Dairy R&D in SA

Dairy breeds originated in the United Kingdom and Western Europe. Both regions have a wet and cool to cold climate. As a result, the environmental comfort zone for dairy cows varies between -5 and 21 °C. Anatomical features that help cows withstand cold conditions include a thick skin, a dense hair coat, subcutaneous fat layers, large muscles and a digestive system that is based on fermentation processes in the rumen which creates internal heat.

For dairy farms to be economically sustainable, herd managers should continuously monitor specific key performance indicators (KPIs). Indicators must be based on quantitative or performance goals which are specific, measurable, attainable and relevant. These may include the average daily milk yield of the cows, their daily feed costs and specific reproduction parameters. These to a large extent are farm specific as each farm is unique in terms of natural resources, infrastructure and management style which will affect milk yield, production costs and breakeven milk yield.

The dairy industry is characterized by a dual production system, comprising of a high input commercial production system and low input smallholder and emerging systems. Performance data from both systems are included in the official national genetic evaluation database, with models which assume homogeneous variances. If variances are heterogeneous, above average animals in more variable herds will be favoured over high performing animals in the less variable herds. This may result in biased selection and inaccurate estimation of breeding values.

Longevity in dairy cows is an important trait affecting the genetic progress, lifetime (birth to cull) performance and lifetime efficiency. An early age at first calving increases productive life (total number of days in milk) while also reducing rearing costs, and financial sustainability of a dairy herd. However, calving problems may increase when age at first calving is too early. For this reason most farmers rear heifers to reach first calving at an older age although not necessarily at a higher live weight.

The purpose of the study by the authors cited below was to characterize Lactobacillus isolates from bovine and dairy origin for their probiotic attributes, with the aim of assessing their safety for human use. The probiotic properties evaluated were acid and bile resistance, bile salt hydrolase activity, antimicrobial activity, antibiotic sensitivity, gelatinase and lipase production, and hemolytic activity.

The Covid-19 pandemic has resulted both in shifts in South Africans’ demand for dairy products as well as changed purchasing habits according to BMi Research, cited below.

What is A1 and A2 milk: The difference is associated with variation in the protein composition of cow’s milk. Both A1 and A2 variants are proteins in the casein group which makes up about 80 % of the proteins. The two variants are almost identical apart from differing in one amino acid at position 67 of the polypeptide (amino acid chain): A1 has histidine whereas A2 has proline.

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.

 Discipline: health;                                                                                        

Discipline: cheese; 

The effect of 4 kGy ionisation irradiation, combined with ripening temperatures at 8°C and 16°C on the ripening of Cheddar cheese was investigated. Changes in cheeses were monitored by sensory, microbiological, and chemical analyses.