Dairy R&D in SA

Discipline: quality; Key words:  flocculation, gelation, precipitation, clotting, roping, curdling

Discipline: quality; Key words: milk flocculation, Alizarol test, plasmin, Bacillus, UHT milk.

 Discipline: udder health; Key words: SCC, quarter milk samples, composite samples, threshold, udder infection. 

The forage herbs chicory (Cichorium intybus) and plantain (Plantago lanceolata) have become regular components of south-eastern seaboard dairy pastures. They are mostly planted in a mixture with grasses and often clover species are added as a minor component. How they do and what benefits they bring to the pasture mix and the cow have not been well researched in these areas. This was then the purpose of the trials cited below. 

Conjugated linoleic acid (CLA) has the ability to inhibit growth in a number of human cancer cell lines. It is also immune-modulating and growth-promoting and was shown to decrease fat mass without significantly affecting body weight. In terms of prevention of heart disease, CLA depressed total cholesterol and lowered the ratio of low-density lipoprotein (LDL) to high-density lipoprotein (HDL).

An elicitation exercise was conducted to collect and identify pressing questions concerning the study of helminths in livestock, to help guide research priorities. The authors cited below are the primary global experts who compiled the report. Whereas this presentation does not cover research results as usual, I consider it important to share their ideas with the reader as a main focus of our R & D is in control of parasites and because prominent researchers in the group are South African or South African of origin.

A RP of 1186 and a validation population of 128 was established, enabling the inclusion of genomic information in estimation of breeding values, based on the INTERBULL verified Logix Genetic Evaluations and a Single-Step approach, using Mix99, to present the industry with GEBVs. These GEBVs reflect the expression of genes in the SA environment, based on the genetic variation and gene frequencies of the SA Jersey population. 

There is not much information on the effect of dietary nitrate addition as a method to mitigate methane in grazing dairy cows. Therefore, the authors cited below did a study aiming to investigate the effect of nitrate addition on daily enteric methane emissions, production performance and rumen fermentation of multi-lactation Jersey cows grazing perennial ryegrass pasture, which contained about 7.3 g nitrate per kg dry matter (DM).

Claw health is an important factor in animal welfare and its evaluation is an early indicator of lameness in dairy cattle. However, claw disorders on many farms are not routinely evaluated and the information not included in genetic evaluations as they are not always considered in terms of productivity. The aim of the study by the authors cited below was to evaluate claw health of dairy cattle housed in dirt lot vs free stall under the TMR systems.

Stillbirth remains a problem in dairy herds in many countries and is increasingly included in national breeding objectives. In South Africa, however, we lack reliable information on the incidence of stillbirth that can be used to improve this trait genetically. Currently, there are no estimated breeding values (EBVs) for any measures of calving performance produced under the national genetic evaluation programmes.