泌乳奶牛日粮中添加不同比例脂肪酸对奶牛生产性能、血液生化指标的影响

Effects of fatty acids supplement with different categories on the production performance and blood parameters in dairy cows

为研究不同比例的脂肪酸对泌乳奶牛干物质采食量(DMI)、生产性能、血清生化指标及氧化应激的影响,采用320头胎次、泌乳天数以及体况相近的荷斯坦奶牛进行该试验。试验分为两组,分别采食试验及对照日粮,各组日粮中脂肪酸饲喂总量保持一致,均为328 g,但棕榈酸(C16:0)和油酸(C18:1)的饲喂比例不同,试验组脂肪酸比例C16:0:C18:1=80:8,对照组C16:0:C18:1=64:23。自由采食及饮水,试验期60 d。结果表明:(1)试验组全期干物质采食量比对照组高0.21 kg,差异极显著(P <0.01)。(2)试验全期产奶量试验组比对照组增加0.63 kg,差异显著(P <0.05)。(3)对照组血清中β-羟基丁酸(BHBA)、酯化脂肪酸(NEFA)、血清中尿素氮(BUN)含量、总胆固醇(TC)及血清中谷丙转氨酶(ALT)含量极显著低于试验组(P <0.01),分别降低0.03 mmol/L、5.37μmol/L、2.1μmol/L、0.76 mmol/L、0.5 U/L;而对照组血清中三碘甲状腺原氨酶(T3)含量及超氧化物歧化酶(SOD)含量极显著高于试验组(P <0.01),分别高0.3 ng/mL、0.63 U/mL。由此可见,试验组中C16:0:C18:1=80:8对采食量和泌乳性能的影响优于对照组。但是从能量代谢及能量平衡的角度分析,试验组对于体脂沉积和体况的维持效果低于对照组,所以配方预测时应着重考虑C18:1的比例,可以既利于泌乳性能的激发又利于体况的维持,从而保证较强的泌乳持续力。

This experiment was conducted to investigate the effect of fatty acid ratio on dry matter intake,performance,blood biochemical index and oxidative stress in Holstein dairy cow.Using 320 high producing cow based on lactating number,day in milk,body condition score,milk production was divided into control group and treatment group.The test and control diets were fed separately.The total amount of fatty acids in the diets of each group remained the same 328 g,but the proportion of palmitic acid(C16:0)and oleic acid(C18:1)was different.The proportion of fatty acids in the test group was C16:0:C18:1=80:8,while that in the control group was C16:0:C18:1=64:23.Ad libitum for feed and water.The results showed that:(1)The total dry matter intake of the test group was 0.21 kg significantly higher than that of the control group(P<0.01).(2)The milk yield during the whole test period in the test group was 0.63 kg higher than that in the control group,with a significant difference(P<0.05).(3)The content ofβ-Hydroxybutyric acid(BHBA),non esterified fatty acid(NEFA),blood urea nitrogen(BUN),total cholesterol(TC)and serum glutamic pyruvic transaminase(ALT)in control group were significantly lower than those in the test group(P<0.01),with 0.03 mmol/L,5.37μmol/L,2.1μmol/L,0.76 mmol/L,0.5 U/L respectively;However,the content of T3 and the content of superoxide dismutase(SOD)in the control group were significantly higher than those in the test group(P<0.01),0.3 ng/mL and 0.63 U/mL higher respectively.Therefore,the treatment group with the ratio of C16:0 against C18:1 at 80:8 had positive effect on the dry matter intake and milk production.But when taken the energy metabolism and balance into consideration,treatment performed less than control,suggesting when we formulated the ration,C18:1 should be put on more consideration to promote the milk production at the same time keep the body condition score from the milk production persistency perspective.