The experiment compared the effects of strain and age on egg quality characteristics in ISA Brown, Hisex Brown and Moravia BSL brown-egg laying hens. One hundred and eight ISA Brown hens, forty-five Hisex Brown and forty-five Moravia BSL 20 to 60 weeks old were housed in conventional cages (550 cm 2 per hen). Feed and water were available ad libitum. Eggs were sampled at 21-day intervals, every collecting week 150 eggs per genotype in three age periods, from 20 to 26 weeks, 37 to 43 weeks and 54 to 60 weeks of age. A total of 4,050 eggs were examined. Egg quality characteristics were affected by genotype and age. Egg weight, yolk weight and percentage, Haugh Units increased with the hens' age in all genotypes, but albumen and eggshell percentage decreased, eggshell thickness and strength improved with age. The highest egg weight (65.3 g) and yolk quality (yolk index 45.1%) were found in Moravia BSL at the end of the experiment. In contrast, the best albumen quality (albumen percentage 60.0) values were in Hisex Brown and the eggshell quality measurements (eggshell thickness 0.38 mm) were higher in ISA Brown. -egg layers, strain, ISA Brown, Hisex Brown, Moravia BSL, age, yolk, albumen, shell quality, correlation Brown

It is important to describe weaknesses in rearing calves not only to improve their welfare, but also to detect areas where current scientific knowledge is poorly integrated into practice. A survey of preweaning calf-rearing practices was conducted using a farmer questionnaire. The survey included 136 farms, representing 11.9% of all dairy cows in the Czech Republic. Mean herd size (± standard deviation) was 326 ± 131.4 cows, and mean milk production 7,413 ± 1,389.5 kg per cow per year. We evaluated 59 farms with Holsteins (H) and 77 with the Czech Fleckvieh breed (C). The survey revealed that (1) calving in group pens predominated (67.6% of farms); (2) no disinfection of calf navels occurred on 11.8% of herds; (3) pooled colostrum was fed on 15.4% of farms; (4) colostrum quality was controlled on only 44.1% of farms, and only 73.5% of farms had reserve colostrum stocks; (5) nonmarket waste milk was fed in 64.7% of herds but it was pasteurized in only in 6.8% of herds and acidified in 35.2% of herds; (6) milk replacer was mixed with nonmarket waste milk on 52.9% of farms; (7) 58.8% of farms enabled calves to obtain milk by sucking and 41.2% by drinking from a bucket; (8) the main criterion in weaning was calf age (61.7%), followed by acceptance of starter and concentrated feed (19.9%) and lack of housing capacity (18.4%); and (9) newborn calves were individually housed on 96.7% of farms and group-housed on 3.3% of farms. The most marked differences in calf-rearing management between Holstein and Czech Fleckvieh farms were (1) a higher proportion of operations calving in tie-stalls or stanchions in C (6.5%) versus H (1.7%) farms; (2) a higher proportion of untreated navels on C (15.6%) versus H (6.8%) farms; (3) a lower proportion of C (11.7%) versus H (20.4%) farms feeding pooled colostrum; (4) a lower proportion of C (39%) versus H (50.9%) farms monitoring colostrum quality; (5) sucking milk from nipple buckets predominated (61%) on C farms, whereas drinking from an open bucket was most common (64.4%) on H farms; (6) age was the main criterion in weaning calves of both breeds (C farms: 55.8%, H farms: 69.5%), whereas the second most important criterion was lack of housing capacity (28.6% of farms) on C farms and the amount of consumed starter (25.4%) on H farms. We observed a difference in duration of colostrum period between C herds (median 5d) and H herds (median 4d). A tendency was observed for age of calves at weaning (C herds: median at 9.1 wk, H herds: median at 10 wk).

Genetic and phenotypic correlations between production traits, selected linear type traits, and somatic cell score were estimated. The results could be useful for breeding programs involving Czech Holstein dairy cows or other populations. A series of bivariate analyses was applied whereby (co)variance components were estimated using average information (AI-REML) implemented via the DMU statistical package. Chosen phenotypic data included average somatic cell score per a 305-day standard first lactation as well as the production traits milk yield, fat yield, protein yield, fat percentage, and protein percentage per the standard first lactation. Fifteen classified linear type traits were added, as they were measured at first lactation in the Czech Holstein population. All phenotypic data were collected within the progeny testing program of the CzechMoravian Breeders Corporation from 2005 to 2009. The number of animals for each linear type trait was 59 454, except for locomotion, for which 53 424 animals were recorded. The numbers of animals with records of milk production data were 43 992 for milk yield, fat percentage, protein percentage, and fat-to-protein percentage ratio and 43 978 for fat yield and protein yield. In total, 27 098 somatic cell score records were available. The strongest positive genetic correlation between production traits and linear type traits was estimated between udder width and fat yield (0.51 ± 0.04), while the strongest negative correlation estimated was between body condition score and fat yield (−0.45 ± 0.03). Other estimated correlations were between those two extremes but generally they were close to zero or positive. The strongest negative phenotypic correlations were estimated between udder depth and milk yield and protein yield (both −0.17), while the strongest positive phenotypic correlations were estimated between milk yield, protein yield, and udder width (both 0.32).

ABSTRACT:The impact of polymorphism of the diacylglycerol acyltransferase (DGAT1), butyrophilin (BTN1A1), oxidized low-density lipoprotein receptor (OLR1), and signal transducer and activator of transcription 1 (STAT1) genes on milk production and reproduction traits in 419 Czech Fleckvieh cows was examined using polymerase chain reaction and restriction fragment length polymorphism. The loci DGAT1 and BTN1A1 were observed simultaneously to affect milk production, estimated breeding value of milk production traits, as well as reproduction parameters. Significant differences were found also between genotypes of the STAT1 loci in relation to estimated breeding value of milk production traits. Similar findings in pure dairy breeds suggest that heterogeneous effects of the observed loci can be explained by different genetic backgrounds in various breed populations selected to achieve different commercial goals. Thus, it is necessary to determine variability and influence of a molecular marker in a specific population when considering its inclusion into a breeding programme.

The objectives of this study were to determine and evaluate effect of breed, age and body condition score (BCS) on qualitative and quantitative parameters of bull’s ejaculate. In total, 16 Holstein (H) and 15 Czech Fleckvieh (F) bulls were collected in September 2009 and May 2010. Volume of semen samples, sperm concentration and percentage of motile spermatozoa were evaluated immediately after collecting. Sperm motility was also evaluated after diluting and freezing/thawing of AI doses and subsequently during the short-term test of sperm survival. Percentages of live and pathologic sperm before diluting also were evaluated. The data set was analyzed using a generalized linear model in SAS/STAT software. A statistically significant effect of the breed, age and body condition on qualitative and quantitative traits of bull’s sperm were determined (P < 0.05–0.01). Sperm activity after collection, dilution and freezing/thawing had significantly decreasing character.