Predicting ad libitum dry matter intake and yield of Holstein cows

• Published in: Journal of dairy science Vol. 80; no. 9; pp. 2188 - 2199
• Main Authors: Holter, J.B, West, J.W, McGilliard, M.L
• Format: Journal Article
• Language: English
• Published: Savoy, IL Am Dairy Sci Assoc 01.09.1997; American Dairy Science Association
• Subjects: ALIMENTACION AD LIBITUM; ALIMENTATION A SATIETE; Animal productions; Animals; Biological and medical sciences; Body Weight; BREEDS (ANIMALS); Cattle - physiology; CONTENIDO DE MATERIA SECA; DAIRY COWS; Dietary Fiber - administration & dosage; DRY MATTER CONTENT; Eating; ENVIRONMENTAL TEMPERATURE; EQUATIONS; ESTRES TERMICO; FEED FORMULATION; FEED INTAKE; Feeding. Feeding behavior; Female; FORECASTING; FORMULACIONES; FORMULATION; FORMULATIONS; Fundamental and applied biological sciences. Psychology; GEORGIA (EUA); GEORGIA (USA); GEORGIE (EU); Growth Hormone - pharmacology; HEAT STRESS; HOLSTEIN-FRIESIAN; INGESTION DE PIENSOS; LACTACION; LACTATION; LACTATION NUMBER; LACTATION STAGE; Lipid Metabolism; MATEMATICAS; MATHEMATICS; MATHEMATIQUE; Milk - metabolism; MILK PROTEIN; Milk Proteins - metabolism; MILK YIELD; Models, Biological; NEW HAMPSHIRE; NUMERO DE LACTACION; NUMERO DE LACTATION; PRISE ALIMENTAIRE (ANIMAUX); PROTEINAS DE LA LECHE; PROTEINE DU LAIT; RACE (ANIMAL); RAZAS (ANIMALES); Regression Analysis; RENDEMENT LAITIER; RENDIMIENTO LECHERO; Silage; STRESS THERMIQUE; TECHNIQUE DE PREVISION; TECNICAS DE PREDICCION; TEMPERATURA AMBIENTAL; TEMPERATURE AMBIANTE; TENEUR EN MATIERE SECHE; Terrestrial animal productions; THERMAL STRESS; UNRESTRICTED FEEDING; VACAS LECHERAS; VACHE LAITIERE; Vertebrates; Vertebrates: anatomy and physiology, studies on body, several organs or systems; Zea mays; Lactation; Diet; Animal feeding; Food intake; Dairy cattle; Dry matter; Female; Forecast model
• ISSN: 0022-0302; 1525-3198
• DOI: 10.3168/jds.S0022-0302(97)76167-8

Two data files, one from New Hampshire (n = 3308) and one from Georgia (n = 678), containing 4-wk or weekly means, respectively, of ad libitum dry matter intakes (DMI) and related variables were used to predict DMI and yields of 4% fat-corrected milk and milk protein in lactating Holstein cows. The DMI ranged from 5.9 to 30.4 kg/d, and milk yield ranged from 5.8 to 64.3 kg/d. Because of the lack of data from 14 d in milk, prediction was not possible for the first 2 wk of lactation. Factors considered for inclusion in the DM1 prediction model were parity number (1 or greater than or equal to 2), treatment with bovine somatotropin (bST), day of year, days in milk, minimum (nighttime) temperature-humidity index, body weight, 4% fat-corrected milk yield, milk protein yield, and corn silage and total silage percentages in forage dry matter. In separate models, the silage predictors were replaced with more specific descriptors of ration dry matter, including percentages of crude protein, fat (ether extract plus soaps of fatty acids), concentrate, acid detergent fiber or neutral detergent fiber, and forage acid detergent fiber or neutral detergent fiber. The square and sometimes natural logarithm of predictors were included in models, which then were subjected to a stepwise backward elimination option of a multiple regression procedure. Several useful equations were developed to predict ad libitum DMI; the best models accounted for about 80% of the variability in DMI, and standard deviations were 9% of mean DMI. Depression in DMI related to heat stress was higher in pluriparous cows than in primiparous cows (22% vs. 6%). The negative coefficient for effects of bST treatment on DMI suggested that milk yield increased proportionally more in response to bST than did DMI. About 74 to 77% of DMI predictions were within 2 kg/d. of observed DMI. Depression DMI related heat stress was higher in pluriparous cows than in primiparous cows (22% vs. 6%)