Heterosis effects on age at first calving in a multibreed beef cattle herd in Panama

G enetic relationships between calving date, calving interval, age at first calving and type traits in beef cattle

In this paper the genetic relationships between major reproductive traits in beef cattle (Calving Date, Calving Interval and Age at First Calving) and type traits have been estimated to evaluate the usefulness of type classification in predicting reproductive performance in beef cattle. We estimated favourable genetic correlations between Calving Interval and type traits ranging from 2 0.027 to...

Factors Affecting Age at First Calving in Kankrej Cattle

The data of 35 years from 1980 to 2014 were analyzed to study the effect of genetic and non-genetic factors viz. period of calving, season of calving as fixed effect and sire as random effect on the reproduction trait (age at first calving) of Kankrej cattle maintained at Livestock Research Station, S.D. Agricultural University, Sardarkrushinagar, Gujarat. The least square mean of age at first ...

Calving Difficulty in Beef Cattle

Utilization of Heterosis in a Beef Cow Herd

George H. Shull, while working as a corn geneticist at the Cold Spring Harbor Laboratory from 1904 to 1915, observed that when two different pure-bred lines of corn were crossbred the resulting progeny exhibited physical traits superior to those of the parents (Glass, 2010). Shull described the offspring of pure-bred crosses as having increased heartiness, size, fruitfulness, speed of developme...

Maternal heterosis and grandmaternal effects in beef cattle: preweaning traits.

Crossbred progeny from females, 3 yr old and older, representing Brown Swiss (B), Red Poll (R), Hereford (H) and Angus (A) maternal grandsires and maternal granddams in a diallel crossing experiment were evaluated to estimate breed mean maternal heterosis (mean hMi) for each breed, maternal heterosis for specific breed cross females (hMij), average maternal heterosis for all crosses (mean hM) a...