Dairy R&D in SA

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.

Discipline: management;

Replacement heifer rearing is often neglected on dairy farms because for farmers the cost of rearing heifers apparently outweighs the advantage of well grown-out heifers. These advantages manifest in early conception and milk yield. To investigate trends in heifer raising, weights for age as a measure of heifer feeding programs were studied in the Western Cape.

Discipline: breeding;

Discipline: environment: 

Discipline: yogurt; 

Discipline: Performance measurement/milk recording;