The Research Column

Crossbreeding is a practice that may help to increase the economic profit by improving health, fertility, longevity or milk components, through the benefits of heterosis, which reduces the likelihood of inbreeding depression by increasing heterozygosity. The main contribution of crossbreeding is the increase of efficiency of the production system due to breeds having their genetic merits in different traits so obtaining benefits of heterosis.

The impact of SARA has mainly been studied by conducting SARA challenges in cows, sheep, and goats based on a combination of feed restriction and high-grain feeding. The methodologies applied in these studies varied considerably. Variations include differences in the duration and amount of grain feeding, the type of grain, the amount and duration of the feed restriction, the number of experimental cows, and the sensitivity of the cows themselves to the SARA challenges.

Cheese production is from fermentation processes by starter cultures used to generate lactic acid enabling gel syneresis, whey expulsion, and curd formation. Natural whey cultures (NWC) are undefined cheese starters obtained by the traditional back-slopping procedure. They play a key role in cheese specificity, uniqueness, and development of sensory characteristics.

Studies evaluating RFI divergence between dairy cows have usually been performed during established lactation. Whether shortening the feeding period and increasing the number of cows would enhance the ability to detect physiological differences between the most efficient and  least efficient cows is largely unknown.

Pregnant cows and heifers (n = 273) were blocked by parity and body condition score and randomly assigned to either STM or OTM diets at 45 ± 3 days before their expected calving date. Both groups received the same diet, except for the source of trace minerals (TM). The STM group was supplemented with Co, Cu, Mn and Zn sulfates and Na selenite, whereas the OTM group was supplemented with Co, Cu, Mn and Zn proteinates and selenized yeast.

Methane emissions and rumen fermentation characteristics of the dairy cows fed 100% plantain (PLT) or 100% perennial ryegrass (RG; Lolium perenne) were measured in two experiments (E1 and E2). The forages were in a vegetative growth stage in E1 and were in a reproductive growth stage in E2. The CH4 emissions from 16 cows in each experiment were measured in respiration chambers for two days.

The consumption of fermented dairy products is thought to potentially prevent or help to control type 2 diabetes mellitus (T2DM) through mechanisms of increased satiety, improved insulin sensitivity, increased glucose tolerance and maintenance of the gut microbiota. However, research results are inconsistent, and a recent meta-analysis of observational studies reported a neutral association between intake of fermented dairy and T2DM. The meta-analysis was limited by the lack of examination of the effect of fermented dairy consumption on diabetes prevention.

The study used 2616 calves entering a calf-rearing facility for veal calves in Canada. The results nevertheless are considered relevant to rearing of heifer calves on farm. Faecal consistency scores were assigned twice daily for the first 28 days following arrival, where a score of 2, indicating runny consistency, and 3, indicating watery consistency, were classified as diarrhoea. Severe diarrhoea was classified by a score of 3. Serum total protein was measured upon arrival and the source of the calf (i.e., whether the calf came from a calf seller, local farm, or auction) was recorded.

Milk consumption is motivated by both familiarity and habit and usually decreases with age. However, consumption during childhood and adolescence increases the chances of lifetime milk consumption. Understanding how parents perceive dairy milk and other dairy foods further enables development of dairy-positive messaging that aligns with their perceptions. The objective of the research by Dr A.N. Schiano and colleagues, done in North-Carolina, therefore was to understand parent belief systems around fluid dairy milk and plant-based alternatives (PBA).

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].