Effect of feeding a reduced-starch diet with or without amylase addition on lactation performance in dairy cows

• Published in: Journal of dairy science Vol. 93; no. 2; pp. 723 - 732
• Main Authors: Gencoglu, H., Shaver, R.D., Steinberg, W., Ensink, J., Ferraretto, L.F., Bertics, S.J., Lopes, J.C., Akins, M.S.
• Format: Journal Article
• Language: English
• Published: New York, NY Elsevier Inc 01.02.2010; Elsevier; American Dairy Science Association
• Subjects: amylase; amylases; Amylases - administration & dosage; Animal Feed - analysis; Animal Nutritional Physiological Phenomena; animal performance; Animal productions; Animals; Biological and medical sciences; Body Weight - physiology; Cattle; cow feeding; dairy cows; Dairying; Diet - veterinary; Diet, Carbohydrate-Restricted; dietary supplements; exogenous sources; experimental diets; fed varying amounts; feed conversion; Female; fermentation; Food industries; Fundamental and applied biological sciences. Psychology; grain; high-moisture corn; lactating cow; lactation; Lactation - physiology; low carbohydrate diet; milk-production; neutral detergent fiber; nutrient digestibility; Particle Size; Random Allocation; reduced-starch diet; ruminal digestion kinetics; ruminant nutrition; site; soy hull; soyhulls; starch; Starch - metabolism; Starch and starchy product industries; Terrestrial animal productions; Time Factors; Vertebrates; lactating cow; soy hull; starch; amylase; Farming animal; Amylase; Lactation; Enzyme; Starch; Dairy cattle; Feeding; Vertebrata; Mammalia; Diet; Dairy industry; Carbohydrate; Artiodactyla; Performance; Amylolytic enzyme; Polysaccharide; Ungulata
• ISSN: 0022-0302; 1525-3198
• DOI: 10.3168/jds.2009-2673

The objective of this study was to determine lactation performance responses of high-producing dairy cows to a reduced-starch diet compared with a normal-starch diet and to the addition of exogenous amylase to the reduced-starch diet. Thirty-six multiparous Holstein cows (51±22 DIM and 643±49kg of body weight at trial initiation) were randomly assigned to 1 of 3 treatments in a completely randomized design: a 3-wk covariate adjustment period during which the cows were fed the normal-starch diet, followed by a 12-wk treatment period during which the cows were fed their assigned treatment diets. The normal-starch TMR did not contain exogenous amylase (NS−). The reduced-starch diets, formulated by partially replacing corn grain with soy hulls, were fed without (RS−) and with (RS+) exogenous amylase added to the TMR. Starch and NDF concentrations averaged 27.1 and 30.6%, 21.8 and 36.6%, and 20.7 and 36.6% (dry matter basis) for the NS−, RS−, and RS+ diets, respectively. Dry matter intake for cows fed the RS− diet was 2.4 and 3.2kg/d greater than for cows fed the NS− and RS+ diets, respectively. Intake of NDF ranged from 1.19 to 1.52% of body weight among the treatments, with the RS− diet being 28% greater than the NS− diet and 13% greater than the RS+ diet. Milk yield averaged 50.4kg/d and was unaffected by treatment. Fat-corrected milk yield was 2.9kg/d greater for cows fed the RS− diet than for cows fed the NS− diet. Body weight and body condition score measurements were unaffected by treatment. Fat-, solids-, and energy-corrected milk feed conversions (kilograms/kilogram of DMI) were 12 to 13% greater for cows fed the RS+ diet than for cows fed the RS− diet. Dry matter and nutrient digestibilities were lowest for cows fed the NS− diet and greatest for cows fed the RS+ diet, and were greater for cows fed the RS+ diet than for cows fed the RS− diet, with the exception of starch digestibility, which was similar. Greater conversion of feed to milk for dairy cows fed reduced-starch diets that include exogenous amylase may offer potential for improving economic performance.