Department of Animal Science, Faculty of Agriculture, Lorestan University, PO Box 465, Khorramabad, Iran.
Animal Science Research Department, Isfahan Agricultural and Natural Resources Research and Education Center, AREEO, PO Box 81785-199, Isfahan, Iran.
Sci Rep. 2023 Oct 20;13(1):17914. doi: 10.1038/s41598-023-45143-x.
The objective of this study was to investigate the effects of corn processing index (CPI)-particularly at 70% and 85%-in starter feed in combination with the provision of forage, either alfalfa hay (AH) or wheat straw (WS), on feed intake, growth performance, rumen pH, and blood metabolites of dairy calves. Forty-eight male Holstein calves (43.0 ± 1.5 kg body weight) were randomly assigned (n = 12 calves per treatment) to one of four dietary treatments: (1) a textured starter diet containing 70% CPI and AH (70CPIAH), (2) a textured starter feed containing 70% CPI combined with WS (70CPIWS), (3) a textured starter feed containing 85% CPI and AH (85CPIAH), (4) a textured starter feed containing 85% CPI combined with WS (85CPIWS). Intake of starter feed (TMR) and milk was individually monitored and recorded daily, while body weight was measured weekly. On days 30 and 65, blood samples were collected from all calves 3 h after morning feeding. No interaction was detected between the CPI of starter feed diets and forage provision for starter intake, dry matter intake (DMI), metabolizable energy intake (MEI), feed efficiency (FE), average daily gain (ADG), and body weight (BW). The preweaning and overall DMI, preweaning, postweaning and overall FE and ADG, preweaning and overall starter intake, preweaning and overall ME intake, and postweaning and overall BW were greater for calves fed 85CPI than those fed 70CPI starter diets. Postweaning and overall ADG and postweaning FE were greater in calves fed WS than those fed AH. Body length and hip width were greater for calves offered 85CPI than in fed 70CPI. Wheat straw supplementation increased rumen pH at day 65 in calves fed 70CPI, but not in those fed 85CPI. No interaction was found between the CPI in the starter feed diet and the forage source for starter intake and DMI, MEI, FE, and BW. The results showed that including corn with 85% processing index in dairy calf starters improved their growth performance.
本研究旨在探究玉米加工指数（CPI）-尤其是 70%和 85%-在犊牛开食料中的作用，以及提供干草（苜蓿干草（AH）或小麦秸秆（WS））对奶牛犊牛的采食量、生长性能、瘤胃 pH 值和血液代谢物的影响。48 头雄性荷斯坦犊牛（43.0±1.5kg 体重）随机分配（n=12 头犊牛/处理）到以下四种日粮处理之一：（1）含有 70%CPI 和 AH 的膨化开食料（70CPIAH），（2）含有 70%CPI 和 WS 的膨化开食料（70CPIWS），（3）含有 85%CPI 和 AH 的膨化开食料（85CPIAH），（4）含有 85%CPI 和 WS 的膨化开食料（85CPIWS）。开食料（TMR）和牛奶的采食量均单独进行监测和记录，体重每周测量一次。在第 30 天和第 65 天，所有犊牛在早上喂食后 3 小时采集血液样本。在开食料采食量、干物质采食量（DMI）、可代谢能采食量（MEI）、饲料效率（FE）、平均日增重（ADG）和体重（BW）方面，开食料日粮的 CPI 与饲草供应之间没有相互作用。在饲喂 85CPI 的犊牛中，断奶前和整个哺乳期 DMI、断奶前和整个哺乳期 FE 和 ADG、断奶前和整个哺乳期开食料采食量、断奶前和整个哺乳期 ME 采食量以及断奶后和整个 BW 均大于饲喂 70CPI 的犊牛。在饲喂 WS 的犊牛中，断奶后和整个哺乳期 ADG 和断奶后 FE 均大于饲喂 AH 的犊牛。在饲喂 85CPI 的犊牛中，体躯长度和髋宽均大于饲喂 70CPI 的犊牛。在饲喂 70CPI 的犊牛中，小麦秸秆的补充增加了第 65 天的瘤胃 pH 值，但在饲喂 85CPI 的犊牛中没有增加。在开食料采食量和 DMI、MEI、FE 和 BW 方面，开食料日粮的 CPI 与饲草来源之间没有相互作用。结果表明，在犊牛开食料中添加 85%加工指数的玉米可提高其生长性能。
