Dairy R&D in SA

Discipline: health and welfare; Key words: plant herbs, immune response, oxidative stress, antioxidants, serum protein, milk composition. 

Discipline: management; Key words: liver fluke, mastitis, milk flocculation, performance.

Discipline: grazing/pastures; Key words: cultivated pastures, fertilisation, nutrient cycling, phosphorus, soil fertility

 Author: Heinz Meissner, Milk SA Program Manager R & D, November 2018.   

1. Mastitis Program:

1.1. PRJ-0210 Antimicrobial resistance on dairy farms - Screening mastitis causing coliforms for the production of extended spectrum Beta-lactamases and Colistin resistance. Dr Inge-Marie Petzer.

The Dairy Industry loses millions of Rand per annum due to age gelation of milk that reduces its shelf life. Age gelation can be induced by anything that has an impact on the suspension of the negative charge on the casein micelle during storage of long life (UHT) milk. This includes the enzymatic or chemical processes that occur during storage. The enzymatic processes involve the action of plasmin (native enzyme) or heat stable microbial proteases.

Banga, Cuthbert and others - ARC-Irene.

1. Projects:

Competitiveness is a function of efficiency, market access (broadening of the market of dairy products is a primary goal) and sustainability. In addition to volatility, structural and consumer needs of markets which with up-to-date information can be addressed only partially, sustainability is progressively also influenced by issues which can be categorized within the three P concepts: Productivity (economic focus), People (sociological focus) and Planet (environmental stewardship focus).

Small effective population sizes and inbreeding are major challenges faced by dairy cattle populations worldwide. Estimates of pedigree-based inbreeding (FPED) are unreliable due to a lack of pedigree data and pedigree errors and that may lead to an underestimation of inbreeding rates. Thus, inbreeding based on runs of homozygosity (FROH) has become the preferred method of estimating inbreeding as it is able to accurately predict the amount of autozygosity within the genome.

Dairy has been targeted as a source of greenhouse gas emissions (GHG). 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.

Among the problems experienced by pasture-based dairy farmers in the southern Cape are required high stocking rates, poor persistence of pastures, an increase in weed ingression in no-till pastures, and increasing input costs associated with irrigation and fertilisation. Research should thus focus on strategies that can improve the resilience and efficiency of pasture systems.