Effects of substitution of different levels of steam-flaked corn for finely ground corn on lactation and digestion in early lactation dairy cows
| Autor: | G.P. Ren, Li Jianguo, Rongzhen Zhong, Zhiliang Tan, Gao Yanxia |
|---|---|
| Rok vydání: | 2008 |
| Předmět: |
animal structures
Rumen Zea mays chemistry.chemical_compound Eating Feces Latin square Ammonia Lactation Genetics medicine Animals Dry matter Food science Lactose Particle Size Dairy cattle Chemistry food and beverages Hydrogen-Ion Concentration Gastrointestinal Contents Diet Neutral Detergent Fiber medicine.anatomical_structure Milk Animal Science and Zoology Cattle Digestion Female Blood Chemical Analysis Food Science |
| Zdroj: | Journal of dairy science. 91(10) |
| ISSN: | 1525-3198 |
| Popis: | Eight multiparous Holstein cows, 4 of them fitted with rumen cannulas, were used to test the effects of substitution of steam-flaked corn (SFC) for equal amounts of finely ground corn (FGC) in diets on feed intake and digestion, blood metabolites, and lactation performance in early lactation dairy cows. Cows were fed 4 diets in a replicated 4 x 4 Latin square design. The fistulated cows formed 1 replicate. Each experimental period lasted for 3 wk. The 4 diets contained 0, 10, 20, or 40% SFC and 40, 30, 20, or 0% FGC (dry matter basis), respectively. The milk protein content and yield, milk solid nonfat content and yield, plasma glucose concentration, and dry matter intake increased as the proportion of SFC increased in diets. Apparent total tract digestibilities of dry matter, organic matter, neutral detergent fiber, acid detergent fiber, and average ruminal fluid NH(3)-N concentration decreased with increasing levels of SFC. The ruminal fluid pH was not affected by the substitution of SFC for FGC. The 20% SFC substitution improved digestion of crude protein, yield of fat-corrected milk, milk lactose content, fat, and fat yield. The 40% SFC substitution increased urea concentration in both plasma and milk. It was concluded that 20% of SFC substitution for FGC appeared to be an appropriate level in diet for early lactation dairy cows. |
| Databáze: | OpenAIRE |
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