Dairy R&D in SA

Prelude: Methane emissions in particular, and nitrous oxide as potent greenhouse gases (GHG), have been in the political, activist and general public debate for some time. Central in the debate has been livestock ruminants, in particular beef and dairy cattle, since estimates show the global production of these gases from livestock may be upwards of 20% of total.

Staphylococcus aureus is internationally recognised as the most important pathogen of intra-udder infection and the foremost reason for economic loss to dairy farmers. South Africa is not different, but the spread and antimicrobial resistance (AMR) of different strains compared to elsewhere in the world is not well documented, which then was the main focus of the review by the authors cited.

Several causes of hepatogenous or secondary photosensitisation have been reported, such as from hepatotoxic plants, water-borne cyanobacteria and saprophytic fungi. In cattle, hepatogenous photosensitivity is associated with the feeding of crops comprising certain cultivars and/or hybrids of forage Brassica, namely turnip, rape and swedes. The bovine clinical case is referred to as Brassica-associated liver disease or BALD, which has been well-described in Australia and New Zealand, but not previously in South Africa. Recently, however, a case of infected Holstein cows in the Humansdorp district was reported.

Maintaining soil health is pivotal towards ensuring that the soil can function as a living ecosystem, keeping it in biological balance to ensure productive agriculture. Through the implementation of careful manure management, regenerative farming practices and sustainable cultivation, many dairy farmers contribute to the sequestration of carbon into soil, as well as replenishing soils with other nutrients which are essential for crop cultivation. Controlled manure application is used in South Africa towards the restoration of soils and has shown to reduce dependence on fertilizer inputs.

The purpose of the study cited was to investigate the association between the economic and environmental facets of sustainability as it relates to milk production in the pasture-based dairy operations of the country.

From results of a research project by the authors cited, a guideline was compiled. The guideline aims to support sustainability in the dairy sector through provision of best practice guidelines for improved management of water resources using riparian buffer zones and enhanced wetlands.

Cattle have been the focus of an intense debate between those concerned about, among other things, the possible negative effects on global warming, land degradation, food competition and human health, and those who are positive toward the possible role of cattle in maintaining global socio-economic and environmental sustainability. The purpose of the investigation by the authors cited, was to evaluate the risk to the global socio-economy and the environment if cattle production increases towards 2050, according to projected needs and demands of the global economy. The most important findings from the review are provided:

The authors postulated that the performance of dairy cows grazing ryegrass pastures may be enhanced if the amino acid balance in the small intestine is enhanced. Being normally in short supply on ryegrass, supplementation with rumen-protected methionine (RPM) and lysine (RPL) could be beneficial. This was then investigated in the study.

The Swartland area utilizes winter cereal crops and mostly relies on small grain cereals as silage in dairy cow diets. These crops are usually lower in crude protein (CP) and result in lower dry matter (DM) yields than either maize or lucerne, which implies that more CP concentrates at extra cost need to be supplemented to achieve the milk yields wanted. Therefore, it has become important to evaluate alternative forage sources to grain-only silages. This then forms the basis for the investigation cited.

As the dairy industry expands to meet demand, there will be a significant increase in the use of scarce water resources and therefore an increased generation of wastewater. The milking parlour is one area where wastewater can be minimised. Here, wastewater is generated through cleaning processes that occur before and after milking. This results in two wastewater streams: 1) wastewater from cleaning, disinfection and sanitation of milking machinery and equipment (i.e. containing water, milk, detergents etc.), and 2) floor washing which generates wastewater containing animal waste in the form of manure and urine, waste milk and dirt.