No abstract

A survey of livestock production systems was conducted in the Vhembe District, located between 22°85′ latitude and 30°71′ longitude in the Limpopo Province of South Africa. The objective of the study was to investigate the benefits obtained from, and key functions of, cattle production, as well as related breeding objectives in smallholder livestock production in the Limpopo Province of South Africa. Data were collected by means of a general survey questionnaire and a participatory rural appraisal (PRA) exercise. The results indicate that almost 60% of farmers own < 10 cattle. Female animals constituted the largest component of the herd (55.02%). Although the bull : cow ratio was extremely high (1 : 3.7), the calving rate was low at 35.60%, with an extremely high herd mortality of 15.70% and a low off-take of 8.70%. In a pairwise ranking, the benefits obtained from cattle by smallholder livestock farmers are as follows: selling and meat consumption (4), wealth, status and savings (3), socio-cultural activities (2) and draught power (1). The ‘cattle complex’, where cattle are kept for prestige and status, is still appropriate, but cattle also make significant contributions in respect to selling and meat consumption, and arable inputs such as draft and fertiliser. It is concluded that benefits obtained from cattle form the basis of decision-making by smallholder cattle owners with respect to livestock production.

The effects of heifer frame size on subsequent performance and the preweaning growth of calves were evaluated using records collected from the Waterburg Estates at Otjiwarongo, Namibia. Based on hip height at 18 months of age, heifers were assigned to three different frame size groups: small (<124 cm), medium (124 to 135 cm), or large (>135 cm). Calving rate (CR), calving date (CD), postnatal calf survival rate (CSR), reproductive efficiency (Sandex), weaning rate (WR), birthweight (BW), weaning weight (WT) and preweaning average daily gain (ADG) were collected from first (n = 830), second (n = 623) and third and greater parity (n = 571) cows. Frame size of heifers significantly influenced (P < 0.001) CR in second and third and greater parity. The postnatal CSR was similar for all frame size and parity groups. WR of large frame size, second-parity cows was less (P < 0.001) than that of small and medium frame size animals. Birthweights of calves born to large frame size animals were significantly higher (P < 0.05) than the small and medium frame size animals. Small frame size animals, as first parity cows, had calves with lower (P < 0.05) WT than those weaned by medium and larger frame size animals. In first parity cows, calves of large frame size had greater ADG (P < 0.05), but in second parity cows the calves from medium frame size (P < 0.05) out performed those of small and large frame size, while calves from third and greater parity cows of medium and larger frame size had greater (P < 0.05) ADG than cows with a small frame size. Male calves were heavier (P < 0.05) at birth, at weaning and grew faster (ADG) than their female counterparts. Due to the later calving dates (P < 0.05), the reproductive efficiency (Sandex) of large frame size at second and third and greater parity groups was lower (P < 0.001). Therefore, selecting cattle for the extensive hot and dry climatic regions of Southern Africa, the recommended cow frame size should be a medium frame.

The effects of different management practices on testicular development of young Bonsmara bulls fed a high energy (HE), medium energy (ME) and low energy (LE) diet after weaning were determined. Testicular histology and seminal traits were examined together with scrotal circumference (SC) development over an 84-day performance test trial period. The SC differed significantly (P < 0.001) between HE-, ME- and LE-fed bulls. Seminal traits, such as semen concentration were significantly (P < 0.001) lower in bulls fed the HE diet (1.3 ± 0.134) compared with those fed the ME diet (2.4 ± 0.18) and LE diet (2.6 ± 0.16). Similarly, linear movement of sperm was also affected by diet and movement was slower (P < 0.05) in bulls fed the HE diet (1.7 ± 0.30) compared with bulls fed the ME diet (2.2 ± 0.31) and LE diet (3.1 ± 0.23). The percentage total major (P < 0.001) and total minor (P < 0.05) sperm defects were also greater in the HE-fed bulls (27.1 ± 6.82 and 7.4 ± 0.91) compared with the ME-fed bulls (9.7 ± 1.45 and 5.5 ± 0.87) and for the LE-fed bulls (5.4 ± 1.26 and 3.9 ± 0.58). Dietary energy level (P < 0.05) influenced the percentage inactive seminiferous tubuli, with bulls fed the HE diet having 35% more seminiferous tubules classified as inactive compared with those bulls fed ME and LE diets. Scrotal fat deposits were higher (P < 0.05) in bulls fed the HE diet (243.4 ± 21.59 g) compared with those fed the ME (110.0 ± 12.1 g) and LE (88.4 ± 9.65 g) diets. Feeding HE diets to young bulls probably reduces their reproductive potential.

The text of the corrigendum is available in the PDF. Corrigendum published: 8 November 2019