Burlinguette, N. A., Strawford, M. L., Watts, J. M., Classen, H. L., Shand, P. J. and Crowe, T. G. 2012. Broiler trailer thermal conditions during cold climate transport. Can. J. Anim. Sci. 92: 109-122. Thermal environments within broiler transport vehicles are dependent on ambient conditions and, if poorly managed, can be a welfare concern. To effectively manage broiler transport, the environmental conditions throughout vehicles must be understood. Under standard commercial practices, temperature and humidity levels in double-trailer broiler vehicles were examined for a range of ambient temperatures (-24 to 11°C). During warmer ambient conditions (9.8°C) trailer roof vents and side curtains were all open, which resulted in a narrowing of the on-board temperature range (10.3 to 16.7°C). As ambient temperature cooled side curtains and some of the roof vents were closed. This resulted in increasingly variable and more extreme thermal conditions, with heat and moisture accumulated along the midline of the load near the front of the lead trailer and near the back of the rear trailer. At an ambient temperature of -22.1°C trailer temperatures ranged from -20.7 to 21.7°C with an estimated 58.6% of the load volume being exposed to temperatures below 0°C. In addition, the trailer humidity ratio rose 14.0 g kg^-1 above ambient and conditions approached saturation (RH>80%) in 55.2% of the load volume. These results support the need to find a means to remove moisture and redistribute heat on broiler trailers during cold ambient conditions.

Steele, M. A., Greenwood, S. L., Croom, J. and McBride, B. W. 2012. An increase in dietary non-structural carbohydrates alters the structure and metabolism of the rumen epithelium in lambs. Can. J. Anim. Sci. 92: 123-130. This study investigated the effect of a grain challenge on the structure and metabolism of the rumen epithelium in lambs. In a randomized design, lambs (n = 8) received either a control diet [30% dry matter (DM) grain], or a diet of increasing amounts of grain to a maximum inclusion of 79% of DM for 12 d prior to slaughter. Rumen papillae were collected from the ventral sac on day 13 and prepared for histological and gene expression analyses. All lambs fed the high-grain diet were diagnosed with ruminal parakeratosis as the thickness of the corneum was higher (P<0.01) compared with control lambs (51.0±2.3 vs. 17.3±2.5 µm). Plasma beta-hydroxybutyric acid concentrations increased linearly (P<0.05) with increased grain consumption compared with the control. However, the relative mRNA expression of the ketogenic enzyme 3-hydroxy-3-methyl-glutaryl CoA-synthase (HMGCS2) in rumen papillae was not different between treatments. The expression of cholesterolgenic enzyme HMGCS1 was down-regulated by 0.70±0.06 (P<0.05) fold in lambs fed the high-grain diet compared with the control. These results suggest that a short-term grain challenge in lambs is associated with altered rumen epithelium metabolism and structural changes indicative of ruminal parakeratosis.

Meagher, R., Bechard, A., Palme, R., Díez-León, M., Hunter, D. B. and Mason, G. 2012. Decreased litter size in inactive female mink (Neovison vison): Mediating variables and implications for overall productivity. Can. J. Anim. Sci. 92: 131-141. Farmed mink vary dramatically in activity: very inactive individuals rarely leave the nest-box, while others spend hours active daily, often performing stereotypic behaviour (SB). SB typically correlates with increased reproductive output, and inactivity, with decreased output. Our objectives were to determine whether SB or inactivity best predicted litter size (LS), and to test three hypothesized reasons for inactive dams′ reduced LS: H1, excess fat; H2, chronic stress (potentially underlying inactivity because fear motivates hiding); and H3, health problems. We assessed time budgets pre-breeding, scored body condition visually, conducted health exams, and assessed stress using faecal cortisol metabolites (FCM) and "glove tests" for fear. Results did not support H2 and H3: inactive females were no more fearful than active females (P>0.10), they excreted lower levels of FCM (P=0.033), and were considered healthy. As predicted by H1, inactive females had higher body condition scores (P<0.0001), which predicted decreased LS (P=0.040). However, path analysis determined this was unlikely to mediate the inactivity-LS relationship. Compared with SB, inactivity more consistently predicted both LS (negatively, P ≤ 0.038) and kit weight (positively, P ≤ 0.037). Therefore, decreasing inactivity in farmed mink, rather than increasing their SB or decreasing their body condition should most improve productivity.

Li, G., Li, J., Tian, Y., Wang, DE., Shen, J., Tao, Z., Xu, J. and Lu, L. 2012. Sequence analysis of a putative goose RIG-I gene. Can. J. Anim. Sci. 92: 143-151. Retinoid acid-inducible gene-I (RIG-I) is a critical cytoplasmic RNA sensor which plays an important role in the recognition of, and response to, influenza virus and other RNA viruses. In the present study, A 3808-bp cDNA encoding goose RIG-I (goRIG-I) was cloned from splenic lymphocytes of geese using RT-PCR and rapid amplification of cDNA ends (RACE) techniques. The encoded protein, which is predicted to consist of 933 amino acids, has a molecular weight of 106.4 kDa and includes an N-terminal caspase recruitment domain (CARD), a domain with the signature of DExD/H box helicase (helicase domain), and a C-terminal repression domain (RD) similar to duck RIG-I (duRIG-I), human RIG-I, and mouse RIG-I. The goRIG-I showed 93.8 and 78.0% amino acid sequence identity with previously described duRIG-I and finch RIG-I, respectively, and 48.9-53.0% sequence identity with mammalian homologs. Quantitative RT-PCR analysis indicated that the goRIG-I gene is strongly expressed in the liver, lung, brain, spleen, and bursa of Fabricius. These findings lay the foundation for further research on the function and mechanism of avian RIG-I in innate immunity.

Msalya, G., Shimogiri, T., Okamoto, S., Kawabe, K. and Maeda, Y. 2012. Short Communication: The double deletion diplotype showed low levels of prion protein at two indel loci ofPRNPin the medulla oblongata of Japanese Brown cattle. Can. J. Anim. Sci. 92: 153-157. Transmissible spongiform encephalopathies (TSEs) are a class of fatal neurodegenerative diseases caused by abnormally folded prion proteins (PrP). The PrP is necessary for the transmission and propagation of TSE diseases. In this study, PrP was quantified in the medulla oblongata of 39 Japanese Brown (JBr) animals that were genotyped for two indels in the PRNP gene - a 23 bp deletion in the promoter region and a 12 bp deletion in the first intron. The mean level of PrP was greater in the / diplotype than in --/-- and -/ - diplotypes, although the differences were not significant. These results suggest that the amount of PrP in the medulla oblongata of animals is related to these indels. However, given that there have been no reported cases of BSE in Japanese Brown animals, the relationship of the indels and PrP levels with the incidence of BSE is unclear.

Cha, M. C. and Purslow, P. P. 2012. Expressions of matrix metalloproteinases and their inhibitor are modified by beta-adrenergic agonist Ractopamine in skeletal fibroblasts and myoblasts. Can. J. Anim. Sci. 92: 159-166. The beta-adrenergic agonist ractopamine is known to promote growth and improve feed efficiency in animal production, in part by suppressing muscle protein degradation. This investigation aims to determine whether ractopamine modifies the expression of enzymes principally involved in intramuscular connective tissue turnover, the matrix metalloproteinases (MMPs) and their inhibitors, in the principal cell types of skeletal muscle. Mouse skeletal muscle fibroblasts (NOR-10 cells) and myoblasts (C2C12 cells) were cultured with or without 2 or 10 µM ractopamine for 6 or 24 h. Cellular MMP-2 expression was increased (P<0.05) by ractopamine in both cell lines. Cellular MMP-3 expression was also increased in response to ractopamine in myoblasts (P<0.03). The amount of a tissue inhibitor of MMPs (TIMP-1) in cell lysates of both cell lines was increased (P<0.05) by the 6-h ractopamine treatment. The extracellular expression of MMP-2 and TIMP-1 was increased (P<0.05) in myoblasts, but not in fibroblasts. The elevated TIMP-1 expression in medium is in the order of three times higher (P<0.02) than the increased activity of MMP-2 expressed by myoblasts at 6 h. In summary, ractopamine treatment results in a higher cellular expression of MMP-2 and MMP-3 as compared with the expression of their inhibitor TIMP-1. However, the increased extracellular MMP-2 activity is counterbalanced by the increased presence of TIMP-1. The findings show that ractopamine has the potential to alter connective tissue turnover in treated animals.

Manunza, A., Zidi, A., Fernández-Cabanás, V. M., Jordana, J., Carrizosa, J., Belaifa, E., Urrutia, B., Polvillo, O., González-Redondo, P., Amills, M. and Serradilla, J. M. 2012. Short Communication: An association analysis between one missense polymorphism at theSREBF1gene and milk yield and composition traits in goats. Can. J. Anim. Sci. 92: 167-173. Sterol regulatory element binding transcription factor 1 (SREBF1) regulates the expression of genes involved in the biosynthesis of fatty acids and cholesterol. Herewith, we have sequenced the near-complete coding region and part of the 3'UTR of the goat SREBF1 gene. In doing so, we have detected a missense c.353C>T polymorphism causing a proline to leucine substitution at position 118 (P118L). An association analysis with milk composition traits recorded in Murciano-Granadina goats only revealed a statistical tendency linking SREBF1 genotype and milk omega-3 fatty acid content. The lack of significant associations suggests that the P118L substitution does not involve a functional change.

Girard, I., Aalhus, J. L., Basarab, J. A., Larsen, I. L. and Bruce, H. L. 2012. Modification of beef quality through steer age at slaughter, breed cross and growth promotants. Can. J. Anim. Sci. 92: 175-188. A 2³ factorial experiment tested the interactions of slaughter age (12-13 or 18-20 mo), growth implants use (Component E-S, TE-S), ractopamine hydrochloride (RAC) feed supplementation use and breed cross [Hereford-Aberdeen Angus (HAA) or Charolais-Red Angus (CRA)] on pH, temperature, objective colour measurements, relative myoglobin states, sarcomere lengths, shear force, and water losses of m. semitendinosus (ST) and m. gluteus medius (GM) from 112 crossbred steers. In the ST, age affected objective colour measurements by increasing chroma and decreasing lightness (L*) and hue angle (P<0.05). Metmyoglobin (MMB) content of the ST also increased with steer age (P<0.05). In the GM, yearling-fed steers had greater MMB content than calf-fed steers, while hue angle varied the opposite way (P<0.05). Other variations in meat colour and myoglobin contents were more complex in the GM than the ST as they involved three-way interactions between the different treatments. Shear force and purge loss of the ST increased with implantation (P<0.05) with no change in sarcomere length (P>0.05). Shear force standard deviation was similar for breed crosses when yearling-fed but greatest for CRA breed cross when calf-fed (P<0.05). In both muscles, purge loss was increased by RAC supplementation (P<0.05). RAC supplementation did not affect sarcomere length and shear force in both muscles (P>0.10). In the GM, shear force increased with age and with CRA genetics (P<0.05). Results indicated that producers seeking to reduce beef toughness should consider using British crossbreds, exclude the use of hormonal implants and slaughter process steers at 12 to13 mo of age.

Felton, C. A., Colazo, M. G., Ponce-Barajas, P., Bench, C. J. and Ambrose, D. J. 2012. Dairy cows continuously-housed in tie-stalls failed to manifest activity changes during estrus. Can. J. Anim. Sci. 92: 189-196. While pedometers are effective for estrus detection in free-stall herds, their efficacy in tie-stalls is not established. The objectives were to determine if pedometers equipped with a behavior tag for monitoring lying activity (AfiMilk Pedometer Plus Tag system) can accurately record cow activity, and if they can facilitate estrus detection in dairy cows continuously housed in tie-stalls. Nineteen lactating Holstein cows were subjected to estrus induction with prostaglandin F_2a, and 18 pregnant cows served as controls. Activity was monitored for 10 d using pedometers and 24-h video recording. Pedometer and video records were compared for 6 d surrounding estrus; stepping (rc=0.85; P<0.01), lying time (rc=0.94; P<0.01), and lying bouts (rc=0.89; P<0.01) were highly correlated. Progesterone concentrations confirmed that 17 of the 19 cows responded to estrus induction; 16 of those 17 cows ovulated. Changes in mean daily activity did not differ (P>0.05) between estrus-induced cows and controls, or in the estrus-induced cows in the 48 to 72 h preceding the day of ovulation. In conclusion, while the pedometers accurately recorded cow activity in lactating cows housed in tie-stalls, they could not facilitate estrus detection because cow activity did not significantly change during estrus.

Reveco, F. E. and Drew, M. D. 2012. Fractionation of wheat distillers' grains and solubles by particle size and density improves its digestible nutrient content in rainbow trout. Can. J. Anim. Sci. 92: 197-205. The nutritional value of wheat distillers' dried grains and solubles (WDDGS) in aquaculture is poor because of its relatively low crude protein (CP) and high fibre content. In this study WDDGS was fractionated using grinding, sieving and elutriation sequentially. The WDDGS was ground in a hammer mill using a 3-mm screen and sieved using six sieves (20M, 30T, 40T, 50T, 60M and 80M) into seven fractions (>841, 590-840, 426-589, 298-425, 251-297, 178-250 and<177 µm). Elutriation was then performed to further fractionate based on particle shape and density. The higher density sub-fractions from the three smallest particle size fractions were mixed to produce a fractionated WDDGS containing 20.7 MJ kg^-1 gross energy (GE), 454.6 g kg^-1 CP, 260.4 g kg^-1 neutral detergent fibre (NDF) and 93.2 g kg^-1 acid detergent fibre (ADF). The digestibility of the unprocessed and fractionated WWDGS products was assessed in rainbow trout. Apparent digestibility coefficient (ADC) of DM, GE, acid ether extract (AEE), ash and amino acids (AA) did not differ between the unprocessed material and the fractionated WDDGS (P>0.05). However, the ADC of CP was higher for fractionated WDDGS (0.88) than the unprocessed WDDGS (0.85) (P<0.05). This fractionation scheme can be used to improve the nutritional value of WDDGS for rainbow trout.

Kim, J. H., Jung, E. Y., Hong, Y. H., Bae, S. H., Kim, J. M., Noh, D. O., Nozaki, T., Inoue, T. and Suh, H. J. 2012. Short Communication: Pet foods with yeast hydrolysate can reduce body weight and increase girth in beagle dogs. Can. J. Anim. Sci. 92: 207-210. Beagle dogs fed pet foods that included yeast hydrolysate (YH) were used in the present study to assess the possible use of YH as a functional anti-obesity ingredient in pet food. The change in weight and girth in the YH groups was significantly (P<0.05) lower than that in the control. Plasma malondialdehyde was significantly (P<0.05) lower in the YH groups compared with that in the control. Plasma levels of the reduced form of glutathione were significantly (P<0.05) higher in the YH groups than those in the control. Therefore, YH could be recommended as an anti-obesity functional feed source for dogs.

Doepel, L., Montgomery, J. E., Beauchemin, K. A., King, J. R. and Acharya, S. N. 2012. Ruminal degradability and whole-tract digestibility of protein and fibre fractions in fenugreek haylage. Can. J. Anim. Sci. 92: 211-217. The purpose of this study was to evaluate the digestibility of fenugreek forage compared with alfalfa in dairy cows. Alfalfa and two genotypes of fenugreek, Quatro and F70, were harvested and prepared as plastic-wrapped high-moisture bales. Fourteen weeks after baling, forage samples were obtained for determination of ruminal degradation and whole-tract digestibility. To determine ruminal degradation, forage samples were placed in polyester bags and incubated in the rumen for various time points (up to 168 h) in lactating Holstein cows. Digestibility in the rumen, intestine and the whole digestive tract was estimated by incubating samples in the rumen, followed by measurements of intestinal digestibility using the mobile bag technique in two non-lactating Holstein cows. Effective ruminal degradability of DM was lower for F70 than for alfalfa, while for ADF and NDF it was equivalent in all forages. Whole-tract disappearance of DM, CP, ADF and NDF was lower for F70 than Quatro. In general, Quatro and alfalfa were similar in terms of ruminal degradation and digestion in the rumen, intestine and whole-tract, while F70 tended to be of lower quality.

Sun, P., Wang, J.-Q., Liu, Q.-S., Khas-Erdene and Yang, G. 2012. Short Communication: Effects of duodenal infusion of increasing amounts of αlinolenic acid on composition and susceptibility to peroxidation of blood lipids in lactating dairy cows. Can. J. Anim. Sci. 92: 219-223. Duodenal infusion of increasing amounts of αlinolenic acid (LNA) in dairy cows linearly decreased the percentages of 18:0, 18:2n-6 and saturated fatty acids (P<0.01), linearly and quadratically reduced 23:0 and 18:1 cis-9 (P<0.01), but linearly increased the content of 18:3 n-3 and PUFA (P<0.01) in blood plasma. As amount infused increased, concentrations of high-density lipoprotein cholesterol and total cholesterol increased quadratically and peaked at 139.9 mg dL^-1 and 182.0 mg dL^-1, respectively (P<0.01). No differences were observed in the activity of blood serum total superoxide dismutase and total antioxidant capacity, but the thiobarbituric acid reactive substances tended (P=0.07) to increase linearly. Duodenally infused increasing amounts of LNA altered the composition of fatty acids and distribution of lipids in blood, but did not affect the oxidative stability of the blood in dairy cows.