Effects of whole cottonseed or niacin or both on casein synthesis by lactating Holstein cows

• Published in: Journal of dairy science 1992-01, Vol.75 (1), p.184-192
• Main Authors: Lanham, J.K. (Texas AandM University, College Station), Coppock, C.E, Brooks, K.N, Wilks, D.L, Horner, J.L
• Format: Article
• Language: English
• Subjects: ACIDE AMINE ESSENTIEL; Amino Acids - blood; AMINOACIDOS ESENCIALES; Animal Feed; Animals; Biological and medical sciences; Blood Glucose - analysis; Caseins - analysis; Caseins - biosynthesis; Cattle - physiology; COMPOSICION QUIMICA; COMPOSITION CHIMIQUE; Cottonseed Oil; DIETA; Dietary Fiber - administration & dosage; Dietary Proteins - administration & dosage; Eating - drug effects; Female; Food industries; Fundamental and applied biological sciences. Psychology; GRAINE DE COTON; INGESTION DE PIENSO; Insulin - blood; LACTACION; LACTATION; Lactation - drug effects; Lactation - metabolism; LAIT; LECHE; Lipids - analysis; METABOLITE; METABOLITOS; Milk - analysis; Milk - secretion; Milk and cheese industries. Ice creams; Milk Proteins - analysis; Niacin - blood; Niacin - pharmacology; NICOTINAMIDA; NICOTINAMIDE; PLASMA SANGUIN; PLASMA SANGUINEO; PRISE ALIMENTAIRE (ANIMAUX); Random Allocation; REGIME ALIMENTAIRE; RENDEMENT LAITIER; RENDIMIENTO LECHERO; SEMILLA DE ALGODON; VACAS LECHERAS; VACHE LAITIERE; VAISSEAU SANGUIN; VALEUR NUTRITIVE; VALOR NUTRITIVO; VASOS SANGUINEOS
• ISSN: 0022-0302; 1525-3198
• DOI: 10.3168/jds.S0022-0302(92)77752-2

Forty Holstein cows in late lactation were offered diets containing niacin and whole cottonseed: 1) 0 g/d, 0%; 2) 0 g/d, 15%; 3) 6 g/d, 0%; and 4) 6 g/d, 15%, to evaluate effects on milk casein synthesis. Cows fed diet 1 had the highest DMI. The FCM (21.4 vs. 18.7 kg/d) and milk fat percentage (4.08 vs. 3.81) were higher for cows fed diet 1 than for those fed diet 4. Milk protein percentage (3.61 vs. 3.50) was higher for cows fed diet 1 than for those fed diet 2. Casein N, as a percentage of total N, was higher (71.9 vs. 68.0%) in milk from cows fed diet 1 than those fed diet 3. Insulin tended to be elevated in cows on the diets containing niacin, but glucose was not affected. Plasma niacin was elevated in cows on the diets supplemented with niacin compared with diet 1. Plasma AA were changed only slightly by treatments. The beneficial effect of niacin on milk casein synthesis, noted in our earlier work when cows were fed whole cottonseed, was not evident in this study with cows in late lactation and during hot weather