Feeding heat-treated full fat soybeans to cows in early lactation.
Forty-six multiparous Holstein cows were fed one of three total mixed diets from 15 to 119 d postpartum with alfalfa silage as the only forage. Each diet contained 50% forage and 50% concentrate on a DM basis. Diets were formulated to be isonitrogenous by replacing corn and solvent soybean meal with raw soybeans or heat-treated soybeans. The proportion of protein supplement in the diet on a DM basis was 10% soybean meal, 13% raw soybeans, or 13% heat-treated soybeans. The soybeans were heat-treated to maximize the amount of available lysine passing to the small intestine. The soybean meal diet was fed to all cows during wk 1 and 2 postpartum for covariate adjustment of DMI and milk production. Intake of DM was similar across treatments. Feeding heat-treated soybeans supported more milk (4.5 kg/d), 3.5% FCM (4.0 kg/d), and milk protein (.09 kg/d) than soybean meal or raw soybeans. Milk fat percentage was not altered by treatments. However, milk protein percentage was depressed in cows fed heat-treated soybeans compared with soybean meal (2.85 vs. 2.99%, respectively). Milk production response of cows fed properly heat-treated soybeans compared with soybean meal with alfalfa silage as the sole forage is thought to be related primarily to improved supply of undegraded intake protein.
Faldet
M A
MA
US Dairy Forage Research Center, Agricultural Research Service, USDA, Madison.
Satter
L D
LD
D000821:Animal Feed; D000818:Animals; D002417:Cattle / Q000502:physiology*; D004044:Dietary Proteins / Q000008:administration & dosage; D004435:Eating; D005260:Female; D005511:Food Handling; D006358:Hot Temperature; D007774:Lactation / Q000502:physiology*; D008055:Lipids / Q000032:analysis; D008239:Lysine / Q000008:administration & dosage; D000455:Medicago sativa; D008892:Milk / Q000032:analysis / Q000378:metabolism; D008894:Milk Proteins / Q000032:analysis; D012820:Silage; D013025:Glycine max
D004044:Dietary Proteins; D008055:Lipids; D008894:Milk Proteins; D008239:Lysine