Dairy R&D in SA

Milk yield of dairy cows is influenced by genetic merit of the cow, its age, days in milk, daily feed intake, feed quality and body condition score. Milk yield in South Africa is much higher today than two decades ago since we produce 54% more with 24% less cows. As milk yield per se is highly correlated with profit, the push towards higher yields is also noticeable in pasture based systems.

For dairy farms to be economically sustainable, herd managers should continuously monitor specific key performance indicators (KPIs). Indicators must be based on quantitative or performance goals which are specific, measurable, attainable and relevant. These may include the average daily milk yield of the cows, their daily feed costs and specific reproduction parameters. These to a large extent are farm specific as each farm is unique in terms of natural resources, infrastructure and management style which will affect milk yield, production costs and breakeven milk yield.

This is a summary of results reported by Dr Craig Galloway (see reference below) of farms where there have been improvements in the carbon balance and other parameters as indicated by data collected between 2013 and 2019. Some of the farms have data for all the years, whereas others only have data for two of the years. All improvements indicated are the most recent data relative to the baseline, which is the first time the assessments were done. The farms are pasture-based dairy farms in the Eastern Cape (Tsitsikamma, Oyster Bay, Humansdorp, Cookhouse, Cradock and Alexandria).

Claw health is an important factor in animal welfare and its evaluation is an early indicator of lameness in dairy cattle. However, claw disorders on many farms are not routinely evaluated and the information not included in genetic evaluations as they are not always considered in terms of productivity. The aim of the study by the authors cited below was to evaluate claw health of dairy cattle housed in dirt lot vs free stall under the TMR systems.

The most popular dairy breed in South Africa is the Holstein. Being of European origin the Holstein is not well adapted to South African veld conditions. Consequently, its milk production on veld is very low, and the animals cannot subsist and produce without some form of supplementary feed. The Nguni breed is an African breed, and is used by communal farmers in KwaZulu-Natal for household milk supply.

Small effective population sizes and inbreeding are major challenges faced by dairy cattle populations worldwide. Estimates of pedigree-based inbreeding (FPED) are unreliable due to a lack of pedigree data and pedigree errors and that may lead to an underestimation of inbreeding rates. Thus, inbreeding based on runs of homozygosity (FROH) has become the preferred method of estimating inbreeding as it is able to accurately predict the amount of autozygosity within the genome.

Female fertility is a fundamental trait for a profitable dairy herd enterprise. Studies have shown a decline in fertility probably because of dedicated selection for increased milk production. Age at first calving (AFC) and calving interval (CI) are prominent indicator traits to improve fertility, but these traits are greatly affected by management decisions. Service data present additional selection criteria with minimum bias.

To maximise production, dairy cow diets are balanced for amino acids through the use of feed formulation programmes. A limitation of these programmes is that the bacterial amino acid profile used is considered constant and based on assumptions about the composition of mixed ruminal bacteria. However, research has shown that the amino acid composition differs between the fluid-associated bacteria (FAB) and the particle-associated bacteria (PAB) and also depends on factors such as diet composition, feed intake, protein source and thus potentially, feed additives.

Smallholder dairy production, which is mainly characterised by a low input–low output production system, currently makes an insignificant contribution to the South African dairy industry. Several reasons can, however, be advanced to motivate the development of this sector. In Sub-Saharan Africa, in general, the performance of smallholder dairy cows is poor, suggesting low herd profitability. In order to develop the smallholder dairy sector, it is therefore important to identify herd production models or management strategies that would improve herd profitability.

Dairy breeds originated in the United Kingdom and Western Europe. Both regions have a wet and cool to cold climate. As a result, the environmental comfort zone for dairy cows varies between -5 and 21 °C. Anatomical features that help cows withstand cold conditions include a thick skin, a dense hair coat, subcutaneous fat layers, large muscles and a digestive system that is based on fermentation processes in the rumen which creates internal heat.