Dairy R&D in SA

A pasture paddock of 3.3 ha was used for the study. It consisted of a mixture of one-year old perennial ryegrass, white clover, and red clover. A 2 × 2 factorial design, arranged as a randomised block with three blocks was adopted, viz. 12 experimental plots. Each plot was approximately 15 × 132 m in size and plots were separated by mobile electric fencing for grazing management. Two factors were studied, grazing period being the first. Winter and summer were chosen as grazing periods, and two grazing cycles per grazing period were examined.

The study cited involves reviewing determination of the impact of Good Agricultural Practices (GAP) and Management Systems on dairy production, dairy processing, and end-product quality. This is a Milk SA funded project, the progress being reported here.

Claw trimming is used as a management tool to control claw lesions. In South Africa, claw data are limited to the use of private hoof trimmers, who record lesions on paper, and data is not necessarily captured in an electronic recording system. In the study cited, routine trimming data from five intensively managed dairy farms over a 6-year period (2014–2019) were analysed to investigate the prevalence and distribution of claw lesions in Holstein cattle in the central region of the country in order to facilitate more effective recording and management.

Selection in dairy cattle primarily emphasizes increasing milk yield and solids. This however may be negative to overall fitness, particularly fertility because of the antagonistic association between fertility and milk yield. Thus, although benefiting from yield, profitability may not improve because of deteriorating reproductive parameters such as increased inter-calf period, more AI services per conception, more days open and increased veterinary costs.

There is a decline in small-scale dairy farming in rural areas of the developing world, also in South Africa. Reasons provided in the literature include shrinking fringes, access to cattle feed, limited interest of future generations, increased cost of cattle, feed and fertilizer, poor cattle health, knowledge and management, poor understanding of livestock diseases, uncertain weather conditions, power failures and high cost of electricity, lack of machinery and equipment, stock theft, quality and safety of the product, poor packaging, and lack of government support, amongst others.

Feed efficiency is highly correlated with economic sustainability on a dairy farm. Cows with higher feed-use efficiency are usually characterized by a higher feed intake per unit live weight, have lower maintenance requirements, partition more metabolizable energy to milk than body tissue, and lose less energy in waste and body weight.

With the support from Milk SA, ASSET Research developed three tools aimed at measuring the economic, social and environmental impact of dairy farming.  These are:

Aim of investigation: To determine whether seasonal stressors affect the cow trace mineral status of dairy cows in the Tsitsikamma region of the Eastern Cape.

Experimental design: Trace mineral status was evaluated with 20 cows per farm on three farms over two years in spring (defined as Oct to Des), summer (Jan to March), autumn (April to June) and winter (July to Sept). The samples were taken at the end of each season.

Because of increased awareness of environmental impacts, the dairy industry has come under scrutiny, resulting in alternative plant-based products being developed; the assumption being that these products have a lesser environmental impact. However, when consulting the literature, the environmental and nutritional attributes of these products are poorly understood.

PRJ-0336: Diagnostic investigation of sporidesmin toxicity: Histological study

Progress: