Fulltext search in archive

The objective of this paper was to determine basic components of pork and beef (fat, protein, water content) using FT NIR spectroscopy. The samples were analysed on an FT NIR Nicolet Antaris device in a reflec-tance regimen. Reference results from classical analyses were used for the calibration of the device. Calibration models were created using PLS algorithm (method of partial least squares) and verified by cross-validation. High correlation coefficients (R) of calibration were calculated (fat 0.998; protein 0.976; water 0.994), and subsequently of validation as well (fat 0.997; protein 0.970; water 0.993) and very low standard deviations of the calibration and validation (SEC, SEP). No statistically significant differences between the reference and predicted values of determination were detected in Z-test. According to the published results, the NIRS method has a high potential to replace an expensive and time demanding chemical analysis of meat composition.

Ultraweak photon emission measurements were found to be a useful tool for investigating the influence of stress factors on cells. In the present study, induced photon emission of boar spermatozoa was investigated using a luminometer during a 12-day storage at 15°C in Biosolwens extender. It was shown that the day of storage had a significant effect on some photon emission parameters. During storage, a significant increase in the Integral, Peak max. and Slope max. parameters and a decline in the T.-half (fall) parameter were observed. A significant correlation was observed between photon emission parameters and sperm motility. In conclusion, the results of the present study indicate that the measurement of induced photon emission can be an alternative, sensitive and relatively simple method for assessing the effect of preservation on oxidative damage to boar spermatozoa.

At present the laying hen rearing is transformed into alternative housing systems which include a deep litter system. As for the poultry nutrition, the replacement of animal protein with vegetable protein in poultry feed is applied. Therefore, in an experiment we evaluated the quality of eggs from laying hens in the cage system as compared to the deep litter system with vegetable protein substituted for animal protein in their feed. 72 ISA Brown laying hens were placed into the experiment. 36 laying hens were kept in the deep litter system and 36 laying hens were kept in conventional cages for laying hens. For the period of 9 months, 36 eggs from the group in the deep litter system were examined, always at intervals of five weeks (i.e. 8 × 36 eggs) and so were 36 eggs from the group in the cage system (i.e. 8 × 36 eggs). We found out that in the deep litter system the mean egg weight was higher (P < 0.01), shell weight was lower (P < 0.01), egg albumen was higher (P < 0.01), yolk weight did not differ (P > 0.05), yolk cholesterol was higher (P < 0.01), yolk colour was darker (P < 0.05), shell strength did not differ (P > 0.05), all in comparison with the cage system of laying hen keeping. The results of the experiment show that where vegetable protein was substituted for animal protein in the nutrition of laying hens, there were differences in the quality of eggs from laying hens kept in the deep litter system and eggs from laying hens kept in the cage system.

The production of adult steers for beef could be a profitable use of the territory in some mountain areas in the south of Europe, where this production is nearly inexistent, owing to an increase in the demand for meat from adult animals in specialized markets. The objective of this study was to evaluate the profitability of beef production in three breeds adapted to these areas but varying greatly in their mature size. The studied breeds were a specialized meat breed Limousin, a dual-purpose breed - Brown Swiss breed and - a Spanish local breed Asturiana de los Valles. Higher growth rates (P < 0.05) and higher carcass weights (P < 0.05) were achieved by Brown Swiss and Limousin. In relation to carcass value, better results of dressing percentage (P < 0.001), conformation (P < 0.001) and saleable meat percentages (P < 0.001) were obtained byLimousin. Due to preferences of the adult steers market for carcass with high fatness, Brown Swiss and Limousin could be more suitable to make this production profitable than Asturiana de los Valles (4.7 and 4.2 vs. 2.7, respectively, on the EUROP scale).

Three groups of Brown fattened young bulls were studied, comparing the effects of rearing method (suckled vs. bucket reared) and of slaughter weight (400 vs. 480 kg). Suckled animals had higher fatness scores (2.2 vs. 1.3), more dissectible fat (14.5 vs. 9.1%), and higher intramuscular fat content (7.8 vs. 4.6%DM), accompanied by better scores in sensory tenderness (5.2 vs. 3.8) than did the bucket-reared ones. Animals slaughtered at a heavier weight showed a higher dressing percentage (57.5 vs. 53.8%), conformation score (9.2 vs. 6.2), and fat content (fatness score, dissectible fat and intramuscular fat). The meat from animals in the heavier group had lower a* (12.4 vs. 14.2) and higher b* (10.8 vs. 12.9) indexes, as well as higher scores in most sensory traits than the lighter ones.

In this study the change in amino acid profile in cow's colostrum and transient milk during the first week after parturition was examined in a Hungarian Charolais herd. Experiments were carried out with n = 37 Charolais cows in the same herd in the spring (March-April) of two consecutive years (Experiment 1: 2002, n = 15; and Experiment 2: 2003, n = 22). Colostrum and milk samples were taken by hand milking immediately after delivery, and in 24, 48, 72, and 168 hours post partum. Amino acid contents (%) in samples were measured in milk protein with an automatic amino acid analyser. Data were processed by the software of SPSS.10 statistical program package. In the postpartal period, among essential amino acids significant increases were recorded in methionine, isoleucine, lysine, and phenylalanine, and among non-essential amino acids glutamic acid and proline increased significantly. Simultaneous decreases were recorded in valine, cysteine, aspartic acid, serine, glycine, and arginine. Inconsistent figures were determined for histidine, leucine, tyrosine, and alanine content between Experiment 1 and Experiment 2.

Amino acid content before and after heat treatment was assessed in grain of six selected amaranth varieties and four species: Amaranthus cruentus, A. hypochondriacus, A. caudatus and A. hybridus, cultivated in the Czech Republic. High content of Lys and Arg was detected in both heat treated and untreated grains, as well as satisfactory content of Cys and lower levels of Met, Val, Ile and Leu. The latter three amino acids appear as limiting. Chemical scores of essential amino acids and essential amino acid index (EAAI) were determined. EAAI value of 90.4% shows the favourable nutritional quality of amaranth protein, which is almost comparable with egg protein. Heat treatment by popping at 170 to 190°C for 30 s resulted in decreased EAAI to 85.4%. Of the essential amino acids under study, Val and Leu contents decreased significantly (P < 0.05). The relatively high content of essential amino acids in amaranth grain predetermines its use as a substitution of meat-and-bone meals.

Wild spawners of common bream, Abramis brama, were caught in the Kortowskie Lake (north Poland) and transported to a hatchery for artificial spawning. Fish were hormonally induced using GnRH analogue combined with metoclopramide (ovopel). The results of bream reproduction in captivity were compared with fish treated with the combination of hCG and CPE and with control group injected saline. Males from treated groups produced significantly more milt (over 4.3 ml/kg vs. 2.1) of better qualities: spermatozoon concentration (over 9.3 × 10⁹ vs. 6.8) and motility (over 85% vs. 62). Females from the control group did not spawn whereas those from hormonally induced groups ovulated: 62% after CPE treatment and 100% after GnRHa treatment. Generally, the fish after ovopel stimulation showed the best hatchery parameters.

The influence of supplementation of a lecithin emulsifier (0.1%) to the feed mixture for piglets after weaning was studied. 16 piglets in the control group (C - without lecithin) and 16 piglets in an experimental (E) group were monitored in three replications in a 28-day experimental period. We observed higher digestibility of monitored nutrients in the experimental group (crude fat: C = 66.28 ± 12.11, E = 69.75 ± 9.85%, crude protein: C = 78.72 ± 5.47, E = 82.17 ± 2.23%, crude fibre: C = 56.70 ± 12.85, E = 59.10 ± 12.04%, nitrogen free extract: C = 86.67 ± 3.32, E = 87.75 ± 3.00%, ash: C = 63.63 ± 11.59, E = 65.73 ± 10.35%). Statistically insignificantly higher daily average gain (C = 374.1 ± 107.0, E = 399.1 ± 104.7 g) of experimental groups and a lower feed conversion ratio (C = 2.285 ± 0.416, E = 1.768 ± 0.048 kg/kg) were found out. It was also confirmed in an additional field experiment (C = 279, E = 312 piglets from birth to 71 days of age) where average daily gain weight was 270 g in control and 290 g in experimental group. The influence of lecithin on the occurrence of haemolytic strains of Escherichia coli was not proved. This experiment confirmed a positive effect of the lecithin emulsifier supplement on the efficiency of piglets.

The present study deals with the use of high-grain diets with a low proportion of fodder for fattened cattle, and with the evaluation of their effect on the growth intensity and metabolic profile of the animals. Thirty Holstein × Czech Pied bulls were given diets containing from 86.69 to 88.54% concentrates based on crushed cereals in the period from 216^th to 327^th day of age. The growth intensity of bulls was high, with the average daily weight gain of 1.64 kg in the course of the whole experiment. When the average body weight of animals reached 343.67 kg and 450.93 kg, blood samples were taken from the vena jugularis of 10 randomly selected animals for the assessment of acid-base balance and selected biochemical parameters. Slightly decreased pH values and increased pCO₂ were detected by the assessment of acid-base balance. The calculated values of base excess and standard bicarbonate were in the reference range; however in samples of the second collection a highly significant decrease was found (P ≤ 0.01). By a biochemical analysis of blood increased levels of plasma phosphorus were detected in samples of both collections in comparison with the accepted reference range. A statistically highly significant increase (P ≤ 0.01) in plasma urea concentrations was detected in samples of the second collection. Other investigated parameters ranged within the accepted reference values. The results of the experiments show that high-grain diets produced intensive growth with high daily weight gains, without adverse effects on the health status of the investigated bulls. Although some depletion of compensatory mechanisms maintaining the acid-base balance was recorded, no serious disturbance of metabolic profile was registered in the animals.

The effects of three doses of vitamin C (100, 200 and 300 mg/kg) added to the feed of reproductive pheasants on egg production, egg fertility and parameters of hatchability were investigated. In experiments I (1999) and II (2000) birds were kept in outdoor aviaries. In 2000, air temperatures recorded on the farm during the experiment were high (25-30^oC), differing considerably from those recorded in the preceding years. In experiment I no statistically significant differences were shown between the control pheasants and those supplemented with 100 and 200 mg/kg vitamin C in terms of egg production, egg fertility and parameters of hatchability. The poorest results were found in the group of birds receiving a feed supplemented with 300 mg/kg vitamin C. In experiment II, statistically higher egg production and egg fertility were noted, compared to the control group, in the groups supplemented with 100 and 200 mg/kg vitamin C. Compared to the control group, pheasants from these groups were also characterized by higher hatchability from set eggs (by approx. 15 percentage units) and fertilized eggs (by approx. 9 percentage units) and smaller number of unhatched chicks and dead embryos after day 10 of incubation. In experiment II, the beneficial effect of 100 and 200 mg supplements of vitamin C on the studied parameters could result from the soothing action of the vitamin on the effects of heat stress. The present results justify the prophylactic use of vitamin C supplement at 100 mg/kg feed in the nutrition of reproductive pheasants reared in aviaries. Under heat stress (high air temperatures) increasing the dose of this vitamin to 200 mg/kg feed seems beneficial.

The covariance structure was estimated by REML for a joint genetic evaluation of production and reproduction traits for Czech Landrace (58 258 records) and Czech Large White (167 161 records) pigs using four-trait animal models. The following traits were analysed: lean mean percentage at the end of the performance test in the field, estimated from ultrasonic measurements unadjusted for live weight (LM), average daily gain in field test (in g/day) calculated as weight at the end of the test divided by age at the end of the test (ADG), number of piglets born alive in parity 1 (NBA1) and number of piglets born alive in parity 2 and subsequent parities (NBA2+). The heritabilities were in the range from 0.30 to 0.37 for LM, from 0.13 to 0.18 for ADG, from 0.09 to 0.13 for NBA1 and from 0.10 to 0.14 for NBA2+, depending on the breed and on the model (herd-year-season random or fixed). Genetic correlations between production and reproduction traits were estimated to be non-zero. Correlations between traits caused by the herd-year-season effect were mostly positive. As a general conclusion, the joint genetic evaluation of production and reproduction traits is recommended. The herd-year-season effect should be preferably considered as random.

Hair roots are a very attractive source of DNA for microsatellite-based parentage control of breeding animals. However, unlike blood samples, irregular DNA typing results have been observed in assays utilizing hair follicles. The amount of starting material and DNA preparation method are the crucial factors. In order to improve DNA typing results for horse hair roots, two quick preparation methods and additional purification steps were evaluated. PCR efficiency for each approach was expressed as percentage of samples with complete DNA profiles for 12 horse microsatellites. The lowest percentage (22%) of complete DNA profiles was obtained for samples prepared by the proteinase K digestion method. The best genotyping results (94%) were achieved after phenol-chloroform extraction of DNA from samples prepared by the proteinase K digestion method. Direct cleanup of DNA samples with an ethanol-sodium acetate mixture gave comparably good results of microsatellite genotyping (91%). DNA preparation from hair roots with proteinase K digestion followed by DNA purification with ethanol was chosen as the most efficient approach for horse DNA typing under parentage testing.

A study was conducted to determine the relationship between abdominal fat and the intake of methionine deficient diet in broilers. In this study, 66 male broilers at the age of 35 days were used. They were divided into two groups (control, n = 13, and methionine deficient group, n = 53) and all birds were housed in individual pens. During the experiment, normal and deficient diet contained 0.55% and 0.25% methionine, respectively. Control group was fed normal diet for 19 days. Treatment group received methionine deficient diet for 4 days and normal diet for 15 days. Body weight and feed intake were recorded daily. High (HG) and low (LG) groups were theoretically created according to the rates of decreases in individual feed intake. Percent decrease in feed intake of HG and LG groups was 29.4 ± 2.0 and -1.3 ± 1.7, respectively. Abdominal fat in HG and LG groups amounted to 1.62 ± 0.1 and 1.73 ± 0.2%, respectively. The feed conversion ratio of HG and LG groups was 3.1 ± 0.1 and 3.4 ± 0.2, respectively. There was a negative correlation (-0.45 in HG and -0.43 in LG) between the percent decrease in feed intake and abdominal fat.

Forty-seven Kivircik ram lambs, aged 2 months, raised and managed under an intensive system were used to measure the development of testis diameter and length, and scrotum circumference, length and volume, and their association with the development of body growth. The effects of age and body weight of lambs, type of birth and dam age on the development of the five testicular parameters from weaning at 2-6 months of age were investigated. In ram lambs, the respective least-squares means of testis measurements: testis diameter, testis length, scrotum circumference, scrotum length and scrotum volume were 2.55 ± 0.099 cm, 5.83 ± 0.165 cm, 15.23 ± 0.650 cm, 7.24 ± 0.287 cm and 87.57 ± 5.921 cm³ at 2 months; and 2.99 ± 0.099 cm, 6.59 ± 0.164 cm, 14.24 ± 0.657 cm, 10.60 ± 0.290 cm and 157.49 ± 5.987 cm³ at 6 months. The effect of birth type on testis diameter and the effect of dam age on testis length were significant (P < 0.05 and P < 0.01), besides the effects of lamb age and live weight of lambs on the whole testis measurements were significant (P < 0.01).

The evaluation of effects of some non-genetic factors (sex, litter size, age of dams and year of study) on the growth of 85 kids of the Brown Short-haired breed was carried out in a period of two successive years. The analysis of the growth of all kids revealed that in the time interval from birth to Day 90 of age daily gain and final body weight were 181.3 g and 19.52 kg, respectively. As far as the effect of sex was concerned, the intensity of growth was significantly higher in males than in females (P ≤ 0.01) in all periods under study. From birth to Day 90, the respective daily gains of males and females were 200.6 g and 162.0 g. As far as the litter size was concerned, it was found out that daily gains of singles and triplets were higher than those of twins and that the differences between single kids and twins were significant (P ≤ 0.01) in all periods under study. Specifically, daily gains of single kids, twins and triplets in the time interval from birth to Day 90 were 201.4 g; 167.1 g and 175.6 g, respectively. The analysis of the effect of age of dams on daily gains revealed significant effects of this factor on daily gains in the time intervals of Day 30 - Day 60; Day 60 - Day 90; Day 30 - Day 90 and from birth to Day 90 (P ≤ 0.05). With the exception of the period from birth to Day 30, the highest daily gains were recorded in kids of four-years-old dams in all other periods under study. In both years of study, all kids were reared under nearly identical conditions but the effect of year of study on the growth was significant.

Green forage of fourteen lucerne varieties grown at four Experimental Stations of the Research Centre for Cultivar Testing in Słupia Wielka was harvested in these stages: the first growth in the budding stage (cut I), re-growths in the pre-bloom stage of maturity (cut II) 35 days after the first cut, and the next cut, 42 days later (cut III). Three bulls equipped with rumen and duodenal cannulas were used to study rumen degradability by the nylon bag technique and intestinal digestibility by the mobile bag method. The nutritive value of lucerne green forage was estimated according to IZ-INRA (2001) feed evaluation system. The composition of the lucerne cuts differed in DM content (P < 0.01); the highest was found in cut III (226.9 g/kg), the lowest in cut II (182.0 g/kg).The crude protein content (CP) in DM of cuts I and II was similar (P > 0.05) but lower in cut III (P < 0.05). Cut II contained the highest (P < 0.05) levels of crude fibre, neutral detergent fibre (NDF), acid detergent fibre (ADF), cellulose (CE), and acid detergent lignin (ADL), and the lowest of non-structural carbohydrates (NFC) and soluble in neutral detergent cell content (CC), (P < 0.01). The differences between cut I and III in the contents of these components were not significant (P > 0.05). The highest DM digestibility in the total alimentary tract was found for cut I (P < 0.05). The DM of cuts II and III was digested at a similar rate (P > 0.05). There were no significant differences between the cuts in effective degradability, digestibility in the small intestine of the fraction not digested in the forestomachs and total digestibility of CP, CF, NDF, ADF, hemicellulose and cellulose (P > 0.05). The digestion of rumen undegraded CP in the post-rumen part of the alimentary tract was lower compared with the digestion of essential amino acids (81% and 98%; respectively). The first cut harvested in the spring in the budding stage contained about 5% more PDIA and PDIN, but 7% less LFU compared with both cuts of regrowth (cuts II and III) which contained on average: 58 g PDIA; 123 g PDIN and 0.93 kg LFU. All the cuts contained similar levels of PDIE, UFL per kg of DM (106 and 0.76 g, respectively).

Two ruminally cannulated Jersey cows were used to determine in situ ruminal degradability and intestinal digestibility of raw (E0) soybeans and soybeans extruded at 145°C (E145), 155°C (E155) and 165°C (E165). The degradation of dry matter (DM) and crude protein (CP) was estimated using nylon bags suspended in rumen for 2, 4, 8, 12, 16, 24 and 48 h calculating the effective ruminal degradabilities (ERD) for an assumed outflow rate of 0.06/h. Four extra sample bags were incubated for 12 h to determine CP digestibility using the mobile nylon bag method. Cows were fed a ration of 30% concentrate and 70% meadow hay. Soybean extrusion at all temperatures decreased the effective protein degradability significantly (P < 0.05). Soybean processing at the highest heat input (E165) decreased ERD (44.0%) in the rumen significantly while the values for E145 and E155 were similar, 50.8 and 50.3% respectively. Soybean extrusion at all tested temperatures was followed by a significant (P < 0.05) reduction in the proportion of the rapidly degraded DM and CP fractions a, and both the increased proportions and reduced breakdown rate (c) of the fraction b. The intestinal protein digestibility values of the rumen-undegraded protein of extruded soybean were somewhat higher, however the observed differences between treatments were not significant (P < 0.05). Estimated intestinal digestibilities were 87.2, 89.7, 92.0 and 92.6% for E0, E145, E155 and E165, respectively.

The aim of the experiment was to compare the carcass composition of 20 Montbeliarde bulls (M) and 20 Czech Pied bulls (C). The carcass weight of the animals in one group varied minimally and was about 380 kg. The Montbeliarde bulls showed a higher growth rate, expressed by a significantly lower (P < 0.01) age at slaughter (562.6 vs. 626 days) while the live weight (682.9 vs. 690.6 kg) and carcass weight (380.4 vs. 382.6 kg) were comparable, which resulted in a significantly higher (P < 0.01) daily weight gain (1.142 vs. 1.045 kg) and net weight gain (0.676 vs. 0.615 kg). The Montbeliarde bulls showed a greater (P < 0.05) height at rump (144.0 vs. 140.2 cm), worse carcass conformation according to SEUROP (3.24 vs. 2.84), lower proportion of forequarter (44.7 vs. 45.7%) and higher proportion of hindquarter (55.3 vs. 54.3%). As for the carcass composition, no significant inter-breed differences were found in weights and proportions of shanks, meat trimmings, separable fat, bones, round, loin, filet, flank with rib, flank, shoulder and chuck. The Montbeliarde bulls had a significantly lower (P < 0.05) weight and proportion of neck (10.1 vs. 11.1 kg and 5.4 vs. 5.9%) and weight of brisket and rib (17.6 vs. 18.7 kg) and proportion of brisket and rib (9.4 vs. 9.9%, P < 0.01).

Chrysopogon gryllus and Festuca vallesiaca are components of a number of meadow-pasture communities in Serbia. We performed the analyses of phenolics that influence quality and digestibility of grasses to a great extent. Total phenolics were measured spectrophotometrically and phenolic acids by HPLC analysis. The aboveground parts of C. gryllus contained 10.6 mg/g whereas F. vallesiaca of 21.6 mg/g total phenolics. Bound phenolics dominated over free ones in both species. The content of both free and bound p-coumaric, ferulic, p-hydroxybenzoic and syringic acid was higher in C. gryllus (6.34 mg/g) than in F. vallesiaca (3.96 mg/g). Derivatives of cinnamic acid prevailed in both species compared to the benzoic acid derivatives. Low quality of C. gryllus is connected with its high tissue phenolic acids and mediocre quality of F. vallesiaca with the high content of total phenolics that act unfavourably on digestibility of such grasses.

Enterococci (58) from faeces of rabbits of various age (from 2 months to 3 years) and 5 different rabbit farms were isolated and tested for survival in the presence of oxgall, lactic acid production, urease activity, resistance to low pH as well as their binding ability was tested. Fifty percent of enterococcal isolates were identified as Enterococcus faecium, 19% as E. faecalis. All strains showed good survival in the presence of 5% oxgall. The urease activity of isolates was in the range from 0.013 to 17.13 nkat/ml, only E. faecalis EE229 strain did not produce any urease. The survival of strains was tested at pH 3.0 and the percentage of their survival ranged between 62.0% and 90.0%. E. faecium EF1819 strain was found to show the best survival ability at low pH. Particle agglutination assay values of selected enterococci expressed only negative (0) or weakly positive (1) binding of heparin, bovine fibrinogen, porcine fibronectin and lactoferrin. Based on the results, most of the selected enterococci could be promising probiotic feed additives.

An in sacco technique was used to measure NDF degradability and release of Mg, Ca, Zn, Cu, Fe from six forages - lucerne hay from the 1^st cut (LH₁), from the 2^nd cut (LH₂), orchard grass (G), grass silage (GS), red clover silage treated with Feedtech (CS_FT) and/or with Kofasil (CS_KO). The forages differed in the content of NDF and minerals. There were large differences (P < 0.01) in element release in the rumen between experimental forages and the particular elements. The rate of release of elements was higher from LH_1, LH_2, CS_FT,CS_KO than from G and GS. The release of individual elements and NDF over all incubation times is very well expressed by cubic polynomials (R²> 0.9). Overall, across forages the release of mineral elements ranked as follows: Mg > Fe > Cu > Ca > Zn. The minimum and maximum disappeared portions of individual minerals from forages are as follows: Mg 74.7% from G and > 91.5% from LH₁, Fe 29.7% from G and 99.9% from LH₁ and LH_2, Cu 64.3% from G and 99.8% from LH₁ and LH₂, Ca 28.4% from G and 75.4% from CS_FT, Zn 12.0% from G and 38.2% from LH₁, respectively. Calcium and zinc need a longer time for their maximum release. It can be concluded from the results of multiple regression analyses that only the Mg and Ca release is associated depending on NDF and time of observations, with a highly significant influence of forage on Zn and Cu.

Two experiments were carried out to investigate the effect of the time of oviposition on egg quality characteristics in two different housing systems (cages vs. litter). ISA brown hens from 20 to 64 weeks of age were housed in battery cages (550 cm²/hen, 19 526 laying hens in the house) and on deep litter (7 hen/m², 4 652 laying hens in the house). In both houses, eggs were collected daily at three oviposition times 06:00, 10:00 and 14:00 h. Every four weeks, 90 eggs for each house (30 eggs for each oviposition time) were used for egg quality assessment. The results indicated that in cages the highest percentages (P ≤ 0.001) of normal (74.47%), non-standard (0.85%) and cracked (1.80%) eggs were laid in the early morning (06:00 h). On deep litter, however, the highest percentages (P ≤ 0.05) of normal sound eggs were produced at10:00 h (35.43%) and at14:00 h (33.03%). In the cage system, the heaviest eggs (63.01 g) were laid in the early morning (06:00 h) and the highest shell percentage (10.33%) was in eggs laid in the afternoon and also at 10:00 h (10.31%). On the other hand, in the litter housing system, the time of oviposition had no significant effect on egg weight and eggshell quality characteristics except for shell thickness. Morning eggs had greater shell thickness (0.398 mm) than afternoon eggs (0.390 mm). In cages and on litter, statistically significant differences in albumen height, albumen index and Haugh Units were observed between early morning eggs and afternoon eggs and data showed a pattern of relatively higher albumen quality for eggs collected in the afternoon in both systems.

The effect of feed additives: antibiotic (group C), probiotic (group E1) and prebiotic (group E2) on the results of fattening and selected slaughter and pork meat quality traits of two genotypes of pigs (PLW × PL) × BL and (PLW × PL) × Dur, gilts and hogs, was determined. The results obtained for the examined traits in the feeding groups under comparison were slightly differentiated. The growth rate and feed conversion differed between the genetic groups in favour of crossbred fatteners with the proportion of Dur breed (P ≤ 0.01). The mean backfat thickness from 5 measurements and loin "eye" area in fatteners derived from Dur sires as compared to hybrids coming from BL sires were significantly lower (P ≤ 0.01) while the length of carcass was higher (P ≤ 0.01). The gilts were characterized by better meatiness than boars: loin "eye" area, loin weight without backfat and skin, ham weight without backfat and skin differed on the level of P ≤ 0.05, and meatiness of carcass and meatiness of basic cuts at P ≤ 0.01. Significant (P ≤ 0.05) or highly significant (P ≤ 0.01) differences in the proportions of acids: C_18:2, C_18:3, C_20:4, C_22:4 and PUFA in the lipid fraction of MLD were found between the feeding groups. The proportion of the above-mentioned acids was lower in group E2 and higher in group E1 as compared to C. The proportion of the acid C_18:1 was significantly higher (P≤ 0.05) in group E2 as compared to E1. The demonstrated differences indicate the need of further studies in this respect. In pig fattening there is a possibility of effectively replacing feed antibiotics with other additives. The application of biostimulators - probiotic Bactocell or oligosaccharide Bio-Mos instead of the antibiotic flavomycin appeared to be favourable. From the production aspect it seems to be justified to supplement the feed rations for fatteners during the first stage of fattening with feed additives from the group of probiotics or prebiotics.

Fifty-one crossbreed young bulls, progenies of Charolais (CH), Czech Pied (CP), Simmental (SI) and Blonde d'Aquitaine (BA) beef cattle bred at the paternal position crossed by Czech Pied at the maternal position, were reared in a typical production system and slaughtered at an average age of 578 days and live weight of 656 kg. The animals were evaluated for fattening performance and carcass quality traits (live weight at slaughter, age at slaughter, total weight gain, carcass weight, dressing percentage, net daily gain) and meat quality characteristics (dry matter, proteins, fat, ash, pH₄₈, water holding capacity, remission, collagen, area of M. longissimus dorsi and cooking loss). Correlation coefficients were determined in order to discover which of the above-mentioned characteristics influenced textural properties measured by Warner-Bratzler (WB) shear device and compression test (TPA). It can be concluded from the overall assessment of the correlation coefficients that slaughter age (r = 0.68, P < 0.001), net daily gain (r = -0.54, P < 0.001), average lifetime daily gain (r = -0.50, P < 0.001) and pH₄₈ (r = -0.51, P < 0.001) had the major influence on the textural properties measured by WB shears. Meat texture expressed by TPA was mainly influenced by live weight at slaughter (r = 0.55, P < 0.001), carcass weight (r = 0.50, P < 0.001) and pH₄₈ (r = -0.54, P < 0.001). Significant differences (P < 0.001) were found out for the age at slaughter (CH × BA) and (CP × BA), slaughter weight (CP × SI) and (CP × BA) and carcass weight (CP × BA). At the same level of significance further differences were found out for pH₄₈ and water holding capacity (CP × SI), (CP × BA) and cooking loss (CH × CP). Highly significant differences (P < 0.01) in the textural properties (measured by WB shears) were determined between the following breeds: (CH × BA) and (CP × BA). At the level of significance P < 0.05, the highest differences were identified between (CH × SI) and (CP × SI). TPA test showed statistically significant differences between (CH × CP), (CP × SI) breeds at the level P < 0.05.

Measurements were done of some lysosomal proteolytic enzyme activities involved in skeletal muscle proteolysis of the masculus longissimus lumborum et thoracis muscle (MLLT) of bulls. Samples from the same region between the 11th and 13th vertebra were taken after slaughter from Limousin (n = 10), Hereford (n = 10), Charolais (n = 10), Angus (n = 11) and Simmental (n = 11) bulls about 15 months old fed complete diet ad libitum. The activity of cathepsin D was determined as pepstatin (cathepsin D inhibitor) sensitive activity (PSCatD) towards 1% haemoglobin. Pepstatin-insensitive acid (PIA) and leupeptin-insensitive (thiol proteinases inhibitor) acid (LIA) autolytic activities were measured in the presence of 1mM Mg⁺⁺. MLLT was also analysed for RNA, DNA and protein variables. The data were processed by analysis of variance. The highest activities in PSCatD (P ≤ 0.05), AAA (P ≤ 0.01) and LIA (P ≤ 0.05) as well as percentage of inhibition by pepstatin in cathepsin D (P ≤ 0.01) were estimated in Angus bulls, and the lowest in Limousin ones. These breeds differed in the above-mentioned activities by 20.3, 21.1, 31.1 and 13.1%, respectively. RNA/g of tissue was highest in Hereford and lowest in Limousin bulls (by about 15.3%, P ≤ 0.01). Similar differences (14.3%) were between Charolais and Limousin (P ≤ 0.01). CPS (10³ RNA/protein) was higher by 18.3% (P ≤ 0.01) in Charolais compared to the value in Simmental bulls; similar differences were between Hereford and Simmental (16.4%, P ≤ 0.01). The DNA concentration was highest in Hereford (by about 30%) compared to Charolais bulls. Protein/10³DNA ratio (mg/mg) - FCS - was higher by 33.4% in Charolais compared toHereford; RNA/DNA ratio was higher by 40.2% in Charolais compared toLimousin bulls. These results indicate the fast turnover of proteins in the groups of examined bulls and it can be concluded that in hypertrophic MLLT of bulls an anabolic decrease in degradation occurred.