Abstract. The study was conducted in 2009–2013 on a total of 1587 (1230 females and 357 males) sheep of meat breeds (Berrichone du cher, Suffolk and Charolaise) and wool-meat breeds (Polish Merino, old type Polish Merino, Corriedale and Żelaźnieńska sheep) at age two to 11 years. Highly significant (P ≤ 0.01) effect of breed on the frequency of scrapie alleles and genotypes, and significant effect (P ≤ 0.05) of sex in the case of old type Polish Merino, were found. Most alleles (ALRR, ALRQ, ALHQ, ALRQ, AFRQ, VLRR, VLRQ) were found in Polish Merino and only two (ALRR and ALRQ) in Suffolk. Amino acid phenylalanine encoded at codon 141 occurred only in combination with AFRQ allele, while leucine in the other six. Seventeen scrapie genotypes were identified, most in Polish Merino and Corriedale (12 each), Żelaźnieńska sheep and Berrichon du cher (5 each), Charolaise (3) and Suffolk (2). Very high frequency of ALRR/ALRR in Suffolk and Berrichon du cher reveals their high genetic resistance to both forms of scrapie. Low frequencies of genotypes susceptible to classical scrapie were found in Charolaise and genotypes suspected to genetic lack of resistance to atypical scrapie in Żelaźnieńska sheep. Many signs of genetic susceptibility to both forms of scrapie were found in Merino and Corriedale, which requires new appropriate breeding programs leading to elimination those conditions from sheep population, especially in old type Polish Merino.
Abstract. The aim of the article has been to provide a comparison of the slaughter value and meat quality in five-week Hubbard Flex and Ross 308 broiler chickens. A higher body weight before slaughter (P ≤ 0.05), weight of eviscerated carcass with the neck and dressing percentage were recorded for Ross 308 crossbreds. Hubbard Flex broiler chicken carcass, as compared with Ross 308 broiler carcass, showed a significantly higher percentage content of wings and leg muscles and a significantly lower content of breast muscle. The breast muscle pH15 values were lower than the leg muscle pH15 values. As for colour lightness (L*) evaluation for breast and leg muscles and the yellowness (b*), in both crossbred groups significant differences (P ≤ 0.05) were found. The discriminants of the sensory broiler chicken breast and leg muscle evaluation compared after thermal treatment were similar. Between the broiler groups, significant differences (P ≤ 0.05) were identified for aroma desirability and leg muscle tenderness.
Abstract. The objective of this study was to investigate variation in productive traits and egg quality in three strains of laying hens: Rhode Island Red (strains R-11 and K-22) and Rhode Island White (strain A-33). The present study confirmed that hen origin (genotype) has an impact on performance, reproductive results, and egg quality traits. The results showed that the analysed strains were in good health during both rearing and production. R-11 and K-22 strains were found to differ considerably from A-33 in terms of the evaluated productive traits, in particular the body weight, the egg weight, and hatchability parameters. The results also demonstrated differences in the quality of eggs from hens of the compared strains. This particularly concerned traits such as shell colour, weight of egg, shell and yolk, and shell quality parameters. It was also confirmed that many of the egg and shell quality traits change with age of the birds. All of the results reported here provide valuable information for characterizing these unique breeding strains.
Abstract. The aim of the study was to analyse the effect of the magnitude of losses in body condition after calving and the duration of the period of its decline on yield in 435 standard lactation periods in Polish Black-and-White Holstein-Friesian cows kept in five barns. The magnitude of losses in body condition after calving and the duration of the period of its decline were estimated on the basis of monthly body condition scores in the 5-point BCS scale, and data pertaining to productivity were obtained from the SYMLEK system. It was determined that the greater the mobilization at the start of lactation of fat accumulated by cows before parturition, the higher was the production of milk, fat, protein and dry matter. The decrease in body condition score was less strongly associated with the basic composition of the milk obtained in the standard lactation period. Longer duration of the negative energy balance was also associated with higher yield of milk, fat and dry matter and with higher content of fat in the milk. Increased length of the period of body condition decline was accompanied by a decrease in protein content in the milk.
Abstract. A key stage in cheese production is the coagulation of milk proteins, leading to the formation of a curd. The aim of the study was to determine how genetic variants of β-lactoglobulin (BLG) and κ-casein (CSN3) are linked to milk coagulability, fat dispersion and the texture of rennet curds. The material for the study consisted of blood and milk samples collected from 213 cows of four breeds: 63 PHF HO, 50 JE, 50 RP and 50 BG. BLG and CSN3 genotypes were determined by PCR-RFLP. A total of 741 milk samples were evaluated, in which chemical composition, the degree of fat dispersion, and coagulation properties were determined. The texture of 228 rennet curds was evaluated. The BLG A allele was associated with significantly (P ≤ 0.01) higher content of non-fat dry matter in the milk and a lower degree of fat dispersion. The presence of the CSN3 B allele was associated with significantly (P ≤ 0.01) higher content of non-fat dry matter and significantly (P ≤ 0.01) shorter coagulation time. The curds from such milk were characterized by greater springiness, gumminess and chewiness (P ≤ 0.05). The most favourable coagulation properties were noted for the milk of cows with the CSN3 B allele. The association between the BLG alleles and the parameters of the suitability of the raw material for processing is less clear.
Abstract. Goose husbandry is characterized by considerable diversity of goslings in terms of body weight. These discrepancies result from a~long laying performance. During different reproductive seasons females lay eggs of different weight. Due to a~positive correlation, egg weight influences body weight of goslings. The influence of egg weight on body weight of geese after rearing and fattening has been investigated. The influence of egg weight on the final body weight of geese as well as egg weight loss during incubation and hatchability indices of chicks have been determined. The research was carried out on 896 hatching eggs of White Kołuda® geese. 160 birds were used for rearing and fattening. The experiment showed a~significant influence of egg weight on egg weight loss in percentage terms during hatching. The biggest loss was recorded in the smallest eggs. Egg weight also influenced the mortality of embryos during incubation. By day 25, the highest mortality was in lighter eggs (below 180 g), whereas, in the last 4 days, the biggest number of unhatched chicks was observed in eggs with more than 181 g. The lowest weight was obtained in chicks from group i~(89 g), and the highest in IV (133 g). Despite significant differences in the weight of one-day-old chicks in week 16, after the end of fattening, no statistically significant differences in weight between the groups were shown. The time of the occurrence of the phenomenon of growth compensation of birds in rearing was determined for the period between weeks 10 and 16 of life.
Abstract. The objective of the study was to analyse productive traits and quality of eggs in two native breeds of laying hens: Greenleg Partridge (Z-11) and Yellowleg Partridge (Ż-33). The populations of these old native breeds of hens are valuable for breeders as a reserve of unique traits, which are not found in the lines selected for increased egg production. The productive results and egg quality of these two breeds showed considerable differences, which confirms their genetic distinctiveness. Yellowleg Partridge hens were characterized by higher body weight, higher egg weight, earlier attainment of sexual maturity, and better egg production and hatchability compared to Greenleg Partridge hens. Age of hens was found to have a significant effect on egg internal quality and egg shell quality, and on reproductive performance of both breeds. The present study confirmed the known relationship of decreasing egg quality with increasing age of hens of both breeds. Much better hatchability of set and fertile eggs was obtained for Greenleg Partridge hens, and for both breeds from eggs set from younger hens (March and April).
Abstract. The work presents and evaluates the reproduction indices of the mares from the stud farm of Polish Konik horses bred during the years 1996–2015 in the Roztocze National Park (RNP). The studies included 46 dams and analyses of 157 breeding seasons. During the analyzed period, 124 successful coverings of mares resulted in 114 live foals. The following differentiated reproduction utilization parameters were determined: foaling rate – 78.98%, fertility rate – 72.61%, fecundity rate – 63.06%, infertility rate – 21.0%, miscarriage rate – 4.03%, rearing efficiency – 86.84% and reproductive utilization index – 79.84%. In the population under study, only 20% of mares maintain reproductive activity for 6 years and more, therefore the overall mean 3.41 for the herd breeding season is not satisfying. At present, the RNP stud farm houses the mares representing four dam families, i.e. Urszulka, Tarpanka, Traszka and Zaza. The average gestation length of all the mares in the study group was 327.53 days ranging from 306 (Tora) up to 355 days (Temida). Pregnancy duration averaged 328.8 days for colt foals and 326 days for filly foals. The results of the reproduction and productivity indices obtained in the analyzed herd were considerably affected by individual traits of a mare. A foaling season in the studied mare group is characteristic for the representatives of this species and commonly occurs between February and April (84 animals – 67.74%). The analysis of the reproduction and productivity measures of the stud farm mares in Zwierzyniec has indicated the need of drawing attention to some breeding efforts towards improvement of the breeding indices.
Abstract. The aim of this study was to compare the inbreeding coefficients (F) in Polish Halfbred (PH) and Holstein (H) stallions in the area of their Associations’ activity in 2004 and 2012. A total of 184 PH and 209 H stallions covering in 2012 in Poland and the area of Holstein Horse Breeders Association were investigated. The calculated F values were compared depending on the stallion’s breed. In addition, all the stallions were assigned to one of the four groups depending on the F value. The mean F value for the PH stallions (0.22%) was significantly lower than that for the H stallions (0.89%). Most animals of both breeds (88.59% and 69.38%, respectively) were not inbred. The F values in 2004 and 2012 for the H stallions did not differ significantly, whereas those for the PH stallions were significantly higher in 2012 compared with 2004. It can be concluded that using a greater kinship level in order to increase horses’ performance value becomes popular.