The Research Column

Listeria monocytogenes is a pathogen which may cause listeriosis with sometimes grave consequences. It is a ubiquitous, gram-positive, facultative anaerobe that grows at refrigeration temperatures and is found throughout the environment, specifically in soil and water. Listeria monocytogenes may survive in food that has a relatively high acid and salt content and can tolerate high and low temperatures.

Discipline: probiotics; Keywords: fermentation, flavour, human health, starter culture, propionibacteria.

Researchers F.Y. Ekinci and M. Gurel thought so and tested the concept in their research published in the paper: Effect of using propionic acid bacteria as an adjunct culture in yogurt production. The paper was published in The Journal of Dairy Science, Volume 91, pages 892-899.

Discipline: birth weight; keywords: mortality, stillbirths, reproductive performance, calf-cow size index.

It is known that heavier calves tend to be more prone to stillbirths, dystocia and lower calf survivability than lighter, smaller calves, but it is not known whether calf birth weight is also associated with other factors affecting the economic efficiency of the dairy herd. A number of such factors were included in the study of T.C. Linden and co-workers reported here; the title being: Calf birth weight and its association with calf and cow survivability, disease incidence, reproductive performance, and milk production. The paper was published in the Journal of Dairy Science, Volume 92 of 2009, page 2580 to 2588.

Discipline: reproduction; Keywords: fertility traits, selection indices, breeding values.

Discipline: Lactation management; Keywords: energy intake, roughage, productivity, longevity

Discipline: dairy & health; Keywords: conjugated linoleic acid, feed conversion, milk fat, lean meat, metabolic functions.

Should CLA be increased through the diet of the cow, or supplemented in the dairy product? In this presentation I will attempt to address this question after studying the  literature on the subject.

Discipline: breeding; Keywords: genetically superior sires, artificial insemination, embryo transfer, feed intake, profits, managerial ability. 

Discipline: reproduction; Key words: nutrition, fertility, reproductive performance, high-yielding dairy cow.

Discipline: cheese; Keywords: natural contamination, farmhouse cheese, Listeria monocytogenes, food safety.

Discipline: animal welfare/ethics; Key words: lameness, body condition score,