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An experiment was conducted with 1 680 one-day-old turkey poults (720 males and 960 females) of the Hybrid Converter^TM genotype to compare the growth performance of male and female turkeys. The experiment lasted until 119 days of age for males and 126 days for females, during which 6 commercial-type feeds were administered, with changes occurring at 21, 42, 63, 84 and 102 days of age. Performance was evaluated by weekly weighing and measuring feed consumption in each pen at weekly intervals. At 1, 7, 14, 21, 35, 56, 77, 119 (males) and 126 (female) days, 12 birds from each sex were sampled for weights of carcass, liver, gizzard, heart, thighs and breast. The Gompertz equation fitted separately to male and female growth data suggested that the mature weight of males would be by 16 kg heavier than in females (34.6 vs 18.7 kg) and that the females would mature 36% faster than males (0.023 2 vs 0.017 0/day). The weights of liver, gizzard and heart were similar in males and females in the early part of the growth period but they diverged from 35 days for the gizzard, 56 days for the liver and 77 days for the heart. However, the allometric coefficients describing the growth of each of these internal organs in relation to body weight were the same for males and females. Thigh weight was allometrically related to body weight, with males and females sharing the same relationship, but although the slope of the allometric relationship for breast weight in males and females was the same, breast weights in females were heavier than in males at any given body weight. Female turkeys became fatter than males from 56 days onwards.

The aim of this study was to determine the proportion of feed consumed by pigs when they had the choice to meet their nutrient requirements offering a low (LND) or a high (HND) nutrient dense diet on animal performance and feeding behaviour. In total 120 barrows and gilts were allotted to three dietary treatments (LND, HND and a feed choice group, FC). Diets were calculated to keep a constant ratio of megajoule net energy (MJ NE) to nutrient standardised ileal digestible (SID) lysine, SID methionine and cysteine, SID threonine, SID tryptophan, Ca, available P and Na. Pigs of the feed choice treatment that could choose between LND and HND chose an energy content between 13.3 and 13.6 MJ ME or rather 10.1 and 10.4 MJ NE. The ratio between LND and HND changed during the growing period to a higher percentage of HND (26.2% : 73.8% in the starter, 22.0% : 78.0% in the grower and 20.0% : 80.0% in the finisher phase). No differences between barrows and gilts were detected regarding the selected diet. As a result, similar zootechnical performance data were observed for HND and FC, whereas LND led to a declined (P < 0.05) performance. Regarding the feeding behaviour no differences in the parameters meal size and daily feeder visits between LND and HND (P > 0.1) were observed. However, within the FC treatment more and greater meals were consumed (P < 0.05) at the HND feeder compared to the LND feeder. Pigs of modern genetics still have the ability to cover their nutrient requirements choosing between diets differing in nutrient density without impairing performance. Furthermore, the results give no indication for the necessity of different energy levels in diets for sexed pigs.

The aim of the present study was to compare carcass characteristics and meat quality of fast- (Ross 308), medium- (Hubbard JA757) and slow-growing (ISA Dual) chickens (n = 1 980). When the chickens reached an average live weight of 2 kg, 40 birds (males to females, 1 : 1) of each genotype were randomly selected and slaughtered for carcass analysis. Pectoralis major (PM) muscle samples were taken to determine the physical and chemical parameters of the meat quality. The fast- and medium-growing genotypes had higher (+3.24% and +3.84%, respectively) dressing out percentages than the slow-growing chickens. As expected, the breast percentage significantly decreased in the order of fast growth > medium growth > slow growth. The abdominal fat percentage was the lowest in Ross 308 chickens, but the abdominal fat percentage in JA757 and ISA Dual chickens did not differ. For edible organs, fast- and medium-growing chickens had heavier hearts and livers than slow-growing chickens. In contrast, ISA Dual chickens showed heavier gizzards. Genotype dramatically affected the chemical composition of PM muscle. The ISA Dual chickens exhibited a significantly higher proportion of dry matter and protein and lower ether extract and cholesterol content than Ross 308 chickens, with intermediate values for JA757 chickens. The ISA Dual group had a lower ash content than Ross 308 and JA757 groups. In terms of physical parameters, the ISA Dual chickens had higher lightness and yellowness and lower redness, pH 24, and cooking loss than those of the other genotypes. Concerning all genotypes, the shear force values increased from fast- to slow-growing chickens. In conclusion, this study found a difference between the genotypes. Although the slow-growing chickens showed the lowest dressing out and breast percentages compared with the other genotypes, the breast meat of the slow-growing chickens had more favourable nutritional properties.

The aim of the study was to compare the effects of feed restriction on the growth performance and carcass composition of chicken, rabbit and nutria males and females. Feed restriction was applied at a rate of 70% ad libitum from 14 to 21 days of age in chickens, 70% ad libitum from 42 to 49 days of age in rabbits, and 70% ad libitum from 12 to 15 weeks of age in nutrias. Animals were fed ad libitum prior to and following restriction. Carcass composition was evaluated at common slaughter ages, i.e., 31 days in chickens, 70 days in rabbits, and eight months in nutrias. The results showed stronger effects of feed restriction, sex, and their interaction in broiler chickens than in rabbits and nutrias. In chickens, feed restriction increased the sex differences in final body weight, which were associated with interaction of feed restriction and sex (P = 0.009). Feed restriction as a fixed factor significantly affected growth and feed conversion in chickens and it was with no effect in rabbits and nutrias. The effect of feed restriction on carcass composition was negligible in all selected species. With respect to sex, significant differences were observed in chickens in final body weight, daily weight gain, dressing out percentage and breast percentage, in rabbits in loin percentage, and in nutrias in growth and perirenal fat percentage. Results of the study indicated that interactions of feed restriction and sex in growth might be associated with a short realimentation period.

This study investigated the effects of the dietary addition of wormwood (Artemisia montana Pampan) on growth performance, blood characteristics, carcass traits, and meat quality in growing-fattening pigs. One hundred eighty crossed pigs (Landrace × Yorkshire × Duroc), weighing approximately 70 kg, were divided into four groups of 15 head (eight barrows and seven gilts) per pen, and the experiment was replicated thrice. The basal diet (C) was supplemented with 0.5% (T1), 1.0% (T2), and 1.5% (T3) of dried powdered wormwood, and the pigs were fed an experimental diet for six weeks. The average daily weight gain and feed efficiency were significantly higher (P < 0.05) in treatments than in C. On the contrary, the total cholesterol concentration was significantly lower (P < 0.05) in treatments than in C. Additionally, the high-density lipoprotein cholesterol concentration was significantly higher (P < 0.05), and the carcass grade was better (P < 0.05) in the treatments than in C. The ether extract content of the longissimus dorsi (LD) muscle was lower (P < 0.05) in T2 and T3 than that in C. In contrast, the unsaturated fatty acid (USFA) composition in LD muscle was higher (P < 0.05) in the treatments than in C. Additionally, the marbling and flavour of cooked meat were better (P < 0.05) in the treatments than in C. The dietary addition of wormwood increased (P < 0.05) lightness and yellowness of the surface meat colour and decreased (P < 0.05) juiciness of the LD sensory evaluation. Therefore, the dietary addition of wormwood improved growth performance, feed efficiency, carcass grade, USFA composition, and oxidation of protein and lipids in the LD muscle of growing-fattening pigs.

The method of approximating reliabilities of genomic breeding values in the single-step genomic BLUP evaluation procedure of Misztal et al. (2013) was used to evaluate the increase in reliability of breeding values for milk production in dairy cattle brought about by the inclusion of genomic data. Three strategies for approximation of reliabilities were compared: using only domestic records from performance testing of cows in the Czech Holstein dairy cattle population, using the same records in combination with Interbull breeding values of sires expressed as deregressed proofs, and using only the Interbull breeding values of sires expressed as deregressed proofs. The highest average reliability of genomic breeding values was achieved by the strategy using both domestic and Interbull data, for which the approximated reliabilities of genotyped bulls increased by 0.063. This general increase in reliability of genomic breeding values was small due to the small number of reference bulls available for the study. The overall increase in reliabilities for the entire population of dairy cattle was low but detectable. That modest increase was partially dependent on the unfavourable ratio of the number of genotyped bulls to the size of the analyzed population. Inclusion of Interbull data dramatically increased the benefits of genotyping in our test case - a relatively small population with substantial genetic contributions of foreign genes.

In this study, the effect of water temperature, predator's sex, prey density, and the presence of conspecifics on prey consumption of pikeperch (Sander lucioperca) was experimentally tested. In Experiment 1, predators of both sexes [males: total length (TL) = 473 ± 22 mm and body weight (BW) = 1 070 ± 100 g and females: TL = 464 ± 12 mm and BW = 1 060 ± 100 g] were kept in separate tanks and exposed to different densities of prey (Pseudorasbora parva; 3, 6, 12, 24 and 48 prey fishes per tank) under fixed water temperatures of 4.5 °C, 8.5 °C, and 12.5 °C. After 63 days of this experiment, it was found that pikeperch predation was significantly affected by increasing water temperature. The effect of prey density was significant at all tested temperatures. Pikeperch females tended to have the higher prey consumption than males, although that trend was statistically insignificant. Results suggest that increased feeding demands at temperatures above 4.5 °C can lead to predator starvation in conditions of low prey availability. Due to the higher prey consumption, pikeperch females could be more vulnerable to low prey availability during their culture. In Experiment 2, pikeperch were kept at different densities of 1, 2, 4, and 8 individuals per tank supplied with a prey rate of 50 individuals per predator, ensuring ad libitum feeding rate. The average daily prey consumption was significantly higher in the tanks with multiple predators, accounting for 17.6 ± 3.57 prey fishes/day compared to 11.6 ± 2.33 prey fishes/day in the tank with a single predator. These results indicate that pikeperch predation activity and prey consumption can be significantly affected by the water temperature, prey availability, and the presence of conspecifics. The findings contribute to understanding the predatory function, natural feeding request of pikeperch and its potential importance for broodstock culture and broodstock final maturation for a successful spawning season. Also, this information can be used for better management of pikeperch pond aquaculture or bio-melioration process in open water bodies and ecosystems.

The aim of this study was to monitor the Czech Aberdeen Angus population for backfat thickness (BT), musculus longissimus lumborum et thoracis (MUSCLE) and live weight (LW) in relation to environmental and genetic conditions. In this study, we also wanted to display the potential for future inclusion of these parameters into national monitoring. Parameters of BT, MUSCLE and LW were measured at 120, 210, and 365 days of age in 769 Aberdeen Angus calves (417 bulls and 352 heifers) on seven farms. Statistical evaluation was performed in the SAS v9.3 software. The bulls achieved significantly higher (P < 0.01) weights and larger MUSCLE compared to the heifers, although the heifers had higher BT. The age of the dam at calving significantly influenced the growth ability of tested calves, but it did not influence BT nor MUSCLE. The nested effect of the year-season, farm and sire bulls (or genetic background) significantly affected LW, BT and MUSCLE of tested calves. The use of the same breeding bulls on different farms resulted in significant differences in growth parameters. Our results displayed the potential of nationwide monitoring of MUSCLE and BT of beef breeds, as official parameters of the beef performance testing in the Czech Republic. The inclusion of these globally used traits in the Czech breeding system would allow to predict breeding values for the Czech beef population. This would lead not only to general improvement of MUSCLE in the population, but also to the production of better breeding animals and slaughter animals with higher value.

Portulaca oleracea is a widespread herbaceous plant particularly rich in polyunsaturated fatty acids (PUFA), antioxidant compounds and characterised by a healthy omega-6/omega-3 ratio. The focus of this research was to evaluate the effects of Portulaca oleracea supplementation to the diet of laying hens on productive performance, egg physical traits, fatty acid composition and cholesterol content. Twenty-six 24-week-old Warren strain layers were randomly assigned to two different groups of 18 and eight birds, respectively: one group received a commercial diet (C) whereas the other group was given the same control diet supplemented with 20% of dried Portulaca oleracea (PO). Hens were fed for 21 days. Feed and water were provided ad libitum. The poor palatability of the PO diet compromised the optimisation of the productive performance, with a significant reduction of the oviposition efficiency (0.69 vs 0.88 for PO and C, respectively; P < 0.05) and egg physical traits. Considering the egg nutritional traits, dietary PO significantly decreased the yolk proportion of saturated fatty acid (43.0% vs 44.1%, P < 0.05), while it increased the content of PUFA (19.4% vs 17.8%, P < 0.001), and within the latter, both omega-6 and omega-3 proportion significantly increased in comparison with C group (16.4% vs 17.6%, P < 0.001 and 1.46% vs 1.80%, P < 0.001, for n-6 and n-3, respectively). This resulted in an improvement of the omega-6/omega-3 ratio (10.4 vs 11.3 for PO and C, respectively; P < 0.05). Egg yolk cholesterol content did not vary between dietary treatments. It could be concluded that the use of Portulaca oleracea for producing omega-3-enriched eggs is feasible once the problem of palatability has been overcome and the energy requirements of the hens have been covered.

This study was conducted to investigate the effect of Lactobacillus zeae LB2 on the gut microbiota in piglets infected with enterotoxigenic Escherichia coli (ETEC). Thirty-two healthy 7-day-old piglets were randomly divided into four treatment groups: control group (basal diet), LB2 group (supplemented with 1 × 10⁸ CFU/pig/day L. zeae LB2), ETEC group (infected with 1 × 10¹⁰ CFU/pig/day ETEC) and ETEC+LB2 group (LB2 supplementation + ETEC infection). Intestinal contents were collected for DNA extraction and Illumina sequencing. Significant result was observed for alpha diversity in the four intestinal sections, and both ETEC infection and LB2 supplementation showed a higher Chao1 alpha diversity. At the phylum level, Firmicutes and Bacteroidetes were dominant in the healthy piglets, while Proteobacteria were dominant in the ETEC-infected piglets. At the genus level, ETEC infection decreased the abundance of Prevotella, Ruminococcaceae, Lactobacillus, Alloprevotella, Flavobacterium, and Sutterella and increased the abundance of Actinobacillus. The LB2 supplementation reduced the abundance of Ruminococcaceae, Actinobacillus, Porphyromonas, and Alloprevotella, and increased the abundance of Prevotella and Lactobacillus. Both ETEC infection and LB2 supplementation affected several functional pathways associated with cellular processes, environmental information processing, genetic information processing, diseases, metabolism, and organismal systems. In summary, ETEC infection induced dysbiosis of the gut microbiome in piglets, while L. zeae supplementation could positively regulate the gut microbiome during ETEC infection. Therefore, L. zeae LB2 may be an ideal probiotic for the prevention or treatment of ETEC infection.

In this study, the relationships of temperature humidity index (THI) with milk yield and some physiological responses in dairy cattle were investigated. Our goal in the meta-analysis was to find the parameter(s) primarily affected under heat stress. A total of 16 studies with the temperature humidity index value higher than 72, which is an important factor in determining the effect of heat stress, were included in the meta-analysis. The variables of interest in the meta-analysis included: milk yield (kg/day), respiratory rate (breaths/min), rectal temperature (°C). In addition to the meta-analysis, principal component analysis (PCA) was also performed. In the meta-analysis, high variation or heterogeneity (I² > 99%) was determined between the results of the studies. This may depend on many factors (climate, region, number of samples and management etc.). Heterogeneity is desirable in the meta-analysis, because it provides accurate and reliable interpretations of the variances of parameters. Due to high heterogeneity, the results of the studies were combined according to the mixed model. According to the mixed model and PCA results, a linear relationship was determined between the temperature humidity index and these physiological parameters. According to the meta-analysis, at THI > 72, the mean effect size of milk yield was 50%, and the effect sizes of respiratory rate and rectal temperature were approximately 65% and 38%. All three parameters have a significant effect under heat stress (P < 0.000 1). As a result, there is a linear relationship between temperature humidity index, milk yield and physiological parameters. According to the other characteristics, the respiratory rate was determined as the primary response parameter in parallel with the increase in temperature humidity index.

The effect of the reference population size and the number of missing single nucleotide polymorphisms (SNPs) on imputation accuracy was determined. The population imputation method using the FImpute software was applied. The dataset used for the purpose of this study was taken from the database of the Holstein Cattle Breeders Association of the Czech Republic. It contains 1000 animals genotyped with the Illumina BovineSNP50 v.2 BeadChip. Two datasets were created, the first containing the original genotypes, including the missing SNPs, the second containing the same genotypes modified to avoid missing data. In these datasets, animals were randomly selected for a reference population (10, 25, 50 and 75%) and there were randomly selected SNPs for deletion (15, 30, 55, 70, and 95%) in animals that were not used as the reference population. Subsequently, the data accuracy was determined by two parameters: correlation between original and imputed SNPs and percentage of correctly imputed SNPs. Since animals and SNPs were randomly selected, the process including data imputation was repeated 100 times. Accuracy was determined as the average accuracy over all repetitions. It was found that the imputation accuracy is influenced by both parameters. If the size of the reference population is sufficient, the imputation accuracy is higher despite the large number of missing SNPs.

Abstract: Genetic parameters and accuracy of genomic prediction for production traits in a Duroc population were estimated. Data were on 24 828 purebred Duroc pigs born in 2000-2016. After quality control procedures, 30 263 single nucleotide polymorphism markers and 560 animals remained that were used to predict the genomic breeding values of individuals. Accuracies of predicted breeding values for average daily gain (ADG), backfat thickness (BF), loin muscle area (LMA), lean percentage (LP) and age at 90 kg (D90) between pedigree-based and single-step methods were compared. Analyses were carried out with a multivariate animal model to estimate genetic parameters for production traits while univariate analyses were performed to predict the genomic breeding values of individuals. Heritability estimates from pedigree analysis were moderate to high. Heritability estimates and standard error for ADG, BF, LMA, LP and D90 were 0.35 ± 0.01, 0.35 ± 0.11, 0.24 ± 0.04, 0.42 ± 0.11 and 0.37 ± 0.03, respectively. Genetic correlations of ADG with BF and LP were low and negative. Genetic correlations of LMA with ADG, BF, LP and D90 were -0.37, -0.27, 0.48 and 0.31, respectively. High correlations were observed between ADG and D90 (-0.98), and also between BF and LP (-0.93). Accuracies of genomic breeding values for ADG, BF, LMA, LP and D90 were 0.30, 0.33, 0.38, 0.40 and 0.28, respectively. Corresponding accuracies using pedigree-based method were 0.29, 0.32, 0.38, 0.39 and 0.27, respectively. The results showed that the single-step method did not show significant advantage compared to the pedigree-based method.

Supernumerary teats are commonly found in sheep. To investigate the expression levels of hormone receptors in supernumerary teats of Hu sheep, mammary tissue samples were collected from two groups of Hu sheep, four- and two-teat sheep, during adolescent (A), pregnancy (P), lactation (L), and non-pregnancy (N). Using hematoxylin and eosin staining, we found that mammary alveoli were denser in the four-teat sheep than in the two-teat sheep during P and L. Immunohistochemistry and Western blotting were used to detect the expression patterns and relative protein expression levels of the estrogen receptor 1 (ESR1), prolactin receptor (PRLR), growth hormone receptor (GHR), and insulin-like growth factor 1 receptor (IGF1R) in Hu sheep mammary glands during the four periods. All four receptors were mainly expressed in mammary epithelial cells and adipose cells. Furthermore, the expression levels of PRLR and GHR in the four-teat sheep were significantly higher than those in the two-teat sheep during P and L. Our data suggest that four-teat sheep have more developed mammary gland tissue compared with two-teat sheep.

Pregnancy is strictly regulated by neuronal and hormonal factors with an essential role being played by the pituitary gland. We screened for differentially expressed genes (DEGs) in the pituitary that function in goat gestational development. Pregnant (AWGp) and non-pregnant Anhui white goats (AWGn) were analysed by deep-sequencing technology. A total of 12 774 092 and 13 872 327 clear reads were obtained in the AWGp and AWGn libraries, respectively. A total of 2593 genes were labelled as significantly differentially expressed in AWGp compared to AWGn, including 2158 upregulated genes and 435 downregulated genes. These genes included follicle stimulating hormone beta (FSHB) and luteinizing hormone beta (LHB), which showed an involvement in reproductive regulation and downregulation (AWGp vs AWGn). Quantitative real-time PCR (qPCR) results validated the DEG data. Subsequent gene ontology analysis indicated that a large number of these DEGs function in cellular processes, cell structures, and cell binding. The DEGs were also found by Kyoto Gene and Genomic Encyclopaedia analysis to be significantly enriched in 54 pathways, including the GnRH and TGF-beta signalling pathways that affect cell proliferation and hormone secretion. These data also identify genes that may play a role in pregnancy and reproduction in the goat and thus provide avenues for future research.

The influence of calculated inbreeding coefficients on the conception of heifers and cows was analysed by a two-trait binary model for conceived/not conceived after each insemination on 677 234 Czech Holstein cows and heifers with 3 248 299 insemination records as the covariable in a statistical model. The data between 1996 and 2014 were analysed. Various effects and their statistical influence on traits were tested by a generalized linear model. Consequently, genetic parameters were estimated by the Gibbs sampling method and used in predicting breeding values using the best linear unbiased prediction by animal model (BLUP-AM). The mean for the conception rate of cows averaged over lactations was 33.7% and for heifers it reached 53.8%. Average inbreeding coefficient increased from 1% in 1996 to almost 5% by 2013 and was in the range of 0-45%. The rate of inbreeding per generation was 0.20%. Although the effect of inbreeding was statistically significant (P = 0.05) for both traits, the proportion of variability explained by the models was relatively low. Estimated genetic parameters were low for both traits. Coefficient of heritability was 2.00% and 1.30% for cows and heifers, respectively, whereas coefficients of repeatability reached 6.09% and 7.08% for cows and heifers, respectively. The random effect of the permanent environment (PE) reached higher values than the additive genetic variance (G) and explained 5.67% and 4.09% of variability for cows and heifers, respectively. A negative impact of inbreeding on heifer and cow conception was observed, whereby every 10% increase in inbreeding coefficient resulted in a conception decline by 2.23%. Calculated Spearman's rank correlation coefficient between estimated breeding values considering and not considering the effect of inbreeding was close to one. Presented results indicate that inbreeding has a negligible influence on the breeding values of conception. The results also indicate that it is not necessary to include inbreeding coefficient in the routine breeding value evaluation of conception rate of heifers and cows. On the other hand, monitoring of inbreeding is necessary to avoid an increase of its rate.

Genetic parameters for fertility traits in Czech Holstein population were estimated. The database obtained from the Czech-Moravian Breeders Corporation with 6 414 486 insemination records between years 2005-2015 was used. Date of calving of the selected animals was taken from the database of milk records from 2005-2015. Fertility traits were age at first service (AFS), age at first calving (AFC), days open (DO), calving interval (CI) and first service to conception interval in cows (FSC-C) and heifers (FSC-H). The heritability of each trait was estimated using single-trait animal models. The model included fixed effects of herd-year-season of birth, herd-year-month of calving, lactation order, parity, last calving ease, linear and quadratic regressions on age at first insemination in heifers or on age at first calving in cows. Random effects were animal, permanent environmental effect and random residual error. After edits, the final data set included up to 599 901 observations from up to 448 037 animals dependent on traits. The range of heritability estimates was from 0.010 to 0.058. The lowest heritability was for first service to conception interval in heifers, and the highest heritability was for age at first service. Variances of random permanent effects were higher than variance of additive genetic effect in all traits manifested in mature cows. Repeatability ranged from 0.060 to 0.090. Genetic correlations between traits were estimated using a bivariate animal model. High positive genetic correlations were found between AFS-AFC, DO-CI, FSC-C-DO and FSC-C-CI. A moderate genetic correlation was found between AFS-FSC-H and between AFC. A negative correlation was found between AFS-FSC-C. Correlations between other traits were close to zero. The results suggest that the level of these reproductive traits can be improved by selection of animals with high genetic merit.

The effects of the dietary inclusion of a polyherbal formulation based on three powdered herbs (W. somnifera, T. cordifolia, O. sanctum) on some physiological and immune parameters were studied in healthy and stressed laying hens. The effects of the dietary polyherbal formulation were also compared with those of dietary ascorbic acid (AA) supplement, nowadays considered one of the most potent immunostimulant substances widely used as a food supplement.Experimental data did not show any positive effects, or very low ones, on the assessed parameters in healthy hens as a consequence of the two dietary supplementations. On the contrary, the dietary inclusion of the polyherbal mixture or AA partially counteracted the adverse effects in hens subjected to a moderate and transient dexamethasone-induced stress, when ameliorating effects on natural IgM antibody level, specific antibody response, total immunoglobulin content, respiratory burst activity and total antioxidant capacity were shown. The obtained results justify the ethnomedical use of this polyherbal mixture in stressed laying hens in which faster recovery has been demonstrated, whereas healthy specimens did not seem to substantially benefit from the dietary integration, neither with the polyherbal product nor with AA. Thus, the presence of nutraceutical compounds in several herbal plants exerting no side-effects might be useful for exploring them as an alternative to allopathic substances for preventive or therapeutic purposes in poultry.

Fertility in dairy cows has decreased over the last fifty years while milk production per cow has increased. Furthermore, dairy herds become larger resulting in fewer employees per cow, which might also influence reproductive performance. To elucidate the situation in Germany, selected parameters (conception rate, service rate, pregnancy rate, days to first insemination and days open) were studied using data on 148 herds. For statistical analysis the herds were categorized concerning milk yield: (1) < 30 kg, (2) 30‒35 kg, and (3) > 35 kg/cow/day as well as concerning herd size: (1) < 200, (2) 200‒400, (3) 400‒1000 and (4) > 1000 milking cows. There was no difference in conception rate among herds. That means on dairy farms of larger size or with high milk yield the chance of an inseminated cow to become pregnant is the same as in small herds or in herds with low milk yield. Small herds (< 200 cows) had lower pregnancy rates than larger herds (200-400 cows). The pregnancy rate in herds with different milk yield was not statistically different. Though there was a trend that dairy farms with higher milk yield (> 30 kg) had higher pregnancy rates. The statistical differences and trends of pregnancy rates are due to higher service rate in larger herds as well as in herds with high milk yield. Therefore, service rate is the key factor for high reproductive performance on dairy farms. Poor fertility is not associated with high milk yield on herd basis or large herd size but may represent inappropriate farm management.

The aim was to characterize the expression patterns of several genes in the gastrointestinal tracts of Tibetan pigs (TP) and Yorkshire pigs (YP) and to explore their correlation with digestion and growth difference of the two breeds. The body weights and growth of YP and TP were studied at 6, 12 and 24 weeks of age, and their plasma levels of ghrelin (GHRL), leptin (LEP), somatostatin (SST) and cholecystokinin (CCK) were determined by enzyme linked immunosorbent assay (ELISA). Blood and gastrointestinal sections (stomach, duodenum, jejunum, ileum, caecum and colon) were collected and assayed for mRNA expression of the six genes (GHRL, ghrelin receptor (GHSR), LEP, leptin receptor (LEPR), SST and CCK) by reverse transcription-qPCR (RT-qPCR). TP generally had higher mRNA expressions of GHSR, LEP, LEPR, SST and CCK genes compared to YP, and expressed lower levels of the GHRL gene in most tissues of the digestive tract. In both breeds, plasma levels of the expressed proteins were more closely correlated with the feed intake and growth than with mRNA levels of the target genes. Our data indicate that TP possess special gene expression patterns in the gastrointestinal tract compared to YP, which is consistent with its unique feed intake and adaptation to harsh environment.

The objective of this study was to evaluate the association of hoof health on reproduction and production performance, somatic cell count, and longevity in dairy cattle. The data set consisted of records from 19 145 dairy cows at 11 dairy farms in the Czech Republic during years 1998 to 2016. Observations were grouped according to the number of hoof disease (HD) incidence. Each record included a binary variable indicating if HD was observed. The prevalence (% of all cows) observed with HD and its changes according to parity, milk yield, and calving interval were calculated. Great variability among farms was observed. HD detected in the first month of first lactation was associated with 1.5 kg/day lower milk yield and 58 000 cell/ml higher somatic cell count during first lactation. HD detected in the first month of second lactation was associated with 2.6 kg/day lower milk yield and 45 000 cell/ml higher somatic cell count during second lactation. Results from completed lactations showed that observed HD was associated with significantly lower milk yield: 124 kg less during first lactation and 308 kg less during second lactation. Reproductive performance was the poorest in the group with the highest number of HD observations (frequency) within a single lactation (≥ 4). The higher the number of HD frequency per lactation, the greater was the negative association on production and reproductive performance.

Verbascoside, the main component of Lippia citriodora extract, is one of the most powerful free radical scavengers exhibiting a wide biological activity. In in vivo study 20 adult New Zealand white rabbit bucks were divided into two homogeneous groups, one control (CON) and one verbascoside-supplemented (0.1%) in feed mixture (EXP) and later in vitro effects of verbascoside on the motility aspects of rabbit spermatozoa were analysed. The spermatozoa concentration, ejaculate volume, spermatozoa motility, progressive motility, distance parameters, velocity parameters and type of spermatozoa movement were negatively affected by Lippia citriodora leaves extract after the first 4 weeks of dietary treatment, till the end of experiment (8 weeks). Four weeks after the suspension of feed additive supplementation, all spermatozoa traits values returned to the normality, and in line with CON group. For in vitro findings, ejaculates from 10 male New Zealand white bucks were collected using an artificial vagina. Then it was diluted in physiological saline solution containing different concentrations of verbascoside at the concentration of 0, 0.0024, 0.0219, 0.157, 120.0 mg/ml (Ctrl, VB1, VB2, VB3, VB4 groups, respectively), using a dilution ratio of 1 : 4. The obtained data proved that verbascoside at the concentration of 0.0024 and 0.0219 mg/ml had no adverse effect on spermatozoa. Additionally, we found that verbascoside at higher concentrations (0.157 and 120.0 mg/ml) significantly altered all the motility parameters analysed in the experiment. In conclusion a possible negative effect of verbascoside supplementation into feed mixture (0.1%) on semen quality parameters in rabbit bucks as well as in vitro can be stated, obviously considering that target organs of antioxidant activities of phenylpropanoid glycosides are various. In addition it has to be emphasized that the extract showed a reversible action, since the semen traits of treated animals returned to the normality after the dietary administration period.

Although several studies have investigated the factors affecting imputation accuracy, most of these studies involved a large number of genotyped animals. Thus, results from these studies cannot be directly applied to small populations, since the population structure affects imputation accuracy. In addition, factors affecting imputation accuracy may also be intensified in small populations. Therefore, we aimed to compare different imputation strategies for the Portuguese Holstein cattle population considering several commercially available single nucleotide polymorphism (SNP) panels in a relatively small number of genotyped animals. Data from 1359 genotyped animals were used to evaluate imputation in 7 different scenarios. In the S1 to S6 scenarios, imputations were performed from LDv1, 50Kv1, 57K, 77K, HDv3 and Ax58K panels to 50Kv2 panel. In these scenarios, the bulls in 50Kv2 were divided into reference (352) and validation (101) populations based on the year of birth. In the S7 scenario, the validation population consisted of 566 cows genotyped with the Ax58K panel with their genotypes masked to LDv1. In general, all sample imputation accuracies were high with correlations ranging from 0.94 to 0.99 and concordance rate ranging from 92.59 to 98.18%. SNP-specific accuracy was consistent with that of sample imputation. S4 (40.32% of SNPs imputed) had higher accuracy than S2 and S3, both with less than 7.59% of SNPs imputed. Most probably, this was due to the high number of imputed SNPs with minor allele frequency (MAF) < 0.05 in S2 and S3 (by 18.43% and 16.06% higher than in S4, respectively). Therefore, for these two scenarios, MAF was more relevant than the panel density. These results suggest that genotype imputation using several commercially available SNP panels is feasible for the Portuguese national genomic evaluation.

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.

Genome editing technology can make specifically target genomic modifications, resulting in site specific DNA insertion, deletion or replacement in the genome of an organism. We have recently produced genetically engineered (GE) Meishan pigs containing a ZFN-edited myostatin (MSTN) loss-of-function mutation that leads to a clear "double muscle" phenotype as observed for Belgian cattle. In this study, whole genome resequencing was used as an approach to evaluate the safety risk, if any, associated with the introduction of a ZFN-edited myostatin (MSTN) loss-of-function mutation in a local pig breed, the Meishan pigs. The results of resequencing analyses show that the effective data from pigs of wild-type group and MSTN-edited GE group is greater than 99%. The 1× coverage rate is > 98%, and the 4× coverage rate is > 96%. The genetic variation on each chromosome is close to 1. From this whole genome resequencing study, our results demonstrated that 99.7% of single nucleotide polymorphisms (SNPs) are the same in the same genetic variation from both wild-type group and MSTN-edited GE group, implying genomic sequence variations are highly similar between the two groups of pigs.

The aim of the study was to analyze retrospectively the influence of inbreeding on fertility traits in five dog breeds: German Shepherd dog (GSD), Golden (GR) and Labrador (LR) Retrievers, Beagle and the Tatra Shepherd dog (TSD). The data were 436 litters, with the total of 2560 puppies: 1307 males and 1206 females. The parents of the litters were 163 dogs and 228 bitches. For each litter the litter size, number of male and female puppies, sex ratio, and sex difference were calculated. The fixed effects of breed, of litter birth year and linear regression coefficients on litter and parents' inbreeding were included in the linear model for litter traits. The correlations between litter traits and litter parents' inbreeding were also estimated. The average litter size was 5.87 (± 2.53) for all breeds. GSD had the smallest average litter size differences in years and the lowest fluctuations of sex ratio with litter size. In other dog breeds those differences were much bigger. The difference between the number of male and female offspring in a litter depended on the breed. The lowest percentage of inbred parents was found for LR, and the highest for TSD. Mating non-inbred animals, in most cases also unrelated, was frequent in all breeds. The inbreeding level of parents had significant influence on the litter traits only for TSD. For the Beagles low, positive and significant correlation between the number of female offspring in a litter and the dam's inbreeding level and the sex ratio below 0.5 suggests sex ratio disturbance. The correlation coefficients between litter inbreeding and litter size for majority of examined dog breeds were positive but not significant. The conclusion is that in Poland at first obligatory monitoring of the inbreeding level for all breeds should be applied.

Current animal breeding approaches are strongly associated with the development of sophisticated molecular genetics methods and techniques. Worldwide expansion of genomic selection can be achieved by the identification of genetic DNA markers and implementation of the microarray ("chip") technology. Further advancement was associated with next-generation sequencing methods, high-throughput genotyping platforms, targeted genome editing techniques, and studies of epigenetic mechanisms. The remarkable development of "omics" technologies, such as genomics, epigenomics, transcriptomics, proteomics and metabolomics, has enabled individual genomic prediction of animal performance, identification of disease-causing genes and biomarkers for the prevention and treatment and overall qualitative progress in animal production.

Light during incubation can influence embryonic and postembryonic development of chickens, but the underlying mechanisms are poorly understood. Previous studies have demonstrated that red and blue lights during incubation had opposite effects on the development of embryonic melatonin biosynthesis; red light results in the highest and blue light in the lowest amplitude of the daily rhythm. Therefore, in this study, we investigated if exposure to monochromatic red (632 nm) and blue (463 nm) light during incubation can differently influence growth, selected biochemical (glucose, cholesterol, triacylglycerols) and endocrine (corticosterone and thyroid hormones) traits and behavioural parameters during postembryonic development in broiler chickens. For analysis, we used 10 and 11 hatchlings incubated in red and blue light, respectively and 10 birds per each group (six males and four females) in 3-weeks-old broilers. During the rapid growth phase (days 18, 20 and 21 of age), higher body weight was recorded in broilers incubated under red compared to blue light, whereas endocrine and metabolic traits did not differ between the treatments. The improved growth rate was related to behavioural traits, mainly because chickens incubated in red light exhibited more passive (resting, standing, preening, dust bathing) and less active behaviours (walking, foraging, fighting, wing-flapping) than the blue-light incubated birds. The time spent for eating and drinking and the results of the tonic immobility test did not differ between both groups. Our results suggest that red and blue monochromatic light during incubation can differently program the postembryonic development of broilers, with possible consequences for their growth and welfare.

This study compared different methods of determining starch digestibility (in vivo vs in vitro) in wheat grains and evaluated the influence of extrusion on digestibility. In vivo starch digestibility was determined in broiler chickens by calculating the residual starch content in their ilea and the digestibility using a chromium oxide indicator. In vitro digestibility was examined using pepsin and pancreatin. During in vivo testing, the highest digestibility coefficient (DC) was achieved by the Bonanza variety in its extruded form (91.19 ± 0.40%). In contrast, the lowest DC was achieved by the Tobak variety in its non-extruded form (81.45 ± 1.92%). Generally, a higher DC was observed in vivo for extruded forms of wheat. During in vitro testing, the highest DC was achieved by the Stefii variety in its non-extruded form (96.10 ± 0.55%), whereas the lowest DC was observed in the Yetti variety in its extruded form (49.72 ± 0.41%). Overall, the in vitro experiments did not exhibit significant differences between extruded and non-extruded forms of wheat. Linear regression analysis showed a strong relationship (r² = 0.860; 85.98%) between in vivo- and in vitro-derived DC values in all wheat varieties, both in extruded and non-extruded forms. The study showed that in vivo testing is a suitable method for the determination and control of starch levels in extruded materials. However, despite the accuracy of this technique, it is also very demanding in terms of time, space, equipment, and methodological knowledge. Therefore, based on the strong correlation between the in vivo and in vitro assays, we recommend in vitro digestibility testing as a preferable alternative.

The most appropriate model for genetic parameters estimation for calving ease and birth weight in beef cattle was selected. A total of 27 402 field records were available from the Czech Charolais breed. For estimation of genetic parameters for calving ease and body weight, three bivariate models were tested: a linear-linear animal model (L-LM) with calving ease classified into four categories (1 - easy; 2-4 - most difficult), a linear-linear animal model (SC-LM) in which calving ease scores were transformed into Snell scores (Snell 1964) and expressed as percentage of assisted calving (ranging 0-100%), and a bivariate threshold-linear animal model (T-LM) with calving ease classified into four categories (1 - easy, 2-4 - most difficult). All tested models included fixed effects for contemporary group (herd × year × season), age of dam, sex and breed of a calf. Random effects included direct and maternal genetic effects, maternal permanent environmental effect, and residual error. Direct heritability estimates for calving ease and birth weight were, with the use of L-LM, SC-LM, and T-LM, from 0.096 ± 0.013 to 0.226 ± 0.024 and from 0.210 ± 0.024 to 0.225 ± 0.026, respectively. Maternal heritability estimates for calving ease and birth weight were, with the use of L-LM, SC-LM, and T-LM, from 0.060 ± 0.031 to 0.104 ± 0.125 and from 0.074 ± 0.041 to 0.075 ± 0.040, respectively. Genetic correlations of direct calving ease with direct birth weight ranged from 0.46 ± 0.06 to 0.50 ± 0.06 for all tested models; whereas maternal genetic correlations between these two traits ranged from 0.24 ± 0.17 to 0.25 ± 0.53. Correlations between direct and maternal genetic effects within-trait were negative and substantial for all tested models (ranging from -0.574 ± 0.125 to -0.680 ± 0.141 for calving ease and from -0.553 ± 0.122 to -0.558 ± 0.118 for birth weight, respectively), illustrating the importance of including this parameter in calving ease evaluations. Results indicate that any of the tested models could be used to reliably estimate genetic parameters for calving ease for beef cattle in the Czech Republic. However, because of advantages in computation time and practical considerations, genetic analysis using SC-LM (transformed data) is recommended.