Population and Production Characteristics of Red Sindhi Cattle in Ceylon

Summary The mechanism of population changes in the 16-year history of a large herd of Red Sindhi cattle in Ceylon indicates that there is a considerable reserve of fecundity in these animals that could be utilized to enable the population to double itself, if necessary, every 8 years. This would involve increasing the rearing proportion to 0.33 and the average reproductive life to five lactations and keeping down mortality rates at 20%. The prevailing generation interval is about 6 years. Analyses of the production statistics of the herd show that sufficient variability exists in regard to most characters affecting milk production to warrant the possibility of a reasonably rapid advance in production in future years. Such improvement appears possible in the following directions: reduction of age at first calving, shortening of calving intervals and dry periods, and increase of lactation lengths. The coefficients of variation of total milk yield and average daily milk yield too are large enough to permit rapid improvement. Estimates of genetic changes in the herd through selection of breeding females have also been made. The various factors that would enable a greater selection pressure to be applied for accelerating annual genetic improvement in milk yield in tropical cattle are discussed.