REDUCING THE AGE AT FIRST CALVING THROUGH NUTRITIONAL MANIPULATIONS IN DAIRY BUFFALOES AND COWS: A REVIEW

Raising heifers is the most expensive component of the dairy farm operations. Poor growth rate resulting in delayed age at maturity in our local dairy animals further aggravates the situation. However, cost of heifer production can be reduced through better management, balanced feeding, use of performance modifiers and better health care. Selection for higher milk yield is likely to have a favorable impact on age at first calving. Yet, the current age at maturity in buffalo and Sahiwal cow can be reduced to 2 and 1.5 years, respectively, with better feeding and management. Protein and energy are the most critical nutrients affecting the weight and consequently age at puberty in heifers. Higher protein levels than current recommendations of NRC for dairy cattle can reverse the adverse effects of high plane of nutrition on udder development. Accelerated growth rate through performance modifiers to reduce the age at maturity is also helpful provided they do not adversely affect development of secretory tissue of udder for future milk production. Judicious use of balanced feed and performance modifiers has led to reduced age at puberty in exotic dairy heifers. These data can be used to device optimum heifer production systems in the country. However, for offering solid recommendations on optimum heifer production requires well planned research to see the effects of proteins, energy, minerals and other performance modifiers for economical heifer production in our country