Productivity of different farm sizes in commercial ewe-lamb production systems in Central Java Province, Indonesia

Abstract

This study evaluated the productivity and identified factors influencing ewe-lamb production in 40 commercial sheep farms across Central Java Province. A survey method with stratified sampling was employed. At the first level, districts/cities were selected based on three population density categories (high, medium, and low). At the second level, sheep farms within these districts/cities were purposively sampled based on the following criteria: operational for at least two years, maintaining a minimum of 25 ewes, and having at least one lactating ewe. At the third level, individual ewes were purposively selected if they had given birth at least twice and were nursing lambs younger than five months. The results indicate that commercially managed ewe-lamb farms in Central Java Province produced an average of 227.29 ± 67.67 weaned lambs per 100 ewes per year. The average lambing interval, pre-weaning mortality, and twin birth percentage were 9.22 ± 2.49 months, 14.71 ± 16.29%, and 36.00 ± 27.62%, respectively. Farm size and age did not significantly affect (P > 0.05) reproductive performance. Variations in lambing interval, pre-weaning mortality, and twin birth rate contributed 18.6% to the number of weaned lambs per 100 ewes per year (Y = 8.832 + 12.641X₁ + 0.562X₂ + 0.962X₃; R² = 18.6%). In conclusion, commercial ewe-lamb farming in Central Java Province demonstrates satisfactory performance, with lambing interval, pre-weaning mortality, and twin birth rates reaching optimal levels.