Dairy R&D in SA

Age gelation is a process in which there is formation of a three-dimensional protein network within UHT milk which occurs during storage, and is marked by increasing viscosity before observable gelation. In South Africa, the dairy industry loses millions of Rands annually as a result of the condition in UHT milk. As such, there is a need to study and evaluate the possible correlation of variables that may contribute to the occurrence of age gelation in UHT milk.

Conception and re-conception rates of high-producing dairy cows remain of concern in dairy production systems, especially in the subtropics. Apart from the major effects of nutrition and specific nutrients on reproduction, other risk factors such as negative energy balance, inflammation and impairment of the immune response have been shown to affect re-conception rates. Dietary energy levels interact with blood urea nitrogen (BUN) and may influence the pregnancy rates of dairy cows.

Kikuyu-ryegrass may no longer be optimum in the south-eastern Cape because of a number of reasons:
•    Extended periods of lower than expected rainfall
•    Poor persistence of ryegrass, with a decline of as much as 44% reported in even the most productive ryegrass cultivars from year one to year two

Discipline: environment; Keywords: GHG, emission reduction, net zero, carbon sequestration, systems dynamic model, dairy production systems. 

There is reason to believe that diurnal patterns for enzymatic activity exist, as bacterial numbers have been shown to be influenced by time of feeding. Also, when performing ruminal in vitro studies, little attention is given to the time of day when rumen fluid is sampled, thereby not controlling variation caused by diurnal patterns and the effect it might have on starch, NDF, and protein digestibility. Additionally, often results are compared between in vitro studies without considering time of rumen fluid collection or feeding time.

Heat stress is defined as an event that affects an animal’s homeostasis and health owing to a physiologically harmful heat load. Heat stress may prompt physiological dysfunction, which affects an animal’s production and reproduction capacity negatively, and causes economic losses that are estimated to be billions of dollars worldwide. Heat stress also influences a cow’s immune system which may manifest in a higher incidence of udder health problems during summertime.

The overemphasis on economic challenges to small-scale farmers often overshadows the debate about potentiality of artisanal cheeses, which can be processed using local resources, with low input of ingredients and machinery. There is a need to evaluate the processing of artisanal cheeses in rural areas with appropriate economic approaches that consider the local people’s social-economic status, culture, and region. Strategies that could improve farmers’ productivity include technical training, indigenous knowledge development, mentorship, financial support and working as cooperatives.

Antimicrobial resistance (AMR) is a global threat to human and veterinary medicine. Often it is not known to which antimicrobials specific mastitis-causing pathogens such as Streptococcus uberis are resistant or to which new antimicrobials they are sensitive to. A complicating factor is that one of the resistance strategies of many pathogens which makes it more difficult to treat than their planktonic counterparts, is biofilm formation. A further complicating issue is that virulence factors of Str.

The response of pasture yields to nitrogen (N) fertilization is a long-standing topic of debate. In dairy-pasture systems, N application is often thought to be directly proportional to pasture yield. The question is: is it. This was evaluated using data from 153 pasture camps over five years. Fertilizer application rates were grouped into three treatments: <200, 200-350 and >350 kg N per hectare (ha) and the herbage yield response over the five years was recorded.

Mastitis results in large economic loss to both farmer and processor. In addition it has welfare implications for the cow and antimicrobial resistance concerns. Therefore, describing and analysing the measures used to prevent the disease and to minimize the losses remain important. For example, somatic cell count (SCC) directly affects revenue from the sale of milk and in one of the investigations the revenue loss was studied.