Gelvin A A, Lardy G P, Soto-Navarro S A, Landblom D G, Caton J S
Department of Animal and Range Sciences, North Dakota State University, Fargo 58105, USA.
J Anim Sci. 2004 Dec;82(12):3589-99. doi: 10.2527/2004.82123589x.
Two experiments evaluated digestive and performance effects of field pea-based creep feed in nursing calf diets. In Exp.1, eight nursing steer calves (145 +/- 27 kg initial BW) with ruminal cannulas were used to evaluate effects of supplementation and advancing season on dietary composition, intake, digestion, and ruminal fermentation characteristics. Treatments were unsupplemented control (CON) and field pea-based creep (SUP; 19.1% CP, DM basis) fed at 0.45% BW (DM basis) daily. Calves grazed native range with their dams from early July through early November. Periods were 24 d long and occurred in July (JUL), August (AUG), September (SEP), and October (OCT). Experiment 2 used 80 crossbred nursing calves, 48 calves in yr 1 and 32 calves in yr 2 (yr 1 = 144 +/- 24 kg; yr 2 = 121 +/- 20 kg initial BW), to evaluate effects of field pea-based creep on calf performance. Treatments included unsupplemented control (CON); field pea-based creep feeds containing either 8% (LS); or 16% (HS) salt; and soybean meal/field pea-based creep containing (as-fed basis) 16% salt (HIPRO). Masticate samples from SUP calves in Exp.1 had greater CP (P = 0.05) than those from CON calves. Forage CP and ADIN decreased linearly with advancing season (P = 0.01 and 0.03, respectively). In vitro OM digestibility of diet masticate decreased from JUL to OCT (P < 0.01; 58.5 to 41.3%). Forage intake did not differ (P = 0.33) between treatments but increased linearly with advancing season (1.67, 1.90, 3.12, 3.38 kg/d for JUL, AUG, SEP, and OCT, respectively; P < 0.01). Milk intake (percentage of BW) did not differ (P = 0.56) between CON and SUP calves but decreased linearly (P < 0.01) with advancing season. Supplemented calves had greater (P = 0.03) total intake (g/kg of BW; forage + milk + creep) compared with CON calves. Treatment did not affect (P < 0.30) rate of in situ disappearance of forage or creep. Forage DM, CP, and creep DM disappearance rate decreased linearly (P < or = 0.02) with advancing season. Supplementation decreased (P = 0.05) ruminal pH, whereas ruminal ammonia and VFA concentrations were greater (P < or = 0.02) in SUP calves. In Exp. 2, creep-fed calves had greater ADG and final BW than CON calves (P < 0.01). Calves offered HS tended (P = 0.07) to have increased gain efficiency above CON than LS calves. Field peas can be used as an ingredient in creep feed to increase calf weight gain without negatively affecting ruminal fermentation and digestion.
两项试验评估了以饲用豌豆为基础的犊牛早期补饲对哺乳犊牛消化和生产性能的影响。在试验1中，选用8头装有瘤胃瘘管的哺乳小公牛犊（初始体重145±27千克），评估补饲和季节推进对日粮组成、采食量、消化率和瘤胃发酵特性的影响。处理组包括不补饲对照组（CON）和以饲用豌豆为基础的早期补饲组（SUP；干物质基础下粗蛋白含量为19.1%），按每日体重的0.45%（干物质基础）饲喂。犊牛从7月初至11月初与其母牛在天然牧场放牧。试验期为24天，分别在7月（JUL）、8月（AUG）、9月（SEP）和10月（OCT）进行。试验2选用80头杂交哺乳犊牛，第1年48头，第2年32头（第1年初始体重144±24千克；第2年初始体重121±20千克），评估以饲用豌豆为基础的早期补饲对犊牛生产性能的影响。处理组包括不补饲对照组（CON）；含8%（LS）或16%（HS）食盐的以饲用豌豆为基础的早期补饲料；以及含16%（风干基础）食盐的豆粕/饲用豌豆早期补饲料（HIPRO）。试验1中SUP组犊牛的咀嚼样本粗蛋白含量高于CON组犊牛（P = 0.05）。随着季节推进，牧草粗蛋白和酸性洗涤不溶性氮呈线性下降（分别为P = 0.01和0.03）。日粮咀嚼样本的体外有机物消化率从7月至10月下降（P < 0.01；从58.5%降至41.3%）。处理组间牧草采食量无差异（P = 0.33），但随季节推进呈线性增加（7月、8月、9月和10月分别为1.67、1.90、3.12和3.38千克/天；P < 0.01）。CON组和SUP组犊牛的牛奶采食量（占体重的百分比）无差异（P = 0.56），但随季节推进呈线性下降（P < 0.01）。与CON组犊牛相比，补饲组犊牛的总采食量（克/千克体重；牧草+牛奶+早期补饲料）更高（P = 0.03）。处理对牧草或早期补饲料的原位消失率无影响（P < 0.30）。牧草干物质、粗蛋白和早期补饲料干物质消失率随季节推进呈线性下降（P≤0.02）。补饲降低了瘤胃pH值（P = 0.05），而SUP组犊牛的瘤胃氨和挥发性脂肪酸浓度更高（P≤0.02）。在试验2中，早期补饲的犊牛平均日增重和末重高于CON组犊牛（P < 0.01）。与LS组犊牛相比，饲喂HS组的犊牛增重效率高于CON组的趋势更明显（P = 0.07）。饲用豌豆可用作早期补饲料的一种成分，以增加犊牛体重，且对瘤胃发酵和消化无负面影响。
