Vang Alysia L, Bresolin Tiago, Frizzarini Waneska S, Campolina Joana P, Menezes Guilherme L, Rosa Guilherme J M, Dorea Joao R R, Hernandez Laura L
Department of Animal and Dairy Sciences, University of Wisconsin-Madison, Madison, WI 53706.
Department of Animal Sciences, University of Illinois Urbana-Champaign, Urbana, IL 61801.
JDS Commun. 2024 May 31;5(6):725-728. doi: 10.3168/jdsc.2024-0586. eCollection 2024 Nov.
Existing literature on the long-term effects of nutritional manipulation on milk production is incomplete and inconsistent as animals are typically culled before lactation. In addition, longitudinal studies are rarely conducted due to high costs and constraints related to tissue sampling; therefore, additional research is necessary to better understand the effect of early nutrition and growth on subsequent growth and milk production. Thirty Holstein heifer calves were pair-fed high (H; 27% CP and 20% fat) or low (L; 22% CP and 15%) milk replacers. Mammary gland ultrasound images and BW were collected twice weekly, and blood samples weekly, for the first 8 wk of life. Calves fed H had higher ADG and mammary gland growth through 8 wk of life. Calves from the H group also had larger fat pads at 8 wk of age. Glucose and insulin concentrations were increased in H calves compared with L calves, whereas nonesterified fatty acid concentrations were not different between treatments. Our results suggest that ultrasound is a practical, noninvasive tool to monitor udder development preweaning, although additional research is necessary to improve image analysis techniques to analyze tissue composition. Our preliminary work provides data suggesting that the use of mammary gland ultrasound could provide a method of longitudinal analysis of the effects of preweaning nutrition on milk production.
由于动物通常在泌乳前被淘汰，现有关于营养调控对产奶量长期影响的文献并不完整且相互矛盾。此外，由于成本高昂以及与组织采样相关的限制，纵向研究很少进行；因此，有必要进行更多研究，以更好地了解早期营养和生长对后续生长及产奶量的影响。30头荷斯坦小母牛犊被配对饲喂高（H；27%粗蛋白和20%脂肪）或低（L；22%粗蛋白和15%）代乳粉。在犊牛出生后的前8周，每周两次采集乳腺超声图像和体重，每周采集一次血样。饲喂H组的犊牛在8周龄前具有更高的平均日增重和乳腺生长。H组的犊牛在8周龄时也有更大的脂肪垫。与L组犊牛相比，H组犊牛的葡萄糖和胰岛素浓度升高，而不同处理间非酯化脂肪酸浓度无差异。我们的结果表明，超声是断奶前监测乳房发育的一种实用、非侵入性工具，尽管需要更多研究来改进图像分析技术以分析组织成分。我们的初步工作提供的数据表明，使用乳腺超声可为纵向分析断奶前营养对产奶量的影响提供一种方法。
