The Research Column

Discipline: composition; Key words: conjugated linoleic acid, dietary protein, fatty acid, milk, cheese

Discipline: nutrition/feeding; Key words: transition cow, health, welfare, Hypocalcaemia.

Discipline: hormone; Key words: somatotropin, lactation performance, lactation persistency, Boostin, Lactotropin. 

Discipline: genetic evaluation; Key words: genome-wide association study, residual feed intake, feed efficiency. 

Discipline: behaviour; Key words: automatic jaw movement recorder, grazing behaviour, validation.  

Discipline: breeding; Key words: genomic testing, rate of genetic gain, sexed semen   

Bacteria are ubiquitous microorganisms present in all known environments, including various areas of the animal body as well as in fermented dairy foods, where they are organized in complex consortia. The microbial ecology of fresh cheese has been extensively investigated, and has lead to the generally accepted understanding that bacteria residing in milk may contribute beneficially to the aroma of fermented dairy products. Here, lactic acid bacteria are particularly important due to their positive or negative impacts on fresh and ripened cheese.

The utilization of functional foods has increased since the last decade. In many instances they form part of the daily diet where they have the potential to lessen the risk of disease along with their accepted nutritional efficacy. The beneficial effects are due to the presence of physiologically active components, which have the ability to lessen the threat of chronic diseases.

The health, well-being and reproductive status of dairy cows, apart from profitability in production, should be the most important considerations in animal breeding. Normally though, genetic evaluation focuses mostly on the genotypic background which influences economically important traits such as milk yield and composition. However, in many countries selection for enhanced milk performance has caused a decline in cow reproduction and consequently, this has led to increased interest associated with non-production traits, including reproductive efficiency, longevity and health.

Bacterial contamination of foods may lead to reduced shelf life due to outgrowth of spoilage organisms and, in the case of pathogens, to food-borne illness upon consumption of contaminated products. To inactivate bacteria that may grow in finished products, heat treatment is often used. Pasteurisation usually is effective to inactivate vegetative cells, but bacterial spores will survive, after which they may germinate and grow in finished liquid products.