Accounting for the Effects of Environment on the Nutrient Requirements of Dairy Cattle

• Published in: Journal of dairy science 1998-11, Vol.81 (11), p.3085-3095
• Main Authors: Fox, D.G., Tylutki, T.P.
• Format: Article
• Language: English
• Subjects: AGE; Animal Nutritional Physiological Phenomena; Animals; APLICACIONES DEL ORDENADOR; APPLICATION DES ORDINATEURS; BESOIN NUTRITIONNEL; BODY WEIGHT; Cattle - physiology; COAT; COMPUTER APPLICATIONS; COMPUTER SIMULATION; COMPUTER SOFTWARE; COSTOS; COSTS; COUT; DAIRY COWS; EDAD; ENERGIA; ENERGIE; ENERGY; ENERGY REQUIREMENTS; ENTRETIEN; Environment; environmental effects; ENVIRONMENTAL TEMPERATURE; ESTRES TERMICO; FANGO; FEED FORMULATION; FEED INTAKE; Female; FORECASTING; FORMULACIONES; FORMULATION; FORMULATIONS; GAIN DE POIDS; GANANCIA DE PESO; GENISSE; HEAT STRESS; HEIFERS; HUMEDAD RELATIVA; HUMIDITE RELATIVE; INGESTION DE PIENSOS; Lactation; LIVEWEIGHT GAIN; LOGICIEL; MAINTENANCE; maintenance requirements; MANTENIMIENTO; Models, Biological; MUD; NECESIDADES DE NUTRIENTES; NOVILLA; nutrient requirements; NUTRITIONAL REQUIREMENTS; PARTO; PARTURITION; PESO CORPORAL; POIDS CORPOREL; PRISE ALIMENTAIRE (ANIMAUX); PROGRAMAS DE ORDENADOR; RELATIVE HUMIDITY; SIMULACION; SIMULATION; STRESS THERMIQUE; TECHNIQUE DE PREVISION; TECNICAS DE PREDICCION; TEMPERATURA AMBIENTAL; Temperature; TEMPERATURE AMBIANTE; THERMAL STRESS; VACAS LECHERAS; VACHE LAITIERE; VASE; VELOCIDAD; VELOCITY; VENT; VIENTO; VITESSE; WEIGHT GAIN; WINDS
• ISSN: 0022-0302; 1525-3198
• DOI: 10.3168/jds.s0022-0302(98)75873-4

The maintenance requirements of the Cornell Net Carbohydrate and Protein System were revised to evaluate the effects of activity, temperature, and humidity. Four dairy heifer situations were simulated (1 = clean and dry, 2 = moderately matted hair coat, 3 = condition 2 plus 10-cm lot mud from November to March, and 4 = condition 1 plus 16-kph wind) to represent typical conditions of the northern and southwestern US. In the northern condition, predicted daily gain was 0.88, 0.60, 0.53, and 0.68 kg/ d for the four environmental situations; corresponding values for the Southwest were 0.88, 0.88, 0.78, and 0.88. Environmentally neutral daily gain was 0.94 kg/ d to a BW of 603kg at first calving at 20.3 mo of age. Calving age was increased when environmental stress extended the age at which puberty weight was reached. Calving weight was decreased when environmental stress occurred after conception. Twelve environmental conditions (variable temperature, humidity, and housing) for lactating dairy cows were simulated. At 30°C and no night cooling, predicted milk production decreased 2.6 and 11.9 kg/d at 20 and 80% humidity, respectively. Increased activity reduced predicted milk production to 0.4 to 1.3 kg/d in confinement scenarios and to 0.9 to 7.5kg in grazing scenarios.