Effect of controlled breeding on performance of beef cattle in Central Bushveld bioregion

In most extensive beef production systems in South Africa, calves are weaned at specific dates. This implies that cows that calve late in the season wean younger and lighter calves. In the current study, Bonsmara cows were mated naturally after synchronization over six years (2009 - 2014) in an extensive production system on natural veld in the Central Bushveld bioregion. Within the herd, 50% of cows were synchronized prior to the commencement of the summer breeding season and they were mated naturally for 90 days. The results indicated that calving rate did not differ significantly between cows that were synchronized and non- synchronized. However, there was a significant difference between years in calving rate. Oestrous synchronization prior to natural breeding influenced the average days to conception. The difference in percentage of cows that calved within 293 days of the onset of the breeding season between those that were oestrous synchronized and non-synchronized was 15% in favour of the synchronized cows. Although calves from synchronized cows achieved higher average weaning weights, the cost implications of synchronization offset the benefit of higher calf weights. Keywords: calving rate, oestrous synchronization, natural breedin

Reproductive Performance of Extensively Managed Beef Heifers Mated at 14 Or 26 Months in the Central Bushveld Bioregion

In South Africa, little local information is available on the value of early mating of extensively kept beef heifers. In contrast, international information is mainly restricted to dairy cattle and intensive production systems. The research was undertaken to evaluate the calving percentage of Bonsmara heifers mated for the first time in an extensively managed beef herd at either 14 or 26 months. Fifty percent of the heifers were mated at 14 months, while the other 50% were mated at 26 months of age for 90 days during the summer mating season (January to March). The research was conducted over six years (2009 to 2014). A 23 factorial analysis of variance (ANOVA) was performed using the six years as block replications. This was done because different animals were evaluated every year. The calving percentage of heifers mated at 26 months was significantly higher than heifers mated at 14 months. From the current study, it seems unlikely that mating heifers at 14 months of age can improve on the traditional extensive system of mating heifers at 26 months on natural veld in the Central Bushveld Bioregion

Impact of Two Grazing Strategies on Rangeland Basal Cover and Beef Production in the Sourish Mixed Bushveld

The sustainability of beef cattle producers in South Africa is greatly dependent on the availability of natural resources. The aim of the study was first to evaluate the effect of two different strategies in the utilisation of rangeland over four years (2011/12 – 2014/15) on the basal cover—secondly, the study compared animal production results from the two extensively managed rotational grazing strategies. Grazing strategies include a traditional rotational system (TRG), where approximately 60% of fodder was utilised, compared with light selective grazing (LSG), where about 30% of fodder was used. Basal cover for TRG ranged from 19% (2011/12) to 15% (2014/15) and for LSG from 18% (2011/12) to 16% (2014/15). The calving percentage varied between 62% and 73%. The calving percentage and cow and calf weight did not differ between the two grazing strategies, although differences between years were observed. Both grazing systems can be implemented successfully in the Sourish Mixed Bushveld without negatively affecting the rangeland. However, basal cover may be more vulnerable during drought conditions under a TRG system. The study further indicates that mainly small-scale farmers, where utilisation levels of rangelands are usually high, are more vulnerable to drought conditions

Pooled analysis of WHO Surgical Safety Checklist use and mortality after emergency laparotomy

Background: The World Health Organization (WHO) Surgical Safety Checklist has fostered safe practice for 10 years, yet its place in emergency surgery has not been assessed on a global scale. The aim of this study was to evaluate reported checklist use in emergency settings and examine the relationship with perioperative mortality in patients who had emergency laparotomy. Methods: In two multinational cohort studies, adults undergoing emergency laparotomy were compared with those having elective gastrointestinal surgery. Relationships between reported checklist use and mortality were determined using multivariable logistic regression and bootstrapped simulation. Results: Of 12 296 patients included from 76 countries, 4843 underwent emergency laparotomy. After adjusting for patient and disease factors, checklist use before emergency laparotomy was more common in countries with a high Human Development Index (HDI) (2455 of 2741, 89·6 per cent) compared with that in countries with a middle (753 of 1242, 60·6 per cent; odds ratio (OR) 0·17, 95 per cent c.i. 0·14 to 0·21, P < 0·001) or low (363 of 860, 42·2 per cent; OR 0·08, 0·07 to 0·10, P < 0·001) HDI. Checklist use was less common in elective surgery than for emergency laparotomy in high-HDI countries (risk difference -9·4 (95 per cent c.i. -11·9 to -6·9) per cent; P < 0·001), but the relationship was reversed in low-HDI countries (+12·1 (+7·0 to +17·3) per cent; P < 0·001). In multivariable models, checklist use was associated with a lower 30-day perioperative mortality (OR 0·60, 0·50 to 0·73; P < 0·001). The greatest absolute benefit was seen for emergency surgery in low- and middle-HDI countries. Conclusion: Checklist use in emergency laparotomy was associated with a significantly lower perioperative mortality rate. Checklist use in low-HDI countries was half that in high-HDI countries