Valacta (Canada)

Intramammary infection (IMI) treatment and prevention at drying-off is one of the leading causes for using antimicrobials on dairy farms. The objective of the current paper is to describe the protocol used for conducting a systematic review of the literature on non-antibiotic strategies that can be used on dairy cows at dry off to treat and prevent IMI. Relevant literature will be identified using a combination of database search strategies and iterative screening of references. To be included in the review, articles will have to: (1) be published after 1969; (2) be written in English, French, or Spanish; (3) use a study design such as a controlled trial, an observational study, or an experimental study conducted in vivo; (4) be conducted on commercial dairy cows; (5) investigate a non-antibiotic intervention used at dry off; and finally, (6) report on a relevant mastitis outcome. Titles and abstracts, then full articles will be reviewed for inclusion. Specific data will be extracted and risk of bias will be assessed for all included articles. The planned systematic review will be the first to colligate, in a coherent whole, studies investigating non-antibiotic strategies for treating and preventing IMI at drying-off.

Adoption of automatic milking system (AMS) increased exponentially over the last years around the world. In 2014, 5% of Canadian dairy farms owned an AMS. The objective of this study was to evaluate the economic impact following AMS introduction in Canadian dairy herds. Data were first collected during a phone interview on 213 Canadian dairy farms having shifted to AMS (British-Colombia, n = 8; Alberta, n = 42; Saskatchewan, n = 6; Manitoba, n = 12; Ontario, n = 73; Québec, n = 65; and Atlantic provinces [New-Brunswick, Nova-Scotia, Prince-Edward-Island], n = 7). Second, 151 farms out of 213 have answered a more detailed online survey. After AMS adoption, herd size, milk production, and number of robots per herd averaged 100.2 ± 64.3 cows, 10,764 ± 1,663 kg, and 1.94 ± 1.36 robots, respectively. Milk production, reproduction, and culling data were provided by Valacta and CanWest DHI. Partial budgets were computed using an Excel spreadsheet; surveyed data were completed with literature data. Results of the partial budgets were divided by the respective number of cows after the AMS introduction to allow comparison regardless of herd size. Average parameter values were calculated for herds below percentile 25 and above percentile 75 for the net margin per cow and were compared with either a t test or a Wilcoxon signed-rank test. On average, after AMS introduction, herd size, milk production and culling rate were increased by 7.3 cows, 741.6 kg/cow/yr and 1.5%, respectively, and calving interval and labor requirement were decreased by 6.8 d and 15.1 h/cow/yr, respectively. Net margin per cow following AMS adoption was negative and averaged CAN $-1,204.41 ± 1,080.06. Introducing AMS resulted in increased costs of CAN $2,277.45 ± 1,362.21/cow mainly due to robot, barn construction or modifications and cow purchase amortizations (41.9% of total increased costs) and interest (27.8%). Increase in income averaging CAN $1,073.04 ± 1,739.10/cow was explained by milk production increase (55.1% of total increased income) and labor requirement decrease (29.8%). Highest net margin herds (P75) were characterized by having higher increased income (P75, CAN $2,331.76 and P25, CAN $-315.81; P < 0.0001) as compared with P25 herds. No difference was noted for increased costs (P = 0.82) between P25 and P75 herds. Difference in profitability between P75 and P25 herds was mainly due to milk production increase (CAN $524.47/cow; P = 0.0004). In summary, only 6% of dairy producers shifting to AMS have an expected payback less than 12 yr, which is the theoretical milking robot useful life.

Alfonso-Ávila, Á. R., Charbonneau, E., Lafrenière, C. and Berthiaume, R. 2015. Effect of glycerol in combination with alfalfa on in vitro gas production and microbial protein synthesis. Can. J. Anim. Sci. 95: 577–588. This study sought to determine the effect of added glycerol on microbial protein synthesis, ruminal degradation and utilization of alfalfa at different concentrations of nonstructural carbohydrates (NSC), using in vitro gas production. The 2×3 factorial plus one treatment consisted of oven-dried alfalfa with two NSC levels [high: 17.9 (HNSC) or low: 7.4% dry matter (DM) (LNSC)] and three glycerol treatments [control without glycerol, 15% crude glycerol (CG) and 15% pure glycerol (PG)], the additional treatment was LNSC+exogenous sugars (LNSC+ES: LNSC with 5% sucrose+5% starch). Five pre-planned contrasts were evaluated from the seven treatments: (1) HNSC vs. LNSC alfalfa; (2) with glycerol vs. without; (3) interaction of alfalfa and glycerol; (4) CG vs. PG, and; (5) LNSC+ES vs. HNSC. Gas production over 24 h was higher for HNSC than LNSC (202 vs. 179 mL g−1 DM) and with glycerol than without glycerol (202.2 vs. 168 mL g−1 DM). A decrease in the acetate:propionate ratio was observed for HNSC compared with LNSC (2.87 vs. 3.27) and for the addition of glycerol vs. no glycerol (2.78 vs. 3.65). Reduced microbial mass (185.5 vs. 240.5 mg g−1 DM) was observed for CG compared with PG. The LNSC+ES treatment had lower microbial protein synthesis and propionic acid production in relation to HNSC. No significant interaction was observed between the effect of NSC content of alfalfa and glycerol utilization. When effects were studied separately, results indicate that increasing NSC in alfalfa stimulates the synthesis of microbial protein. Also, the addition of glycerol promotes the synthesis of glucose precursors. Finally, the type of glycerol has an impact on results obtained suggesting caution when extrapolating results for PG to CG.

While minimizing total losses (sum of production loss and disease control expenditures) is recognized to be the most profitable approach, dairy producers still have flexibility regarding the timing of their decisions, the liberty to make individual choices (e.g., genetic selection), or the handling of certain constraints (e.g., regulations, quotas, etc). Farmer's socio-psychological characteristics were demonstrated to be more important to farm performance than herd-level variables describing production, health, and fertility. Research on motivational and behavioural aspects of farmers’ decision utility are sparse, and nonexistent regarding culling expectations and the associated decision process. Our goal was to identify shared criteria on culling decision held by dairy producers and farm advisors, using a Q-methodological study, which allows for the systematic exploration of subjectivity.

Sheppard, S. C., Bittman, S., Donohoe, G., Flaten, D., Wittenberg, K. M., Small, J. A., Berthiaume, R., McAllister, T. A., Beauchemin, K. A., McKinnon, J., Amiro, B. D., MacDonald, D., Mattos, F. and Ominski, K. H. 2015. Beef cattle husbandry practices across Ecoregions of Canada in 2011. Can. J. Anim. Sci. 95: 305–321. Beef production in Canada is diverse in many dimensions with numbers of cattle per operation ranging over 10 000-fold, pasture usage from nil to 100%, and types of operations from solely cow–calf to exclusively feedlot finishing. This study summarizes management information obtained from a survey conducted in 2012 (about 2011) on 1009 beef operations in Canada. Many of the results clearly differentiate the practices in the Prairies from those in Ontario and Quebec. Compared to eastern Canada, the Prairies had earlier and shorter calving seasons, higher weaning weights, utilized more winter grazing with a variety of strategies, grew and fed more barley than corn, used more seasonal feeding areas and feedlots (and hence fewer barns), and more commonly spread manure in the fall. Many of the management practices used by cow–calf operations would have low environmental impact, including extensive use of grazing even in winter, low fertilizer inputs and feeding perennial forages with a high content of legumes. Some practices such as not covering forages or manure storage structures were common and could be changed to improve forage quality and reduce manure emissions. Most forage was harvested 3–7 d after full bloom. Earlier harvest has the potential to improve forage quality, which could reduce dependence on arable crops. Finishing operations used more housing, fed more arable-land crops and less perennial forages, and practiced little grazing. Rationale regarding the adoption of many of the management strategies was reported by the producers. For example, winter grazing was adopted primarily to reduce costs and labour, but for some it was also linked to a late calving season. Preferred sources of technical information included their own experience, farm print media, producer organisations and demonstrations at field days. The survey also identified several areas in which the industry may realize improved sustainability.

Cet article s’intéresse à l’application des règles énoncées par la Cour suprême du Canada à l’égard de l’appréciation de la « raisonnabilité » de la décision d’un tribunal administratif faisant l’objet d’un contrôle judiciaire. Elle révèle l’existence d’un écart significatif entre les principes énoncés par la Cour suprême depuis l’arrêt Dunsmuir c. Nouveau-Brunswick et leur application par la Cour d’appel du Québec. Pour y parvenir, l’auteur a d’abord fait une synthèse des règles fondant la détermination de la norme de contrôle judiciaire et de son évolution jurisprudentielle auprès des cours de juridiction fédérale et provinciale. Il s’est ensuite attardé au pouvoir d’intervention des cours judiciaires lors d’un contrôle judiciaire, notamment au regard la norme de la décision raisonnable. Il termine son analyse par une étude comparative des jugements de la Cour suprême avec 82 jugements de la Cour d’appel du Québec contenant l’expression « issues possibles acceptables pouvant se justifier au regard des faits et du droit » mentionnée au paragraphe 47 de l’arrêt Dunsmuir.