Nafferton Ecological Farming Group, School of Natural and Environmental Science, Newcastle University, Nafferton Farm, Stocksfield, Northumberland NE43 7XD, United Kingdom; Animal, Dairy and Food Chain Sciences Division, University of Reading, School of Agriculture, Policy and Development, Centre for Dairy Research, PO Box 237, Earley Gate, Reading RG6 6AR, United Kingdom.
Department of Livestock Sciences, FiBL Research Institute of Organic Agriculture, Ackerstrasse 113, P.O. Box 219, CH-5070, Frick, Switzerland.
Food Chem. 2018 Jun 15;251:93-102. doi: 10.1016/j.foodchem.2018.01.077. Epub 2018 Jan 11.
This study investigated the effect of, and interactions between, US Brown Swiss (BS) genetics and season on milk yield, basic composition and fatty acid profiles, from cows on low-input farms in Switzerland. Milk samples (n = 1,976) were collected from 1,220 crossbreed cows with differing proportions of BS, Braunvieh and Original Braunvieh genetics on 40 farms during winter-housing and summer-grazing. Cows with more BS genetics produced more milk in winter but not in summer, possibly because of underfeeding potentially high-yielding cows on low-input pasture-based diets. Cows with more Original Braunvieh genetics produced milk with more (i) nutritionally desirable eicosapentaenoic and docosapentaenoic acids, throughout the year, and (ii) vaccenic and α-linolenic acids, total omega-3 fatty acid concentrations and a higher omega-3/omega-6 ratio only during summer-grazing. This suggests that overall milk quality could be improved by re-focussing breeding strategies on cows' ability to respond to local dietary environments and seasonal dietary changes.
本研究调查了瑞士低投入农场奶牛的美国棕色瑞士牛（BS）遗传因素和季节对产奶量、基本成分和脂肪酸谱的影响。从 40 个农场的 1,220 头具有不同 BS、Braunvieh 和 Original Braunvieh 遗传比例的杂交奶牛中收集了牛奶样本（n=1,976），这些奶牛在冬季圈养和夏季放牧期间。具有更多 BS 遗传基因的奶牛在冬季产奶量更多，但在夏季却没有，这可能是由于低投入的牧场基础日粮可能使高产奶牛的饲养不足。具有更多 Original Braunvieh 遗传基因的奶牛全年牛奶中含有更多（i）营养上可取的二十碳五烯酸和二十二碳五烯酸，以及（ii）反式-11 十八碳烯酸和α-亚麻酸、总 omega-3 脂肪酸浓度和更高的 omega-3/omega-6 比值，仅在夏季放牧期间。这表明，通过重新聚焦于奶牛对当地饮食环境和季节性饮食变化的反应能力的育种策略，可以提高整体牛奶质量。
