Large Scale Crossbreeding of Bos Indicus with Bos Taurus in the Tropical Rain Forest Climate of Kerala in South India

Abstract

The state of Kerala in India has predominantly an agrarian economy, with crop production providing the major income for farmers. The economy is also supported by animal husbandry in many of the farm households. Geographically Kerala lies in the tropical rain forest belt with a two season pattern and two monsoons spread over eight months. The main food crops are paddy and tapioca, while the cash crops grown are coconut, rubber, pepper, cashews, tea, coffee and spices. The population density is one of the highest in the world with 654 people per km2, therefore placing extraordinary pressure on land availability for crops and cattle. The native non-descript zebu-type cattle of Kerala, evolved over long periods, are poor in milk and reproductive performance but have adapted very well to the tropical environment with regards to heat and disease resistance. The local zebu are small in stature with an average body weight of 150-250 kg standing 1.1-1.2 meters high. The average age at first calving is 51 months and the average lactation yield is estimated at 500-700 kg/200 days.1,2 The average calving interval is long at 21 months2. The number of AI per conception is 2. 4 for field animals2.These non-descript zebu type cattle could not satisfy the milk needs of the state. To improve the milk production to 1500 L per lactation by genetic improvement alone would have taken 150-200 years. Replacement of local stock with exotic dairy breeds was not practical. Past experience has shown that transplantation of such temperate breeds into the tropical rain forest climate is not economical because of poor adaptability, susceptibility to tropical diseases and non-availability of suitable management. Therefore, a programme of limited crossbreeding of local zebu cattle with Bos taurus dairy breeds was implemented as a practical means enhancing the milk yield. Crossbreeding offered the most promising approach to evolve a type of cow which could be maintained economically under prevailing village conditions. The purpose of this paper is to present data supporting crossbreeding between local nondescript milk breeds with top genetic material of temperate Bos taurus milk breeds, as the best currently available means to converse local poor producing cattle into crossbreds of high productivity.