Influence of Adding Malic Acid to Dairy Cattle Rations on Milk Production, Rumen Volatile Acids, Digestibility, and Nitrogen Utilization

Abstract

Thirty-two lactating Holstein cows (16 in early and 16 in midlactation) were fed for 100 days either 0, 70, 105, or 140 g of malic acid per day. Rations were corn and corn silage, and 25% of the total nitrogen was urea. Milk persistency was greater for the group fed 140 g malic acid per day. Malic acid increased total volatile fatty acids during early lactation. Intake of dry matter, milk composition, glucose and urea in plasma, and rumen ammonia and pH did not differ among treatments. In another study, six steers with rumen fistulas received 0, 100, or 200 mg/kg body weight of malic acid in a Latin square design. The basal diet was ground shelled corn and corn silage (equal dry matter) supplemented with urea to increase crude protein to 12% (of dry matter) and minerals. Malic acid increased rumen propionate, but digestibilities of nutrients, retained nitrogen, urea and ammonia in plasma, and rumen ammonia did not differ among treatments. In a third trial four rumen-fistulated steers received malic acid at 0 and 200 mg/kg body weight in a 2 × 2 Latin square. In this trial 80% of the dry matter was high moisture corn, and 20% was corn silage. Rumen propionate again tended to be greater for steers fed malic acid. No differences among treatments were shown for other rumen and blood measurements. © 1982, American Dairy Science Association. All rights reserved.