Substitution of neutral detergent fiber from forage with neutral detergent fiber from by-products in the diets of lactating cows.
Four lactating dairy cows that were ruminally and duodenally cannulated were used in an experiment with a 4 x 4 Latin square design to determine the effects of the substitution of neutral detergent fiber (NDF) from forage with NDF from wheat middlings, corn gluten feed, or a blend of distillers dried grains and hominy. Dietary crude protein and NDF averaged 18 and 31%, respectively, for the diet with 71.2% of the NDF from forage (control diet) and for diets with 55% of the NDF from forage (by-product diets). The substitution of NDF from these by-products for forage NDF did not affect dry matter intake (20.1 kg/d) or digestibility of organic matter. Total tract digestibility of acid detergent fiber was lower for cows fed the diet containing a blend of distillers dried grains and hominy than for cows fed the diet containing corn gluten feed. Microbial crude protein synthesis, milk production (23.9 kg/d), and milk fat percentage were similar for all cows, regardless of diet. Cows fed the diets containing wheat middlings or a blend of distillers dried grains and hominy had reduced ruminal pH compared with that of cows fed the diet containing corn gluten feed or the control diet. Diets containing 55% of total NDF from forage with 31% of total NDF from corn gluten feed, wheat middlings, or a blend of distillers dried grains and hominy can supply sufficient effective fiber to maintain normal ruminal function.
Zhu
J S
JS
Department of Animal Science and Food Nutrition, Southern Illinois University, Carbondale 62901, USA.
Stokes
S R
SR
Murphy
M R
MR
D000641:Ammonia / Q000378:metabolism; D000821:Animal Feed; D000818:Animals; D002417:Cattle / Q000502:physiology*; D004043:Dietary Fiber / Q000032:analysis* / Q000378:metabolism; D004063:Digestion; D004386:Duodenum / Q000378:metabolism; D005232:Fatty Acids, Volatile / Q000378:metabolism; D005260:Female; D006863:Hydrogen-Ion Concentration; D007774:Lactation; D008055:Lipids / Q000032:analysis; D008892:Milk / Q000737:chemistry; D008894:Milk Proteins / Q000032:analysis; D009584:Nitrogen / Q000008:administration & dosage / Q000378:metabolism; D012417:Rumen / Q000378:metabolism
D004043:Dietary Fiber; D005232:Fatty Acids, Volatile; D008055:Lipids; D008894:Milk Proteins; D000641:Ammonia; D009584:Nitrogen