Dairy R&D in SA

The sustainability of current nitrogen (N) fertilization regimes for minimum tillage kikuyu-ryegrass (Pennisetum clandestinum, Lolium multiflorum) pastures in the southern Cape is questioned. The guidelines, originally, were developed for conventional tillage and non-grazing systems. It may well be that these guidelines may not apply any more. In fact, there is the possibility that the N levels applied are too high with implications to both economics and leaching of unutilised N.

Some interesting results have been reported by Dr Jan van Wyk, who is responsible for the Milk SA project: Fasciola hepatica: Impact on Dairy Production and Sustainable Management on Selected Farms in South Africa. The report is from the fourth quarter of 2018.

The economic benefits of restoring natural capital have been well known. Also, the economic value of ecosystem goods and services, when taking a natural capital accounting approach, often far exceeds the usually accepted value of natural capital. Yet, despite the obvious value in restoring and maintaining natural capital, the world is facing a crisis with respect to environmental breakdown.

Routine bulk tank milk testing is an adjunct to monitor milk quality and udder health as total bacterial counts, and enumerating psychrotropic and thermoduric bacteria counts, may provide useful information on the cleanliness of milking procedures and equipment, the effectiveness of milk cooling and system sanitation. Also, differential bacterial counts may provide information on the occurrence of and changes in mastitis pathogens.

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 impact of mastitis is significant and costly. Mastitis leads to economic losses to both the farmer and processor, welfare implications for the cow and antimicrobial resistance concerns. Describing and analyzing the measures used to prevent this disease and to minimize the losses is important from an economic perspective. In evaluating the economics of managing mastitis, farmers need to take into account losses incurred subsequent to the disease (failure cost, FC) and those invested to prevent the disease (preventive cost, PC).