摘要
The objectives of this research were to test interactions of supplement type, liquid versus dry, and forage type, hay versus corn stover, on digestibility and ruminal metabolism of beef cattle. Ruminally fistulated steers were fed in a replicated 4 × 4 Latin square with a 2 × 2 factorial arrangement of treatments: 1) hay with liquid supplement, 2) hay with dry supplement, 3) corn stover with liquid supplement, and 4) corn stover with dry supplement. The liquid supplement was molasses and glycerin based (23.3% CP and 1.63 Mcal/kg NEm) whereas the dry supplement was ground corn based (16.8% CP and 1.81 Mcal/kg NEm). Each period, steers were adapted to diets for 14 d and samples were collected for 8 d. In situ disappearance was determined by a 24-h incubation of Dacron bags, containing soybean hulls, in the rumen. There were no interactions (P ≥ 0.25) of supplement and forage type on DMI, apparent total tract digestibility, or ruminal pH. There was a tendency (P = 0.08) for a forage × supplement type interaction for in situ NDF disappearance (ISNDFD). There were no differences in ISNDFD in steers fed hay, but liquid supplement increased ISNDFD in steers fed corn stover. There were no main effects (P ≥ 0.12) of supplement type on DMI, apparent total tract or in situ digestibility, or ruminal pH. There was a supplement × hour interaction (P = 0.04) for acetate concentrations. Although no effect occurred at 0 h after feeding, at 3 and 6 h after feeding, acetate concentrations were reduced in steers fed liquid supplements when compared with those fed dry supplements. In addition, there was a supplement × hour (P = 0.02) interaction for butyrate concentrations, where at all time points, butyrate concentrations increased (P ≤ 0.01) in steers fed liquid supplements when compared with those fed dry supplements. Steers fed hay had increased DMI (P < 0.01) and apparent total tract NDF digestibility (P = 0.07) when compared with steers fed corn stover, regardless of supplement type. At 0, 1.5, and 18 h after feeding, ruminal pH was greater (P ≤ 0.01) in cattle consuming corn stover when compared with those fed hay, regardless of supplement type. However, steers fed hay had increased (P < 0.01) concentrations of acetate and total VFA compared with steers fed corn stover, regardless of supplement. Feeding liquid supplement increased ISNDFD when steers were fed corn stover; however, these changes were not associated with differences in total tract digestibility. Regardless of forage type fed, the liquid supplement increased ruminal butyrate concentrations.
摘要译文
这项研究的目的是测试补充类型，液体与干燥，饲料类型，干草与玉米秸秆，肉牛的消化率和瘤胃代谢的相互作用。反刍兽医饲喂重复的4×4拉丁广场与2×2因子安排治疗：1）干草与液体补充，2）干草与干补充，3）补充液体玉米秸秆，4）补充干燥玉米秸秆。液体补充剂是糖蜜和甘油基（23.3％CP和1。63 Mcal / kg NEm），而干补品是基于玉米粉（16.8％CP和1.81 Mcal / kg NEm）。每个时期，阉牛适应饮食14天，样品收集8天。通过在瘤胃中包含大豆皮的Dacron袋孵育24小时来确定原位消失。 DMI与补充饲料类型没有相互作用（P≥0.25）表观全消化道消化率或瘤胃pH。对于原位NDF消失（ISNDFD），饲料×补充型相互作用存在趋势（P \x3d 0.08）。饲喂干草的阉牛的ISNDFD没有差异，但液体补充剂增加了饲喂玉米秸秆的阉牛的ISNDFD。补充类型对DMI没有主效应（P≥0.12）表观总道或原位消化率，或瘤胃pH。对于醋酸盐浓度，存在补充×小时相互作用（P \x3d 0.04）。喂食后0小时没有发生效果，在喂食后3小时和6小时，与喂食干燥补充剂的那些相比，喂食液体补充剂的转向中乙酸盐浓度降低。另外，有一个补充×小时（P \x3d 0。02）相互作用丁酸盐浓度，其中在任何时间点，丁酸盐浓度增加（P≤0.01）在阉牛饲喂液体补充剂时，与那些干喂养补充剂相比。无论补充剂类型如何，与饲喂玉米秸秆的阉牛相比，饲喂干草的阉牛增加了DMI（P 0.01）和表观总消化道NDF消化率（P \x3d 0.07）。在0,1.5，饲喂18 h后，饲喂玉米秸秆的牛的瘤胃pH值高于饲喂干草的猪（P≤0.01），无论补充类型如何。然而，饲喂干草的阉牛增加了（P 0。01）醋酸和总挥发性脂肪酸（VFA）的浓度与喂食玉米秸秆的阉牛相比，无论补充。喂食玉米秸秆时，补充液体增加了ISNDFD;然而，这些变化与全消化道消化率的差异无关。无论饲喂何种饲料，液体补充剂都会增加瘤胃丁酸盐的浓度。
M. R. Stierwalt;H. M. Blalock;T. L. Felix. Effects of the interaction of forage and supplement type on digestibility and ruminal fermentation in beef cattle[J]. Journal of Animal Science, 2017,95(2): 892–900