Effects of Differences in Starch Content of Diets with Whole Cottonseed or Rice Bran on Milk Casein

• Published in: Journal of dairy science 1991-04, Vol.74 (4), p.1314-1320
• Main Authors: Wilks, D.L., Coppock, C.E., Brooks, K.N., Gates, C.E.
• Format: Article
• Language: English
• Subjects: ALIMENT POUR ANIMAUX; ALIMENTACION DE LOS ANIMALES; ALIMENTATION DES ANIMAUX; ALMIDON; AMIDON; Animal Feed; Animals; ARROZ; Biological and medical sciences; BOVIN; CASEINA; CASEINE; Caseins - biosynthesis; Cattle - physiology; Cottonseed Oil; Dietary Carbohydrates - metabolism; Eating; Feed and pet food industries; Female; Food industries; Fundamental and applied biological sciences. Psychology; GANADO BOVINO; GLUCOSA; GLUCOSE; GRAINE DE COTON; INGESTION DE PIENSO; INSULINA; INSULINE; LACTACION; LACTATION; Lactation - physiology; Least-Squares Analysis; Milk - chemistry; Milk - secretion; milk casein; Oryza; PIENSOS; PLASMA SANGUIN; PLASMA SANGUINEO; PRISE ALIMENTAIRE (ANIMAUX); PROTEINAS DE LA LECHE; PROTEINE DU LAIT; Random Allocation; RENDEMENT; RENDEMENT LAITIER; RENDIMIENTO; RENDIMIENTO LECHERO; rice bran; RIZ; SALVADO; SEMILLA DE ALGODON; SON; Starch - metabolism; starch differences; VACAS LECHERAS; VACHE LAITIERE; whole cottonseed
• ISSN: 0022-0302; 1525-3198
• DOI: 10.3168/jds.S0022-0302(91)78287-8

Forty lactating Holstein cows in early to midlactation were used in a randomized complete block design to measure the effects of the following diets on milk casein. Treatments were four complete rations fed for ad libitum intake consisting of 1) 60% concentrate, 10% alfalfa hay, and 30% corn silage; 2) 45% concentrate, 10% alfalfa hay, 30% corn silage, and 15% whole cottonseed; 3) 60% concentrate, 5% alfalfa hay, 20% corn silage, and 15% whole cottonseed, and 4) 45% concentrate, 10% alfalfa hay, 30% corn silage, and 15% rice bran. Least squares means for daily DM intake all were significantly different and were 3.51, 3.90, 3.28, and 3.74% BW, respectively. Cows fed diet 3 had higher arterial glucose and insulin and venous insulin. Least squares means were significantly different for milk yield, 30.1, 31.4, 28.4, and 31.6 kg/d; for milk protein, 3.30, 3.13, 3.48, and 3.12%; and for casein N, .376, .358, .373, and .330%, respectively. However, milk protein and casein N yields were similar for all cows. The diet that contained the highest percentage of starch did not result in a significantly higher percentage of casein N in the milk but had the lowest milk production. Both whole cottonseed and rice bran, substituted for concentrate, depressed milk protein percentage.