Paengkoum P, Chen S, Paengkoum S
School of Animal Technology and Innovation, Institute of Agricultural Technology, Suranaree University of Technology, Muang, Nakhon Ratchasima, 30000, Thailand.
Program in Agriculture, Faculty of Science and Technology, Nakhon Ratchasima Rajabhat University , Muang, Nakhon Ratchasima, 30000, Thailand.
Trop Anim Health Prod. 2019 Jun;51(5):1151-1159. doi: 10.1007/s11250-019-01799-0. Epub 2019 Jan 23.
The objective of this study was to investigate growth performance, nutrients apparent digestibility, nitrogen utilization, rumen fermentation, and rumen microorganism of growing Thai-indigenous beef cattle receiving different levels of crude protein (CP) and undegradable intake protein (UIP) diets. Eighteen healthy growing Thai-indigenous beef cattle were used in a 2 × 3 factorial randomized complete block design (RCBD). There were six treatments: two levels of CP (10% and 12% of dry matter (DM)) and three levels of UIP (15%, 25%, and 35% of CP). The results indicated that dry matter intake (DMI) and average daily gain (ADG) increased linearly (P < 0.01) with increasing UIP level. The apparent digestibility of DM, organic matter (OM), acid detergent fiber (ADF), and neutral detergent fiber (NDF); rumen fermentation parameters; microbes counts; and microbial nitrogen synthesis (MNS) were unaffected (P > 0.05) by CP and UIP levels. The nitrogen (N) intake and N retained increased linearly (P < 0.01) with increasing UIP level. Specifically, the metabolizable protein (MP) requirement of 1 g/kg BW gain was 0.34 g MP/kg BW; the 10% dietary CP of DM was able to meet animals' normal nutrition requirements and 6.5% DIP of DM can provide adequate N source for the requirement of rumen microbe growth in. Collectively, it was indicated that the supplemental level of 10% CP and the ratio of UIP to DIP was 35:65 in diets shown the best growth performance for growing Thai-indigenous beef cattle under the conditions in the current study.
本研究的目的是调查不同粗蛋白（CP）和非降解摄入蛋白（UIP）水平日粮对生长中的泰国本土肉牛生长性能、养分表观消化率、氮利用率、瘤胃发酵和瘤胃微生物的影响。18头健康的生长中的泰国本土肉牛用于2×3析因随机完全区组设计（RCBD）。有六种处理：两种CP水平（干物质（DM）的10%和12%）和三种UIP水平（CP的15%、25%和35%）。结果表明，随着UIP水平的增加，干物质摄入量（DMI）和平均日增重（ADG）呈线性增加（P<0.01）。DM、有机物（OM）、酸性洗涤纤维（ADF）和中性洗涤纤维（NDF）的表观消化率；瘤胃发酵参数；微生物数量；以及微生物氮合成（MNS）不受CP和UIP水平的影响（P>0.05）。随着UIP水平的增加，氮（N）摄入量和N保留量呈线性增加（P<0.01）。具体而言，每千克体重增加1克所需的可代谢蛋白（MP）为0.34克MP/千克体重；日粮中10%的DM CP能够满足动物的正常营养需求，6.5%的DM可消化不可降解蛋白（DIP）可为瘤胃微生物生长需求提供充足的N源。总体而言，在本研究条件下，日粮中10%的CP补充水平以及UIP与DIP的比例为35:65时，生长中的泰国本土肉牛表现出最佳生长性能。
