The Research Column

Dairy cattle and calves are regularly transported by calf buyers and to auctions and abattoirs by livestock transport vehicles from about 12,000 dairy farms in the United Kingdom (UK). UK Government guidelines require transport vehicles to be cleaned and disinfected within 24 hours of use or before re-use within that period.

Genetic selection, optimizing feed, inseminations, and housing conditions are among the major strategies aimed at improving production and profit in the dairy industry, with a great number of studies focusing on those topics. Absent from the list is a strategy that explores the ability to control the mineral composition of drinking water.

There are several CH4 (methane) inhibitors on the market with promising but variable results.

The transition period is defined as the three weeks before and three weeks after calving. It is a period of high demand for nutrients, as there are drastic metabolic and hormonal changes that carry over to la

Dry matter intake (DMI) plays a major role in characterizing feed efficiency in dairy cattle and has been widely used in dairy nutrition research. As feed represents the largest operating cost in dairy production, feed efficiency has gained increased attention for genetic selection.

Waste milk (WM) may be colostrum and milk derived from cows undergoing treatment for several ailments, including clinical mastitis, foot and reproductive diseases etc. Additionally, WM may have elevated SCC, rendering it unsuitable for commercial use. Yet despite this adversity, the use of WM in suckling programs is worldwide a common practice, since producers perceive the use thereof as an economical feed alternative which can effectively replace calf nutrition derived from bulk tank milk (BTM) or milk replacer.

A total of 42 Holstein heifer calves on a commercial dairy farm were enrolled in groups of three to different housing treatments; IH (n = 21) or GH (n = 21). Each treatment was composed of seven groups of three calves each. Calves in the GH treatment were housed in groups of three from six to ten days until 70 days of age. Individual pens consisted of one polyethylene hutch with a 1.5 m × 1.2 m outside exercise area. Group pens were constructed by assembling three polyethylene hutches with a 1.5 m × 3.6 m outside exercise area of wire panel fencing.

Butters were produced using milks collected from three feeding systems: outdoor pasture grazing (high pasture allowance); indoor TMR (no pasture allowance); and a partial mixed ration (medium pasture allowance) system, which involved outdoor pasture grazing during the day and indoor TMR feeding at night. Butters were manufactured during early, mid, and late lactation.

Milk production data of 23 908 first lactation and multi lactation cows from 87 herds were used. Persistency was measured by a lactation curve characteristic decay, representing the time taken to halve milk production after peak yield. Decay was calculated for eight DPC (0, 30, 60, 90, 120, 150, 180, and 210 days after DIMc), which served as the dependent variable. Independent variables included DPC, DIMc (≤60, 61–90, 91–120, 121–150, 151–180, 181–210, >210 days), parity group, DPC × parity group, DPC × DIMc, and variables from 30 days before DIMc as covariates. 

An 8 × 8 incomplete Latin square design was conducted with 48 lactating Danish Holstein cows over 6 periods of 21 days each. Eight diets were 2 × 2 × 2 factorially arranged: FAT (30 or 63 g crude fat/kg DM), NITRATE (0 or 10 g nitrate/kg DM), and 3-NOP (0 or 80 mg 3-NOP/kg DM), and cows were fed ad libitum. Milk samples were analyzed for general composition, fatty acids (FA) and thermal properties of milk fat.