The Research Column

by Heinz Meissner

Click on any of the publications below to read more about the specific topic:

 

Title Date Discipline Extract
Genetic and non-genetic factors associated with lactation length in seasonal-calving, pasture-based dairy cows.

Lactation yield estimates standardized to common lactation lengths of 270 or 305 days are commonly used in management decisions and genetic evaluations. The use of such measurements to quantify the merit of individual cows fails to penalize cows that do not reach the standardized lactation length, or vice versa to reward cows that lactate for more than the standardized lactation length. The objective of a study by Dr M.

Low dietary protein resilience is an indicator of the relative protein efficiency of individual dairy cows.

To try and improve the efficiency of protein use in dairy production has been the goal of many studies in the past 40 years. Lower dietary protein with the same milk protein output should increase protein efficiency and profitability. However, reduced production is a potential risk of feeding diets with less protein, as feeding less protein may reduce the energetic and economic efficiency of producing milk. Thus, the challenge is to identify ways to feed less protein while maintaining or enhancing milk production.

A mycotoxin-deactivating feed additive counteracts the adverse effects of regular levels of Fusarium mycotoxins in dairy cows.

Mycotoxins are a diverse group of secondary metabolites produced by many fungi in the genera Aspergillus, Fusarium and Penicillium. They may cause toxic responses when ingested by humans and farm animals. Among the mycotoxins, those produced by Fusarium spp.

Soil life spans and how they can be extended by land use and management change.

Soils underpin the requirements for health and longevity of mankind. They are critical, providing the basis of food production, a store and filter for water resources, the largest organic carbon store and a platform for development. Pressures on the soil resource grow as food demands rise and land degradation increases.

When do dry cows get heat stressed? Correlations of rectal temperature, respiration rate, and performance.

Numerous studies have shown the negative effects of heat stress during the dry period on dairy cow performance during the subsequent lactation. Exposure of cows to heat stress during the dry period is associated with compromised mammary cell formation and decreases in milk yield in the subsequent lactation. Moreover, a greater incidence of postpartum disorders and lower reproductive performance are associated with exposure of cows to heat stress during the dry period. Dry period heat stress also decreases dry matter intake and body weight, gestation length, and calf weight.

A comprehensive quantification of global nitrous oxide sources and sinks.

Nitrous oxide (N2O) is a long-lived stratospheric ozone-depleting substance and greenhouse gas with an atmospheric lifetime of about 110-120 years. The concentration of atmospheric N2O has increased by more than 20% from 270 parts per billion (ppb) in 1750 to 331 ppb in 2018, with the fastest growth being in the last fifty years. Two key biochemical processes—nitrification and de-nitrification—control N2O production in both land and water ecosystems.

Total-tract digestibility and milk productivity of dairy cows as affected by trace mineral sources.

Trace minerals such as Cu, Zn, and Mn are essential to life, and their deficiencies in livestock result in health deterioration. In an effort to prevent such deficiencies, dairy cows are commonly supplemented with Cu, Zn, and Mn. Various sources of trace minerals are used for this purpose, with inorganic sources (oxides, chlorides, sulphates, and carbonates) being the most commonly supplemented to dairy cows. Alternative sources such as organically complexed trace mineral supplements (chelates) are specifically developed to provide greater nutritional bioavailability.

Associating mobility scores with production and reproductive performance in pasture-based dairy cows.

In some countries lameness has been identified as the third most important health-related economic loss, after fertility and mastitis. Lameness has serious negative consequences on animal welfare and the environment. Secondly, lameness may reduce the overall lifetime performance of dairy cows due to milk production loss and culling, as well as having the potential to further affect sustainability by increasing the total greenhouse gas emissions per unit of milk produced. Furthermore, lame cows are more at risk for developing future mobility issues.

3-Nitrooxypropanol decreases methane emissions and increases hydrogen emissions of early lactation dairy cows, with associated changes in nutrient digestibility and energy metabolism.

Enteric methane is to varying degrees an end product of microbial fermentation in the rumen and hindgut of ruminant livestock. Because it is a potent greenhouse gas (GHG) that contributes to global warming, enteric methane has become one of the main targets of GHG mitigation practices in the dairy industry. Several dietary strategies may contribute to mitigating enteric methane production, including the use of feed additives.

Physical and economic comparison of pasture-based automatic and conventional milking systems.

Technological advancements allow dairy farmers to increase the efficiency of use of land, labour, and capital to produce milk. Automatic milking systems (AMS) offer the possibility to increase productivity and profitability by potentially improving labour efficiency, milk production, animal welfare, and lifestyle.