Reprodutive efficiency in a Jersey herd of cattle in Paraiba Valley, E. S. P.)

Abstract

Reproductive effciency of a Jersey herd of cattle, raised in Jacareí, estado de São Paulo, Brasil, for a period of 15 years (1946-1961) is presented in this paper. The analysis of data offered the following averages:
1 — Services per conception .................. 1.34
2 — Age at first service .................... 18 months — 19 days
3 — Age at first calving ........................ 29 months — 3 days
4 — Interval from calving to conception 3 months — 18 days
5 — Calving interval .............................. 14 months — 12 days
6 — Period of gestation .......................... 273.9 ± 1.05 days