|ANDERSON, JILL - South Dakota State University
|GARCIA, ALVARO - South Dakota State University
|SCHINGOETHE, DAVID - South Dakota State University
Submitted to: Journal of Dairy Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 4/25/2015
Publication Date: 8/1/2015
Publication URL: http://handle.nal.usda.gov/10113/62911
Citation: Anderson, J.L., Kalscheur, K., Garcia, A.D., Schingoethe, D.J. 2015. Feeding fat from distillers dried grains with solubles to dairy heifers: III. Effects on long-term reproductive and lactation performance. Journal of Dairy Science. 98:5720-5725.
Interpretive Summary: Distillers dried grains with solubles (DDGS), a byproduct of the ethanol industry, is an economic feed source for dairy cattle and is used extensively in ruminant diets. But there have been questions about feeding it to dairy heifers, with one concern being whether the higher fat concentration provided in DDGS might negatively affect the prepubertal growth period and subsequently the reproductive and lactation performance of heifers. In this study, Holstein heifers from 4.5 to 10.5 months of age were fed three different diets containing: 1) soybean products with ground corn; 2) low-fat DDGS with ground corn; or 3) high-fat traditional DDGS. Post-trial reproductive performances were similar among treatments. Milk yield for the first four months of lactation was maintained by heifers fed the traditional DDGS and greater in heifers fed the low-fat DDGS diet compared to the heifers fed the corn and soybean diet. Based on these findings, feeding prepubertal dairy heifers either DDGS or low-fat DDGS with corn are viable alternatives to feeding corn and soybean feedstuffs.
Technical Abstract: During the prepubertal growth phase, 33 Holstein heifers (133 ± 18 d old) were used in a 24-week randomized complete block design. Treatments included: 1) a control diet (CON) containing ground corn (15.9% of DM) and soybean products (17.9%); 2) a low-fat diet (LFDG) formulated with 21.9% fat-extracted dried distillers grains and 11.9% ground corn; and 3) a high-fat diet (HFDG) formulated with 33.8% traditional dried distillers grains with solubles (DDGS). All diets contained 39.8% grass hay, 24.8% corn silage, and 1.5% vitamins and minerals with the remaining 33.9% as concentrate mix. Results demonstrated that growth performance was maintained, despite differences in metabolic profiles, such as greater plasma cholesterol and fatty acid concentrations in the heifers fed the HFDG diet compared to other treatments. Previous results also indicated that 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. Data on reproductive performance and milk production for the first four months of lactation were collected for each heifer from dairy herd records. At 3 weeks prepartum and at calving, body weights, body condition scores and body measurements were taken. There were no differences among treatments for age at conception, or age at calving. At calving, heifers fed the HFDG were shorter in wither height compared to heifers fed the other diets. Milk yields and components were similar to, or improved in, heifers fed the distillers grains diets compared to heifers fed CON. Heifers fed LFDG had greater milk production and a tendency for greater milk protein yields compared to 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 impact milk production, despite earlier attainment of puberty compared to other treatments. Based on these findings, producers can feed either DDGS or low-fat DDGS with corn in replacement of soybean products and corn to pre-pubertal 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 long-term performance.