Dairy R&D in SA

Discipline: contamination; Key words: identification, spoilage, Chryseobacterium, Empedobacter, dairy  

The Dairy Sustainability framework (DSF) of the IDF proposed that the Baseline for the global dairy sector should be set at the FAO (2013) figure of 2.9 CO2 eq per kg of fat and protein corrected milk (FPCM). It is accepted that different countries will vary substantially as GHG emissions are influenced by milk yield, feeding practices and efficiency of production. Thus, the figure for some developed country industries is as low as 1.6 CO2 eq per kg FPCM, whereas the figure of Sub-Saharan Africa is 9.0 CO2 eq per kg FPCM.

In recent years, there has been an increase in the prevalence of environmental pathogens as a cause of within udder infections in dairy cattle. Increases in prevalence could potentially be ascribed to improved control methods for contagious pathogens, difficulties in controlling pathogens from an environmental reservoir and the ability of Streptococcus uberis and Escherichia coli to persist in the udder. Streptococcus uberisshowed an increase in prevalence over an 11-year study period (1996–2007) in South African dairies.

The preservation of the teat canal is crucial for udder health, as the main route for bacterial infection is via the teat canal. Milking machines differ in layout and settings and continue to be a challenge to the primary immune system of the bovine udder namely the teat canal. Different levels of teat end vacuum during machine milking may influence milking performance and teat condition. When there is little or no milk flow the vacuum at the teat end increases to that in the milking machine system.

1. A newly developed system of obtaining Dairy Cattle farm-recorded data from automated systems to be used for biological and economic benchmarking as well as future genetic merit predictions

     by DA Kruger, RR vd Westhuizen & D Victor, SA Stud Book, Bloemfontein, South Africa.

Vitamins, mostly A, C and E, and minerals, such as selenium, copper and zinc, have been used to mitigate oxidative stress. However, in confined systems, the risk of over- or undersupplying micro elements is high, hence the overproduction of pro-oxides is common. Additionally, in semi-intensive feeding systems, trace elements, particularly antioxidant supplementation, are limited owing to restricted or lack of supplementation. Therefore, research focus has shifted to exploration of the potential of natural antioxidants in improving animal production and health.

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.

Recent research shows that the contribution of methane (CH4) to the atmosphere by shale gas and other earth sources is much higher than accepted in IPCC calculations, which implies that much less is from ruminants (Howarth, 2019). Secondly, in carbon footprint calculations the CO2 capture by photosynthesis through the biogenic cycle in plant foods (say maize) (which apart from CO2 may also have resulted indirectly from atmospheric CH4) is not taken into account (Frankelius, 2020). This is actually a carbon sink.

The main greenhouse gases (GHG) contributing to global warming potential from the agricultural sector are carbon dioxide (CO2), methane (CH4), and nitrous oxide (N2O). Nitrous oxide has a 121-year life span in the atmosphere and a global warming potential of 265 times that of CO2, if compared over a 100-year period. This makes the control of N2O from the agricultural sector crucial to assist in mitigation of GHG emissions.

Dairy has been targeted as a source of greenhouse gas emissions. However, research has shown that grazing livestock on pasture-based dairy farms restore carbon to the soil, enhancing its biodiversity and countering climate change. This poses the question: If farms can have a positive impact, but are also a source of negative impact, what is the net effect? This is an important consideration when assessing the negative contribution that dairy farming makes to climate change.