Growth of mashona cattle on range in Zimbabwe. I. Environmental influences on liveweight and weight gain

Abstract

Data from 1,456 purebred Mashona calves were analysed to determine environmental influences on growth rate and liveweight at birth, weaning (205 days) and 18 months of age. Calves were born between mid-September and mid-December each year. Year of birth was highly significant for all traits (P less than 0.001). Pre-weaning liveweight and weight gain increased as age of dam increased to seven years after which growth tended to decline. Post-weaning compensatory growth was apparent in calves of young dams. Male calves grew faster and were heavier at all stages than female calves (P less than 0.001). Calves from previously non-lactating cows grew more rapidly and were heavier at all ages than those from previously lactating cows. Birth weight increased as calving season advanced and calves born late maintained their growth advantage until 18 months of age. The results indicate that environmental influences experienced in early life persist long after weaning.

Studies on milk production and growth of friesian x Bunaji crosses: II. Growth to yearling age

“…This seems to agree with the report of Tawonezvi (1989) who observed that heavy calves at birth tend to maintain their growth advantage to later ages, in his study of the growth of Mashona.cattle in Zimbabwe. On the other hand, this fmding is contradicted by our seasonal data which showed that heifers born during the harmattan season were heavier at birth than those born during the dry and wet seasons, but lost their superiority when they reached 9 months of age or more.…”

“…(30.9 kg). The most probable explanation for this dbservation could be that the requirement of the dam for the rapid growth of the foetus at the last trimester of pregnancy for calves born during the harmattan, coincided with the availability of good quality forage (Tawonezvi, 1989). Similar reports of significant seasonal effects on birth weights of Friesian, Boran and Bunai i calves have been published by Badran and El-Barbary (1986), Mpiri (1987) and Oni et al (1988), respectively.…”

The Borana Plateau of Southern Ethiopia. Synthesis of Pastoral Research, Development and Change

“…The sixmonth advantage may also be heavily influenced by a succission, by chance, of favourable rainfall years and other density-dependent interactions (see below). The ability of control animals to compensate for early nutritional deprivation agrees with other studies (Richardson et al, 1978;Tawonezvi, 1989). All of this research found differences in weaning weight to persist from 1.5 to 11 months past weaning.…”

Sex of calf and age of dam adjustment factors for birth and weaning weight in Tswana and Composite beef cattle breeds in Botswana

“…Corresponding adjustment factors for the Tswana were 2.75 and 8.21 kg, respectively. The sex of calf adjustment for birth weight in the Tswana was higher than adjustment factors reported by Kars et al (1994) for Nguni cattle in South Africa (1.86 kg) and Tawonezvi (1989) for Mashona cattle in Zimbabwe (1.0 kg). Tswana, Nguni and Mashona cattle are all Sanga type cattle found predominantly in southern Africa.…”

“…The differences in the correction factors therefore underline the fact that correction factors can vary significantly within the same breed group of cattle in the same geographical region. The correction factor for weaning weight (8.21 kg) obtained for the Tswana was closer to the correction factor of 8.0 kg derived for the Mashona by Tawonezvi (1989). The sex of calf adjustment factors for the Composite were lower than the adjustment factor of 16.5 kg reported by Newman et al (1993) for a composite line of beef cattle.…”