Dairy R&D in SA

Body condition scoring (BCS) is a subjective manual method based on experience of individuals to assess fat reserves in the cow, of value to milk production, re-conception, regaining reserves and feeding. This is normally done at intervals to assist in monitoring loss and gain in body condition to ensure expected milk production, optimal health, conception and ease of calving.

Dairy farming is a water-intensive land use and one which can degrade water quality. Examples of potential impacts include:

M. van Niekerk, a student from South Africa, reported genotype x environment interaction in SA Holstein dairy cattle, clear differences being seen in genetic parameters between herds using a total mixed ration (TMR) or pasture-based system. Specifically, genotype by environment interaction for persistency of production between the two production systems were indicated with genetic correlations for the first three lactations of below 0.64 throughout.

1. Viability of Bifidobacterium species in probiotic yoghurt as influenced by reducing agents.

The camera frame was deployed at the University of Pretoria experimental farm. The frame was placed over the crush above the weighing platform. Three 3D cameras were used to capture the cow body from different angles – top, rear, angled – in order to obtain enough body information. During the course of the investigation several changes were made to the system and the data collection procedure to ensure the process went smoothly and as much of the collected data was accurate and usable as possible.

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.

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.

In recent years, there has been an increase in the prevalence of environmental pathogens as a cause of within udder infections in dairy cattle. Increases in prevalence could potentially be ascribed to improved control methods for contagious pathogens, difficulties in controlling pathogens from an environmental reservoir and the ability of Streptococcus uberis and Escherichia coli to persist in the udder. Streptococcus uberisshowed an increase in prevalence over an 11-year study period (1996–2007) in South African dairies.

The preservation of the teat canal is crucial for udder health, as the main route for bacterial infection is via the teat canal. Milking machines differ in layout and settings and continue to be a challenge to the primary immune system of the bovine udder namely the teat canal. Different levels of teat end vacuum during machine milking may influence milking performance and teat condition. When there is little or no milk flow the vacuum at the teat end increases to that in the milking machine system.

1. A newly developed system of obtaining Dairy Cattle farm-recorded data from automated systems to be used for biological and economic benchmarking as well as future genetic merit predictions

     by DA Kruger, RR vd Westhuizen & D Victor, SA Stud Book, Bloemfontein, South Africa.