日粮NFC/NDF水平对泌乳后期奶牛生产性能、血液生化及抗氧化指标的影响

Effects of NFC/NDF levels on performance,blood biochemical and antioxidant index of cows in late lactation

为了研究不同非纤维性碳水化合物/中性洗涤纤维（NFC/NDF）水平日粮对泌乳后期奶牛产奶量、乳成分、血液生化及抗氧化指标的影响,采用3×3拉丁方设计,选取18头胎次、泌乳时间和泌乳量相近的荷斯坦奶牛,随机分成3组,每组6头奶牛,分别饲喂NFC/NDF比为1.38（A）、1.19（B）、1.08（C）的3种日粮,分3个阶段进行,每个阶段试验28 d,分别于第14、21、28天记录采食量和产奶量并采集奶样（50mL）,第28天采集血样（10 mL）。结果显示：和A组相比,B组的血清总抗氧化能力（T-AOC）显著升高（P〈0.05）,丙二醛（MDA）含量显著降低（P〈0.05）,但产奶量、乳成分和血液生化指标无显著差异（P〉0.05）。结果表明：泌乳后期适当降低日粮NFC/NDF水平对奶牛生产性能和血液生化指标无显著影响,NFC/NDF为1.19时可显著增强奶牛血清中抗氧化能力,减少丙二醛的产生,有利于维持奶牛健康生产。

The aim of this study was to investigate the effects of NFC/NDF levels on milk production,milk composition,blood biochemical,and antioxidant index in late-lactation cows. Eighteen Chinese-Holstein cows were randomly divided,using 3×3 Latin square design,into three groups（ 6 cows in each group） according to parities（ 2. 00± 0. 22）,days in milk（ 202. 53 ± 17. 13 days）,and milk production（ 24. 47±1. 27 kg/d）. The cows were fed with three types of diets with different NFC/NDF ratios（ A（ 1. 38）; B（ 1. 19）; and C（ 1. 08））,respectively. The experiment was conducted in three periods of 28 days each. On days 14,21,and 28 of each period,feed intake and milk yield were recorded and milk samples（ approximately 50 mL） were collected. On day 28 of each period,blood samples（ approximately 10 mL） was collected via the tail vein. The results showed that,compared with group A,the serum T-AOC（ total antioxidant capacity） in group B was increased and the MDA（ malondialdehyde） concentration was decreased（ P〈0. 05）. In terms of milk yield,milk composition,and blood metabolism,the three groups did not differ significantly（ P〈0. 05）. In summary,proper reduction of dietary NFC/NDF level has no significant effect on lactation performance and blood metabolism in late-lactation cows. An appropriate dietary NFC/NDF level（ 1. 19） can improve antioxidant capacity in dairy cows and ensure their healthy production performance.