen microbiota or on the ruminal concentration of volatile fatty acids (VFA) and ammonia. In some cases significant correlations (-0.83 and -0.93; 0.82 and 0.90) were found between the composition of rumen microbiota and ruminal VFA concentration. Feeding a diet of higher starch content (28.5 vs 14.2%) in the first 45 days of life did not affect rumen fermentation, rumen microbiota and the most important blood metabolites, apart from a few exceptions. The production parameters of calves, including total feed intake and body weight gain, were similar in the experiment.

Multi-breed herd approach to detect breed differences in composition and fatty acid profile of cow milkOriginal Paper

Carmen L. Manuelian, Mauro Penasa, Giulio Visentin, Anna Benedet, Martino Cassandro, Massimo De Marchi

Czech J. Anim. Sci., 2019, 64(1):11-16 | DOI: 10.17221/18/2018-CJAS

The objective of the present study was to estimate the effect of breed on milk fatty acid (FA) composition of dairy (Brown Swiss, Holstein-Friesian, and Jersey) and dual-purpose cows (Simmental and Alpine Grey) in multi-breed herds. Information on individual milk samples was collected during routine cow milk testing between 2011 and 2014, and consisted of 285 606 observations from 17 445 cows in 617 herds. Fixed effects included in the mixed model were breed, parity, stage of lactation and the interaction between parity and stage of lactation, and random effects were cow, herd-test-date and residual. Contrast estimates for the studied traits were used to compare specific sets of breeds. Holstein-Friesian produced more milk than the other cattle breeds, with the greatest trans FA and C18:1 and the lowest C18:0 content. Comparison between the specialised dairy vs the dual-purpose breeds highlighted significant differences for all traits except for polyunsaturated FA and trans FA content. Specialised dairy breeds had greater milk saturated FA, short-chain FA, medium-chain FA, C14:0 and C16:0 content, and dual-purpose breeds produced milk with greater content of monounsaturated FA, long-chain FA, C18:0 and C18:1. Results demonstrated that, although specialised dairy produced more milk than dual-purpose breeds, milk FA profile of the latter was more favourable from a human nutrition point of view.

Phosphorus and nitrogen utilization efficiency in rainbow trout (Oncorhynchus mykiss) fed diets with lupin (Lupinus albus) or soybean (Glycine max) meals as partial replacements to fish mealOriginal Paper

A.J. Hernández, D. Roman

Czech J. Anim. Sci., 2016, 61(2):67-74 | DOI: 10.17221/8729-CJAS

The study was conducted to compare two plant ingredients as dietary protein sources for rainbow trout on the basis of feed acceptability, survival, growth, feed conversion, nitrogen and phosphorus utilization efficiency and loading. Two extruded diets were formulated with the inclusion of a soybean meal (DS) and a lupin meal (DL). The control diet was a fish meal (FM) based diet. All diets were isonitrogenous and isolipidic. Triplicate groups of 65 fish (5.10 ± 0.10 g) were assigned to each diet. At the end of the experiment (66 days), all groups of fish fed diets had a similar final growth and feed utilization efficiency (P > 0.05). Nitrogen retention rate was higher for the group fed the control diet and in consequence the calculated loading amount of this nutrient resulted lower when compared with the test diets. However, phosphorus retention was higher in the groups of fish fed the experimental diets (DL 26.58 ± 0.22 and DS 27.67 ± 3.05) when compared to the control diet (22.08 ± 1.12) (P < 0.05). This represents a phosphorus loading of 8.33 ± 0.23, 8.96 ± 1.02, and 11.55 ± 0.67 kg/t production for the diets DL, DS, and control, respectively. Therefore, the results indicate that lupin meal can be used as a possible plant protein source for the formulation of low-phosphorus loading diets for rainbow trout without affecting feed acceptability and growth performance. This legume represents a clear opportunity to supply the high demand for plant protein sources for aquaculture. Further studies are needed to evaluate and compare different lupin species and varieties.

Expression analysis of the porcine Homeobox A11 gene and its association with litter size in Large White pigsOriginal Paper

R. Lin, H. Jia, S. Chen, S. Zhao

Czech J. Anim. Sci., 2016, 61(5):243-249 | DOI: 10.17221/127/2014-CJAS

The homeobox A11 (HOXA11) gene, a well-known transcriptional regulator, plays a critical role in normal development of the uterus. In this study, the porcine HOXA11 gene, including its promoter region, was cloned and sequenced (GenBank Accession No. KF724933). Differential expression levels of HOXA11 in the endometrium at one stage of the estrous cycle and three stages of gestation for Meishan and Large White pigs were investigated. Association between the single nucleotide polymorphism (SNP) and litter size was conducted. Results suggested that expression of the HOXA11 gene was the highest on day 15 and decreased on day 26 of gestation, reaching a minimum level of expression on day 50 of gestation in Large White pigs. Expression of the HOXA11 gene tended to be consistent between day 15 of the estrous cycle and day 26 of gestation, and decreased on day 50 of gestation in Meishan pigs. Series deletion analysis and reporter expression assays identified a promoter region of the HOXA11 gene which possessed a five times higher promoter activity than the pGL3-Basic vector. Using comparative sequencing, a candidate SNP (KF724933:g.2325C>A) was identified. In a Large White pig population, this polymorphism was associated with the number of piglets. In a combined analysis containing all parity groups, sows with the AC genotype had greater total number of born (1.80; P < 0.05) and number of born alive (1.82; P < 0.05) piglets compared with the CC genotype sows. These results indicate HOXA11 may play a role in the regulation of embryo implantation in pigs.

Response to selection of a breeding program for Suffolk sheep in the Czech RepublicOriginal Paper

Martin Ptáček, Jaromír Ducháček, Jitka Schmidová, Luděk Stádník

Czech J. Anim. Sci., 2018, 63(8):305-312 | DOI: 10.17221/21/2018-CJAS

Lamb growth performance traits in relation to parental breeding values (BVs) for these traits were evaluated in a purebred Suffolk sheep population in the Czech Republic. The research lasted over 8 years and included 24 886 lambs. Four relevant parental BVs were observed: BV predicted for lamb live weight direct effect (BVLW-DE), BV predicted for lamb live weight maternal effect (BVLW-ME), BV predicted for lamb musculus longissimus lumborum et thoracis depth (BV-MLLT), and BV predicted for lamb backfat thickness (BV-BT). The lamb live weight (LW; kg), musculus longissimus lumborum et thoracis depth (MLLT; mm), and backfat thickness (BT; mm) were assessed at 100 days of age. A dataset was created using the most current parental BVs for each year (2007-2014) and subsequent growth traits of their lambs in the next season (2008-2015). Linear regressions showed an increased tendency when one point in dam BVs was associated with an increase in lamb LW (0.393 kg; P < 0.01 in BVLW-DE and 0.090 kg; P < 0.05 in BVLW-ME), MLLT (0.340 mm; P < 0.01 in BV-MLLT), or BT (0.243; P < 0.01 mm in BV-BT). Lower (but significant - P < 0.01) values on linear regression were detected for sire BVs, when 0.135 kg of LW, 0.217 mm of MLLT, and 0.214 mm of BT corresponded to 1-point increases of BVLW-DE, BV-MLLT, or BV-BT. This was confirmed by ANOVA evaluation, especially for LW and MLLT traits. Maximal differences (P < 0.05) in lamb LW were 1.84 kg or 0.88 kg regarding to dam or sire BVLW-DE groups. Similarly, the difference (P < 0.05) in lamb MLLT reached 0.82 mm in dam BV-MLLT, while 0.57 mm was detected in sire BV-MLLT groups. These results have practical implications for the objectives of selection schemes used in the Suffolk sheep population in the Czech Republic.

Nonlinear models of Brazilian sheep in adjustment of growth curvesOriginal Paper

Claudia Cristina Paro de Paz, Guilherme Costa Venturini, Enio Contini, Ricardo Lopes Dias da Costa, Luara Paula Lameirinha, Celia Raquel Quirino

Czech J. Anim. Sci., 2018, 63(8):331-338 | DOI: 10.17221/87/2017-CJAS

Growth curves of the Morada Nova sheep males and females were described using nonlinear models and the relationships between body weight and thoracic circumference were evaluated. Altogether 1516 repeated measures of body weight and thoracic circumference of the Morada Nova sheep (668 males and 848 females) taken since birth till 730 days of age were used. The Brody, Richards, von Bertalanffy, Gompertz, and Logistic models have been tested. The Fisher's test (F) was used to verify the differences (P < 0.05) in growth curves between males and females. The Gompertz model presented a significant difference (P < 0.001) for growth curve parameters between males (asymptotic weight (A) = 40.5 kg and maturing rate (k) = 0.0043 kg/day) and females (A = 36.44 kg and k = 0.0028 kg/day). The relationships between body weight and thoracic circumference presented R2 above 0.7 and a high significance (P < 0.0001) for all categories, showing that the thoracic circumference may be a good indicator of body weight. In addition, a significant effect (P < 0.05) of the relationship between thoracic circumference and prediction of animal's body weight was verified using the models of linear, quadratic, and cubic regression. Among the models studied, the Gompertz model presented the best fit and biological interpretation. Furthermore, the Gompertz model indicated the need to separate animals by sex in order to properly meet nutritional requirements and determine adequate slaughter age. Thoracic circumference can be used to predict animal body weight with a high accuracy.

Placental characteristics of German Landrace sows and their relationships to different fertility parametersOriginal Paper

Andreas Vernunft, Melanie Maass, Klaus-Peter Brüssow

Czech J. Anim. Sci., 2018, 63(9):339-346 | DOI: 10.17221/23/2017-CJAS

The placenta is the central foetal organ that ensures a sufficient exchange of nutrients and metabolites for adequate foetal growth. Specific data profiles for placental characteristics from modern pig lines with high fertility and today's genetics are not currently available. This study focuses on describing the placental weight and size of German Landrace pigs and any subsequent relationship to litter number and important fertility parameters for these sows. As a basis for data collection, 55 litters from primi- and multiparous German Landrace sows with a total of 832 piglets were used. From these births, 766 placentas were recovered and weighed, with their lengths measured and the placental efficiency per litter also calculated. Mean placental weights ranged from 179 ± 60 to 422 ± 96 g between litters, and the mean length was between 61 ± 12 and 145 ± 19 cm. The placental efficiency was at a level of 5.1 ± 0.7. The investigated parameters were only slightly affected by the litter number (r = 0.3), and the means did not significantly differ between different litter numbers. With increasing litter size, the piglet weights and placental lengths were significantly decreased (r = -0.4 and r = -0.3), possibly due to limited uterine space. However, litter size had a strong positive correlation with the total litter placental weight (r = 0.7); therefore, in this study, the placental efficiency was not affected by a higher number of piglets per sow. Higher means for placental weights (r = 0.7) and lengths (r = 0.7) in a particular litter significantly improved the piglet birth weights. The reported variability in placental characteristics between litters suggests that there is an opportunity to selectively breed for improved piglet weight and homogeneity and thus improved piglet health and survival.

Genetic differences in eggshell ultrastructural properties of Saudi native chicken breeds kept at high ambient temperaturesOriginal Paper

Moataz Fathi, Tarek Ebeid, Gamal Rayan, Salah El-Safty, Osama Abou-Emera

Czech J. Anim. Sci., 2018, 63(9):363-370 | DOI: 10.17221/29/2018-CJAS

Egg quality and eggshell ultrastructural properties of four Saudi native chicken breeds were compared to detect genetic differences. A total of 480 laying hens at 28 weeks of age, representing four Saudi native breeds of chicken (black, black-barred, gray, and brown) kept under hot environmental conditions (34 ± 1°C) were randomly assigned to the current experiment. Laying hens were housed in individual cages in an open-sided house during hot summer season. A total of 360 intact eggs were randomly collected (90 from each breed) for egg quality assessment. Eggshell samples were prepared to evaluate ultrastructural measurements using a scanning electron microscope. No significant variations between the breeds concerning egg weight, egg-shape index, yolk index, albumen (%), yolk (%), shell (%), and shell thickness traits were detected. Brown breed showed significantly higher Haugh units compared to the other breeds. Moreover, brown breed scored the best for eggshell breaking strength trait (the highest crack resistance), followed by gray, black, and black-barred breeds, respectively (P < 0.005). Total ultrastructural score for mammillary layer measurements was significantly higher in black-barred breed if compared with black, brown, and gray breeds. Gray, brown, and black Saudi native breeds had an outstanding eggshell ultrastructure and, in turn, stiffer and stronger eggshell comparable with black-barred counterpart under high ambient temperatures. At the national level, for cross-breeding and selection programs aimed at producing good quality table and hatching eggs the use of gray, brown, and black breeds can be recommended due to excellent ultrastructural properties of their eggshell.

Linkage disequilibrium and haplotype block structure in Portuguese Holstein cattleOriginal Paper

Mohamed Mahmoud Ibrahim Salem, Gertrude Thompson, Shanyuan Chen, Albano Beja-Pereira, Julio Carvalheira

Czech J. Anim. Sci., 2018, 63(2):61-69 | DOI: 10.17221/56/2017-CJAS

The objectives of this study were to estimate linkage disequilibrium (LD), describe and scan a haplotype block for the presence of genes that may affect milk production traits in Portuguese Holstein cattle. Totally 526 animals were genotyped using the Illumina BovineSNP50 BeadChip, which contained a total of 52 890 single nucleotide polymorphisms (SNPs). The final set of markers remaining after considering quality control standards consisted of 37 031 SNPs located on 29 autosomes. The LD parameters historical recombinations through allelic association (D') and squared correlation coefficient between locus alleles frequencies ( r2) were estimated and haplotype block analyses were performed using the Haploview software. The averages of D' and r2 values were 0.628 and 0.122, respectively. The LD value decreased with increasing physical distance. The D' and r2 values decreased respectively from 0.815 and 0.283 at the distance of 0-30 kb to 0.578 and 0.090 at the distance of 401-500 kb. The identified total number of blocks was 969 and consisted of 4259 SNPs that covered 159.06 Mb (6.24% of the total genome) on 29 autosomes. Several genes inside the haplotype blocks were detected; CSN1S2 gene in haplotype block 51 on BTA 6, IL6 and B4GALT1 genes in haplotype blocks 6 and 33 on BTA 8, IL1B and ID2 genes in haplotype blocks 19 and 29 on BTA 11, and DGAT1 gene in haplotype block 1 on BTA 14. The extension of LD using BovineSNP50 BeadChip did not exceed 500 kb and its parameters r2 and D' were less than 0.2 and 0.70, respectively, after 70-100 kb. Consequently, the 50K BeadChip would have a poor power in genome wide association studies at distances between adjacent markers lower than 70 kb.

Genome-wide analysis of CpG islands in some livestock genomes and their relationship with genomic featuresOriginal Paper

A. Barazandeh, M.R. Mohammadabadi, M. Ghaderi-Zefrehei, H. Nezamabadi-pour

Czech J. Anim. Sci., 2016, 61(11):487-495 | DOI: 10.17221/78/2015-CJAS

CpG islands (CGIs) are an important group of CpG dinucleotides in the guanine- and cytosine-rich regions as they harbour functionally relevant epigenetic loci for whole genome studies. As a matter of fact, since there has not been a formal comparative analysis of CGIs in domestic even-toed ungulate genomes, this study was performed to serve this comparison. The Hidden Markov Model was used to detect CGIs in the genomes. The results indicated that the CGIs number and CGI densities had scant variations across genomes. The goat genome had the highest number of CGIs (99 070), whereas the alpaca genome had the highest CGI density (43.39 CGIs/Mb). Significant positive correlations were observed among CGI densities with chromosome pair number, observed CpG/expected CpG, recombination rate, and gene density. When the size of chromosomes increased, the CGI densities decreased and a trend of higher CGI densities in the telomeric regions was observed. Only 10.96% of CGIs were methylated underscoring this postulation that the majority of CGIs remains to be unmethylated. The highest amount of the methylated CGIs was observed in the introns, intergenic, and coding (CDS) regions and the lowest amount of the methylated CGIs was observed in the promoter regions, implying that the DNA methylation of CGIs may control gene expression at the genome level. Detected differences between even-toed ungulate and other vertebrate genomes showed that CGI densities varied greatly among the genomes. These findings would contribute to better understanding the even-toed ungulate (epi) genomes, the role of CGIs in epigenomic functions and molecular evolution.

Claw health and feed efficiency as new selection criteria in the Czech Holstein cattle Krupová Z., Wolfová M., Krupa E., Přibyl J., Zavadilová L.Original Paper

Zuzana Krupová, Marie Wolfová, Emil Krupa, Josef Přibyl, Ludmila Zavadilová

Czech J. Anim. Sci., 2018, 63(10):408-418 | DOI: 10.17221/44/2018-CJAS

The objective of this study was to calculate economic weights for ten current breeding objective traits and for four new traits characterising claw health and feed efficiency in Czech Holstein cattle and to investigate the impact of different selection indices on the genetic responses for these traits. Economic weights were estimated using a bio-economic model, while applying actual (2017) and predicted (2025) production and economic circumstances. For the actual situation, the economic weights of claw disease incidence were -100.1 € per case, and those of daily residual feed intake in cows, breeding heifers, and fattened animals were -79.37, -37.16, and -6.33 €/kg dry matter intake per day, respectively. In the predicted situation, the marginal economic weights for claw disease and feed efficiency traits increased on average by 38% and 20%, respectively. The new traits, claw disease incidence and daily residual feed intake, were gradually added to the 17 current Holstein selection index traits to improve the new traits. Constructing a comprehensive index with 21 traits and applying the general principles of the selection index theory, a favourable annual genetic selection response was obtained for the new traits (-0.008 cases of claw disease incidence and -0.006 kg of daily residual feed intake across all cattle categories), keeping the annual selection response of the most important current breeding objective traits at a satisfactory level (e.g., 73 kg of milk yield per lactation, 0.016% of milk fat). Claw health and feed efficiency should be defined as new breeding objectives and new selection index traits of local dairy population.

Rumen undegradable protein (RUP) and its intestinal digestibility after steam flaking of cereal grainsOriginal Paper

Maria Chrenkova, Zuzana Formelova, Zuzana Ceresnakova, Catalin Dragomir, Matus Rajsky, Ana Cismileanu, Martin Riis Weisbjerg

Czech J. Anim. Sci., 2018, 63(4):160-166 | DOI: 10.17221/74/2017-CJAS

While it is known that heat treatment of cereal grains generally improves the nutritional value for ruminants, simultaneous information on rumen degradability and intestinal digestibility of the rumen by-pass is scarce, especially for non-starch constituents. The effect of steam flaking at 90°C for 30 min on protein quality of maize, wheat, and barley was studied. In addition to proximal chemical analyses, protein rumen degradability was determined in vitro and intestinal digestibility of rumen undegraded protein was determined using the mobile bag method. No significant effects of steam flaking on chemical composition of cereal grains (crude protein, acid detergent fibre, neutral detergent fibre, and starch) were observed. The protein fractions that are relevant to rumen degradability were significantly influenced by the steam flaking: the non-protein nitrogen fraction (A) was reduced (P < 0.05) by 43-93% for all three cereal grains, whereas the fraction that represents true soluble protein (B1) was reduced (P < 0.05) for wheat grains (by 77%) and barley (by 93%). Although the difference was not significant, a decrease of 41% for B1 fraction was also observed for maize. On the other hand, steam flaking markedly increased buffer insoluble but neutral detergent soluble protein fraction (B2) by 15-25% for all three cereal grains, whereas effects on B3 fraction were not significant. Steam flaking was also associated with an increase of the rumen undegradable protein fraction (C) in the case of barley, from 6.6 to 11.1% of total N (P < 0.05) and wheat, from 5.2 to 8.4% of the total N (P < 0.05). Overall, the changes of the protein fractions led to a considerable increase of the rumen undegradable protein (RUP) for all steam-flaked cereal grains (P < 0.05). Steam flaking also increased (P < 0.05) intestinal digestibility of RUP of the cereal grains (by 3.6-34.8%), leading to a more efficient protein use in ruminants.

Effect of different dietary oil sources on the growth performance, blood characteristics, fatty acid profiles, and expression of lipogenic genes in the liver of broiler chickensOriginal Paper

B.X. Yan, R. Zhao, J.P. Wang, W. Chen, Y.Q. Huang, Z.X. Wang, J.S. Zhang, L.L. Liu, D.F. Qi

Czech J. Anim. Sci., 2015, 60(11):487-497 | DOI: 10.17221/8557-CJAS

The effect of different levels of corn oil (CO) and flaxseed oil (FO) on growth performance, blood characteristics, fatty acid composition, and expression of lipogenic genes in the liver of broiler chickens was studied. Two hundred forty female Cobb-500 broiler chickens at the age of one day (body weight (BW) = 46 ± 4 g) were fed a corn soybean meal based diet containing 5% CO (LC), 3.75% CO + 1.25% FO (FO1), 2.5% CO + 2.5% FO (FO2) or 5% FO (FC). Chickens fed FO1 diet had better BW gain (P = 0.049) and gain/feed ratio (P = 0.006) than those fed LC and FC diets during days 1-21 of age. However, for the whole experimental period (1-42 days of age), the dietary lipid source had no effect on the growth performance. On day 42 of age, the hepatic percentages of 18:3n-3 (P = 0.001) and 20:5n-3 (P < 0.001) were higher in FC than in LC group, which led to a higher content of total n-3 PUFA and lower n-6/n-3 PUFA ratio. The contents of 18:2n-6 (P < 0.05) and Σ n-6 PUFA (P = 0.009) were lower in FC than in LC group. Chickens fed FO1 and FO2 diets had higher Ca2+-ATPase activity and lower lipoprotein lipase activity than those fed LC and FC diets, whereas activities of lactate dehydrogenase and Na+,K+-ATPase were increased by FO2 than by LC diet (P < 0.05). The relative mRNA expression level of lipin 1 in chickens fed FO2 and FC was higher (P < 0.01) than in those fed LC and FO1 diets. Our results demonstrated that higher levels of FO led to hepatic enrichment of n-3 PUFA content and lower n-6/n-3 PUFA ratios in liver and increased the expression of lipin 1 whereas the expression of lipin 2, NADH dehydrogenase subunit 2, Δ-6 fatty acid desaturase, WD and tetratricopeptide repeats 1, and glyceraldehyde-3-phosphate dehydrogenase was not affected.

The "female effect" positively affects the appetitive and consummatory sexual behaviour and testosterone concentrations of Alpine male goats under subtropical conditionsOriginal Paper

E. Carrillo, C.A. Meza-Herrera, A. Olán-Sánchez, P.A. Robles-Trillo, C. Leyva, J.R. Luna-Orozco, R. Rodríguez-Martínez, F.G. Véliz-Deras

Czech J. Anim. Sci., 2014, 59(7):337-343 | DOI: 10.17221/7532-CJAS

The aim of this study was to evaluate the possible action of the "female effect" by evaluating if exposure to estrogenized females would affect sexual behaviour and testosterone concentrations while affecting the length of the reproductive season of Alpine bucks in northern Mexico (26°N). In January, two experimental groups were formed: (i) treated males (MH; n = 8) kept in a pen aside to another pen with four estrogenized females during four weeks; pens were separated by a metal mesh, and (ii) control males (GC; n = 8) which had no contact with any female during the same period. At the end of the study, an appetitive and consummatory sexual behaviour test was performed by exposing males from both groups to estrogenized females. Besides, serum concentrations of testosterone were quantified in each male on days 0 and 28. On day 0 the serum levels of testosterone were similar in both groups (217 ± 86 vs 320 ± 89 ng/dl in MH and GC respectively; P > 0.05). However, on day 28, serum testosterone levels favoured to the MH group (164 ± 56 vs 49 ± 18 ng/dl; P = 0.06). With respect to the consummatory (80%) and appetitive (62%) sexual behaviour, the best reproductive performance was depicted by the MH group with respect to the GC group (P < 0.05). Results obtained confirm a positive action of the "female effect" upon behavioural, reproductive, and endocrinological outcomes, while extending the breeding season of Alpine male goats. These findings should be relevant in the design of clean, green, and ethical reproductive management strategies in goat production systems and potentially important to the animal industry.

Effect of light colour on egg production and egg contaminationOriginal Paper

J. Svobodová, E. Tůmová, E. Popelářová, D. Chodová

Czech J. Anim. Sci., 2015, 60(12):550-556 | DOI: 10.17221/8597-CJAS

The objective of this study was to compare the performance of laying hens, quality of air in poultry house, and microbial contamination of eggshell in laying hens kept under blue, green, red, and yellow light colour in enriched cages. The daily photoperiod consisted of 15 h light, light intensity of 10 lx at bird head level. The laying performance characteristics (hen-day egg production, mortality, and egg weight) were not affected by light colour. Similarly, microbial contamination of the air was not significantly different related to the light colour. There were significant interactions in eggshell contamination between the position of the cage floor and light colour in Escherichia coli (P ≤ 0.042) and Enterococcus (P ≤ 0.019). The highest number of Escherichia coli was detected in eggs from hens housed on the middle floor given yellow light (6.06 log colony forming units (cfu)/eggshell) and the lowest values (3.30 log cfu/eggshell) on the upper floor also under yellow light colour. Similar results were observed in Enterococcus, where the highest contamination was on the middle floor under yellow light colour (5.26 log cfu/eggshell), while the lowest contamination (2.45 log cfu/eggshell) was found on the upper floor under blue colour. The results of our study indicate that the light colour has a minor effect on microbial contamination but the significant influence was in the floor position. The highest microbial egg contamination was found on eggs from the middle floor.

Differences in oviposition and egg quality of various genotypes of laying hensOriginal Paper

Eva Tůmová, Jana Vlčková, Darina Chodová

Czech J. Anim. Sci., 2017, 62(9):377-383 | DOI: 10.17221/22/2017-CJAS

The differences in egg production traits in six laying hen genotypes (brown-egg hens Bovans Brown, Bovans Sperwer, ISA Sussex; white-egg hen Dekalb White; laying hens with tinted shells Moravia Barred and Moravia BSL) and the interactions of genotype and oviposition on egg quality were evaluated. The genotype affected the laying rate (P ≤ 0.003), mean sequence length (P ≤ 0.001), and time of oviposition (P ≤ 0.001). The brown-egg genotypes laid eggs approximately 1 h earlier than the white-egg genotypes and approximately 2 h earlier than the tinted-egg genotypes. Egg shell strength was the lowest in tinted-egg genotypes (P ≤ 0.001) and declined with the time of oviposition (P ≤ 0.002). Egg shell percentage (P ≤ 0.011) and thickness (P ≤ 0.011) were affected by the interaction of genotype and oviposition. None of the effects affected egg weight; however, the proportion of egg components was significantly influenced by the interaction of genotype and oviposition. The study confirmed that the differences in the egg production and egg quality of various genotypes are associated with the laying pattern.

Equilibration and freezing interactions affecting bull sperm characteristics after thawingOriginal Paper

M. Doleľalová, L. Stádník, Z. Biniová, J. Ducháček, R. Stupka

Czech J. Anim. Sci., 2016, 61(11):515-525 | DOI: 10.17221/23/2016-CJAS

The objective was to determine effects of equilibration length and freezing curve type as well as their interactions on motility and live spermatozoa proportion in bull sperm after thawing. The ejaculates of 6 sires were repeatedly collected. Fresh semen was diluted with one extender and divided into 3 groups equilibrated for 30, 120, and 240 min. Subsequently, half straws of each group were frozen using standard 3-phase or 2-phase freezing curve differing in the rate of temperature decrease. The spermatozoa motility (M) was evaluated immediately after thawing and at 30, 60, 90, and 120 min of thermodynamic test (TDT). Live spermatozoa proportion was evaluated after thawing and at the end of TDT. Average of spermatozoa motility (AM), decrease of spermatozoa motility (MD), average proportion of live spermatozoa (ALS), and decrease of live spermatozoa proportion (DLS) through the TDT were calculated. Significant inter-sire differences in AM (0.45-17.0%; P < 0.05-0.01), MD (0.76-12.57%; P < 0.05-0.01), and ALS (0.99-23.8%; P < 0.01) were detected. The longest equilibration ensured the highest M during TDT and AM (+2.72 and +4.58%; P < 0.05-0.01), however higher MD (+4.06%; P < 0.01) compared to standard length as well. Straws freezed using 2-phase curve achieved higher M through TDT, AM (+7.3%; P < 0.01) as well as ALS (+11.77%; P < 0.01). The 2-phase curve presented higher M compared to the 3-phase freezing curve within all equilibration lengths. Significant differences in AM, MD, and ALS (0.45-6.78%, 0.62-5.35%, and 20.79-21.11%; P < 0.05-0.01) between equilibration length vs freezing curve interactions were determined. Results document the importance of equilibration length, freezing curve, and their interaction effect on live spermatozoa proportion and sperm motility after thawing as well as necessity of individual conditions for bulls semen processing and insemination doses production.

Effects of age and nutritional status at mating on the reproductive and productive traits in Suffolk sheep kept under permanent outdoor management systemOriginal Paper

Martin Ptáček, Jaromír Ducháček, Luděk Stádník, Milena Fantová

Czech J. Anim. Sci., 2017, 62(5):211-218 | DOI: 10.17221/63/2016-CJAS

This study examined the variability of reproductive and productive traits in Suffolk sheep (a commercial flock, n = 316 ewes) with regard to the dams' age or the nutritional status of sheep at mating under a year-round outdoor management. Data were collected across a 3-year monitoring period (totally 655 observations). The fixed effects of dam's age (dams grouped as: 2, 3, 4, 5, 6 years and older), ewe's live weight (LW; ewes grouped as: < 72 kg; 72-83 kg; > 83 kg), and backfat thickness at mating (BT; ewes grouped as: < 7.9 mm; 7.9-10.5 mm; > 10.5 mm) were evaluated. The dam's age influenced reproductive and productive traits such that 2- and 6-year and older ewes reached the lowest values. Ewes with LW > 83 kg had significantly higher lambing rate (11.8%) compared to those with LW < 72 kg. The group of ewes with LW < 72 kg gave birth to a significantly lower number of live lambs in litter (-8.9%) in comparison with LW < 83 kg group. An increase (9.9%; P < 0.01) of total litter weight at birth or an increase (12.5%; P < 0.05) of total litter weight at 100 days of age were detected in LW > 83 kg group compared to LW < 72 kg group. BT > 10.5 mm ewes had by 8.9% lower lambing rate (P < 0.05), by 6.8% lower litter size (P < 0.05), by 14.5% lower number of live lambs in litter (P < 0.01), and by 8.6% lower total litter weight at birth compared to BT < 7.9 mm ewes. A significantly lower total litter weight at 100 days of age (-10.8%) and a significantly lower total litter gain from birth to 100 days of age (-11.5%) were detected in BT > 10.5 mm ewes in comparison to BT 7.9-10.5 mm ewes.

Effects of thermal manipulation during late incubation period on post-hatch thermotolerance in ostrichOriginal Paper

M.A. Elsayed

Czech J. Anim. Sci., 2016, 61(9):421-431 | DOI: 10.17221/79/2015-CJAS

The effects of thermal manipulation (TM) during late ostrich embryonic development on hatchability, body weight, biochemical and hormonal changes, and the ability of hatching chicks to cope with thermal challenge in days 6-8 of age were examined. At 35 days of incubation, two hundred fertile eggs were weighed and divided into two equal groups with five replicates. The first group was exposed to 36.5°C and 25% relative humidity (RH) (control), while the second group was exposed to 38.5°C and 45% RH for 3 h daily in days 35-37 of incubation (thermal manipulation). At days 6-8 of age, the hatched chicks from each treatment were randomly divided into two groups: control group (exposed to 32 ± 1°C), and thermal challenge group (exposed to 40 ± 1°C for 3 h daily). Hatchability rate was significantly lower with high incubation temperature as compared to the normal incubation temperatures. Embryonic TM and thermal challenge in days 6-8 of age reduced significantly total protein, albumin, and triiodothyronin concentrations and elevated uric acid, creatinine, triglycerides, and glucose concentrations as compared with the control. The level of corticosterone was significantly higher in the thermal challenge group as compared to the control. In conclusion, exposing the ostrich embryos to TM (38.5°C) during late embryonic development induced physiological changes that may represent epigenetic adaptation to TM. The same mechanisms are employed for increasing the ability to improve thermotolerance post-hatch.

Structure of 0+ juvenile fish assemblages in the modified upper stretch of the River Elbe, Czech RepublicOriginal Paper

Z. Valová, M. Janáč, J. ©vanyga, P. Jurajda

Czech J. Anim. Sci., 2014, 59(1):35-44 | DOI: 10.17221/7192-CJAS

In August 2007, the 0+ juvenile fish assemblage of the upper River Elbe was surveyed using electrofishing. Thirty-six localities were sampled along a 177 km long section between the towns of Verdek and Brandýs nad Labem (river km (RKM) 136-313). Four localities with natural riverbeds, 14 channelized stretches, nine beaches, and nine backwaters were sampled. Altogether, 4521 0+ juvenile fishes were caught, belonging to 26 species. A decrease in species richness and abundance was evident near Hradec Králové, while decreased species abundance was noted along the navigated stretch below Přelouč. The highest catch-per-unit-effort (CPUE), species richness, and Shannon index values were observed at beach habitats, the lowest in channelized habitats, and intermediate values in backwaters. Generally, rare beach habitats had significantly more rheophilic species than other habitats, while backwaters had significantly more eurytopic species and higher CPUE for limnophilic species. Backwaters and channel habitats, however, did not differ in any other 0+ fish assemblage parameter studied. The study demonstrated the importance of beaches for fish assemblages along navigable channels. Surprisingly, however, backwaters were not confirmed as important nursery habitats.

Bones quality indices in laying hens fed diets with a high level of DDGS and supplemented with selected feed additivesOriginal Paper

S. ¦wi±tkiewicz, A. Arczewska-Włosek, D. Józefiak

Czech J. Anim. Sci., 2014, 59(2):61-68 | DOI: 10.17221/7230-CJAS

An experiment with 192 caged ISA Brown laying hens, fed a diet containing a high level of corn distillers dried grains with solubles (DDGS), was conducted to determine the influence of selected feed additives on biomechanical and geometrical indices of tibia and femur bones. At 26 weeks of age hens were randomly assigned to 8 treatments with 12 replicates (cages of two hens). To week 55, hens were fed isocaloric and isonitrogenous experimental diets either containing or not containing a high level of DDGS (200 g/kg). The diet containing 200 g/kg of DDGS was supplemented or not supplemented with feed additives, i.e. enzymes (xylanase and phytase), sodium butyrate, probiotic bacteria (L. salivarius), herbal extract mixtures (Taraxaci siccum, Urticae siccum, and Salviae siccum), inulin or chitosan. At week 55, inclusion of DDGS in the diet had no effect on biomechemical (bone breaking strength, yielding load, and stiffness) or geometrical (cortex thickness, cross-section area, weight, and length) indices of tibia and femur bones (P > 0.05). Some of the supplements used had a beneficial effect on bone quality in hens fed the diet with a high level of DDGS. Thus, the addition of probiotic bacteria or herb extracts increased the breaking strength of femurs and breaking strength and yielding load of tibias (P < 0.05). The results of this study indicate that DDGS may be included to a level of 20% in the diet of laying hens without any negative influence on bone quality, while such feed additives as probiotic bacteria and herbal extracts may improve the selected biomechanical indices of bone quality of layers fed diets with a high level of DDGS.

Inclusion of yeast-derived protein in weanling diet improves growth performance, intestinal health, and anti-oxidative capability of pigletsOriginal Paper

L. Hu, L. Che, G. Su, Y. Xuan, G. Luo, F. Han, Y. Wu, G. Tian, C. Wu, Z. Fang, Y. Lin, S. Xu, D. Wu

Czech J. Anim. Sci., 2014, 59(7):327-336 | DOI: 10.17221/7531-CJAS

The effects of yeast-derived protein (YP) on growth performance, intestinal health, and oxidative status of weanling piglets were investigated. A total of 80 weaned piglets (PIC 327 × 1050, 26 ± 2 days old, 6.20 ± 0.10 kg) were randomly allocated into 2 groups, 5 pens per each group and 8 piglets per each pen, receiving control diet and diet with inclusion of 4% YP at the expenses of fish meal (YP diet) for a period of 28 days. The diets were formulated to contain similar nutrient levels. Compared with control, piglets fed YP diet had markedly higher overall average daily growth (+14%, P < 0.05) and lower final feed conversion ratio (-8%, P < 0.01). Concentrations of serum serine, cystathionine, histidine, hydroxyproline, and urea were decreased in piglets fed YP diet (P < 0.05), whereas alanine and aspartate were increased (P < 0.01). Moreover, serum antioxidant enzyme activity (glutathione peroxidase) was markedly increased (+19%, P < 0.01) in piglets fed YP diet relative to piglets fed control diet. In addition, feeding YP diet considerably (P < 0.05) increased the copy numbers of lactobacilli and total bacteria in the colon of piglets at the end of the experiment. Furthermore, the mRNA abundance of innate immunity-related genes (TLR4, NF-κB1, and IL-6) was increased (P < 0.06) in the ileum of piglets fed YP diet. Collectively, results of this study indicated that diet with the inclusion of YP improved growth performance and partially enhanced anti-oxidative capability as well as intestinal innate immunity of weaning piglets.

Energy content and amino acid digestibility of extruded and dehulled-extruded corn by pigs and its effect on the performance of weaned pigsOriginal Paper

D.W. Liu, J.J. Zang, L. Liu, N.W. Jaworski, Z.J. Fan, T.T. Wang, D.F. Li, F.L. Wang

Czech J. Anim. Sci., 2014, 59(2):69-83 | DOI: 10.17221/7231-CJAS

Three experiments were conducted to compare raw corn, extruded corn, and dehulled-extruded corn in piglets' feeding. In Experiment (Exp.) 1, 8 barrows (19.9 ± 0.6 kg) were fed experimental diets containing one out of three corn samples and a rice-soybean meal basal diet in a double 4 × 4 Latin square design to determine the digestible energy (DE) and metabolizable energy (ME) in the corn samples using the difference method. The DE content in extruded (14.29 MJ/kg) and dehulled-extruded (14.42 MJ/kg) corn was greater (P < 0.05) than in raw corn (13.57 MJ/kg). In Exp. 2, 5 barrows (26.2 ± 1.3 kg) were fitted with ileal T-cannulas and used in a 5 × 5 Latin square design to determine the apparent (AID) and standardized (SID) ileal digestibility of amino acids (AA). The diets comprised the basal diet, the three corn diets from Exp. 1, as well as a nitrogen-free diet to estimate basal endogenous losses of AA. The AID and SID of isoleucine, leucine, lysine, threonine, and valine in dehulled-extruded corn was lower (P < 0.05) than in raw or extruded corn. In Exp. 3, 108 weaned 35 days old piglets (8.4 ± 1.2 kg) were allotted to one of the three diets based on corn type. Weaned pigs fed diets containing extruded or dehulled-extruded corn exhibited reduced (P < 0.05) weight gain and feed intake than pigs fed diets containing raw corn. The diet containing dehulled-extruded corn resulted in a higher incidence of diarrhoea. In summary, extrusion of corn did not result in improvements in digestibility and dehulling corn prior to extrusion appeared to result in heat damage which reduced ileal digestibility of AA. Substitution of raw corn with extruded or dehulled-extruded corn in starter diets formulated to equal quantities of ME and SID AA content did not improve the performance of weaned pigs.

Effect of housing system and genotype on rabbit meat qualityOriginal Paper

D. Chodová, E. Tůmová, M. Martinec, Z. Bízková, V. Skřivanová, Z. Volek, L. Zita

Czech J. Anim. Sci., 2014, 59(4):190-199 | DOI: 10.17221/7343-CJAS

The effect of the housing system on the carcass characteristics, physical parameters of meat quality, fatty acid composition, and muscle fibre characteristics was studied in some Czech breeds. Ninety-six rabbits from seven different breeds of Czech genetic resources (Moravian Blue, Czech White, Czech Solver, Czech Spotted, Moravian White of Brown Eye, Czech Gold, and Czech Black Guard Hair) and one rabbit commercial hybrid (Hyplus), kept in two housing systems: intensive system (wire-net cages) or alternative (straw-bedded pen), were slaughtered at the age of 91 days. Alternatively housed rabbits had lower weight at slaughter, lower weight of loin, of hind legs meat, and of renal fat than rabbits from cages. The interactions between housing system and genotype were reflected significantly in pH value, and lightness and yellowness of biceps femoris. The highest (P ≤ 0.047) pH was observed in Hyplus (6.68) from cages, while the lowest value was noted in Moravian White of Brown Eye (6.26). The significantly (P ≤ 0.010) lightest meat was detected in Czech Solver (60.93) and the darkest in Czech Gold (47.81). Alternatively reared rabbits showed significantly (P ≤ 0.001) lower monounsaturated fatty acids (MUFA) (26.63%) and higher (P ≤ 0.001) polyunsaturated fatty acids (PUFA) (36.73%) contents than rabbits from cages (36.94% MUFA and 26.23% PUFA). The alternatively housed group had also higher n-3 and n-6 PUFA contents and higher PUFA : SFA ratio than the intensively housed one. Significant interactions (P ≤ 0.001) were observed in cross sectional area (CSA), diameter, and perimeter of muscle fibres of type I. The largest (P ≤ 0.001) CSA of type I muscle fibre had Czech Black Guard Hair from cages (2573.1 μm2), while in pens this breed exhibited the smallest CSA (1219.6 μm2), diameter (38.68 μm), and perimeter (130.2 μm). Fibre type distribution was not affected by any of the monitored parameters. The effect of interactions of the housing system and genotype was manifested mainly in physical and muscle fibre characteristics.

 previous    ...   3   4   5   6   7  8   9   10   11   12   ...    next