Ferraretto, Luiz F.Shaver, Randy DuncanEspineira, M.Bertics, Sandra J.2021-12-072021-12-072011-03Ferraretto, LF. vd. (2011). "Influence of a reduced-starch diet with or without exogenous amylase on lactation performance by dairy cows". Journal of Dairy Science, 94(3), 1490-1499.0022-03021525-3198https://doi.org/10.3168/jds.2010-3736https://www.sciencedirect.com/science/article/pii/S0022030211001020http://hdl.handle.net/11452/23030The objective of this trial was to determine lactation performance responses in high-producing dairy cows to a reduced-starch versus a normal-starch diet and to the addition of exogenous amylase to the reduced-starch diet. Forty-five multiparous Holstein cows, 68 +/- 29 d in milk and 696 +/- 62 kg of body weight (BW) at trial initiation, were randomly assigned to 1 of 3 treatments in a completely randomized design; a 2-wk covariate adjustment period with cows fed the normal-starch diet was followed by a 10-wk treatment period with cows fed their assigned treatment diets. The normal-starch total mixed ration did not contain exogenous amylase (NS-). The reduced-starch diets, formulated by partially replacing corn grain and soybean meal with whole cottonseed and wheat middlings, were fed without (RS-) and with (RS+) exogenous amylase addition to the total mixed ration. All diets contained 50% forage and 19.8% forage neutral detergent fiber (dry matter basis). Starch and neutral detergent fiber concentrations averaged 27.0 and 30.9%, 22.1 and 35.0%, and 21.2 and 35.3% (dry matter basis) for the NS-, RS-, and RS+ diets, respectively. Expressed as a percentage of BW, dry matter intake was greater for cows fed RS- than for cows fed NS- or RS+. Intake of neutral detergent fiber ranged from 1.09 to 1.30% of BW among the treatments, with that of RS- being 21% greater than that of NS-. Milk yield tended to be greater for cows fed NS- compared with the RS diets. Milk fat content and yield were unaffected by treatment. Milk protein content and yield were greater for cows fed NS- compared with the RS diets. Concentrations of milk urea nitrogen were greater for cows fed RS diets compared with the NS- diet. Body weight, BW change, and body condition score were unaffected by treatment. Feed conversion (kg of milk/kg of dry matter intake) was 10% greater on average for cows fed NS- than for cows fed the RS diets, and tended to be 6% greater for cows fed RS+ compared with RS-. Feeding a reduced-starch diet formulated by partially replacing corn grain and soybean meal with a wheat middlings and whole cottonseed mixture compared with a normal-starch diet without addition of exogenous amylase to either diet reduced milk and component-corrected feed conversions. Addition of exogenous amylase to a reduced-starch diet was of minimal benefit in this study.eninfo:eu-repo/semantics/openAccessAgricultureFood science & technologyAmylaseByproduct feedsLactating cowStarchMilk-productionNutrient digestibilityProtein-synthesisWhole cottonseedCrude proteinFiberCarbohydrateCattleFermentationDigestionBosGlycine maxMicropusTriticum aestivumZea maysAmylasesAnimal nutritional physiological phenomenaAnimalsCattleDietDiet, carbohydrate-restrictedFemaleLactationMilkStarchArticle0002874735000412-s2.0-799516854831490149994321338813Agriculture, dairy & animal scienceFood science & technologyRumen Fermentation; Acid Detergent Fiber; Dry Matter DigestibilityAmylaseStarchAnimalAnimal diseaseAnimal foodArticleCattleClinical trialControlled clinical trialControlled studyDietFemaleLactationLow carbohydrate dietMetabolismMilkPhysiologyRandomized controlled trialSecretion