Effects of Differences in Starch Content of Diets with Whole Cottonseed or Rice Bran on Milk Casein
| Autor: | K.N. Brooks, D.L. Wilks, C.E. Coppock, C.E. Gates |
|---|---|
| Rok vydání: | 1991 |
| Předmět: |
Cottonseed Oil
Silage Starch Randomized block design Biology Cottonseed Eating Random Allocation chemistry.chemical_compound Milk yield Casein Dietary Carbohydrates Genetics Animals Lactation Food science Least-Squares Analysis Bran Caseins food and beverages Oryza Animal Feed Milk chemistry Alfalfa hay Cattle Female Animal Science and Zoology Food Science |
| Zdroj: | Journal of Dairy Science. 74:1314-1320 |
| ISSN: | 0022-0302 |
| DOI: | 10.3168/jds.s0022-0302(91)78287-8 |
| Popis: | 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. |
| Databáze: | OpenAIRE |
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