Effect of age on the energy requirements of lactating Hereford cows.
D000367:Age Factors; D000704:Analysis of Variance; D000824:Animal Nutritional Physiological Phenomena; D000818:Animals; D001827:Body Height; D001835:Body Weight; D002417:Cattle / Q000502:physiology*; D005260:Female; D007774:Lactation; D009751:Nutritional Requirements; D011247:Pregnancy