Santschi, D. E. and Lefebvre, D. M. 2014. Review: Practical concepts on short dry period management. Can. J. Anim. Sci. 94: 381-390. Increased production of dairy cows over the past years has triggered interest in reviewing optimal duration and management for the dry period. Results from recent studies suggest reduced early lactation negative energy balance, reduced ketosis, improved reproduction and no negative effects on production for multiparous cows. With regard to primiparous cows, production following lactation is reduced, but compensated for by the additional end of lactation milk. Reduced dry period length does not impair udder health, but is associated with increased risk of antibiotic residues in early lactation in the case of an early calving. Although the literature is scarce, calf health and immunity transfer are not affected by a short dry period. The objectives of the present review are to summarize results from recent trials and propose avenues for further research on short dry period management. Precise management conditions as well as specific cow characteristics for which short dry period results are optimized still need to be defined.

Wang, T., Wang, Z., Cao, J., Dong, Y. and Chen, Y. 2014. Monochromatic light affects the development of chick embryo liver via an anti-oxidation pathway involving melatonin and the melatonin receptor Mel1c. Can. J. Anim. Sci. 94: 391-400. Monochromatic light can influence muscle development during incubation and post-hatching. This process is related to IGF-1, which is primarily secreted by the liver. However, the effect of monochromatic light on liver development of chick embryo is unclear. In this study, 600 Arbor Acres fertile broiler eggs were randomly assigned to four incubators and exposed to continuous red light (R-group), green light (G-group), blue light (B-group), or a dark environment (D-group, control). The liver index of the G-group was higher than that of other groups (6.47-15.46%) at E21, accompanied by a higher percentage of proliferating cell nuclear antigen (PCNA). The superoxide dismutase (T-SOD), glutathione peroxidase (GSH-PX), and total antioxidant capability (T-AOC) contents were the highest in the G-group, and this trend was positively correlated with plasma melatonin (Mel) levels and the Mel receptor Mel1c expression of liver, while the malondialdehyde (MDA) content appeared to follow an opposite trend. In vitro, the administration of exogenous melatonin (250 pg mL^-1) increased the proliferative activity and the antioxidant status of hepatocytes. However, this effect was significantly inhibited by Prazosin, a Mel1c inhibitor. These results suggest that green light improves the antioxidant status of the liver, which is mediated by melatonin and mel1c, and finally accelerates liver development.

Bilal, G., Cue, R. I., Mustafa, A. F. and Hayes, J. F. 2014. Effects of parity, age at calving and stage of lactation on fatty acid composition of milk in Canadian Holsteins. Can. J. Anim. Sci. 94: 401-410. The objectives of the present study were to study the effects of parity, age at calving and stage of lactation on individual fatty acids and fatty acid unsaturation indices in milk of Canadian Holsteins. One morning milk sample was collected from each of 3185 dairy cows between February and June 2010 from 52 commercial herds enrolled in the Quebec Dairy Production Centre of Expertise, Valacta. Individual fatty acid proportions (g 100 g^-1 of total fatty acids) were determined for each sample by gas chromatography. Editing for registration status, cow, sire and dam identification, breed, country, age at calving and stage of lactation reduced the data set to 2573 cows representing 46 herds. The statistical model included the fixed effects of parity, age at calving and stage of lactation each nested within parity and random effects of herd-year-season of calving and residual. First-parity cows had relatively higher proportions of beneficial unsaturated fatty acids, from a human health standpoint, and lower proportions of potentially undesirable saturated fatty acids in milk fat as compared with later parity cows. Milk fatty acid profile varied with stage of lactation. The proportions of short- and medium-chain fatty acids (C6:0 to C14:0) were low in the beginning of lactation and increased during the early part of lactation. Long-chain fatty acids (especially C18:0 and oleic acid) and unsaturation indices (C16, C18 and total) showed an opposite trend to that of short- and medium-chain fatty acids. The study showed that parity and lactation stage contribute to variation in bovine milk fat composition.

Gao, J., Jiang, Z.-R., Liu, X., Zhao, Y.-H., Huang, L., Peng, H.-J., Zedan, D., Jin, S.-Y. and Zheng, Y.-C. 2014. Comparison of MUC1 variable number tandem repeat polymorphisms in three yak breeds/populations. Can. J. Anim. Sci. 94: 411-416. The objective of this study was to compare the MUC1 variable number tandem repeat polymorphisms with adjacent distribution regions in three yak (Bos grunniens) breeds/populations. A total of 215 yaks of three yak breeds/populations (Maiwa yak breed, Jiulong yak breed and Changtai yak population) were surveyed by the polymorphisms of Mucin 1 gene (MUC1). Six MUC1 alleles (B, C, D, F, G and H) forming 16 genotypes were identified. Cloning and sequencing of these alleles demonstrated that they differed in the numbers of variable number tandem repeats (VNTR) units ranging from 14 to 20, and allele H (14 VNTR units) was a new allele in yaks and observed only in Maiwa yak with a very low frequency. Cluster analysis based on MUC1 polymorphisms suggested that Changtai yak population has a closer association with Maiwa yak breed than with the Jiulong yak breed, and may represent an independent yak breed/population. These results provided useful genetic information on the three yak breeds/populations and could be used in yak breeding practice.

Hu, W., Li, T., Lu, M., Wu, L., Meng, X. and Tian, Y. 2014. Effects of microRNA-mediated IGF-1 gene silencing on telomerase activity and cell proliferation in deer antler cells. Can. J. Anim. Sci. 94: 417-425. This study aimed to assess deer antler cell proliferation and telomerase activity after transfection with IGF-1microRNA eukaryotic expression recombinants. Four pairs of pre-microRNA were designed and synthesized based on the IGF-1 mRNA sequence, cloned into the pcDNA6.2-GW/EmGFPmiR eukaryotic vector and transfected into deer antler cells. IGF-1 expression after transfection with recombinants was measured by Real-time PCR and Western blotting. Telomerase activity in deer antler cells was assessed by TRAP-PCR-EB. Finally, the effects of IGF-1 silencing on cell proliferation and cell cycle were determined by MTT assay and flow cytometric analysis, respectively. The oligonucleotide sequences for microRNA expression were successfully inserted, and IGF-1 expression levels were significantly decreased in the pIGF1-miR-2 recombinant group in comparison with negative control and normal cells (P<0.01). The pIGF-1-miR-2 recombinant was selected as the optimal interfering target. We found that IGF-1 silencing by pIGF-1-miR-2 significantly reduced telomerase activity in deer antler cells (P<0.01). In addition, cell proliferation was inhibited, with a decreased percentage of cells in the S phase, indicating cell arrest in the G0/G1 phase. These findings demonstrate that miRNA-mediated IGF-1 gene silencing decreases telomerase activity in deer antler cells, and provide further evidence that IGF-1 gene expression is correlated with telomerase activity during rapid growth of the antlers.

Bao, N., Qin, G., Zhang, P., Zhao, Y., Sun, Z. and Pan, L. 2014. Strain screening for lowering immune activity of β-conglycinin in defatted whole soybean flour through fermentation. Can. J. Anim. Sci. 94: 427-436. β-conglycinin is one of the major allergenic soybean proteins that can lead to hypersensitivity in newly weaned pigs or calves. The goal of this study was to evaluate the activities of various microorganisms on the immunogenicity of β-conglycinin in newly weaned pigs following fermentation. Defatted whole soybean flour (SBM) was separately fermented in a 5-L fermenter with one of 10 microorganisms (Bacillus subtilis subsp. spizizenii, Bacillus licheniformis, Bifidobacterium breve, Bifidobacterium animalis, Bifidobacterium longum, Aspergillus oryzae, Aspergillus niger, Lactobacillus fermentum, Saccharomyces cerevisae and S-8) for 4, 8, 12, 16, 20, 24, 28, 32, 36, 40, 44, or 48 h. The molecular weight and the reactogenicity of β-conglycinin (intact β-conglycinin and/or its degradation product) in the SBM before and after fermentation were measured using sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE), Western blot, and enzyme-linked immunosorbent assay (ELISA). After 12 h of fermentation with Bacillus licheniformis, S-8, Bacillus subtilis subsp. spizizenii, or Bifidobacterium longum, the reactogenicity was lowered to less than 40% and their inactivating immunogenicities were more effective than those of the other microorganisms (P≤0.01). The a and a' levels of β-conglycinin decreased significantly in the samples (P<0.05) fermented for 48 h with Bacillus subtilis subsp. spizizenii, Bacillus licheniformis, Bifidobacterium breve, Bifidobacterium animalis, or Bifidobacterium longum. The level of β-conglycinin in the SBM fermented with S-8 was decreased by 44.73% after 8 h (P<0.01) and completely hydrolysed to small (<20 kDa) peptides after 24 h. These data demonstrated that S-8 was the most effective microorganism for inactivating the allergenicity of β-conglycinin in SBM. This study may directly benefit the production of low soybean allergen food for animals.

Zongo, M., Traoré, I., Pitala, W., Boly, H., Sanou, D., Belemtougri, R. et Sawadogo, L. 2014. Estimation du poids du fœtus de la chèvre sahélienne à partir des mesures échographiques des paramètres fœtaux. Can. J. Anim. Sci. 94: 437-443. Cette étude vise à estimer le poids du fœtus de chèvre sahélienne à partir des longueurs du dos (LD), du fémur (LF), du tibia (LT) et des diamètres bipariétal (DBP), des placentômes (DPl), du cordon ombilical (DCO) et de la corne utérine (DCU). Les examens échographiques sont pratiqués à l'aide d'une sonde linéaire de 5 Mhz sur des utérus gravides (n = 44) collectés à l'abattoir. Les données ont été analysées avec le système de régression curvilinéaire. L'équation d'estimation du poids est de type y = ax^b, où y = paramètre biométrique (millimètre), a et b = constantes et x = poids (gramme). Les poids des fœtus sont compris entre 2 et 600 g. Les coefficients de corrélation entre les LD (R = 0,85), LT (R = 0,92), LF (0,81), DBP (R = 0,93), DCO (R = 0,84), DCU (R = 0,86) et le poids du fœtus sont hautement significatifs (P<0,001). Le DPl est par contre faiblement corrélé (R = 0,60) avec le poids du fœtus. Les paramètres LD, LT, LF, DBP, DCO et DCU sont de meilleurs estimateurs du poids du fœtus. Par contre, le DPl n'est pas approprié pour l'estimation du poids du fœtus de cette race.

Prieto, N., López-Campos, Ó., Zijlstra, R. T., Uttaro, B. and Aalhus J. L. 2014. Discrimination of beef dark cutters using visible and near infrared reflectance spectroscopy. Can. J. Anim. Sci. 94: 445-454. This study examined the potential of visible and near infrared reflectance spectroscopy (Vis-NIRS) to segregate dark cutters from normal beef. One hundred and twenty beef carcass sides were selected from a slaughter plant by experienced graders according to their carcass grade: 60 A grade carcasses (normal) and 60 B4 grade carcasses (dark cutters). At approximately 48 h post mortem, a 2.5-cm-thick steak (at ~7/8th thoracic vertebrae) was removed, vacuum packaged and frozen at -25°C until spectra collection. Four Vis-NIRS analyses were performed with different instruments and sample presentation. Partial least squares discriminant analysis based on Vis-NIR spectra correctly classified 95% of the intact non-oxygenated beef samples from both A and B4 grade carcasses using a portable LabSpec^®4 spectrometer, and 88 and 93% of the intact beef samples from A and B4 grade carcasses, respectively after 20 min of exposure to atmospheric oxygen. When a bench top NIRSystems 6500 monochromator was used, 90% of the bloomed intact beef samples were correctly assigned to both A and B4 grading categories, and 90 and 91%, respectively, of the bloomed homogenized samples. Further work remains to be carried out to develop robust Vis-NIRS models to be implemented on-line in the abattoir, where portable equipment applied directly on the carcass could objectively assist in dark-cutting carcass segregation.

Tullio, R. R., Juárez, M., Larsen, I. L., Basarab, J. A. and Aalhus, J. L. 2014. Short Communication: Influence of some meat quality parameters on beef tenderness. Can. J. Anim. Sci. 94: 455-458. Steaks from longissimus lumborum and semimembranosus muscles, aged 2 or 27 d, were obtained from a population of steers (n=112) managed to produce a range in tenderness (shear force range from 2.57 to 17.2 kg). All available carcass (live weight, hot commercial weight, pH, temperature, marbling, rib-eye area) and meat (objective colour, cook loss, cook time, Warner-Bratzler shear force, myoglobin content, proximate composition and collagen content) quality data were used for the analyses. Multivariate analyses determined which factors influenced tenderness between and within muscles, both before or after ageing. In unaged muscles, soluble collagen explained differences in tenderness among muscles, while factors related to the myofibrillar component explained differences within a muscle. In contrast, in aged muscles, total collagen content was related to tenderness among muscles and the percent soluble collagen content was related to tenderness differences within a muscle.

Oliveira, A. F., Rodrigues, S., Leite, A., Paulos, K., Pereira, E. and Teixeira, A. 2014. Short Communication: Quality of ewe and goat meat cured product mantas. An approach to provide value added to culled animals. Can. J. Anim. Sci. 94: 459-462. The effect of species on quality of a cured meat product (mantas) was analyzed in eight culled ewes and eight culled goats. Carcasses were aged at 4°C for 4 d, deboned, salted for 96 h and dried for 48 h. Samples (in triplicate) from the longissimus dorsi (LD) were analyzed for pH and water activity (a_w). Samples of cured LD were subjected to chemical analyses. It was possible to conclude that cured goat meat had higher moisture content (P<0.001) than cured ewe meat, 44 and 51%, respectively. Directly related to the moisture content, a higher total, saturated, mono- and polyunsaturated fat content (P<0.001) was found in ewes. The others chemical determinations did not present differences (P>0.05) for the species effect.

Stewart, A. A., Alemu, A. W., Ominski, K. H., Wilson, C. H., Tremorin, D. G., Wittenberg, K. M., Tenuta, M. and Janzen, H. H. 2014. Whole-farm greenhouse gas emissions from a backgrounding beef production system using an observation-based and model-based approach. Can. J. Anim. Sci. 94: 463-477. Backgrounding, raising weaned beef cattle in preparation for finishing in a feedlot, is a common practice in western Canadian beef production systems. The objectives of this study were: (i) to assess the whole-farm greenhouse gas (GHG) emissions from a pasture-based backgrounding system using an observation-based and model-based approach and (ii) to compare model-based estimated emissions with observation-based emissions from the key components of the farm, in order to identify the knowledge gaps that merit further study. For the observation-based approach, emissions were garnered from a multi-disciplinary field study that examined three fertility treatments applied to the pasture grazed by beef cattle: (i) no liquid hog manure application (control); (ii) split application of liquid hog manure, half applied in fall and half in spring (split) and (iii) single spring application of liquid hog manure (single). The model-based approach used a systems-based model, adapted from Intergovernmental Panel on Climate Change algorithms, to estimate annual net farm GHG emissions from the three fertility treatments and a hypothetical synthetic fertilizer treatment. Total farm emissions included methane (CH₄), nitrous oxide (N₂O) emissions from farm components and carbon dioxide (CO₂) emissions from energy use. Net farm GHG emissions using the observation-based approach ranged from 0.4 to 2.2 Mg CO₂ eq ha^-1 and from 4.2 to 6.5 kg CO₂ eq kg^-1 liveweight gain exported; the model-based approach resulted in net farm emissions ranged from 0.6 to 3.7 Mg CO₂ eq ha^-1 and from 7.0 to 12.9 kg CO₂ eq kg^-1 liveweight gain exported. Except in the control treatment, both enteric CH₄ and soil N₂O emissions were the major contributors to total farm emissions. Emissions intensity for the hypothetical synthetic fertilizer treatment (9.4 kg CO₂ eq kg^-1 liveweight gain) was lower than for the split and single scenarios. Although individual GHG emission estimates varied appreciably, trends in emissions intensity were similar between the two approaches. Efforts to reduce GHG emissions should be directed towards components such as enteric CH₄ and soil N₂O, which have larger impacts on overall system emissions.

Sugiharto, S., Jensen, B. B., Hedemann, M. S. and Lauridsen, C. 2014. Comparison of casein and whey in diets on performance, immune responses and metabolomic profile of weanling pigs challenged with Escherichia coli F4. Can. J. Anim. Sci. 94: 479-491. The differences in amino acid composition in casein and whey have been thought to exert different immunomodulatory and metabolic effects. The objective of this study was to compare the effects of casein and whey on performance, immune responses and plasma metabolomic profile of weanling pigs challenged with Escherichia coli F4. Two factorial experiments involving 24 weanling pigs were conducted. Diets containing casein or whey, and challenge with E. coli O149:F4 or not, were the two factors. Blood was sampled on the day before challenge and 4 and 7 d postchallenge. For measurement of mucosal immune responses and intestinal dimensions, samples were collected from the small intestine (SI) immediately after killing at 7 d postchallenge. Feeding the whey diet decreased (P<0.05) mucosal immunoglobulin (Ig) A concentration and percentage of CD3 T cells in the blood, and tended (P=0.114) to upregulate the gene expression of tumor necrosis factor (TNF)-α in SI tissue, compared with feeding the casein diet. The diarrhea occurrence (P<0.05) and CD4 :CD8 T cell ratio (P=0.058) were higher, whereas the percentage of lymphocytes to total leukocytes was lower (P<0.05) in challenged pigs compared with unchallenged pigs. The challenge reduced (P<0.05) daily gain and tended to reduce the daily feed intake (P=0.067) and the intestinal mucosa weight (P=0.073), but an effect of diet was not observed. The metabolomic analysis showed discrimination between challenged and unchallenged pigs after inoculation with E. coli, but no discrimination was observed between pigs fed casein and whey diets before and after challenge. In conclusion, the feeding of casein or whey to weanling pigs differed in immunological responses, whereas no distinctions were observed with regard to performance and plasma metabolomic profile of pigs. Challenge of the pigs with E. coli F4 increased the diarrhea and appeared to modulate the immune function of the piglets through changes in T cells populations and plasma metabolite profile.

Santos, T. T., Walk, C. L., Wilcock, P., Cordero, G. and Chewning, J. 2014. Performance and bone characteristics of growing pigs fed diets marginally deficient in available phosphorus and a novel microbial phytase. Can. J. Anim. Sci. 94: 493-497. The efficacy of a novel microbial 6-phytase on pig performance, bone breaking strength, and bone ash was evaluated. Pigs were allotted to one of six diets with 12 replicate pens/treatment and five pigs/pen. Diets consisted of a positive control (PC), negative control (NC) 1 with Ca and available phosphorus (avP) reduction by 0.11 and 0.10%, NC 1 plus 250 FTU kg^-1 phytase, NC 2 with Ca and avP reduction by 0.16 and 0.15%, NC 2 plus 500 and 2,000 FTU kg^-1 phytase. On day 43, one pig per pen was euthanized and the 4th metacarpal was obtained to determine bone parameters. Average daily gain (ADG) was higher (P<0.05) in pigs fed NC 2 plus 500 or 2000 FTU kg^-1 compared with PC. NC 2 with 2000 FTU kg^-1 improved (P<0.05) G:F compared with PC. NC 1 or NC 2 had reduced (P<0.05) bone ash weight and NC 2 had reduced (P<0.05) bone breaking strength compared with PC. Phytase supplementation in NC 1 or NC 2 improved bone ash weight compared with PC. Bone breaking strength or bone ash weight was more sensitive to low dietary Ca and avP than bone ash percent. Phytase supplementation at 2000 FTU kg^-1 improved G:F beyond that of the PC.

Wood, K. M., Montanholi, Y. R., Fitzsimmons, C. F., Miller, S. P., McBride, B. W. and Swanson, K. C. 2014. Characterization and evaluation of residual feed intake measured in mid- to late-gestation mature beef cows and relationships with circulating serum metabolites and linear body measurements. Can. J. Anim. Sci. 94: 499-508. To evaluate the use of residual feed intake (RFI) models measured in mid-to-late gestating beef cows, a dataset was used combining data from five experiments containing nine treatment and/or replicate groups for a total of 321 animal records. Investigations of RFI models included the effects of age, ultrasound measures of body composition, pregnancy corrected gain, and dietary treatment group. A subset of animals had serum analyzed for circulating metabolites (glucose, non-esterified fatty acids, urea, beta-hydroxybutyrate; n=227) and/or linear body measures (hip height and width, body length, body circumference at the heart, mid-body and at flank; n=114) for correlation analysis with efficiency traits. Goodness-of-fit for all RFI models was assessed using R², CV, and Bayesian information criteria. Across treatment/replicate groups, the largest improvements in model fit were made by accounting for management group and dietary treatment. Circulating urea concentrations were positively correlated (P ≤0.05) with average daily gain, dry matter intake, gain:feed, and group RFI model. Linear body measures and circulating metabolites measured (with the exception of urea) were not correlated (P>0.05) with economically relevant traits. Measures of RFI as an indication of feed efficiency may be challenging for use in gestating beef cows. Large variation in efficiency between cows remain, and may be related to mechanisms influencing maintenance and energy expenditures.

Ellis, J. L., Dijkstra, J., Bannink, A., Kebreab, E., Archibeque, S., Benchaar, C., Beauchemin, K. A., Nkrumah, J. D. and France, J. 2014. Improving the prediction of methane production and representation of rumen fermentation for finishing beef cattle within a mechanistic model. Can. J. Anim. Sci. 94: 509-524. The purpose of this study was to evaluate prediction of methane emissions from finishing beef cattle using an extant mechanistic model with pH-independent or pH-dependent volatile fatty acid (VFA) stoichiometries, a recent stoichiometry adjustment for the use of monensin, and adaptation of the underlying model structure, to see if prediction improvements could be made for beef cattle. The database used for independent evaluation of methane predictions consisted of 74 animal means from six studies. For the “Bannink” stoichiometries, pH-dependence of stoichiometry improved the root mean square prediction error (RMSPE) statistic (38.8 to 36.6%) but the concordance correlation coefficient (CCC) statistic was reduced (0.509 to 0.469). Inclusion of monensin in the stoichiometry improved both pH-independent and pH-dependent predictions. For the “Murphy” stoichiometries, pH-dependence worsened the RMSPE (31.2 to 33.7%) as well as the CCC (0.611 to 0.465) statistic. Inclusion of monensin in the stoichiometry improved predictions with the pH-independent but not with the pH-dependent stoichiometry. Results indicate that although improvements have been made to the mechanistic model, further improvement in the representation of VFA stoichiometry, and likely the representation and prediction of pH and neutral detergent fiber digestibility, are required for more accurate prediction of methane emissions for finishing beef cattle. However, inclusion of an adjustment for monensin feeding generally lead to improved methane predictions.

Amat, S., McKinnon, J. J., Simko, E. and Hendrick, S. 2014. Evaluation of feeding corn or wheat dried distillers' grains with solubles on animal health of finishing feedlot steers. Can. J. Anim. Sci. 94: 525-531. Using dried distillers' grains with solubles (DDGS) as a replacement for barley grain is believed to reduce the incidence of rumen acidosis and liver abscessation due to its low starch content. However, feeding DDGS has the potential to induce polioencephalomalacia (PEM) owing to its high sulfur (S) content. The present commercial feedlot study was conducted to evaluate the effects of feeding corn or wheat DDGS on the health of finishing steers with a focus on the impact of these by-products on mortality, prevalence of ruminitis, cystitis, PEM and liver abscessation. The trial was conducted as a complete randomized design with three treatments using a total of 6815 crossbred steers in 10 pens per treatment. The control group diet consisted of 93.1% dry-rolled barley, 5.0% barley silage and 1.9% supplement (dry matter basis). The two treatment group diets included the replacement of 22.5% barley with corn or wheat DDGS. A complete necropsy and post-mortem were performed on all animals that died or were euthanized. In addition, rumen, bladder and brain tissues were collected for histopathological examinations. Liver abscess scoring was also performed. A total of 178 animals died and the overall mortality rate was not different between treatment groups (P=0.34). Bovine respiratory disease, lameness, metabolic disease, suspected Histophilus somni or miscellaneous mortalities did not differ (P>0.05) among the treatment groups. Incidence of ruminitis confirmed by histopathology in cattle either fed corn or wheat DDGS did not differ (P=0.16) from the control cattle. No particular bladder lesions, central nerve system infections or incidences of clinical PEM associated with feeding DDGS were detected. The prevalence of liver abscess at slaughter was not affected by treatment (P>0.05). The results of the present study indicate that feeding 22.5% corn or wheat DDGS in barley based finishing diet did not affect animal health of finishing feedlot steers.

Zenobi, M. G., Lardner, H. A., Jefferson, P. G. and McKinnon, J. J. 2014. Blended by-product feed pellets for backgrounding cattle. Can. J. Anim. Sci. 94: 533-543. Two trials were conducted to evaluate the performance of cattle fed blended by-product pellets (BP) formulated to be high in starch (HS 45% DM) or fat (HF 8.5% DM) and low (LSP; 27% of CP DM) or high (HSP; 37% of CP DM) in soluble protein. In trial 1, 300 crossbred steers (320±21.6 kg, mean±SD) were assigned to one of 25 pens and fed one of five diets. The control diet consisted of 46.9% forage and 53.1% barley-based concentrate. The four treatments were 48.5% forage and 51.5% BP (DM). Diets were formulated to 1.63 and 1.02 Mcal kg^-1 NEm and NEg, respectively (DM). In trial 2, 180 crossbred steers (326±20.3 kg) were assigned to one of 15 pens, each assigned to one of three treatments. The control was 54.3% forage and 45.7% concentrate, while the two HF BP treatments were 56.6% forage and 43.4% BP (DM). All diets were formulated to 1.57 and 0.97 Mcal kg^-1 NEm and NEg, respectively (DM). In trial 1, no (P=0.36) effect of treatment was observed on average daily gain (ADG); however, dry matter intake (DMI) was reduced (P<0.01) with the HS BP relative to the control and HF BP. Gain:feed (G:F) was poorest (P<0.01) for the HF BP. In Trial 2, no effect of treatment was observed on ADG (P=0.80) or DMI (P=0.06); however, cattle fed the control diet had the highest (P<0.01) G:F. Relative to the control, the calculated dietary NEg content (Mcal kg^-1 DM) was 8.0% lower (P<0.01) for the HF BP in Trial 1 and 6.7% lower (P<0.01) in Trial 2. No effect (P>0.05) of soluble crude protein was observed. The results indicate that BP can be a viable supplemental energy and protein source for growing cattle.