Molik Edyta, Błasiak Michał, Pustkowiak Henryk
Department of Animal Nutrition and Biotechnology, and Fisheries, Faculty of Animal Sciences, University of Agriculture in Krakow, al. A. Mickiewicza 24/28, 30-059 Krakow, Poland.
Department of Genetics and Animal Breeding and Ethology, Faculty of Animal Sciences, University of Agriculture in Krakow, al. A. Mickiewicza 24/28, 30-059 Krakow, Poland.
Animals (Basel). 2020 Sep 23;10(10):1721. doi: 10.3390/ani10101721.
The aim of the study was to determine the effect of photoperiod and exogenous melatonin on milk yield and chemical composition of sheep's milk. Sheep ( = 60) were randomly divided into three groups: lambing in February (Group 1- = 20), lambing in June (Group 2- = 20), and lambing in June and treated with subcutaneous melatonin implants (Group 3- = 20). Milk yield was higher for Group 1 and Group 2 than for Group 3 ( < 0.01). The milk of ewes of Groups 2 and 3 had a significantly ( < 0.01) higher content of dry matter, protein, and fat. Group 3 sheep's milk contained significantly more ( < 0.01) of SFA (Saturated Fatty Acids). The highest content of MUFA (Monounsaturated Fatty Acids) and PUFA (Polyunsaturated Fatty Acids) was found in the samples collected from Group 1, the lowest was in the milk of Group 3 animals. The highest ( < 0.01) CLA, content was identified in the milk of Group 1, while the lowest was recorded for the milk obtained from sheep treated with exogenous melatonin (Group 3). The experiment carried out has shown that day length and treatment with exogenous melatonin modulate the chemical composition of milk.
本研究的目的是确定光周期和外源性褪黑素对羊奶产量和化学成分的影响。绵羊（n = 60）被随机分为三组：2月产羔（第1组，n = 20）、6月产羔（第2组，n = 20）以及6月产羔并皮下植入褪黑素（第3组，n = 20）。第1组和第2组的产奶量高于第3组（P < 0.01）。第2组和第3组母羊的奶中干物质、蛋白质和脂肪含量显著更高（P < 0.01）。第3组羊奶中饱和脂肪酸（SFA）含量显著更高（P < 0.01）。第1组采集的样本中单不饱和脂肪酸（MUFA）和多不饱和脂肪酸（PUFA）含量最高，第3组动物的奶中含量最低。第1组奶中共轭亚油酸（CLA）含量最高（P < 0.01），而外源性褪黑素处理的绵羊（第3组）所产奶中CLA含量最低。所进行的实验表明，日照时长和外源性褪黑素处理可调节奶的化学成分。
