Anderson J L, Kalscheur K F, Garcia A D, Schingoethe D J
Dairy Science Department, South Dakota State University, Brookings 57007.
Dairy Science Department, South Dakota State University, Brookings 57007.
J Dairy Sci. 2015 Aug;98(8):5720-5. doi: 10.3168/jds.2014-9164.
The objective of this research was to determine the subsequent effects on lactation and reproductive performance from feeding fat from distillers dried grains with solubles (DDGS) to growing dairy heifers. During the prepubertal growth phase, 33 Holstein heifers (133±18 d old) were used in a 24-wk randomized complete block design. Treatments included (1) a control diet (CON) containing ground corn and soybean products, 2) a diet with low-fat DDGS (LFDG), and (3) a higher-fat diet with traditional DDGS (HFDG). All diets contained 39.8% grass hay, 24.8% corn silage, and 1.5% vitamins and minerals. Previous results demonstrated that growth performance was maintained across treatments, but plasma cholesterol and fatty acids were greater and puberty may occur earlier in heifers fed HFDG. It was hypothesized that differences among treatments in metabolic profile and puberty may influence reproductive and first-lactation performance. Posttrial data on reproductive performance and milk production for the first 4 mo of lactation were collected for each heifer from dairy herd records. At 3wk prepartum and at calving, body weights, body condition scores, and body measurements were taken. No differences were observed among treatments for age at conception or age at calving. At calving, heifers fed the HFDG were shorter in withers height compared with heifers fed the other diets. Milk yields and components were similar or improved in heifers fed the distillers grains diets compared with heifers fed CON. Heifers fed LFDG had greater milk production and a tendency for greater milk protein yields compared with the heifers fed CON. Energy-corrected milk yields were similar among treatments. Feeding increased dietary fat from DDGS during the prepubertal growth phase did not negatively affect milk production, despite earlier attainment of puberty compared with other treatments. The overall ADG for all 3 treatments was 0.96kg/d during the prepubertal period, which is greater than recommended and may have compromised milk yield across treatments. Based on these findings, producers can feed either DDGS or LFDG with corn in replacement of soybean products and corn to prepubertal heifers and maintain or enhance subsequent reproductive and lactation performance. Dietary fat from DDGS can replace starch from corn as an energy source for prepubertal heifers without detriment to later performance.
本研究的目的是确定给生长中的奶牛小母牛饲喂含可溶物的干酒糟（DDGS）中的脂肪对泌乳和繁殖性能的后续影响。在青春期前的生长阶段，33头荷斯坦小母牛（133±18日龄）被用于一项为期24周的随机完全区组设计。处理包括：（1）含有磨碎玉米和大豆制品的对照日粮（CON）；（2）低脂DDGS日粮（LFDG）；（3）含传统DDGS的高脂日粮（HFDG）。所有日粮均含有39.8%的禾本科干草、24.8%的玉米青贮以及1.5%的维生素和矿物质。先前的结果表明，各处理间生长性能保持一致，但与饲喂HFDG的小母牛相比，血浆胆固醇和脂肪酸含量更高，且青春期可能更早出现。据推测，各处理间代谢特征和青春期的差异可能会影响繁殖性能和首次泌乳性能。从奶牛群记录中收集了每头小母牛泌乳前4个月的繁殖性能和产奶量的试验后数据。在产前3周和产犊时，测量了体重、体况评分和体尺。在受孕年龄或产犊年龄方面，各处理间未观察到差异。产犊时，与饲喂其他日粮的小母牛相比，饲喂HFDG的小母牛体高较矮。与饲喂CON的小母牛相比，饲喂酒糟日粮的小母牛产奶量和成分相似或有所改善。与饲喂CON的小母牛相比，饲喂LFDG的小母牛产奶量更高，且有乳蛋白产量更高的趋势。各处理间能量校正后的产奶量相似。尽管与其他处理相比青春期更早到来，但在青春期前生长阶段增加日粮中来自DDGS的脂肪并未对产奶量产生负面影响。在青春期前阶段，所有3种处理的总体平均日增重为0.96千克/天，高于推荐值，这可能对各处理的产奶量产生了不利影响。基于这些发现，生产者可以给青春期前的小母牛饲喂DDGS或LFDG并搭配玉米，以替代大豆制品和玉米，并维持或提高后续的繁殖和泌乳性能。来自DDGS的日粮脂肪可以替代玉米淀粉作为青春期前小母牛的能量来源，而不会对后期性能产生不利影响。
