Canadian Journal of Animal Science 

About: Canadian Journal of Animal Science is an academic journal published by Canadian Science Publishing. The journal publishes majorly in the area(s): Dry matter & Feed conversion ratio. It has an ISSN identifier of 0008-3984. Over the lifetime, 5708 publications have been published receiving 94771 citations. The journal is also known as: Revue canadienne de science animale & Revue canadienne de zootechnie.

An improved procedure for the determination of chromic oxide in feed and feces

Abstract: A spectrophotometric procedure was developed using ashing at 450 °C followed by acid digestion in beakers and reading the diluted digests at 440 nm. Errors were minimized by use of blanks and maintenance of a constant acid concentration in the diluted digests.

A rapid procedure for purine measurement and its use for estimating net ruminal protein synthesis

Abstract: A rapid method for separation and quantitation of purines was applied to ruminal and intestinal digesta for estimating net microbial protein synthesis in the rumen. The procedure combines standard literature methods for hydrolysis of nucleotides by perchloric acid followed by precipitation of free purines with silver nitrate to separate the purines from interfering compounds. Acid resolubilized purines were quantitated spectrophotometrically at 260 nm. Microbial protein was estimated by the ratio of purines to N of isolated bacteria. The procedure is rapid, simple, precise and not costly. Duodenal passage of microbial N estimated by this procedure for steers fed semipurified and purified diets containing no protein was highly correlated (R2 = 0.98; P < 0.01) with duodenal passage of tungstic acid precipitable N. Results indicate that purines may be useful as a marker for quantitating microbial protein. Key words: Purine, RNA, DNA, microbial protein

Factors affecting the nutritional value of canola meal: A review

Abstract: In this review canola meal (CM), its nutritionally significant components and the availability of its nutrients to poultry, pigs and cattle were discussed. Avenues for possible improvement in available energy, protein and lysine were identified. Recent findings on glucosinolates were also discussed with the conclusion that a further reduction of glucosinolates through plant breeding is both possible and desirable. The role of the anti-nutrients sinapine, tannins and phytic acid were also considered. The potential impact of improvements to CM on its economic value was examined using linear program least-cost ration formulations applied to typical market situations. Key words: Canola meal, energy, protein, carbohydrates, anti-nutritional factors, economics

The use of MIXED models in the analysis of animal experiments with repeated measures data

Abstract: The analysis of data containing repeated observations measured on animals (experimental unit) allocated to different treatments over time is a common design in animal science. Conventionally, repeated measures data were either analyzed as a univariate (split-plot in time) or a multivariate ANOVA (analysis of contrasts), both being handled by the General Linear Model procedure of SAS. In recent times, the mixed model has become more appealing for analyzing repeated data. The objective of this paper is to provide a background understanding of mixed model methodology in a repeated measures analysis and to use balanced steer data from a growth study to illustrate the use of PROC MIXED in the SAS system using five covariance structures. The split-plot in time approach assumes a constant variance and equal correlations (covariance) between repeated measures or compound symmetry, regardless of their proximity in time, and often these assumptions are not true. Recognizing this limitation, the analysis of contrast...

Mitigation strategies to reduce enteric methane emissions from dairy cows: Update review

Abstract: Enteric methane (CH4) emission is a major contributor to Canadian greenhouse gas emissions, and also a loss of feed energy during production. The objective of this paper is to provide an update on current management practices and new dietary strategies recently proposed to reduce CH4 emissions from ruminants. Existing mitigation strategies for dairy, e.g., the addition of ionophores, fats, use of high-quality forages, and increased use of grains, have been well researched and applied. These nutritional changes reduce CH4 emissions by manipulating ruminal fermentation, directly inhibiting methanogens and protozoa, or by diverting hydrogen ions away from methanogens. Current literature has identified new CH4 mitigation options. These include the addition of probiotics, acetogens, bacteriocins, archaeal viruses, organic acids, plant extracts (e.g., essential oils) to the diet, as well as immunization, and genetic selection of cows. These new strategies are promising, but more research is needed to validate t...