Hill T M, Quigley J D, Suarez-Mena F X, Bateman H G, Schlotterbeck R L
Nutrition and Research Center, Provimi, 10 Nutrition Way, Brookville, OH 45309.
Nutrition and Research Center, Provimi, 10 Nutrition Way, Brookville, OH 45309.
J Dairy Sci. 2016 Aug;99(8):6352-6361. doi: 10.3168/jds.2015-10812. Epub 2016 Jun 8.
Calves fed large amounts of milk replacer (MR) gain more body weight preweaning than calves fed less MR; however, postweaning growth may be reduced because of impaired digestion of nutrients. This was explored in the current research, as was the inclusion of functional fatty acids (NT) that could ameliorate some poor growth and digestion issues in calves fed large amounts of MR. Two MR rates [moderate (MOD) or aggressive (AGG)] with and without NT were compared using 48 male Holstein calves initially 3d old (43±1.5kg of body weight) randomly assigned to treatments. The MOD rate was fed at 0.66kg of dry matter (DM) for 49d. The AGG rate was fed for 4d at 0.66kg of DM, 4d at 0.96kg of DM, then 34d at 1.31kg of DM, followed by 0.66kg of DM for the last 7d. Calves were completely weaned at 49d. The MR contained 27% crude protein and 17% fat. The textured starter was 20% crude protein. Starter and water were fed free-choice for the first 56d when calves were housed in individual pens. From 56 to 112d, calves were grouped (4 calves/pen), maintaining the same MR rate and NT treatments, and fed starter blended with 5% chopped grass hay free-choice with free-choice water. Digestibility was estimated from fecal collections made on d 19 to 23, 40 to 44, and 52 to 56. Data were analyzed as a completely randomized design with a factorial arrangement of MR rate and NT using repeated measures with a mixed procedure. Fiber and starch digestion increased with age and was lower for AGG versus MOD. Calf average daily gain and hip width change were greater before approximately 6wk of age for AGG versus MOD, but this was reversed from approximately 6 to 16wk. Calves fed AGG had lower average daily gain per unit intake of DM, crude protein, and metabolizable energy from 8 to 16wk than calves fed MOD. Preweaning starter intake was less for calves fed AGG versus MOD. Calves fed AGG had greater body weight gain than MOD over 112d, but hip width change did not differ. Feeding NT improved digestibility of organic matter, DM, neutral detergent fiber, and acid detergent fiber (over 50% improvement for neutral detergent fiber and acid detergent fiber), which resulted in 10.7kg (13%) more body weight gain and 1.4cm (16%) more hip width change over 112d. This was a greater improvement in growth than the difference in AGG and MOD programs over 112d.
与喂食较少代乳粉（MR）的犊牛相比，喂食大量MR的犊牛在断奶前体重增加更多；然而，断奶后的生长可能会因营养物质消化受损而减缓。本研究探讨了这一问题，同时还研究了添加功能性脂肪酸（NT）是否可以改善喂食大量MR的犊牛生长不良和消化问题。使用48头初始年龄为3日龄（体重43±1.5千克）的雄性荷斯坦犊牛，比较了添加和不添加NT的两种MR饲喂率[适度（MOD）或激进（AGG）]，犊牛被随机分配到各处理组。MOD饲喂率为每天0.66千克干物质（DM），持续49天。AGG饲喂率在开始的4天为每天0.66千克DM，接下来的4天为每天0.96千克DM，然后在34天内为每天1.31千克DM，最后7天为每天0.66千克DM。犊牛在49日龄时完全断奶。MR含有27%的粗蛋白和17%的脂肪。颗粒开食料含有20%的粗蛋白。在犊牛单独饲养的前56天，开食料和水自由采食。从56日龄到112日龄，犊牛分组饲养（每组4头），保持相同的MR饲喂率和NT处理，并自由采食混合了5%切碎禾本科干草的开食料和自由饮水。在第19至23天、40至44天和52至56天收集粪便来估计消化率。数据采用完全随机设计进行分析，采用MR饲喂率和NT的析因安排，并使用重复测量的混合程序。纤维和淀粉消化率随年龄增长而增加，AGG组低于MOD组。在大约6周龄之前，AGG组犊牛的平均日增重和髋宽变化大于MOD组，但在大约6至16周龄时情况相反。在8至16周龄期间，与MOD组犊牛相比，AGG组犊牛每单位DM、粗蛋白和代谢能摄入量的平均日增重较低。与MOD组相比，AGG组犊牛断奶前的开食料摄入量较少。在112天内，AGG组犊牛的体重增加大于MOD组，但髋宽变化没有差异。添加NT提高了有机物、DM、中性洗涤纤维和酸性洗涤纤维的消化率（中性洗涤纤维和酸性洗涤纤维提高超过50%），这使得在112天内体重增加多10.7千克（13%），髋宽变化多1.4厘米（16%）。这一生长改善比112天内AGG和MOD方案之间的差异更大。
