Dordaneh Khorasan-e-Razavi Animal and Poultry Feed Co., Mashhad 917794883, Iran; Department of Animal Sciences, University of Florida, 2250 Shealy Drive, Gainesville 32601.
Department of Animal Sciences, University of Florida, 2250 Shealy Drive, Gainesville 32601.
J Dairy Sci. 2021 Dec;104(12):12486-12495. doi: 10.3168/jds.2021-20858. Epub 2021 Sep 16.
We aimed to evaluate the effects of feeding super-conditioned corn at different temperatures on intake, growth performance, total-tract starch digestibility, rumen fermentation, blood metabolites, and feeding behavior of dairy calves. Thirty-six Holstein female dairy calves (40 ± 1.72 kg of body weight, ± SD) were randomly assigned to 1 of the following 3 treatments: (1) ground corn (control; CON; n = 12), (2) corn super-conditioned at 75°C (T-75; n = 12), and (3) corn super-conditioned at 95°C (T-95; n = 12). Three mash starter feeds with an identical nutritional composition were blended with 5% chopped alfalfa hay and fed to individually-housed calves from d 3 to 77 of their birth. All calves were fed 4 L/d of pasteurized whole milk twice daily since d 3 to 56, followed by 2 L/d of morning feeding from d 57 to 63 of age. Calves were weaned on d 63 and remained in the study until d 77. The T-75 and T-95 diets increased total-tract starch digestibility compared with the CON diet. Dry matter intake and weaning or final BW were not affected by treatments; however, average daily gain and feed efficiency increased in calves fed T-95 in the overall period. The T-95 diet increased withers height and tended to increase hip height compared with other diets, but feeding behavior did not change throughout the experimental period. Ruminal pH decreased in calves fed the T-95 diet compared with T-75 and CON diets. The molar proportion of ruminal propionate increased, whereas the acetate-to-propionate ratio tended to decrease in calves fed the T-95 compared with CON diet. Calves fed the T-95 diet had the highest blood glucose concentration, whereas a trend for increased insulin concentration was observed in calves fed T-95 compared with other diets. In conclusion, super-conditioning temperature of corn (T-95 vs. T-75 and CON) improved the average daily gain, feed efficiency, and skeletal growth, but did not influence dry matter intake during the first 77 d of age. Finally, the total-tract starch digestibility increased, whereas ruminal pH dropped during the postweaning period as super-conditioning temperature elevated.
我们旨在评估不同温度下喂养超级调理玉米对奶牛犊牛采食量、生长性能、全肠道淀粉消化率、瘤胃发酵、血液代谢物和饲养行为的影响。36 头荷斯坦雌性奶牛犊牛（体重 40 ± 1.72kg，±SD）被随机分为以下 3 种处理之一：（1）粉碎玉米（对照；CON；n = 12），（2）75°C 条件下的玉米（T-75；n = 12），和（3）95°C 条件下的玉米（T-95；n = 12）。从出生第 3 天到 77 天，将 3 种含有相同营养成分的糊化 starter 饲料与 5%切碎的苜蓿干草混合，单独喂养到每头犊牛。所有犊牛从第 3 天到 56 天每天两次喂养 4L 巴氏消毒全牛奶，然后从第 57 天到 63 天每天早上喂养 2L。犊牛在第 63 天断奶，在第 77 天断奶前一直留在研究中。与 CON 日粮相比，T-75 和 T-95 日粮增加了全肠道淀粉消化率。干物质采食量和断奶或最终体重不受处理影响；然而，在整个时期，T-95 喂养的犊牛平均日增重和饲料效率增加。与其他日粮相比，T-95 日粮增加了肩部高度，并且倾向于增加臀部高度，但在整个实验期间，饲养行为没有改变。与 T-75 和 CON 日粮相比，T-95 日粮喂养的犊牛瘤胃 pH 降低。与 CON 日粮相比，T-95 日粮喂养的犊牛瘤胃丙酸摩尔比例增加，而乙酸丙酸比趋于降低。T-95 日粮喂养的犊牛血糖浓度最高，而与其他日粮相比，T-95 日粮喂养的犊牛胰岛素浓度有增加的趋势。总之，玉米的超调理温度（T-95 与 T-75 和 CON）提高了平均日增重、饲料效率和骨骼生长，但在出生后 77 天内，干物质采食量没有影响。最后，随着超调理温度的升高，总肠道淀粉消化率增加，而瘤胃 pH 在断奶后下降。
