The Research Column

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.

Farm animals are now exposed to more heat-stress events due to an overall increase in global temperature than ever before, and the dairy industry is highly affected by climate change because Holstein cows, which comprise the vast majority of the global dairy population, are very sensitive to high temperatures. Heat-abatement technologies are often used on dairy farms to mitigate the effects of heat stress.

Bovine somatotropin (bST) or popularly referred to as growth hormone, is a naturally produced hormone which is a key regulator of growth and milk production.

Milk, a staple in many diets worldwide, is often considered a nutritional powerhouse. Being rich in calcium, phosphorus, vitamin D, and high-quality protein, it plays a pivotal role in bone health, immune function, and overall well-being. Numerous studies have linked adequate milk consumption to a reduced risk of various chronic diseases, including osteoporosis, cardiovascular disease, and certain types of cancer.

Achieving high levels of pasture utilization by pasture-based dairy cattle are the cornerstone of profitable grazing systems. Whereas the productivity of such systems is often considered in terms of milk output per cow or per ha, milk production efficiency necessitates that individual animal milk production and pasture DMI are evaluated simultaneously.

The productive performance of first-lactation cows is a crucial indicator of their overall productive potential and health. This is also linked to milk production in subsequent lactations and the cow’s productive performance, longevity, and ability to live a long life.

Research has shown that the dietary supplementation of specific branch-chain volatile fatty acids (BCVFA) (e.g., iso-butyrate, 2-methybutyrate, and iso-valerate), either individually or in combinations with another straight-chain FA, valerate (collectively known as isoacids; ISO), significantly improves cellulolytic bacterial grow

The urea nitrogen excreted by animals with their urine, which is subsequently degraded by the microbial enzyme urease, is a major source of ammonia emissions. In case of an imbalance between protein and energy supply in the feed, the surplus of ammonia is detoxified to urea in the liver and enters the bloodstream, where it diffuses or is transported to other fluid pools, such as milk or rumen liquid.