竹叶和茶叶渣对断奶犊牛生长性能、消化代谢及血清抗氧化和免疫指标的影响

本试验旨在研究全混合日粮(TMR)中相同中性洗涤纤维(NDF)水平下,以竹叶或茶叶渣替代苜蓿对断奶犊牛生长性能、消化代谢及血清抗氧化和免疫指标的影响。按照随机区组设计将45头105日龄的荷斯坦公犊牛分成3组,每组15头犊牛,分别饲喂苜蓿(AH组)、竹叶(BL组)或茶叶渣(TR组)为主要NDF来源的TMR。预试期15 d,正试期60 d。结果表明:1)180日龄时,TR组的体重显著低于AH组(P<0.05);试验期间,BL组与AH组之间的平均日增重、干物质采食量和料重比无显著差异(P>0.05)。2)与AH组相比,BL组的干物质(DM)和酸性洗涤纤维(ADF)表观消化率显著降低(P<0.05),而有机物(OM)和NDF表观消化率差异不显著(P>0.05);TR组的NDF表观消化率显著提高(P<0.05),而DM、OM和ADF表观消化率差异不显著(P>0.05)。3)与AH组相比,BL组的尿能、总能消化率、总能代谢率和消化能代谢率显著降低(P<0.05)。4)与AH组相比,BL组的尿氮显著提高(P<0.05),氮沉积率显著降低(P<0.05);TR组的粪氮显著提高(P<0.05),氮表观消化率显著降低(P<0.05)。5)与AH组相比,BL和TR组的血清谷胱甘肽过氧化物酶(GSH?Px)和过氧化氢酶(CAT)活性显著降低(P<0.05),血清免疫球蛋白A(IgA)、丙二醛(MDA)含量显著升高(P<0.05);BL组的血清总抗氧化能力(T?AOC)显著降低(P<0.05)。由此可见,与饲喂苜蓿饲粮相比,饲喂竹叶饲粮的断奶犊牛生长性能及OM、NDF表观消化率相近,但能量和氮的利用率降低;饲喂茶叶渣饲粮的断奶犊牛能量利用率相近,而NDF表观消化率显著提高,生长性能和氮的利用率降低;饲喂竹叶饲粮和茶叶渣饲粮的断奶犊牛血清IgA含量显著提高,抗氧化能力降低。综上所述,断奶犊牛阶段可以用竹叶(24.38%)替代苜蓿作为饲粮的粗饲料。

Influences of Bamboo Leaf and Tea-Leaves Residue on Growth Performance,Digestion and Metabolism and Serum Antioxidant and Immune Indices of Weaned Calves

This study was aimed to investigate the effects of bamboo leaf or tea?leaves residue replacing alfalfa hay on growth performance,digestion and metabolism,serum antioxidant and immune indices of weaned calves fed with total mixed ration(TMR)at the same neutral detergent fiber(NDF)level.Forty?five 105?day?old Holstein male calves were allotted to 3 groups according to the randomized block design,and with 15 calves in each group,and calves were fed a TMR with alfalfa hay(AH group),bamboo leaf(BL group)and tea?leaves residue(TR group)as the main NDF sources.The pre?experimental period lasted for 15 days,and the experimental period lasted for 60 days.The results showed as follows:1)on 180 days of age,the body weight of TR group was significantly lower than that of AH group(P<0.05);during the experimental period,no significant differences were found on the average daily gain,dry matter intake and feed to weight ratio be?tween AH group and BL group(P>0.05).2)Compared with the AH group,the apparent digestibilities of dry matter(DM)and acid detergent fiber(ADF)of BL group were significantly decreased(P<0.05),while the apparent digestibilities of organic matter(OM)and NDF were no significant difference(P>0.05);the NDF apparent digestibility of TF group was significantly increased(P<0.05),while the apparent digestibilities of DM,OM and ADF were no significant difference(P>0.05).3)Compared with the AH group,the urine en?ergy,gross energy digestibility,gross energy metabolic rate,digestible energy metabolic rate were significantly decreased(P<0.05).4)Compared with the AH group,the urine nitrogen of BL group was significantly in?creased(P<0.05),while the nitrogen deposition rate was significantly decreased(P<0.05);the fecal nitro?gen of TR group was significantly increased(P<0.05),while the apparent digestibility of nitrogen was signifi?cantly decreased(P<0.05).5)Compared with the AH group,the activities of glutathione peroxidase(GSH?Px)and catalase(CAT)in serum of BL and TR groups were significantly decreased(P<0.05),and the contents of immunoglobulin A(IgA)and malondialdehyde(MDA)in serum were significantly increased(P<0.05);the serum total antioxidant capacity(T?AOC)of BL group was significantly decreased(P<0.05).In conclusion,compare with feeding alfalfa hay diet,weaned calves feeding bamboo leaf diet have similar growth performance and apparent digestibilities of OM and NDF,while the utilization of energy and nitrogen is decrease;weaned calves feeding tea?leaves residue diet have similar energy utilization,while the NDF apparent digestibility is significantly increase,the growth performance and nitrogen utilization are decrease;the serum IgA content of weaned calves feeding bamboo leaf diet and tea?leaves residue diet is significantly increase,while the antioxidant capacity is decrease.In summary,bamboo leaf(24.38%)can replacing alfalfa hay in weaned calves period as the roughage in diet.