Fina, M., Casellas, J. and Piedrafita, J. 2011. Short Communication: Estimating abundance, survival and age structure of the Alberes cattle using recapture techniques. Can. J. Anim. Sci. 91: 343-347. The Alberes breed is an endangered bovine breed with an unknown population size. In this study, we estimated a total of 447.9 (435.5 to 456.6) individuals using capture-recapture methods. Overall survival and recapture estimates were 0.85±0.01 and 0.94±0.01, respectively, leading to an average longevity of 5.64 yr and with the highest death rate concentrated in the first 3 yr of life (38.94%). For breeding cows, the average length of the productive life was 8.35 yr. The current population of this local breed is too small to prevent future losses of genetic variability, and a conservation program is essential to ensure the long-term viability of the breed.

Veira, D. M., Chapinal, N. and Nadalin, A. 2011. Short Communication: Does the presence of the cow influence the absorption of immunoglobulins by the neonatal dairy calf? Can. J. Anim. Sci. 91: 349-352. Holstein calves were kept with their dams for 0.5, 6 or 24 h after birth. Calves were fed 85 g colostrum kg^-1 birth weight 1 h after birth, and were prevented from suckling their dam. At 24 h, all calves had similar serum IgG levels indicating that the presence of their dam had no effect on IgG absorption.

Tang, G., Stewart-Smith, J., Plastow, G., Moore, S., Basarab, J., MacNeil, M. D. and Wang, Z. 2011. Optimizing a beef production system using specialized sire and dam lines. Can. J. Anim. Sci. 91: 353-361. Crossbreeding is an effective method for improving the efficiency of production in commercial cow-calf operations. It exploits available heterosis (hybrid vigour) and complementarity between different breeds or populations (lines). Before adopting a crossbreeding system, commercial cattle producers should evaluate available genetic resources and feasible crossbreeding systems, and choose one that is most beneficial for their own environment, resources, and management. This study compared profitability of alternative crossbreeding systems based on Beefbooster beef cattle breeding strains through computer simulation. Biological and economic data were collected from commercial customers of Beefbooster in Montana and western Canada, and breeding records from the database of Beefbooster, Inc. Three maternal strains (M1, M2 and M4) and two specialized paternal strains (M3 and TX), were evaluated with two simulated crossbreeding systems. System 1 uses a rotational cross between M1 and M4 with yearling crossbred heifers bred to M3 sires. System 2 is based on a three-strain rotation of M1, M2 and M4 with yearling crossbred heifers bred to M3 to facilitate ease of calving and crossbred cows bred to a classical terminal sire strain TX. Simulated base profit from system 2 was $29.57 greater ($215.21 vs. $185.64 yr^-1 per cow) than from system 1.

Lu, L., Wang, F., Chen, X., Yuan, H., Tian, Y., Li, J., Shen, J., Tao, Z. and Fu, Y. 2011. cDNA cloning, expression and regulation analysis of goose adipose triglyceride lipase (ATGL) gene. Can. J. Anim. Sci. 91: 363-369. Adipose triglyceride lipase (ATGL) has an important role in adiposome turnover in mammals. In avian species, the ATGL gene has been reported in chicken, duck, quail, turkey and parrot. We describe here the cloning and characterization of the ATGL in goose. Goose ATGL encodes a 482-amino-acid protein, which contains a “GXSXG” motif and 169-amino acid “patatin” domain. The deduced goose ATGL protein shows more than 85% identity to the reported avian species. Quantitative real-time RT-PCR analysis reveals that the goose ATGL mRNA is more highly expressed in subcutaneous fat. We also identify changes of goose ATGL mRNA expression pattern after over-feeding treatment, which may reveal that expression of ATGL in obesity is tissue-specific in goose. Moreover, we conclude that the mRNA level of ATGL can be regulated by oleic acid in goose adipocytes.

Wang, F., Lu, L., Yuan, H., Tian, Y., Li, J., Shen, J., Tao, Z. and Fu, Y. 2011. cDNA cloning, characterization and expression analysis of toll-like receptor 4 gene in goose. Can. J. Anim. Sci. 91: 371-377. Toll-like receptor 4 (TLR4) plays an important role in activating proinflammatory pathways in response to various pathogens and fatty acids in mammals. In avian species, the TLR4 gene has been reported in chicken and zebra finch. We describe here the cloning and characterization of the TLR4 in goose. Goose TLR4 encodes an 843-amino-acid protein, which contains a signal peptide, extracelluar leucine-rich repeat domain, a transmembrane region and a toll-interleukin-1 receptor signaling domain. The deduced goose TLR4 protein shows more than 70% identity to chicken and zebra finch, but less than 50% identity to its mammalian counterparts. Quantitative real-time analysis reveals that the goose TLR4 mRNA is more expressed in abdominal fat and liver. We also identify the changes of goose TLR4 mRNA expression pattern after over-feeding treatment, which may reveal that the expression of goose TLR4 could respond to over-feeding treatment.

Hu, X. F., Guo, Y. M., Li, J. H., Yan, G. L., Bun, S. and Huang, B. Y. 2011. Effects of an early lipopolysaccharide challenge on growth and small intestinal structure and function of broiler chickens. Can. J. Anim. Sci. 91: 379-384. Two experiments were conducted to determine the effect of early exposure to lipopolysaccharide (LPS) on small intestinal structure and function of broiler chickens. Seven-day-old birds were randomly allotted to two equal treatments: an LPS-injected treatment in which the birds were injected intraperitoneally with LPS 500 μg kg^-1 body weight (dissolved in 1 mL saline) on 8, 10, 12, 15, 17, and 19 d of age, i.e., on days 1, 3, and 5 d for 2 continuous weeks, and a control treatment (CTRL) in which the birds were similarly injected with 1 mL saline as a placebo. In exp. 1, food intake and weight gain were monitored over the 2 wk, the weight of the small bowel was determined at 14 and 21 d of age and duodenal and jejunal villus height and crypt depth, D-xylose uptake were also measured at 21 d. In exp. 2, additional measurements of the intestinal peristalsis ratio and the BrdU-labeling index and duodenal sodium-glucose co-transporter-1 (SGLT1) mRNA level were made at 21 d of age. The results showed that LPS challenge decreased feed intake, daily gain, duodenal and jejunal villus height and crypt depth, plasma D-xylose concentration and intestinal BrdUrd-labeling index, respectively (P<0.05) as well as small bowel weight at 14 and 21 d of age (P<0.05). Conversely, LPS injection increased SGLT1 mRNA level in the small intestine (P<0.05) and the small intestinal relative weight at 14 (P<0.05) and 21 d of age (P=0.063). Following LPS injection there were non-significant changes in feed conversion ratio and intestinal peristalsis ratio (P>0.05). In conclusion, early LPS challenge delayed the growth of intestine and impaired small intestinal structure and absorptive function.

Habibi, A., Hosseini, A., Farrokhi, N., Amidi, F., Carvalhais, I., Chaveiro, A. and Moreira da Silva, F. 2011. Short Communication: Successful vitrification of mouse oocytes using the cryotop method with moderate cryoprotectant concentrations. Can. J. Anim. Sci. 91: 385-388. The response of vitrified mouse M_II oocytes in the presence of two concentrations of cryoprotectants [vit₁ (15%: 7.5% dimethyl sulfoxide (DMSO) 7.5% ethylene glycol (EG) and vit₂ (30%: 15% DMSO 15% EG)] was analyzed to investigate whether reducing cryoprotectant concentrations can affect oocyte survival after cryopreservation by the cryotop method. After thawing the survival, fertilization, cleavage and blastocyst rates were compared with unfrozen oocytes. It can be concluded that 15% cryoprotectant (7.5% DMSO 7.5% EG), instead of the commonly used 30% (15% DMSO 15% EG), could be helpful by moderating the probable toxic effects of vitrification solution in mouse oocyte during vitrification by cryotop.

Kong, C., Lee, J. H. and Adeola, O. 2011. Supplementation of β-mannanase to starter and grower diets for broilers. Can. J. Anim. Sci. 91: 389-397. Two experiments were conducted to investigate the efficacy of β-mannanase on ileal nutrient digestibility, total tract utilization of dry matter (DM), N, energy, and apparent metabolizable energy (AME, exp. 1), and growth performance (exp. 2) of birds fed practical corn-soybean meal (SBM)-based diets. In each experiment, 192 male broilers were assigned to four diets arranged in a 2×2 factorial of energy level [corn-SBM-based diet that met or exceeded NRC nutrient requirements (AE) or low energy (LE) diet containing 100 kcal of ME kg^-1 less than the AE diet] and enzyme supplementation (with or without β-mannanase) for 21 d. Supplementing the diet with β-mannanase increased the birds' apparent ileal DM digestibility of the experimental diets (P<0.05), whereas there was no effect of energy level. Neither β-mannanase supplementation nor energy level had any effect on apparent ileal digestibility of any of the amino acids. The interaction between enzyme and energy levels was not significant for any criteria measured in the excreta except for DM (P=0.05). Addition of β-mannanase improved (P<0.01) the apparent total tract utilization of DM and energy in the broilers, and there was the same trend (P=0.06) for N utilization. Supplementing the diet with β-mannanase also improved the AME and AMEn of diets by 4.6 and 5.0%, respectively. For all growth performance responses in exp. 2, the interaction between enzyme and energy levels was not significant. During the starter period (day 2 to 22 post-hatch), β-mannanase supplementation significantly (P<0.05) increased the body weight (BW) gain of birds. During the grower period (day 22 to 44 post-hatch) and for the overall period there was no significant difference in BW gain or feed intake of birds regardless of energy level and β-mannanase supplementation. There were no dietary effects on feed efficiency of birds during the starter and the grower periods, whereas the birds fed AE diets had higher feed efficiency (P<0.01) than the birds fed LE diets. The results indicate that supplementing with β-mannanase may improve gain and energy utilization of broilers, whereas it may not affect ileal amino acid digestibility.

Onyango, E. M. and Adeola, O. 2011. Dietary cholecalciferol lowers the maximal activity of intestinal mucosa phytase in ducklings fed low-phosphorus diets. Can. J. Anim. Sci. 91: 399-404. The role of cholecalciferol and phosphorus in the regulation of intestinal mucosa phytase was investigated in White Pekin ducklings. Ninety-six 7-d-old male ducklings were grouped by weight into six blocks of four cages with four ducklings per cage. The average weights of the individual birds in the six subgroups were: 282, 270, 263, 255, 247 and 236 g, respectively. Four corn-soybean meal-based mash diets were randomly assigned to cages within each block. The four diets consisted of cholecalciferol at 0 or 75 µg kg^-1 and total phosphorus at 3.6 or 7.0 (or 0.12 or 0.46 available phosphorus, respectively) g kg^-1 in a 2×2 factorial arrangement. Birds were fed the experimental diets for 9 d under conditions that excluded ultraviolet light. Ducklings fed diets with cholecalciferol concentration at 75 µg kg^-1 of diet showed a lower maximal activity and K_m value of intestinal mucosa phytase (P<0.05), and higher apparent ileal digestibility of calcium (P<0.0001). Ducklings fed diets with total phosphorus concentration at 7.0 g kg^-1 of diet showed no change in intestinal mucosa phytase activity, but had higher weight gain, feed intake, tibia ash, ileal digestibility of phosphorus (P<0.0001), and feed efficiency (P<0.001). In conclusion, dietary cholecalciferol decreased the maximal activity and K_m value of intestinal mucosa phytase in ducklings fed low-phosphorus diets.

Olukosi, O. A., Paton, N. D., Van Kempen, T. and Adeola, O. 2011.Short Communication:An investigation of the use of near infrared reflectance spectroscopy to predict the energy value of meat and bone meal for swine. Can. J. Anim. Sci. 91: 405-409. The feasibility of using near infrared reflectance spectroscopy (NIRS) for predicting metabolizable energy of meat and bone meal (MBM) for swine was investigated. Thirty-three MBM samples were analyzed for chemical composition and their metabolizable energy content was determined in metabolism assays. Near infrared reflectance spectroscopy calibrations were developed for gross and metabolizable energy of the samples. Coefficients of determination for calibration and cross-validation were greater for gross energy compared with metabolizable energy. Poorer prediction of metabolizable energy by NIRS may be due to sources of variation unaccounted for by NIRS. It was concluded that NIRS is feasible for predicting gross energy but not metabolizable energy of meat and bone meal.

Koenig, K. M. and Beauchemin, K. A. 2011. Optimum extent of barley grain processing and barley silage proportion in feedlot cattle diets: Growth, feed efficiency and fecal characteristics. Can. J. Anim. Sci. 91: 411-422. A study was conducted to evaluate the effects of forage proportion and extent of processing of barley grain on growth, intake, feed conversion efficiency, and fecal characteristics of feedlot cattle. Crossbred steers (120; 407±31 kg) were housed individually and assigned to 10 diets (n=12): two degrees of temper rolling of barley grain [processing index (PI) of 82% (standard) or 87% (coarse)] were combined with five levels of barley silage [3, 6, 9, 12, and 15% of dietary dry matter (DM)]. The PI was determined as the weight of grain after processing expressed as a percentage of the weight before processing. Cattle were slaughtered after 104-109 d on feed, at a final weight of 576 kg, SEM = 5.1. There were very few interactions between grain processing and silage proportion for the variables measured. Grain processing had no effect (P>0.05) on average daily gain (1.59 kg d^-1, SEM = 0.057) or final weight. Feeding PI-87% barley tended to increase dry matter intake (DMI) over the experiment (7.63 vs. 7.34 kg d^-1, SEM = 0.123, P=0.10) compared with feeding PI-82% barley. Higher DMI of cattle fed PI-87% barley corresponded to lower estimated starch digestibility, as a result of increased appearance of whole kernels and grain fragments in feces. Consequently, gain:feed ratio tended (0.210 vs. 0.219, SEM = 0.0035, P=0.06) to decrease by 4% with PI-87% versus PI-82% barley. Similarly, silage proportion had no effect on gain but DMI increased (P=0.05) linearly from 7.19 to 7.75 kg d^-1 (SEM = 0.194) with increasing proportion of silage. Consequently, gain:feed ratio decreased linearly from 0.225 to 0.202 (SEM = 0.0056) with increasing silage proportion. Optimum proportion of barley silage to maximize feed conversion efficiency was 3 to 6% of DM. Decreasing the extent of barley processing or increasing the silage proportion may reduce the risk of acidosis, but feed conversion efficiency is lowered. Formulating diets to reduce the incidence of digestive disorders may decrease the cost of mortalities and treatment of sick animals, thereby improving animal health and welfare, but these costs are unlikely to offset the increased cost of gain in commercial feedlots.

Van De Weyer, L. M. and Waldner, C. L. 2011. Geographic determinants of copper and molybdenum concentrations in serum at the end of the grazing season and associations with reproductive performance in beef cows from western Canada. Can. J. Anim. Sci. 91: 423-431. Serum concentrations of Cu and Mo were measured at the end of the summer grazing season in an observational field study of 783 breeding females from 66 cow-calf herds located in western Canada. The mean Cu concentration was 0.82 ppm (S, 0.30 ppm) and the mean Mo concentration was 0.056 ppm (S, 0.055 ppm). Serum Cu concentration differed across ecoregions (P=0.013). Serum Mo concentrations varied by ecoregion (P =0.002), soil type (P =0.011), soil color (P=0.018), and total precipitation during the growing season (P =0.004). Copper and Mo serum concentrations at the end of the grazing season were not associated with reproductive outcomes. Herd location is an important determinant of the risk of primary and secondary Cu deficiency and can inform the need for trace mineral testing of feed samples as well as supplementation.

Castro-Montoya, J. M., Makkar, H. P. S. and Becker, K. 2011. Chemical composition of rumen microbial fraction and fermentation parameters as affected by tannins and saponins using an in vitro rumen fermentation system. Can. J. Anim. Sci. 91: 433-448. Post-rumen chemical composition of the microbial fraction is one of the factors that determines the nutrients absorbed and available for maintenance and production of the animal. The hypothesis was that tannins and saponins alter chemical composition of rumen microbes and fermentation parameters in the rumen. Purified quebracho, mimosa, chestnut and sumach tannins; and quillaja and gypsophilla saponins were incubated with 380 mg of substrate (hay:concentrate 70:30 wt/wt) for 24 h in an in vitro gas production system at concentrations from 0.25 to 1.25 mg mL^-1. Saponins increased N and reduced sugar contents of the liquid-associated microbes. The ratio of crude protein to purine bases significantly increased on adding sumach and chestnut tannins and decreased on the addition of quebracho and mimosa tannins. Quebracho, mimosa and chestnut tannins reduced total short-chain fatty acid production. The acetate:propionate ratio decreased for all additives. Results suggest that in vitro (a) depending on the source and the concentration, tannins would have an effect on the nitrogen and sugar contents of the liquid associated microbes, (b) saponins are likely to increase N and reduce sugar contents of rumen liquid associated microbes, and (c) estimation of microbial protein synthesis based on purine bases may lead to under- or over-estimations in the presence of tannins and saponins. In vivo studies are required to validate these results.

Su, R., Munns, K., Beauchemin, K. A., Schwartzkopf-Genswein, K., Jin-Quan, L., Topp, E. and Sharma, R. 2011. Effect of backgrounding and transition diets on fecal concentration and strain types of commensalEscherichia coliin beef cattle. Can. J. Anim. Sci. 91: 449-458. The aim of the study was to assess the effect of four different backgrounding diets [55% corn silage in combination with 40% of either temper rolled barley-grain, wheat dried distillers' grain, corn dried distillers' grain or millrun (dry matter basis)] and a transition diet containing increasing amount of concentrate (60 to 90%) on fecal Escherichia coli in feedlot heifers. Heifers were fed backgrounding forage based diets for 91 d and then were shifted to a transition diet for an additional 18 d. Strain characterization of E. coli (n=224) was carried out at time time points over 109 d and indicated that heifers fed the barley-grain diet shed higher (P<0.001) total and tetracycline-resistant (Tet^r) E. coli in the backgrounding phase. Of the total E. coli examined (n=224), 70.3% showed resistance to one or more of the 14 antimicrobials examined, which increased to 82.3% by day 109. Among the recovered E. coli, 23 phenotypes and 154 pulsed field gel electrophoresis patterns grouped into 38 clusters indicative of extensive E. coli diversity in heifers. Although supplementation of 40% barley-grain was correlated to higher total E. coli shedding in the backgrounding phase, the backgrounding diets did not influence strain clustering. Strains collected during the transition phase clustered more closely than those collected during the backgrounding phase. This increased strain clustering with high concentrate inclusion in the transition diet was observed within 18 d of the transition phase. Our study indicated variations in E. coli shedding rates and strain clustering in relation to time and diet.

Sheppard, S. C., Bittman, S., Swift, M. L., Beaulieu, M. and Sheppard, M. I. 2011. Ecoregion and farm size differences in dairy feed and manure nitrogen management: A survey. Can. J. Anim. Sci. 91: 459-473. This paper describes the activity of dairy farmers in Canada in 2005 related to the use of nitrogen (N) and especially practices that led to loss of ammonia (NH₃). The data were obtained from a large-scale, statistically structured survey conducted across Canada. The survey sampling was stratified into 10 Ecoregions and across farm size. Numbers of lactating cows per farm were nearly twofold more in the west than the east. In western Canada less than 31% of barns were “tie-stall” type whereas 80% were tie-stall in the St. Lawrence Lowlands. The numbers of hours lactating cows spent in barns, standing yards, exercise fields and pasture varied with Ecoregion and farm size, important data in relation to NH₃ emissions. Pasturing was more common in the east than west. Matching feed crude protein concentrations to physiological needs seems a potential best management practice, and smaller farms with tie-stalls seemed more prone to adjusting feed to individual cows compared with large farms with loose housing. Manure handling was divided, with slurry prominent especially in the west. Manure spreading practices also varied by Ecoregion. Overall, it is clear that national averages do not well represent dairy farm management: Ecoregion and farm size differences are significant.