Lactation Response of Dairy Cows Fed Distillers Grains Versus Oilseed Meals

With the raising costs of protein supplements this study was conducted to determine the lactation response of dairy cattle feed distillers grains versus the traditional protein supplements. The first study was conducted to determine the optimum level of dried distillers grains with solubles in a dairy ration. A lactation trial was designed as a 4 x 4 Latin square design with 4 wk per period utilizing 12 cows. Distillers grains with solubles were included in the diets at 0, 12, 24, and 36% on a dry matter basis. The diets consisted of 49% forage and 51 % concentrate on a dry matter basis. Diets were balanced for 17.5% crude protein, 10.1 % ruminal degraded protein, and 7.4% ruminal undegraded protein. Dry matter intake (23.2 kg/d) was equal among all treatments. Cows fed increasing levels of distillers grains had a quadratic response for milk yield with 0 and 3 6% being the highest. Milk fat percentage (4.13 %) and protein percentage (3.1 7%) were similar for all treatments. Milk protein fractions were further investigated and increasing dried distillers grains with solubles in the diet had no effect on both non-protein N and true crude protein; however, casein percent of total crude protein showed a tendency to linearly decrease as dried distillers grains with solubles increased in the diets A second study was conducted to compare high protein dried distillers grains against soybean meal, canola meal, and dried distillers grains with solubles as protein supplements for lactating dairy cows. A lactation trial was designed as a 4 x 4 Latin square design with · 12 cows. Each treatment diet consisted of 5 5% forage and one of the four protein supplements in a concentrate mix. Milk production (31.8 kg/d) and dry matter intake (24.4 kg/d) were similar for all four treatments. Milk fat and protein percentages were the lowest in the dried distillers grains with solubles diet. Feed efficiency (1.44) was not affected by the treatments. Total milk nitrogen and true milk nitrogen were the highest in the high protein dried distillers grains. Acetate (68.3 Mmol/100 mol) propionate (18.2 Mmol/100 mol) and the acetate to propionate ratio (3. 81) were not affected by the dietary treatment. Feeding high protein dried distillers grains can be a good way to cut some soy based protein from dairy cattle diets. Feeding of distillers grains can be an effective method of improving income over feed costs as milk production is maintained on diets that can cost less than traditional protein supplements