Dairy R&D in SA

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.

Understanding, and where possible, quantifying the stress that dairy cows experience has become a focal point in animal welfare studies. Whereas the environmental stressors have been well-studied, the addition of sensory stimuli, some of which are associated with indoor comfort, is relatively new. Auditory stimuli have been shown to have potential in reducing stress in the parlour, but is seldom applied. Therefore, the study of the authors cited below, aimed to explore the effect of auditory stimuli in a Holstein herd by monitoring the faecal glucocorticoid metabolite concentrations. The glucocorticoid metabolite is a non-invasive stress-associated biomarker. Cow activity level and milk yield were also measured.

The study was conducted employing a system dynamics model which has been developed to assist dairy farmers to calculate and monitor the impact of environmental indicators. Farm information was collected from six dairy farms on the south-eastern seaboard varying in cow-in-milk numbers between 260 and 706 and milk productions between 4600 and 8000kg FPCM per year.

Goal: Is to develop best practice guidelines for improved wetland and river management on dairy farms.

General aim of the project: To develop an acceptable probiotic yoghurt product containing selected probiotic strains with the potential to prevent candidiasis, listeriosis and diarrhoea.

Goals in 2022: