Dairy R&D in SA

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. Further factors to bear in mind when considering economic sustainability are, (1) cows’ weight loss during the high production phase should be short-term as long-term weight loss may predispose them to metabolic disorders and poor reproductive performance, and (2) milk price is largely determined by milk protein and fat production in South Africa.

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. Also, despite the critical role of bovine milk in diets worldwide, the environmental, nutritional and economic constituents of sustainability have not been comprehensively compared to the plant-based beverages of these products.

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.

PRJ-0339: The significance of Enterobacteriaceae, coliforms and E. Coli in milk in the SA market with the aim of updating microbial specifications in R1555 of 1997 (Act 54 of 1972)

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

Progress:

The practice of rearing, transport and slaughter of excess dairy calves, in particular bobby calves, is often negatively perceived by the public. From the farmers’ perspective, there is very little use for bull calves and therefore they want to dispose of them as quickly as possible. This should be done as humanely as possible and therefore the project of the Dairy Standard Agency (DSA) as cited below has the intention to improve humane handling of dairy calves over the next five years in a way that is measurable.

Environmental regulations and waste management in SA are governed by the National Environmental Management Act (NEMA) and other related legislation. Waste management, including dairy waste, falls under the jurisdiction of the Department of Environment, Forestry, and Fisheries (DEFF) (Government Gazette, 2013). According to the National Water Act 36 of 1998 (NWA) authorization enables the disposal of wastewater from dairy farming activities into on-site or off-site slurry ponds, as well as irrigation with wastewater from slurry ponds if certain conditions are met, such as the slurry pond must be at least 100 meters away from a stream and 500 meters away from a wetland, and irrigation must be at least 500 meters away from a wetland.

Body condition scoring (BCS) is a subjective manual method based on experience of individuals to assess fat reserves in the cow, of value to milk production, re-conception, regaining reserves and feeding. This is normally done at intervals to assist in monitoring loss and gain in body condition to ensure expected milk production, optimal health, conception and ease of calving. With increasing herd size the manual method is laborious which suggests that if an automated method can be developed which is quick, consistent and accurate, the method would benefit management in time, labour and genetic assessment. Such automated methods based on regression and Convolutional Neural Network (CNN) approaches have been reported in the literature.

The purpose of milking machines is to harvest milk at an optimum speed while maintaining cow comfort and preserving teat functioning against mastitis pathogens. To achieve this, milking machine functioning should be optimal, units should be attached and detached timely, milk let-down should be proper, cows should be handled quietly, mastitis should be identified effectively and equipment cleaned efficiently in case of mastitis, units should be timely adjusted, and alignment should be proper.

Two wastewater streams from the dairy parlour are relevant: (1) wastewater originating from cleaning, disinfection and sanitation of milking equipment, containing water, milk and detergents; and (2) wastewater from floor washing, containing manure, urine, waste milk and dirt. These are usually flooded into wastewater settling ponds which, depending on design, are variably effective in terms of utilisation of irrigation and settled solids thereafter. They do, however, increase the potential risk of surface and ground water contamination, since dairy wastewater contains a variety of suspended and dissolved solids, nutrients, fats, sulphates, chlorides, and trace and soluble organic compounds, and is characterised by a high biological (BOD) and chemical (COD) oxygen demand.