Statistical efficiency in bull progeny testing for calving difficulty

Reducing Calving Difficulty in Simmental

Many factors contributed by calf, dam and sire are associated with CD and many of these are interrelated. Deutscher (1988) came to the conclusion that "the primary cause of CD in young cows is due to a disproportion between size of calf (birth weight) and size of birth canal (pelvic size) of the cow." The relationship of these two factors are presented in the figure below quoted by Deutscher (1...

Calving Difficulty in Beef Cattle

Testing For Efficiency Wages In Iran

Pelvic Measurements For Reducing Calving Difficulty

producers. This loss is estimated at $750 million annually nationwide. Calving difficulty increases calf death loss, cow mortality, labor and veterinary costs; it delays the return of cows to estrus and reduces conception rates. It also lowers calf weaning weight and market value, which results from breeding of young heifers and cows to easy calving bulls to reduce calving difficulty. Studies s...

Factors influencing calving difficulty in beef heifers.

Records of 547, 2-yr-old heifers of three breed groups were used to evaluate the relative influence of dam's body and pelvic measurements, calf birth weight, sire birth weight and some relative measures (ratios) of calf birth weight and dam weight at calving on calving difficulty. The data were analyzed by regression and least squares procedures. The full model explained 32.5% of the variation ...