Dairy R&D in SA

The claims and accusations in the campaign have been researched from various perspectives. The response by the author plus associated information is summarized below:

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 aim of the paper by the authors cited below was to review the state of fertility of female dairy cattle in South Africa and to compare it with international efforts at improving fertility. Fertility in dairy cows is defined as the ability to conceive from first insemination soon after calving and to carry the calf full term to calving.

The severe droughts in successive years in several parts of the country have suggested that more regular droughts and water shortages could become the norm in future farming. This, of course, is also predicted by climate change scientists and it implies that farmers will have to look at ways to make the most of the water they have. Soil management, rainwater harvesting and proper storage of water will determine how efficiently farmers make use of water resources.

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.

The efficiency of milk production of dairy cows has been a common point of discussion among dairy farmers, veterinarians, feed and breeding consultants. Whereas there are different ways of expression, it primarily should be a financial metric of the value of product(s) produced in relation to the production cost of all product(s). For dairy cows this mainly includes milk production income in relation to the feed cost to produce milk. For the lifetime efficiency the beef production income of cows should probably also be included.

Cattle in South Africa produced a total of 35.37 million tonnes (Mt) of carbon dioxide equivalent (CO2 e) emissions in 2019, inclusive of emissions from pasture, range and paddock. Methane (CH4) from enteric fermentation accounted for 64.5% of the total emissions followed by emissions from pasture, range and paddock (27.7%). Manure management contributed 4.34% of N2O (nitrous oxide) to the total emissions while this source also produced 3.45% of CH4 emissions.

South Africa and Kenya rank among the top milk producing countries in Africa, whereas Zimbabwe ranks in the middle. These countries are unique on the continent in that they implement dairy production breeding programmes. South Africa has the highest milk yield per cow, with opportunities to export to other countries. South Africa is also often used as the main reference point for dairy improvement in Africa because countries such as Kenya, Zimbabwe and Rwanda source South African animals to improve their national dairy herds.

One of the key traits in profitable milk production is somatic cell count (SCC). It is used as a measure of udder health and management thereof in terms of cleanliness, cow health and selection is paramount. Over years, a substantial data base has accumulated from the milk recording and management system, allowing analyses from different perspectives to better understand factors influencing SCC. Some factors not normally thought of provide interesting results as shown by the author cited below. 

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.