不同蛋白质和碳水化合物饲料来源对牛瘤胃洗涤纤维降解和瘤胃液产物的定量研究

Effect of protein and carbohydrate supplements on changes of the detergent fibers and the ruminal metabolites in the rumen of heifers

试验采用3×3拉丁方设计,3头安装永久性大口径瘤胃瘘管的青年母牛饲喂3种不同精饲料的日粮,3种精饲料分别为豆粕+玉米(日粮1),猪血粉+玉米(日粮2)和豆粕+小麦(日粮3)。精料日喂量按活牛体重的1%喂给,干玉米秸等量组成的日粮配给。试验为3个试验周期,每一周期为37d,其中适应期26d,在早晨采食后2、4、8、16和24h,分别5次实施瘤胃掏空,全量测定瘤胃物存留量。结果表明:日粮1在采食后2～8h瘤胃干物质、液体和NDF的存留量最低,与其他两种日粮相比差异显著(P<0.05);日粮1和日粮3瘤胃液氨氮存留量在采食后2～8h始终高于日粮2(P<0.05),但日粮3在采食4h后瘤胃液氨氮开始下降,而日粮1至采食后16h开始下降,日粮1瘤胃液氨氮数量采食后2～8h处于高峰状态,说明瘤胃微生物在瘤胃环境长时间一直保持稳定的降解能力;日粮1和日粮3在采食2～4h后处于较高的总挥发性脂肪酸(VFA)瘤胃存留量,日粮1在采食后8～16h瘤胃存留量降低,与日粮2和日粮3相比差异显著(P<0.05),日粮1对瘤胃VFA的快速移除,意味着瘤胃液的快速流出以及可能解释瘤胃固体物的快速移除。因此,日粮1和日粮3在牛瘤胃洗涤纤维降解和瘤胃液产物代谢模式发挥不同作用。

Three ruminally fistulated Chinese heifers were used in a 3 × 3 Latin Square to study the total changes of the detergent fibers and the ruminal metabolites in the tureen. Three trial diets consisted of corn ＋ soybean meal （dietl）, corn ＋ pig blood meal （diet2） and wheat ＋ soybean meal （diet3）. Each heifer had a 26 d adaptation, following by a 11 d tureen evacuation in situ that rumen content was evacuated after feeding 2, 4, 8, 16 or 24 h, respectively. Dry matter （DM） intakes were similar for all diets. The results showed that rumen DM, tureen liquid or NDF pooling was the lowest for dietl after feeding 2, 4 and 8 h （P〈0.05）; tureen NHB-N pooling reached the higher plateau for the dietl or 3 compared with diet2 after feeding 2, 4 or 8 h（P〈0.05）, but trended to decline for diet3 after feeding 4 h, the rumen microbes maintain a long time of stable degradable capacity for dietl; the higher rumen VFA pooling was shown for diet l or 3 after feeding 2 or 4 h, but the lower VFA pooling was observed for dietl after feeding 8 or 16 h （P〈0.05）, the fast removal of total VFA means the fast now of rumen liquid and may explain the rapid passage of rumen solid content for dietl. Therefore, the different roles of dietl and 3 were played in the total changes of the detergent fibers and the ruminal metabolites in the rumen of cattle.