Petit H V, Santos G T
Sheep Research Farm, Agriculture and Agri-Food, Canada, La Pocatière, QC, Canada.
J Dairy Sci. 1996 Dec;79(12):2292-6. doi: 10.3168/jds.S0022-0302(96)76607-9.
Thirty-six Ayrshire cows were assigned to 18 pairs and were blocked within parity (5 pairs of primiparous heifers and 13 pairs of multiparous cows); pairs had similar calving dates. The study, which was conducted over 3 yr, was designed to determine the effects of high moisture grain on milk yield and composition and to determine in vitro DM digestibility and ruminal degradabilities of DM, N, and starch of high moisture grains. Treatment diets consisted of isonitrogenous and isoenergetic concentrates that were based on high moisture wheat or high moisture corn. Both groups were fed a mixture of grass silage, grass hay, protein supplement, and a vitamin and mineral mix for ad libitum intake. Treatment diets were fed from wk 4 to 29 and from wk 4 to 37 of lactation for cows in first and second lactations, respectively. There was no interaction between treatment diet and year of lactation. Cows fed high moisture wheat had higher 4% FCM than did cows fed high moisture corn. Milk composition was similar for the two treatment diets. Ruminal degradabilities of DM and starch were higher for high moisture wheat than for high moisture corn. In vitro DM digestibility was higher for high moisture wheat (90.5%) than for high moisture corn (71.6%). This greater digestibility contributed to the higher milk yield of dairy cows fed high moisture wheat.
36头艾尔夏奶牛被分成18对，并按胎次进行分组（5对初产小母牛和13对经产母牛）；每对奶牛的产犊日期相近。这项为期3年的研究旨在确定高水分谷物对牛奶产量和成分的影响，并测定高水分谷物的干物质体外消化率以及干物质、氮和淀粉的瘤胃降解率。试验日粮由以高水分小麦或高水分玉米为基础的等氮等能量精料组成。两组奶牛均自由采食青贮牧草、干草、蛋白质补充料以及维生素和矿物质预混料。分别在头胎和二胎奶牛泌乳期的第4周到第29周以及第4周到第37周饲喂试验日粮。试验日粮与泌乳年份之间不存在交互作用。饲喂高水分小麦的奶牛4%乳脂校正乳产量高于饲喂高水分玉米的奶牛。两种试验日粮的牛奶成分相似。高水分小麦的干物质和淀粉瘤胃降解率高于高水分玉米。高水分小麦的干物质体外消化率（90.5%）高于高水分玉米（71.6%）。这种更高的消化率促使饲喂高水分小麦的奶牛产奶量更高。
