The Research Column

Transition milk, which is collected between the second and seventh milking after calving, during the transition from colostrum to normal milk, contains maternal leukocytes, growth hormones, cytokines, antimicrobial factors, and nutrients. It has been found to contain 15 immune system proteins, the concentrations of which gradually decrease during subsequent milkings.

As a methane-reducing feed additive, Bovaer or 3-nitrooxypropanol (3-NOP) is one of the most extensively researched additives. Numerous studies have demonstrated the efficacy of 3-NOP in reducing methane emissions.

Since the nineties, a combination of fluctuating and extreme prices of

Staphylococcal species are frequently isolated from milk samples of dairy cows. Among the 20 staphylococcal species commonly recovered, Staphylococcus aureus is the most studied.

Although the most common practice to house dairy calves individually for at least the first weeks of life, animal welfare concerns increasingly promote pre-weaning social housing systems. Housing dairy calves with social contact enables natural behaviours (e.g., social grooming and play), reduces fear and avoidance of novel environments, and is likely to provide affective benefits.

In cow-calf contact (CCC) systems, calves are allowed to have maternal contact until a later age than in conventional dairy production systems, where cow and calf are separated shortly after birth. Although CCC systems may vary in design, for example, dam-calf rearing versus foster cow rearing, or full CCC versus partial CCC.

Fresh milk contains a complex microbial community, including micro-organisms of nutritional and technological importance, such as lactic acid bacteria (LAB). The micro-organisms can be altered, which could influence milk composition, processing, spoilage, and consumer health.

Not all calves are needed as replacements in dairy herds; almost all male calves and any excess females can be termed ‘non-replacements’ (or ‘surplus’ or ‘excess’ calves). Globally, these calves are managed through one of three pathways: early life killing, raised for veal, or raised for beef.

The transition from late pregnancy to early lactation in the cow is a critical period which often results in disruptions to homeostatic mechanisms, including a rapid increase in demand for Ca for synthesis of colostrum and milk. The rapid increase in Ca typically results in decreased circulating Ca concentrations, referred to as hypocalcaemia.

It is well-known that feeding supplementary concentrates can boost milk production and lower CH4 (methane) intensity of dairy production.