Hominy饲料(HF)已在饲养场和乳制品配给中进行了评估,但尚未被评估为泌乳肉牛的补充能源。本研究的目的是确定HF补充水平对摄入量的影响,消化率,瘤胃发酵特性,百慕大草干草的原位干物质(DM)消失。五头泌乳肉牛(体重(BW)=596公斤,SE=13.9)用于5×5拉丁正方形设计的实验中。治疗是百慕大草干草基础饮食,低HF(LH;0.25%BW),中等HF(MH;0.50%BW),低地面玉米(LC;0.25%BW),中等地面玉米(MC;0.50%BW)和无补充(CON)。奶牛被单独饲养,每天提供0800次补品。Hay被要求保持10%的拒绝。周期为16天,10d适应。在每个周期的第14天采样瘤胃液以测量pH值,挥发性脂肪酸,和瘤胃氨-N。对于每种饮食,都完成了百慕大草干草的原位降解实验。干草干物质摄入量(DMI%BW)不受补充影响(p=0.14),但与LH和CON相比,MH和MC的总DMI(DMI%BW)更大(p≤0.05)。与LC相比,MH中的可消化DMI%BW更大(p=0.05),MC是中间的,LH和CON低于所有其他饮食(p≤0.01)。干物质填充,通过率,保留时间因饮食而异(p≥0.31)。观察到氨-N的饮食×时间相互作用(p=0.0002),和丙酸(p=0.02)的时间效应观察到其他参数,但对饮食没有影响.在LH中,百慕大干草的潜在可降解分数大于MH和CON(p≤0.05),但有效的DM降解性在饮食之间没有差异(p=0.39)。总的来说,与CON相比,没有饮食减少干草的摄入量或消失;因此,在本研究提供的水平下,任何补充剂均未观察到负关联效应.
Hominy feed (HF) has been evaluated in feedlot and dairy rations but has not been evaluated as a supplemental energy source for lactating beef cows. The objective of this study was to determine the effect of level of HF supplementation on intake, digestibility, ruminal fermentation characteristics, and in situ dry matter (DM) disappearance of
bermudagrass hay. Five ruminally cannulated lactating beef cows (body weight (BW) = 596 kg, SE = 13.9) were used in an experiment with a 5 × 5 Latin square design. Treatments were a
bermudagrass hay-basal diet with low HF (LH; 0.25% BW), medium HF (MH; 0.50% BW), low ground corn (LC; 0.25% BW), medium ground corn (MC; 0.50% BW) and no supplement (CON). Cows were housed individually, and supplements were offered at 0800 daily. Hay was offered to maintain 10% refusal. Periods were 16-d, with 10 d for adaptation. Ruminal fluid was sampled on d 14 of each period for measurement of pH, volatile fatty acids, and rumen ammonia-N. An in situ degradation experiment for
bermudagrass hay was completed for each diet. Hay dry-matter intake (DMI % BW) was not affected (p = 0.14) by supplement, but total DMI (DMI % BW) was greater (p ≤ 0.05) in MH and MC compared to LH and CON. Digestible DMI % BW was greater (p = 0.05) in MH compared to LC, MC was intermediate, and LH and CON were lesser (p ≤ 0.01) than all other diets. Dry-matter fill, passage rate, and retention time did not differ by diet (p ≥ 0.31). A diet × time interaction was observed for ammonia-N (p = 0.0002), and propionate (p = 0.02) time effects were observed for other parameters, but no diet effects.
Bermudagrass hay\'s potentially degradable fraction was greater (p ≤ 0.05) in LH than MH and CON, but effective DM degradability was not different (p = 0.39) among diets. Overall, no diets reduced hay intake or disappearance compared to CON; therefore, no negative associative effects were observed from any of the supplements at the levels offered in this study.