M Kunowska-Slosarz

Plasma leptin as a predictor for carcass composition in growing lambs

The experiment was conducted on 30 single born Polish Merino ram lambs. At the age of 112xa0d, 10 ram lambs were slaughtered at 20xa0kg (group 1), 25xa0kg (group 2), and 30xa0kg (group 3) live weight. Plasma leptin increased between 20 and 25xa0kg, as well as 25 and 30xa0kg live weight. The differences between group 1 vs. group 3 and group 2 vs. group 3 were statistically important (Pu2009<u20090.001). The lack of differences in meat content of the pelvic limb between the groups and, at the same time, the lower fat content (Pu2009<u20090.001) in group 1, plus the higher fat content of the two remaining groups, are evidence of the higher fatness of carcasses in groups 2 and 3. The fat tissues except the subcutaneous fat were significantly related with the leptin concentrations at slaughter. The leptin concentration of lambs slaughtered at 30xa0kg live weight surpassed significantly the values noted in groups 1 and 2 (Pu2009<u20090.001). The correlations between leptin and body composition indicate that plasma leptin concentration at 30xa0kg live...Abstract The experiment was conducted on 30 single born Polish Merino ram lambs. At the age of 112 d, 10 ram lambs were slaughtered at 20 kg (group 1), 25 kg (group 2), and 30 kg (group 3) live weight. Plasma leptin increased between 20 and 25 kg, as well as 25 and 30 kg live weight. The differences between group 1 vs. group 3 and group 2 vs. group 3 were statistically important (P < 0.001). The lack of differences in meat content of the pelvic limb between the groups and, at the same time, the lower fat content (P < 0.001) in group 1, plus the higher fat content of the two remaining groups, are evidence of the higher fatness of carcasses in groups 2 and 3. The fat tissues except the subcutaneous fat were significantly related with the leptin concentrations at slaughter. The leptin concentration of lambs slaughtered at 30 kg live weight surpassed significantly the values noted in groups 1 and 2 (P < 0.001). The correlations between leptin and body composition indicate that plasma leptin concentration at 30 kg live weight can be a predictor of body fat. The correlation of meat weight with leptin concentration has shown no statistical differences.

Effect of Dairy Cow Crossbreeding on Selected Performance Traits and Quality of Milk in First Generation Crossbreds: Crossbreeding in dairy cattle…

The main goal of crossbreeding Holstein-Friesian (HF) cows with bulls of other dairy or combined breeds is to improve their performance traits. Thus, the aim of this investigation was to compare the dairy performance traits of first generation crossbreds produced by crossbreeding Polish HF cows with bulls of other breeds (Norman, Norwegian Red, Danish Red, Brown Swiss, Montbeliarde, and Simmental). This was done by analyzing the fatty acid profile and technological quality of the milk from these first generation crossbreds. The investigation showed that crossbreeding greatly influenced the performance parameters and technological quality of the milk of the first generation crossbreds obtained from crossbreeding Polish HF cows with bulls of other dairy or combined breeds. The crossbreed cows characterized by the highest both quantity and quality of milk. Also, the best parameters of milk fat dispersion (that is, the highest values of these parameters) that are useful in the production of hard ripening cheeses and butter were found in the milk of crossbreed cows. Health beneficially, saturated fatty acids level in milk of crossbreeds was by 25.96% lower in crossbreds milk when compared to purebred cows. The most beneficial content of whey proteins was found in the milk of Polish HF and Norwegian Red crosses, where it was 19.04% higher than in pure breed Holsteins. F1 cows tend to express better functional traits than Holstein (PHF) cows. Effect of heterosis was larger and gave better results when there was a greater genetic distance between the animals used for crossbreeding.nnnPRACTICAL APPLICATIONnThe effects of heterosis are opposite to the effects of inbreeding depression, and it extends the lifespan and use of animals as well as improves their fertility and health. The main goal of crossbreeding Holstein-Friesian cows with bulls of other dairy or combined breeds is to improve their performance traits. F1 cows tend to express better functional traits than Holstein (PHF) cows. Effect of heterosis was larger and gave better results when there was a greater genetic distance between the animals used for crossbreeding.

The effect of carcass weight on chemical characteristics and fatty acid composition of Longissimus dorsi and Semimembranosus muscles of European wild boar (Sus scrofa scrofa) meat

Abstract: The objective of this study was to investigate the effect of carcass weight on chemical characteristics and fatty acid composition of m. longissimus dorsi and m. semimembranosus of European wild boar (Sus scrofa scrofa) meat. The research was carried out on 50 wild boars shot during four battues at hunting reserves in the central part of Poland. The carcasses were divided into three groups: ≤30 kg (G1), 31–45 kg (G2), and >45 kg (G3). The protein concentration increased with carcass weight (P ≤ 0.01). The concentration of saturated fatty acids was influenced by carcass weight and was higher when weight increased. A significantly higher level of monounsaturated fatty acids (MUFA) was found in the carcasses of wild boars from G3 compared with G1 group (P ≤ 0.01). The content of C18:2n-6 was significantly lower in the lightest carcasses compared with the heaviest (P ≤ 0.05). Statistical analysis confirmed that carcasses weight significantly affected polyunsaturated fatty acids (PUFA) n-3 content. The lightest carcasses contained a significantly higher concentration of PUFA n-3 (P ≤ 0.01). In addition, in G3, the amount of C22:5n-3 was two-fold lower (P ≤ 0.01) than in G1. The research has shown that the meat quality was affected by the carcass weight, resulting better parameters in the lighter than in the heavier carcasses. Therefore, most of the culled wild boars should be squeakers and young boars after the first year of life.