Valente, T. N. P., Detmann, E. and Sampaio, C. B. 2015. Review: Recent advances in evaluation of bags made from different textiles used in situ ruminal degradation. Can. J. Anim. Sci. 95: 493-498. Textile bags are used in the laboratory to analyze the indigestible contents (internal markers) of feedstuffs after in situ ruminal incubation. Information is needed on the rate and extent of degradation in the rumen using bags made from different materials. In situ techniques have been used extensively to measure the degradation of feedstuffs in the rumen. However, in situ techniques are prone to variability. This paper reviews the effects of particle size, the material from which bags are made, pore size, tensile strength of the bags, in situ estimation of the levels of indigestible compounds [indigestible dry matter (iDM), indigestible neutral detergent fiber (iNDF), and indigestible acid detergent fiber (iADF)], rumen degradation profiles, and the use of bags made from nylon (50 µm), F57 (Ankom^*), and non-woven textile (100 g m^-2).

Thompson, D., Wheatley, B. J., Church, J. S., Newman, R. and Walker, J. 2015. Comparing grazing and resting electivity of beef cattle for BC bunchgrass communities using GPS collars. Can. J. Anim. Sci. 95: 499-507. Grasslands in the interior of British Columbia often contain a mosaic of plant communities that provide variable habitat for free-ranging cattle. Global positioning system (GPS) collars have been used to study natural habitat use by cattle on a coarse scale (such as riparian, grassland and forested habitats), but not on a fine scale (such as choice among grassland plant communities). Cows equipped with GPS collars were tracked during the spring grazing period for 4 yr. Six grassland pastures were used as replicates. The activity (grazing or resting) of cattle at GPS locations was classified using a distance travelled algorithm. A detailed plant community map of five plant community types was constructed, and cow relative use within the plant communities was determined. Electivity, which scales for differences in community area, was used to compare the use of plant communities. While grazing, electivity for the Kentucky bluegrass community (mean 0.3) was greater than for the bluebunch wheatgrass community (mean -0.2). While resting, these differences were more pronounced. GPS collars can be used to estimate fine-scale choices among grassland communities.

Roy, R. C., Cockram, M. S. and Dohoo, I. R. 2015. Welfare of horses transported to slaughter in Canada: Assessment of welfare and journey risk factors affecting welfare. Can. J. Anim. Sci. 95: 509-522. There is concern over the welfare of horses transported from the USA for slaughter in Canada. This study provides information on welfare issues associated with the transport of 3940 horses from 150 loads to a slaughter plant in Canada. Multivariable regression analyses were used to examine the association between journey characteristics and welfare outcomes. Injuries are considered in an accompanying paper. Five percent of the horses arrived from within Canada (median journey duration=12 h), and 95% arrived from five states in the USA (median journey durations 15-36 h). Seven percent of horses from Canada and 1% of horses from the USA arrived with pre-existing conditions. Five percent of the horses had a body condition score <3 (scale 1-5) and <1% were lame. Six horses from the USA (0.16%) arrived in a non-ambulatory condition. A linear mixed model showed that plasma total protein concentration increased with journey duration (P<0.001). No pre-transport measurements were possible and lairage and slaughter may have affected some of the results. Fewer severe welfare problems were identified than in similar studies conducted previously in the USA. However, multivariable analyses suggested that long journeys were associated with an increased risk of dehydration.

Roy, R. C., Cockram, M. S., Dohoo, I. R. and Riley, C. B. 2015. Injuries in horses transported to slaughter in Canada. Can. J. Anim. Sci. 95: 523-531. Horses transported in groups on long journeys to slaughter are at risk of injury. Injuries can occur following trauma and aggression from other horses. This study quantified injuries in 3940 horses from 150 loads that arrived at a slaughter plant in Canada. Surface injuries were quantified using visual assessment. Digital thermography was used to detect areas of raised surface temperature. Carcasses were assessed for bruising. Multivariable regression analysis was used to examine the associations between journey characteristics and the risk of injury. There was a significant association between journey duration and the number of horses per load with surface injuries (P<0.001). In 100 horses from 40 loads studied in detail, 33% had surface injuries identified by visual assessment, 48% had areas of raised surface temperature identified by thermography and 72% had bruising identified by carcass assessment. The levels of agreement between identification of injury by thermography and that by identification of visible injuries and carcass bruising were low. Pre-transport assessments could not be performed and hence injuries could not be linked causally to the transport conditions alone. However, the detailed assessments of injury and the use of multivariable regression analysis showed that long journeys were associated with injuries.

Shepley, E., Vasseur, E., Bergeron, R., Villeneuve, A. and Lachance, S. 2015. Short Communication: Birdsfoot trefoil as a preventative treatment for gastrointestinal nematodes in pastured dairy heifers. Can. J. Anim. Sci. 95: 533-537. Bioactive forages, such as birdsfoot trefoil, may serve as an alternative to anthelmintic drugs in pastured dairy heifers. Differences in parasite burden and growth were examined between eight treatment heifers fed a birdsfoot trefoil mixture and nine control heifer fed alfalfa silage 45-min per day for 12 wk. A significant 3.8- to 9.4-fold reduction in fecal egg counts was observed for treatment heifers at weeks 5, 9, 11 and 12. No treatment effect was found for weight gain. Our results suggest that birdsfoot trefoil may reduce parasite fecal egg counts in pastured dairy heifers without detrimental impact on growth.

Kaufman, J., Linington, M., Osborne, V. R., Wagner-Riddle, C. and Wright, T. C. 2015. Short Communication: Field study of air ammonia concentrations in Ontario dairy calf housing microenvironments. Can. J. Anim. Sci. 95: 539-542. The objective of this study was to measure the ammonia concentrations in the microenvironment of the calf housing area on a sample of commercial dairies in Ontario under typical management conditions. Two approaches were used to measure ammonia concentrations: (1) weekly on four farms for a period of 8 wk and (2) one-time samples were taken from the calf areas on 15 other farms. The results indicated that ammonia levels are managed below the existing maximum threshold provided in the national dairy code of practice.

Kuchta-Gladysz, M., Wójcik, E., Szeleszczuk, O., Niedbala, P. and Tyblewska, K. 2015. Spontaneous sister chromatid exchange in mitotic chromosomes of the chinchilla (Chinchilla lanigera). Can. J. Anim. Sci. 95: 543-550. The sister chromatid exchange (SCE) test is a cytogenetic tool with applications as a short-term screen. It is used to assess the influence of physical and chemical factors with potential mutagenic and genotoxic properties on the animal organism. The test results make it possible to eliminate mutagens, as well as helping to predict possible genetic consequences in animal cells and assess animal resistance. The mitotic chromosomes were obtained from an in vitro culture of peripheral blood lymphocytes with added bromodeoxyuridine (BrdU), at five different concentrations: 0.25, 0.5, 1.0, 2.5, and 5.0 µg mL^-1. The chromosomes were stained according to the FPG method. Our analyses revealed the spontaneous SCE level in the chinchilla at the concentration of 0.5 µg mL^-1. Higher concentrations of this substance have a genotoxic effect and cause damage to the DNA structure of the chromosomes by inducing additional SCEs in the chromosomes of this species. The mean SCE/cell incidence in the chinchilla population was 4.34±1.28. We investigated the effects of age on the incidence of SCE and found it significantly affected this phenomenon in both sexes.

Zhang, J., Shao, S.-y., Li, L.-z., Liu, D. and Yang, X.-q. 2015. Molecular cloning and characterization of porcine interferon-induced protein with tetratricopeptide repeats (IFIT) 5. Can. J. Anim. Sci. 95: 551-556. Interferon-induced protein with tetratricopeptide repeats (IFIT) family members play important roles in host defense against viral infection. In the present study, the complete coding sequence (CDS) of porcine IFIT5 gene was cloned using molecular biology techniques, and the genomic structure was determined using the bioinformatic method. The porcine IFIT5 is located on chromosome 14 containing 2 exons. Quantitative real-time PCR revealed that the transcripts of IFIT5 gene were unevenly distributed in all tissues studied, including heart, bladder, liver, large intestine, spleen, small intestine, lung, kidney, stomach, muscle, and lymph. Only one synonymous single nucleotide polymorphism was found in the complete CDS except for the first five nucleotides. IFIT5 is induced by poly(I:C) in a dose- and time-dependent manner, as revealed by using dual-luciferase analysis and reverse transcription-quantitative PCR methods. Furthermore, ectopic expression of porcine IFIT5 had no effect on the activation of interferon regulatory factor 3 (IRF3) significantly (P>0.05), suggesting it might not be a regulator of IRF3 signaling pathway.

Grumpelt, B., Hoffer, W., Curie, O., Jones, O., Jones, K., Kimmel, D., McDonald, B., Paterson, R. and Schaefer, A. 2015. Short Communication:The Pre-transport management of antemortem stress in cattle: Impact on carcass yield. Can. J. Anim. Sci. 95: 557-560. Transport and handling of cattle can have a significant impact on carcass weight loss. The purpose of the present study was to examine the effect of providing pre-transport nutritional therapy containing selective amino acids, electrolytes and an energy source, on carcass weight loss. One hundred and ninety British crossbred steers averaging 611 kg were used in the study. The treatment cattle received 1 kg of a nutritional supplement top dressed onto their normal silage diet 24 h prior to transport. Following a 1-h transport period the cattle were processed at a federally inspected beef plant and both hot and cold carcass yield as well as yield grade and quality grade were assessed. Cattle provided with pre-transport nutritional therapy demonstrated a reduction in percentage live weight loss (P<0.01) as well as 1.2% greater hot carcass yield as a proportion of pre-treatment farm weight (P<0.01). The data suggest the use of nutritional support pre-transport is beneficial to carcass yield.

Hossain, M. M., Begum, M., Nyachoti, C. M., Hancock, J. D. and Kim, I. H. 2015. Dietary fenugreek seed extract improves performance and reduces fecal E. coli counts and fecal gas emission in lactating sows and suckling piglets. Can. J. Anim. Sci. 95: 561-568. This study evaluated the efficacy of fenugreek seed extract (FSE) in sows and suckling piglets. The trial was conducted with 78 multiparous sows and their litters in a 28-d feeding trial, and one of three diets: CON (control, basal diet); FSE1 (basal diet 0.1% FSE), and FSE2 (basal diet 0.2% FSE). Piglets suckling sows fed the FSE1 and FSE2 diets had higher average daily gain compared with those suckling sows fed the CON from week 2 to weaning (linear, P<0.05). At weaning, sows fed the FSE1 and FSE2 diets had higher immunoglobulin G and lower low-density lipoprotein-cholesterol concentrations compared with those fed the CON diet (linear, P<0.05). Sows fed the FSE2 diet linearly reduced total cholesterol concentrations at weaning (P<0.05). Piglets suckling sows fed the FSE2 diet had higher immunoglobulin G and red blood cell concentrations compared with those suckling sows fed the CON diet (linear, P<0.05). Sows fed the FSE2 diet had higher apparent total tract digestibility of N and gross energy and reduced fecal E. coli counts and ammonia gas emission compared with those fed the CON diet at weaning (linear, P<0.05). In conclusion, results indicate that feeding sows a diet supplemented with FSE in late gestation and lactation improved performance in sows and suckling piglets.

Le Thanh, B. V., Lessard, M., Chorfi, Y. and Guay, F. 2015. Short Communication: Antioxidant capacity in the intestinal mucosa of weanling piglets fed diets containing Fusarium mycotoxins and the efficacy of commercial supplements sold as detoxifiers. Can. J. Anim. Sci. 95: 569-575. The ability of commercial feed additives to prevent oxidative damage due to deoxynivalenol (DON) in piglets was studied. Sixty piglets (6.0±0.5 kg) were assigned randomly to six wheat-corn-soybean diets: control (<0.5 mg kg^-1 DON), DON-rich diet (4 mg kg^-1 DON), and four DON-rich diets supplemented with either glucomannan (DON GLUC), yeast, live bacteria, enzymes and plant extract (DON YBP), aluminosilicate (DON ALS), or a mixture of preservatives (DON PV). Malondialdehyde concentration (MDA), glutathione peroxidase activity (GPx), catalase activity (CAT) and superoxide dismutase activity (SOD) in the small intestine were measured after 14 d. The DON-rich diet increased MDA in the jejunum while decreasing CAT in the jejunum and SOD in the ileum and increasing GPx in the ileum (P<0.05). The DON GLUC diet decreased GPx and SOD (P<0.05) and tended to decrease MDA in the jejunum (P<0.10). The DON YBP, DON PV and DON ALS diets all decreased CAT in the jejunum, while DON YBP and DON PV also did so in the ileum (P<0.05). DON GLUC decreased SOD in the jejunum, while DON YBP increased it (P<0.05). In the ileum, DON PV decreased SOD, while DON ALS increased GPx (P<0.05). No significant differences in total antioxidant capacity (TAC) in intestinal tissues were found. This study demonstrates that the mycotoxin DON and anti-mycotoxin additives modify oxidative status, including the antioxidant enzyme activities (CAT, SOD or GPx) in the intestinal mucosa of piglets. However, it was not possible to identify a specific antioxidant enzyme involved in counteracting the effect of DON.

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.

Stanford, K., Gibb, D. J., Schwartzkopf-Genswein, K. S., Van Herk, F. and McAllister, T. A. 2015. Feeding subtherapeutic antimicrobials to low-risk cattle does not confer consistent performance benefits. Can. J. Anim. Sci. 95: 589-597. Two-hundred and forty steers were obtained from the same ranch in each of 2 yr. Growth performance, health status and carcass characteristics from steers fed subtherapeutic antimicrobials were compared with those of control steers without antimicrobial metaphylaxis. Experimental groups included Control, not fed antimicrobials; CTCS-700, fed 350 mg head^-1 d^-1 chlortetracycline (CTC) and 350 mg head^-1 d^-1 sulfamethazine; CTC-11, fed 11 mg kg^-1 CTC; TYL, fed 11 mg kg^-1 tylosin phosphate; and CTC-350, fed 350 mg head^-1 d^-1 CTC. Steers were housed in pens of 10 steers and fed antimicrobials during both backgrounding and finishing periods. The incidence of bovine respiratory disease, pinkeye and bloat did not differ among experimental groups, although the incidence of foot rot was lower in Control steers (P<0.05) than in steers receiving TYL. In both years of the study, overall performance (backgrounding finishing) was not improved by subtherapeutic antimicrobials. Similarly, carcass characteristics and the incidence and severity of liver abscesses were not improved compared with Control steers by feeding subtherapeutic antimicrobials. The results of the present study demonstrate that low-risk steers may be managed in small pens with equivalent growth performance, carcass characteristics and health status to steers fed subtherapeutic antimicrobials.

Nair, J., Penner, G. B., Yu, P., Lardner, H. A., McAllister, T., Damiran, D. and McKinnon, J. J. 2015. Evaluation of canola meal derived from Brassica juncea and Brassica napus seed as an energy source for feedlot steers. Can. J. Anim. Sci. 95: 599-607. This study evaluated the substitution of barley grain with two sources of canola meal (CM) derived from Brassica napus and B. juncea on performance of feedlot cattle. Crossbred steers [n=300; initial body weight (BW)=311±23 kg] were allotted to 25 pens with each pen randomly assigned to one of five treatments. The control backgrounding diet consisted of 39% barley silage, 30.4% barley grain, 22.8% brome hay and 7.8% supplement, while the control finishing diet consisted of 88.3% barley grain, 4.4% barley silage and 7.3% supplement (dry matter basis). The control diets contained no CM during backgrounding and finishing. Treatment diets included 15 and 30% B. napus or B. juncea meal during backgrounding and 10 and 20% during finishing, with canola meal replacing barley grain in both phases. In each phase the data were analyzed as a 2×2 factorial plus a control. Cattle fed CM substituted diets during backgrounding had greater (P<0.05) dry matter intake (DMI), average daily gain (ADG) and final BW relative to those fed the control diet. Gain to feed ratio (G:F) and calculated net energy for maintenance (NE_m) and gain (NE_g) were not affected (P>0.05) by treatment. During finishing, DMI and ADG did not differ (P>0.05) across treatments. Feed efficiency, NE_m and NE_g decreased (P<0.05) at the 20% CM level relative to 10%. Over the entire feeding period, G:F, NE_m and NE_g were reduced (P<0.05) with higher inclusion of CM in the diet. The percentage of cattle grading Canada AAA was reduced (P<0.05) by CM. These results indicate that regardless of type CM has a lower net energy value than barley grain and that it is not an equivalent energy substitute for cereal grains over the entire feeding period.

Rodríguez-Gaxiola, M. A., Domínguez-Vara, I. A., Barajas-Cruz, R., Mariezcurrema-Berasain, M. A., Bórquez-Gastelum, J. L. and Cervantes-Pacheco, B. J. 2015. Effects of zilpaterol hydrochloride and zinc methionine on growth performance and carcass characteristics of beef bulls. Can. J. Anim. Sci. 95: 609-615. Sixty beef bulls with a body weight (BW) of 314.7±16.2 kg were used to evaluate the effects of zilpaterol hydrochloride (ZH) and zinc methionine (ZM) on growth performance and carcass characteristics. The experimental design was a randomized complete block, with a factorial 2×2 arrangement of treatments (ZH: 0 and 0.15 mg kg^-1 BW; ZM: 0 and 80 mg kg^-1 dry matter). The ZH increased (P<0.05) the final BW, average daily gain, feed conversion, carcass yield and longissimus dorsi area. Bulls fed ZH plus ZM had less (P<0.01) backfat thickness and intramuscular fat (IMF) compared with those fed ZH or ZM alone. The ZH increased (P<0.02) the meat crude protein content and cooking loss. It is therefore concluded that ZH increases growth performance, carcass yield, longissimus dorsi area, and meat crude protein. The interaction of ZM and ZH did not present additional advantages. The reason for the reduction in backfat thickness and IMF by ZH plus ZM is unclear, and implies that our knowledge of ß-agonistic adrenergic substances and their interactions with minerals is incomplete.

Lima, L. S., Oliveira, R. L., Garcez Neto, A. F., Bagaldo, A. R., Abreu, C. L., Silva, T. M., Carvalho, S. T. and Bezerra, L. R. 2015. Licuri oil supplements for lactating cows on pasture. Can. J. Anim. Sci. 95: 617-624. As licuri [Syagrus coronata (Martius) Beccari] oil can be a beneficial energy source in the diet of lactating cows managed on pasture, this study aimed to determine the most effective level of licuri oil in feed supplements. Sixteen Holstein×Zebu crossbreed lactating cows grazing on Tanzania (Panicum maximum) pasture grass were grouped into two 4×4 simultaneous Latin squares; there were four experimental periods of 21 d each, with 17 adaptation days and 4 d of data collection. The treatments were diets containing 0.0, 15.0, 30.0 or 45.0 g kg^-1 of licuri oil in concentrated dry matter. The intakes of dry matter, crude protein and non-fiber carbohydrate levels were not affected by the addition of licuri oil; however, the intake of neutral detergent fiber and total digestible nutrients decreased linearly. Neutral detergent fiber digestibility was reduced linearly with increasing levels of licuri oil in the concentrate. There were no changes in blood glucose levels, but blood urea nitrogen levels varied according to the time of the day when the blood was collected. Inclusion of licuri oil at 45.0 g kg^-1 in feed concentrates results in improved dry matter and ether extract digestibility.

Saunders, C. S., Yang, S. Y., Eun, J.-S., Feuz, D. M. and ZoBell, D. R. 2015. Feeding a brown midrib corn silage-based diet to growing beef steers improves growth performance and economic returns. Can. J. Anim. Sci. 95: 625-631. A feedlot experiment was performed to determine growth performance, ruminal fermentation characteristics, and economic returns for growing beef steers when fed a brown midrib corn silage-based total mixed ration (BMRT) compared with a conventional corn silage-based total mixed ration (CCST). Twenty-four Angus crossbred steers (initial body weight=258±23.2 kg) in individual pens were used in a completely randomized design (n=12). Intake of dry matter was not different between the treatments. Steers fed the BMRT tended to have greater average daily gain (1.54 vs. 1.42 kg d^-1; P=0.09) and gain-to-feed ratio (0.165 vs. 0.146; P=0.07) compared with those fed the CCST. Feeding the BMRT increased total volatile fatty acid (VFA) concentration (P=0.01) compared with the CCST, while it decreased molar proportion of acetate (P<0.01), and increased propionate proportion (P=0.01), resulting in decreased acetate-to-propionate ratio compared with the CCST (P<0.01). Steers fed the BMRT increased feed margin (P=0.05) and net return (P=0.02) compared with those fed the CCST throughout the trial. Overall results of this study indicate that feeding the BMRT to growing beef steers enhanced ruminal fermentation and beneficially shifted VFA profiles, which contributed to improved growth and economic performance of steers.