Shaver, Randy DuncanSteinberg, WilhelmEnsink, JeroenFerraretto, LuizBertics, Sandra J.Carrilho Lopes, J.Akins, Matthew2021-11-022021-11-022010-02Gençoğlu, H. vd. (2010). "Effect of feeding a reduced-starch diet with or without amylase addition on lactation performance in dairy cows". Journal of Dairy Science, 93(2), 723-732.0022-03021525-3198https://doi.org/10.3168/jds.2009-2673https://www.sciencedirect.com/science/article/pii/S0022030210715149http://hdl.handle.net/11452/22555The 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 +/- 49 kg of body weight at trial initiation) were randomly assigned to I 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 3.2 kg/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 50.4 kg/d and was unaffected by treatment. Fat-corrected milk yield was 2.9 kg/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.eninfo:eu-repo/semantics/openAccessAmylaseLactating cowSoy hullStarchRuminal digestion kineticsNeutral detergent fiberFed varying amountsHigh-moisture cornsMilk-productionNutrient digestibilityFermentationSoyhullsSiteCarbohydrateAgricultureFood science & technologyZea maysAmylasesAnimal feedAnimal nutritional physiological phenomenaAnimalsBody weightCattleDairyingDietDiet, carbohydrate-restrictedFemaleLactationParticle sizeRandom allocationStarchTime factorsArticle0002741025000292-s2.0-7794928296872373293220105543Agriculture, dairy & animal scienceFood science & technologyRumen Fermentation; Acid Detergent Fiber; Dry Matter DigestibilityAmylaseStarchAnimalAnimal diseaseAnimal foodArticleBody weightCattleDairyingDietFemaleLactationLow carbohydrate dietMetabolismParticle sizePhysiologyRandomizationTime