The Research Column

Although limited in South Africa, many dairy cattle worldwide are still housed in tiestalls, meaning that they are tethered by the neck to individual stalls. On some farms, tied cattle are permitted seasonal access to pasture, but otherwise their movements are restricted compared with cows housed in freestall barns or other loose housing systems. The aim of the systematic review by Dr A Beaver and colleagues was to summarize the scientific literature pertaining to the welfare of tied dairy cattle through comparison with less-restrictive housing systems.

Oestrus detection has become more difficult over the years due to decreases in the oestrus expression of high-producing dairy cows, and increased herd sizes and animal densities. Through the use of hormonal synchronization protocols, also known as timed artificial insemination protocols, it is possible to alleviate some of the challenges associated with oestrus detection. However, timed artificial insemination masks cows’ fertility performance, resulting in a possibly biased comparison of treated animals and innately fertile animals.

In the study four milk production systems over three successive lactations and 20 cows per system during each lactation, were investigated. With winter calving-fully housed (WC-FH), Holstein cows were housed for the entire lactation and offered a complete diet consisting of grass silage, maize silage, and concentrates [approximately 50% forage on a dry matter (DM) basis].

Discipline: starter culture; Keywords: industrial cheese manufacturing, enzymatic coagulation, protein separation, proteolysis.

Miniature cheeses can open up new possibilities to screen cheese starter cultures and study many other aspects of cheese production in the factory. The study was reported by H. Bachmann and coworkers in the Journal of Dairy Science (2009), Volume 92, pages 5868-5882, using the title: A high-throughput cheese manufacturing model for effective cheese starter culture screening.

Discipline: milk powder; Keywords: oxidation, rancidity, off-flavours, light exposure, package atmosphere.

The objective of the study was to establish whether nitrogen flushing and colder than normal storage temperature will be favourable to flavour and shelf life of whole milk powder. This research by Dr M.A. Lloyd and colleagues was published in The Journal of Dairy Science, Volume 92 of 2009, pages 2409 to 2422. The title of the paper is: Effect of nitrogen flushing and storage temperature on flavour and shelf-life of whole milk powder.

Discipline: cheese; Keywords: conceive after birth, cheddar cheese, lactation length, cheese yield, organoleptic properties.

Discipline: lactation management; Keywords: once-a-day milking, extensive dairy production systems, labour requirements, pasture deficit.

Discipline: organic production; Keywords: organic cheese, demand, taste panel, willingness to pay, market.

Discipline: management; Key words: short dry period, conventional dry period, production, lactation number.

Discipline: cow comfort; Key words: bedding material, lying behavior,