Longevity and lifetime productivity of cows in a purebred Hereford and two multibreed synthetic groups under range conditions1

Abstract

Records on 983 cows born during a period of 10 yr (1966 to 1975) were used to estimate longevity and lifetime productivity of cows raised under range conditions. The cows were from a purebred Hereford and two multibreed synthetic groups, one composed of beef breeds (Beef Synthetic #1) and the other composed of two-thirds dairy breeds and one-third beef breeds (Dairy Synthetic). The cows were raised under a stringent culling system in which all heifers were exposed to bulls as yearlings and were expected to wean a calf each year thereafter or they were culled. Cows were also culled for other reasons, such as severe calving problems, bad udders, and leg and feet problems. The mean longevity was 4.2 yr; cows from the synthetic breed groups produced longer (P < .01) than Hereford cows, due to a relatively faster rate of removal at all ages in the purebred Hereford group. The mean values per cow for lifetime productivity traits were 2.7 and 2.5 for number of calves born and weaned and 101.9 kg and 482.9 kg for weight of calf born and weaned, respectively. Male calves were not castrated, and weights of female calves were adjusted to a male basis. Over their lifetimes, Dairy Synthetic cows were more productive, in terms of number and weight of calves born and weaned, than Beef Synthetic #1 cows, which in turn were more productive than purebred Hereford cows (P < .01).

Number of calves born, number of calves weaned, and cumulative weaning weight as measures of lifetime production for Hereford cows1

“…Phenotypic means (SD) for NB ranged from 0.72 (0.45) for NB2 to 2.38 (2.37) calves for NB7. These means are similar to some reported in the literature (Schons et al, 1985;Morris et al, 1987;Arthur et al, 1993). Phenotypic means for NW ranged from 0.55 (0.50) for NW2 to 2.06 (2.27) calves weaned for NW7, which are comparable to some previously reported values (Tanida et al, 1988;Arthur et al, 1993;Davis et al, 1994).…”

“…These Table 3. Estimates (standard errors) of heritability and genetic and environmental correlations from two-trait analyses for lifetime production measured as number of calves weaned for several opportunity groups (e.g., NW2 = total number of calves weaned by 2 yr of age) means are similar to some reports in the literature (Tanida et al, 1988;Arthur et al, 1993;Davis et al, 1994). In general, all three measures of lifetime production were smaller than those reported by Bailey (1991) and Cundiff et al (1992).…”

Effects of breed type and age at first calving on length of productive life in a cow–calf system in Southeastern Mexico

“…Also, it was possible that purebred cows stayed longer in the herd because their main objective was to produce sires for sale, whereas crossbred cattle were kept for calf sale. Beef cattle report of 1,350.5 average days for Hereford and 1642.5±36.5 days for their crosses with Charolais, Angus, and Galloway, among other breeds, were reported by Arthur et al (1993), values which exceed the 799.8 and 666.8 days reported by Magaña and SeguraCorrea (2001) in Zebu and their crosses with Brown Swiss cattle in the Mexican tropics.…”

Productivity of simmental cows Austrian selection

“…Records show that a few animals were exported to Italy as early as the 1400's. During the 19th century, Simmentals were distributed through most of Eastern Europe, the Balkans and Russia [3][4][5].…”