The Research Column

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.

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.

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.

Direct-fed microbials (DFM) defined as “live, naturally occurring microorganisms that have been used to improve digest

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.

Bovaer or 3-Nitrooxypropanol (3-NOP) is an anti-methanogenic feed additive that inhibits a key enzyme involved in the last step of methane (CH4) production by the rumen methane-producing organisms.

Dairy cattle provide a major benefit to the world through utilizing mostly human inedible feedstuffs into milk and associated dairy products. However, as beneficial as this process has become in modern dairies, it does not occur without potential negatives.

The nitrogen use efficiency (NUE; defined as N output in milk/N consumed) of dairy cows within pasture-based systems is rather low, often less than 25%. Excreted N, in particular the rather high urinary N, may thus be lost to the atmosphere as ammonia and nitrous oxide and to waterways as nitrates.

In dairy cattle, the negative correlation between milk lactose content (LC) and SCC has been reported in various breeds and contexts, and several authors have discussed possible causal relationship and mechanisms responsible for the LC decrease associated with mastitis or high SCC.