Awda, B. J., Miller, S. P., Montanholi, Y. R., Vander Voort, G., Caldwell, T., Buhr, M. M. and Swanson, K. C. 2013. The relationship between feed efficiency traits and fertility in young beef bulls. Can. J. Anim. Sci. 93: 185-192. Great efforts have been taken in recent years for improving feed efficiency in beef cattle. Despite there being several studies on biological factors associated with this trait, little is known about the potential relationships between fertility and feed efficiency in beef cattle. The objective of this study was to examine the relationship between feed efficiency traits and bull fertility traits [sperm motility, viability and scrotal circumference (SC)]. From a total of 328 crossbred beef bulls that were subjected to a performance test (112 d in each of 6 yr), SC was measured and semen collected from 110 bulls using the electroejaculation method (average age±SE=417±2.5 d). Sperm were extended, cooled, and frozen in liquid nitrogen. Two residual feed intake (RFI) measures were considered with different prediction models for dry matter intake (DMI), RFI_Koch included size and growth rate and RFI_bkft included the additional adjustment for backfat thickness (BKFT). Sperm viability, motility and progressive motility of the 10 bulls with the greatest RFI_Koch (Hi-RFI_Koch) were greater than those of the 10 bulls with the lowest RFI_Koch (Lo-RFI_Koch; P<0.05, 0.01, and 0.05, respectively). Sperm motility (P<0.01), progressive motility and SC (P<0.05) of the 10 bulls with the greatest RFI_bkft (Hi-RFI_bkft) were greater than those of the 10 bulls with the lowest RFI_bkft (Lo-RFI_bkft). In summary, these data indicate that young beef bulls with greater feed efficiency have decreased sperm motility, sperm viability and SC, which is an undesirable effect of selection for improved feed efficiency that needs to be addressed through multiple trait selection.

Vinsky, M., Islam, K., Chen, L. and Li, C. 2013. Short Communication: Association analyses of a single nucleotide polymorphism in the promoter of OLR1 with growth, feed efficiency, fat deposition, and carcass merit traits in hybrid, Angus and Charolais beef cattle. Can. J. Anim. Sci. 93: 193-197. A single nucleotide polymorphism (SNP) in the promoter region of oxidized low density lipoprotein (lectin-like) receptor 1 (OLR1) (c. -495 T>C) was identified and analyzed for associations with 10 traits related to growth, feed efficiency, body fat deposition and carcass merit traits in hybrid (n=456), Angus (n=567) and Charolais (n=423) beef cattle populations. Significant allele substitution effect (P=0.023) was found for residual feed intake (RFI) in the Angus population. The allele “C”, which had a frequency of 0.24 in the Angus population, was associated with decreased RFI. The Angus steers with the “CC” genotype had a lower RFI value (i.e., more efficient) than the Angus steers carrying the ‘TT’ genotype. The SNP was also found to have significant dominance effects on final ultrasound rib-eye area (FUREA) (P=0.0004) and carcass rib-eye area (CREA) (P=0.009) in the Angus steer population. The Angus steers with the “CT” genotype had smaller rib-eye areas of both ultrasound and carcass measures than the average of the steers with the homozygous genotypes. However, the SNP did not show significant associations with the traits examined in either the hybrid or the Charolais steer population at P<0.05. OLR1 plays a role in lipid metabolism, and analyses of transcript binding site based on the transcription element search system revealed that the “T” allele of the c.-495T>C SNP introduces a presumptive binding site for CCAAT/enhancer binding protein alpha (C/EBPa). However, further investigation is required to delineate the possible regulatory role of the SNP on growth and efficiency of energy utilization in relation to different biological types of beef cattle.

McEvers, T. J., Dorin, L. C., Berg, J. L., Royan, G. F., Hutcheson, J. P., Appleyard, G. D., Brown M. S. and Lawrence, T. E. 2013. Effect of leptin genotype and zilpaterol hydrochloride supplementation on the growth rate and carcass characteristics of finishing steers. Can. J. Anim. Sci. 93: 199-204. Steers (n=960; initial body weight=480.2±35.3 kg) were initially selected by leptin genotype (LG; CC=homozygous normal, CT=heterozygous, and TT=homozygous mutant) from a pool of 1500 candidates, and allocated into 48 pens of which one-half were fed zilpaterol hydrochloride (ZH) for 20 d with a 4-d withdrawal and the balance a control ration. No LG×ZH interaction (P≥0.21) occurred for any measured live production or carcass trait. Cattle of the TT genotype tended (P=0.08) to have lower average daily gain (ADG) and gain to feed ratio (G:F) during the pre ZH treatment period. Cattle fed ZH had greater (P<0.01) ADG and G:F than cattle not fed ZH. Cattle of the TT genotype had greater (P<0.01) lipid depots concomitant with reduced (P≤0.02) lean tissue as compared to cattle of the CC genotype; furthermore, TT cattle tended (P=0.07) to have lighter carcass weights than other genotypes. Cattle fed ZH had increased (P<0.01) hot carcass weight and lean tissue concomitant with decreased (P≤0.01) lipid depots. Commercially available leptin genotyping may allow for antemortem sorting of cattle by genotype, which could augment management strategies ultimately leading to adjustments in feeding duration and timeliness of carcass marketing.

Campbell, C. P., Haley, J., Swanson, K. C. and Mandell, I. B. 2013. Packing plant differences in meat quality for grain-fed veal. Can. J. Anim. Sci. 93: 205-215. Packing plant differences in meat quality were investigated in grain-fed veal from three commercial packing plants and a university research facility. Postmortem chilling rates were investigated in three plants including facilities which encased carcass sides in a polyliner bag intended to reduce shrinkage during chilling. Packing plant differences (P ≤ 0.01) in chilling rates were not always accompanied by plant differences in sarcomere length for longissimus or semitendinosus muscles. Drip and cooking losses and shear force for longissimus varied (P≤0.04) across packing plant with lower (P≤0.02) values found in veal slaughtered at the university research facility vs. veal from commercial packing plants. A packing plant by postmortem ageing interaction (P<0.05) for shear force was due to differences in extent of postmortem tenderization with ageing across packing plants. While use of a polyliner to encase the carcass during chilling decreased (P<0.001) rate of chilling and carcass shrinkage, there was no effect (P>0.20) on drip loss, shear force, or cooking losses vs. carcasses chilled uncovered.

Mason, M., Cuadra, E. J., Elsasser, T. H., Lopez, J. and Yoonsung, J. 2013. Evaluating the interaction between progesterone, tumor necrosis factor-alpha and cortisol on early loss of transferred embryo in beef cows. Can. J. Anim. Sci. 93: 217-225. Fifty-eight non-lactating cows previously synchronized for estrus were assigned to two treatments to assess the effects of progesterone supplementation and its correlation with tumor necrosis factor-a (TNF-a) and cortisol on the survival of the transferred embryos. On day 7 after exhibiting estrus (day 0), cows in both groups received embryos. In contrast with the control group, animals in the CIDR-group had a controlled internal drug release (CIDR) additionally inserted. Blood samples for progesterone, TNF-a and cortisol analysis were taken immediately before insertion and removal of CIDRs and 7 d after insertion. Progesterone did not differ between the control and the CIDR animals at any day of the study; however, it significantly increased at 7 and 14 d after insertion of the embryos in the control animals, compared with the levels observed in that same experimental group at the time of the transfer. Regardless of the treatment, all pregnant cows experienced a significant increase in progesterone from day 0 to day 7. Progesterone on day 0 was correlated to itself (r=0.46) on day 14 and to TNF-a (r=-0.37) on day 0 in pregnant animals; TNF-a on day 7 was significantly higher in pregnant cows compared with non-pregnant and correlated between day 0 and day 14. These results suggest that high levels of progesterone during the first 14 d after the transfer are indicative of the survival of transferred embryos. Additionally, these data also indicate that the decrease in TNF-a concentration on day 7 after the transfer of embryos may be associated with the low concentrations of progesterone observed in the non-pregnant animals.

Loisel, F., Quesnel, H. and Farmer, C. 2013. Short Communication: Effect of silymarin (Silybum marianum) treatment on prolactin concentrations in cyclic sows. Can. J. Anim. Sci. 93: 227-230. An extract (silymarin) from the plant Silybum marianum (milk thistle) was shown to increase circulating concentrations of prolactin in cycling rats. A dose-response study was undertaken to determine if silymarin does have hyperprolactinemic properties in cycling swine. Forty-four weaned sows were allotted to four groups receiving 0, 1, 2 or 4 g d^-1 of silymarin over a period of 8 d. Blood samples were obtained on days 1 (first day of treatment starting 24 to 48 h after the onset of the standing estrus), 2, 3, and 9. Prolactin, progesterone, estradiol-17β and leptin concentrations were determined. Silymarin did not increase prolactin concentrations at any of the doses studied, nor did it affect concentrations of the other hormones (P>0.1).

Pozzo, L., Tarantola, M., Biasibetti, E., Capucchio, M. T., Pagella, M., Mellia, E., Bergagna, S., Gennero, M. S., Strazzullo, G. and Schiavone, A. 2013. Adverse effects in broiler chickens fed a high lycopene concentration supplemented diet. Can. J. Anim. Sci. 93: 231-241. The present investigation was designed to assess the effects of the administration of a high dietary lycopene dose to broiler chickens on growth and slaughter performances, haemato-biochemical parameters, antioxidant enzymes, histological lesions and lycopene accumulation in the tissues. Thirty-six 1-d-old male Hubbard broiler chicks were examined and divided randomly into two groups (three replicates for each dietary treatment): the Control group, which received a basal diet, and the Lycopene group, which received the basal diet supplemented with 500 mg lycopene kg^-1 diet. The experimental period lasted 35 d and growth performance was recorded on a weekly basis. At the end of the experiment (day 35), blood samples (n=12) were collected from the femoral vein. Erythrocyte and leukocyte numbers were assessed and the heterophil-to-lymphocyte ratio was determined. The alpha-1-acid glycoprotein, lysozyme, total protein and the electrophoretic patterns were evaluated in serum samples. Nine chickens per group were slaughtered to measure the carcass yields and the weight of the liver, spleen, bursa of Fabricius and thymus. Spleen, liver, and bursa of Fabricius samples were collected for histological examination and fixed in 10% neutral buffered formalin. The lycopene concentration, thiobarbituric acid reactive substances (TBARS) and chemical composition were assayed in breast meat and thigh samples. The TBARS, glutathione content, catalase and superoxide dismutase activity were measured in liver and kidney samples. The high lycopene concentration supplemented diet did not affect the birds' growth, slaughter performance or antioxidant enzymes in the breast meat, thigh meat, liver and kidney samples. The concentrations of lycopene in the breast and thigh of the lycopene-supplemented group were 0.10±0.05 mg kg^-1 and 0.42±0.35 mg kg^-1, respectively, while no lycopene was found in the Control group. Spleen and bursa of Fabricius of birds fed a diet supplemented with a high level of lycopene showed weight decrease (P<0.05) and degenerative lesions (P<0.05). Moreover, lycopene supplementation reduced the serum protein concentration, albumin, alpha and the gamma globulin serum concentration (P<0.05).

Lu, H., Adedokun, S. A., Preynat, A., Legrand-Defretin, V., Geraert, P. A., Adeola, O. and Ajuwon, K. M. 2013. Impact of exogenous carbohydrases and phytase on growth performance and nutrient digestibility in broilers. Can. J. Anim. Sci. 93: 243-249. The effect of supplementing corn-soybean-based diets with Rovabio^® Max AP, an exogenous enzyme mix with carbohydrase (xylanase and ß-glucanase) and phytase activities to broiler chickens was evaluated. Male Ross 708 broilers were assigned to four diets: positive control (PC), negative control (NC), deficient in metabolizable energy (ME), crude protein (CP), calcium (Ca) and non-phytate phosphorus (nPP), relative to the PC, by 100 kcal kg^-1, 5 g kg^-1, 1.1 g kg^-1 and 1.6 g kg^-1, respectively, in the starter and grower diets; and NC Rovabio^® at 0.05 or 0.075 g kg^-1 diet. Starter diets were fed from day 0 to day 21 and grower diets from day 22 to day 42. Body weight (BW) and body weight gain on days 22 and 42 were increased (P<0.05) by enzyme supplementation. Enzyme addition increased (P<0.05) feed intake from day 22 to day 42 and overall (day 0 to day 42). Gain to feed ratio (G:F) was significantly increased (P<0.05) with enzyme supplementation during both starter and grower phases. Enzyme addition increased (P<0.05) serum phosphorus (P) concentration on day 21. On day 42 enzyme supplementation increased (P<0.05) the apparent ileal digestibility of P, dry matter (DM), energy, and N. Addition of a combination of carbohydrases (xylanase and ß-glucanase) and phytase to corn-soybean-based diets deficient in ME, CP, Ca and P resulted in a significant increase in growth performance and utilization of P, DM, energy and N in broiler chickens.

Yang, W. Z., Oba, M. and McAllister, T. A. 2013. Quality and precision processing of barley grain affected intake and digestibility of dry matter in feedlot steers. Can. J. Anim. Sci. 93: 251–260. A study was conducted to determine the impact of barley quality and precision processing to account for the impact of variable kernel uniformity on ruminal pH and fermentation, and digestibility in the digestive tract of steers. Eight ruminally cannulated steers were used in a replicated 4×4 Latin square experiment. The four diets consisted of light-weight barley (LB) precision-processed with roller setting based on kernel size; heavy-weight barley (HB) precision-processed; LB and HB grain mixed equal parts then processed at a single roller setting (CON); or LB and HB precision-processed and mixed equal parts (PP). The diets consisted of 10% barley silage and 90% concentrate [dry matter (DM) basis]. Dry matter intake by steers fed LB was greater (P=0.04) than by steers fed HB. Intakes of DM and other nutrients were greater (P=0.04) for steers fed PP than for steers fed CON. There were no differences (P>0.14) in ruminal pH and fermentation among treatments. Digestibility of DM in the total digestive tract tended (P=0.06) to be less with LB than with HB. Precision processing increased digestibility of crude proteion (P=0.04) and acid detergent fibre (P=0.06) resulting in a trend (P=0.10) towards increasing organic matter digestibility as compared with CON. The results suggest that screening of blended barley into more uniform fractions and precision processing of each fraction could increase intake of digestible nutrients for feedlot cattle.

Schlau, N., Duineveld, L., Yang, W. Z., McAllister, T. A. and Oba, M. 2013. Precision processing barley grain did not affect productivity of lactating dairy cows. Can. J. Anim. Sci. 93: 261-268. This study evaluated the effects of precision processing (PP; processing based on kernel size) barley grain on ruminal fermentation and productivity of lactating dairy cows. Twenty multiparous Holstein cows, including eight ruminally cannulated cows, were used in a replicated 4×4 Latin square design with 21-d periods. Diets contained light barley grain processed precisely using a narrow roller setting (LB), heavy barley processed precisely using a wide roller setting (HB), processed HB and LB mixed at equal proportions (PP), or equal parts of light and heavy barley grain processed at a single narrow roller setting (CON). All diets consisted of 40% barley grain, 40% barley silage, and 20% of a supplement premix. Comparisons were made between LB and HB to evaluate the effect of barley quality, and between PP and CON to evaluate the effect of precision processing. Dry matter intake, sorting index, ruminal fermentation characteristics, and nutrient digestibility were not affected by diet. In addition, milk yield and concentrations of milk fat, protein, and lactose were not different, although milk urea nitrogen concentration was greater for PP vs. CON and for LB vs. HB. These results suggest that precision processing barley grain based on kernel size may not drastically affect ruminal fermentation and milk production in lactating dairy cows.

He, M. L., Gibb, D., McKinnon, J. J. and McAllister, T. A. 2013. Effect of high dietary levels of canola meal on growth performance, carcass quality and meat fatty acid profiles of feedlot cattle. Can. J. Anim. Sci. 93: 269-280. This study investigated the effect of substituting canola meal (CM) for barley grain on growth performance, carcass quality and meat fatty acid (FA) profiles of feedlot cattle. Cross bred calves (n=140; 285±27 kg) were individually fed diets comprised of a barley grain based concentrate (including 5% supplement) and barley silage at ratios of 45:55 and 92:8 (DM basis) during growing and finishing periods, respectively. Pressed CM from Brassica napus, containing 11.4% residual oil and solvent-extracted CM derived from B. napus or Brassica juncea canola seed were compared. Canola meal was substituted for 0 (control), 15, or 30% barley grain (DM basis) in both growing and finishing diets. Regardless of diet, cattle did not differ (P>0.05) in average daily gain in either the growing or finishing period. For the overall feeding period, inclusion of 30% CM increased (P<0.01) DMI of cattle compared with 15% CM groups, but reduced (P<0.05) gain: feed (G:F) as compared with control and 15% B. juncea and 15% pressed CM. Gain: feed of cattle fed CM was also reduced (P<0.05) during the finishing period as compared with the control diet with this reduction being more notable at the 30% level. Carcass quality and incidence of liver abscesses were not affected (P>0.05) by inclusion of CM. Inclusion of 30% pressed CM resulted in higher (P<0.05)�ME of total polyunsaturated fatty acid, n-3, alpha-linolenic acid and conjugated linoleic acid (CLA), and a decrease (P<0.05) in n-6/n-3 ratio in the pars costalis diaphragmatis muscle as compared with the control diet. In conclusion, inclusion of CM did not alter the growth performance or G:F of beef cattle during the growing period, but did lower G:F during the finishing period. The inclusion of 15 or 30% solvent-extracted CM did not alter carcass quality, whereas 30% pressed CM increased the levels of desirable fatty acids (i.e., n-3 and CLA) in beef.

Yang, W. Z., Xu, L., Li, C. and Beauchemin, K. A. 2012. Short Communication: Effects of supplemental canola meal and various types of distillers' grains on growth performance of backgrounded steers. Can. J. Anim. Sci. 93: 281-286. A growth study was conducted to investigate the effects of protein source on growth performance of backgrounded steers. Partly replacing barley grain with canola meal (CM), corn dried distillers' grains with solubles (cDDGS) or fractionated corn dried distillers grains with solubles (fDDGS) increased averaged daily gain and feed conversion efficiency of backgrounded steers. Steers fed corn DDGS (cDDGS, fDDGS) improved feed conversion efficiency compared with steers fed wheat dried distillers' grain with solubles (wDDGS). These results indicate that inclusion of protein ingredients in barley-based diets is necessary to improve growth performance of growing cattle. To maximize profits, the choice of protein source in cattle rations will depend upon availability and cost of ingredients.

Acosta, D. A. V., Pfeifer, L. F. M., Schmitt, E., Schneider, A., Silveira, P. A. S., Jacometo, C. B., Brauner, C. C., Rabassa, V. R., Corrêa, M. N. and Del Pino, F. A. B. 2013. Effect of prepartum somatotropin injection in late pregnant Holstein heifers with high body condition score on metabolic parameters, resumption of ovulation and milk production. Can. J. Anim. Sci. 93: 287-292. In the early post-partum period of dairy cows the duration and intensity of negative energy balance, the level of body condition score (BCS) loss and the milk yield are strongly associated with the timing of the first ovulation. The aim of this study was to determine the effect of pre-partum injections of somatotropin in dairy heifers with high BCS on the metabolism, resumption of ovarian activity and milk production. Holstein heifers (n=20) with high BCS, were divided randomly into two groups: somatotropin (n=10), which received two doses of somatotropin (500 mg) at -28 and -14 d from calving and Control (n=10), which received placebo. Blood samples were collected for evaluation of ß-hydroxybutyrate (BHBA) and non-esterified fatty acids (NEFA) concentrations. Follicular development was also monitored via ultrasound. Somatotropin had no effect on plasma NEFA (P=0.35 and P=0.46) or BHBA (P=0.20 and P=0.44,) concentrations in the pre-partum and post-partum period, respectively. Milk production was not different between control (17.53±0.66 kg cow^-1 d^-1) and somatotropin groups (16.13±0.67 kg cow^-1 d^-1) (P=0.14). Pre-partum somatotropin administration did not affect (P=0.28) the time of the first post-partum ovulation. The proportion of cows ovulating the first post-partum follicular wave was not different between groups (P=0.49). In conclusion, pre-partum somatotropin treatment in dairy heifers with high body condition score seems not to have any effect on markers of energy balance, milk production or development of the first follicular wave in the early post-partum period.