Devant M, Quintana B, Aris A, Bach A
J Anim Sci. 2015 Oct;93(10):4903-16. doi: 10.2527/jas.2014-8382.
The objectives of this study were to evaluate the effects of high-moisture corn (HMC), either whole or ground, fed separately from concentrate and straw on feeding behavior, rumen fermentation, whole tract digestibility, and nitrogen balance. Twenty-four Holstein heifers (199 ± 5.5 kg BW and 157 ± 6.9 d age) housed in individual pens were assigned to 3 treatments: 1) whole (unprocessed) HMC fed along with concentrate and barley straw, all fed separately and ad libitum (WHMC); 2) HMC ground through a 0.4-cm screen before ensiling and fed along with concentrate and barley straw, all fed separately and ad libitum (GHMC); and 3) a concentrate composed of mainly corn meal, ground through a roller mill with screen openings of 6 mm, and barley straw, both fed separately and ad libitum (Control). Concentrate, HMC, and straw were offered separately ad libitum in a free-choice situation and consumption was recorded daily and BW was recorded weekly. Apparent nutrient digestibility and N balance were determined at the beginning, middle, and end of the study. At the same time points, rumen fluid was collected through rumenocentesis to determine rumen pH and VFA concentrations. Feeding behavior was monitored throughout the study. Animals were harvested after 134 d and HCW, rumen and cecum wall lesions, and liver abscesses were recorded. Treatment did not affect total DMI, feed efficiency, ADG, final BW, and carcass weight or classification. Concentrate consumption (6.6 ± 0.35 kg/d) of Control heifers was greater ( < 0.001) than that of GHMC (4.1 ± 0.35 kg/d) and WHMC heifers (2.8 ± 0.35 kg/d), and GHMC heifers consumed less ( < 0.001) HMC than WHMC heifers (2.3 ± 0.31 and 4.2 ± 0.31 kg/d, respectively). Dietary treatments did not affect rumination, self-grooming, nonnutritive oral behaviors, and rumen pH. However, rumen acetate to propionate ratio decreased when heifers received HMC (1.77 ± 0.276) compared with when heifers received the Control (2.82 ± 0.276). Total tract starch apparent digestibility was greater in Control (97.7 ± 0.47%) and GHMC heifers (99.4 ± 0.47%) than in WHMC heifers (95.2 ± 0.47%), although an interaction between treatment and time was observed ( < 0.01). Treatments did not affect N retention. Feeding HMC, either whole or ground, separately from concentrate and straw resulted in performance and behavioral patterns similar to feeding only concentrate and straw.
本研究的目的是评估高水分玉米（HMC）整粒或粉碎后与精料和秸秆分开饲喂时，对采食行为、瘤胃发酵、全肠道消化率和氮平衡的影响。将24头荷斯坦小母牛（体重199±5.5千克，年龄157±6.9天）单独饲养在栏舍中，分为3组处理：1）整粒（未加工）HMC与精料和大麦秸秆一起饲喂，所有饲料均分开且自由采食（WHMC）；2）HMC在青贮前通过0.4厘米筛网粉碎，与精料和大麦秸秆一起饲喂，所有饲料均分开且自由采食（GHMC）；3）主要由玉米粉组成的精料，通过筛孔为6毫米的辊磨机粉碎，与大麦秸秆一起饲喂，均分开且自由采食（对照组）。在自由选择的情况下，精料、HMC和秸秆分别自由采食，每天记录采食量，每周记录体重。在研究开始、中期和末期测定表观养分消化率和氮平衡。在相同时间点，通过瘤胃穿刺采集瘤胃液，测定瘤胃pH值和挥发性脂肪酸浓度。在整个研究过程中监测采食行为。134天后屠宰动物，记录热胴体重、瘤胃和盲肠壁损伤以及肝脓肿情况。处理对总干物质采食量、饲料效率、平均日增重、最终体重、胴体重或胴体等级没有影响。对照组小母牛的精料采食量（6.6±0.35千克/天）高于GHMC组（4.1±0.35千克/天）和WHMC组小母牛（2.8±0.35千克/天）（P<0.001），且GHMC组小母牛的HMC采食量低于WHMC组小母牛（分别为2.3±0.31和4.2±0.31千克/天）（P<0.001）。日粮处理不影响反刍、自我梳理、非营养性口腔行为和瘤胃pH值。然而，与接受对照组日粮的小母牛（2.82±0.276）相比，接受HMC的小母牛瘤胃乙酸与丙酸比值降低（1.7
