The Research Column

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 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.

Discipline: body condition score; Keywords: body reserve status, fat, hormonal changes, pregnancy, metabolic disorders.

Research in this context was reviewed by J.R.Roche and coworkers in a paper published in the Journal of Dairy Science, Volume 92, pages 5769 to 5801. The title of the paper is: Body condition score and its association with dairy cow productivity, health, and welfare.

Discipline: mastitis; Keywords: dry cow therapy, Staphylococcus aureus, antibiotics, re-infection,teat sealant.

 In a large study this question was addressed in two papers: in the first paper the preventive effect of various dry cow measures on new infections were investigated and in the second paper the cure of existing infections. These studies are unique in the sense that a highly powerful statistical method, called meta-analysis, was used which enable scientists to pool research data from various studies conducted in different circumstances and synthesize a highly reliable result which for all practical purposes can be considered correct to implement. The titles of the respective papers published by T. Halasa and co-workers in the Journal of Dairy Science, Volume 92 of 2009, page 3134 to 3149 and page 3150 to 3157 are: Meta-analysis of dry cow management for dairy cattle. Part 1. Protection against new intramammary infections and Part 2. Cure of existing intramammary infections.

Discipline: lactation management; Keywords: reproduction, model, MDP, daily information, economic implications.

Discipline: dairy & health; Keywords: Calcium, nutraceuticals, osteoporosis, colon cancer, CLA

Discipline: antibiotics; Keywords: gram positive bacteria, altered fermentation, propionate, Streptomyces cinnamonensis, health concerns.

Discipline: economics; Keywords: pasture systems, TMR systems, net margin, cost of production, milk yield per cow,  labour cost, feed costs.

Discipline: dairy & health; Key words: non-alcoholic fatty liver disease, probiotic yogurt, metabolic factors.