Paz, H. A., Castillo-Lopez, E., Ramirez-Ramirez, H. A., Christensen, D. A., Klopfenstein, T. J. and Kononoff, P. J. 2013. Invited Review: Ethanol co-products for dairy cows: there goes our starch … now what? Can. J. Anim. Sci. 93: 407-425. The rise of the grain-ethanol industry has resulted in a dramatic increase in the availability of feed co-products namely, distillers' grains with solubles (DG). The cost of feeds that have traditionally been used for energy continues to increase and there is a need to understand the potential impact of replacing these feeds with DG on milk yield and composition. Using the Dairy National Research Council (2001) model and data from a total of 25 published studies (81 observations), we used a meta-analytical procedure to evaluate the impact of feeding corn milling co-products on lactating dairy cows. Based on our model, the inclusion of DG did not affect dry matter intake (P=0.35) but a trend for an increase in milk yield was observed (P=0. 10). Additionally, the percentages of milk fat and protein in the milk were not affected (P=0.24 and 0.25, respectively). The modeled daily rumen outflow of Lys in grams was significantly (P<0.01) reduced and Met was not affected (P=0.79) when DG were included. The error associated with net energy of lactation allowable milk averaged 5.0±1.0 kg d^-1 and was not affected by DG (P=0.79) but the error associated with metabolizable protein allowable milk tended (P=0.10) to be higher for cows consuming DG by 1.4±1.2 kg d^-1.

Deming, J. A., Bergeron, R., Leslie, K. E. and DeVries, T. J. 2013. Associations of cow-level factors, frequency of feed delivery, and standing and lying behaviour of dairy cows milked in an automatic system. Can. J. Anim. Sci. 93: 427-433. The objectives of this observational study were to quantify the standing and lying behaviour of dairy cows milked in an automatic milking system (AMS) and determine associations of this behaviour with cow-level factors (parity, stage of lactation, production, lameness) and feeding management (frequency of feed delivery). Ninety lactating Holstein cows (178±83 d in milk (DIM); parity: 2.1±1.9), kept in a free-stall barn in one of two pens, each with a free-traffic AMS, were monitored for a period of 70 d. To vary feeding management, in two consecutive 35-d periods, cows in each pen were delivered a total mixed ration (TMR), in a random order, once daily (at 0730) or twice daily (at 0730 and 1730). During the last 7 d of each period, standing and lying behaviour were recorded with data loggers, while milking information was recorded by the AMS. Cows were lameness (gait) scored twice each period. Cows lay down for 10.9±2.0 h d^-1, produced an average of 34.7±8.7 kg d^-1 of milk, and milked 2.6±0.6 times per day. Cows spent more time standing after milking (P=0.04) when fed once daily compared with twice daily. Lying duration tended to increase (P=0.06) when feed was delivered twice daily. Milk yield (P<0.001) and lying bout frequency (P=0.05) were negatively associated with DIM, while lying bout length (P=0.005) and total duration of lying (P=0.01) were positively associated with DIM. Cows with higher gait scores milked less frequently (P=0.04), and spent more time lying per day (P=0.008) and tended to have more lying bouts per day (P=0.06). Overall, the results of this observational study suggest that the standing and lying behaviour of AMS-milked cows may be influenced by feed delivery frequency, but are more consistently associated with stage of lactation and lameness.

Felton, C. A., Colazo, M. G., Bench, C. J. and Ambrose, D. J. 2013. Large variations exist in prepartum activity among dairy cows continuously housed in a tie-stall barn. Can. J. Anim. Sci. 93: 435-444. Electronic activity monitoring might assist with the early detection of calving; however, little work has been done to determine if dairy cows housed in tie-stalls changed their activity as calving approached. The objectives were to describe retrospectively, prepartum activity changes in cows housed in tie-stalls using AfiMilk pedometers, and determine if restless activity preceding parturition differed between primiparous and multiparous cows. Twelve primiparous and 12 multiparous Holstein cows housed in tie-stalls were monitored daily by pedometers for 9 d immediately preceding their calving date. Fifteen consecutive hours (1700 to 0800) of activity was recorded during each 24-h period, when cows remained continuously in their stalls, until day -1 (calving = day 0). Activity data from days -9 to -3 were available from all 24 cows, and up to day -1 from 16 cows; based on these data, there was an overall average increase in stepping activity of 34% (range, 32% decrease to 119% increase) from day -2 to day -1. However, only 56% of cows exhibited a 10% or more increase in stepping activity. Primiparous cows tended to have increased stepping activity (1366 ± 116 vs. 1039 ± 116 steps; P = 0.06) and decreased lying bouts frequency (7.5 ± 0.6 vs. 8.1 ± 0.6; P = 0.07) than multiparous cows. They also had significantly shorter lying durations (376 ± 23 vs. 473 ± 23 min; P < 0.01) than multiparous cows. Holstein cows housed continuously in tie-stalls manifested large variations in prepartum activity. Primiparous cows had significantly shorter lying durations than multiparous cows, and tended to have higher mean stepping activity. Further characterization of prepartum activity in dairy cows housed in tie-stalls and the use of steps-to-lying ratio could be valuable to detect imminent parturition, particularly in primiparous cows.

Li, Y. Z. and Gonyou, H. W. 2013. Comparison of management options for sows kept in pens with electronic feeding stations. Can. J. Anim. Sci. 93: 445-452. A variety of management options exist for group-housed sows and these may affect animal welfare and performance. A study was conducted to examine the effect of two management options on the performance and chronic injuries of gestating sows group-housed with electronic sow feeders (ESF). The management options examined were social management (static vs. dynamic groups) and stage of gestation at mixing (pre-implantation vs. post-implantation of embryos), with sows in stalls serving as reference. Multiparous sows (n = 1569 sow records, parity 1 to 9, PIC genetics) from 100 contemporary breeding groups were used. Group-housed sows (n = 1112 sow records) were assigned to a 2×2 factorial arrangement of management treatments. Each static group consisted of 35 to 40 sows that were grouped simultaneously and no further sows were added to the group. Dynamic groups consisted of 105 to 120 sows, with 35 to 40 sows being added to the group every 5 wk after the same number of sows had been moved out for farrowing. Results indicate that social management did not affect farrowing rate and weight change during gestation. However, sows in static pens sustained fewer (P = 0.01) skin lesions (cuts, swellings, and wounds) and had fewer incidences (P = 0.01) of lameness before farrowing than sows in the dynamic pen. Pre-implant sows had a lower farrowing rate (82.3% vs. 86.7%, P = 0.05), but had fewer skin lesions before farrowing (P <0.01) compared with post-implant sows. Neither social management nor stage of gestation at mixing affected total born, born alive or stillborn litter sizes. In general, sows group-housed with ESF performed similar to sows in stalls, but sustained fewer skin lesions before farrowing. These results demonstrate that management options can affect the reproductive performance and injuries of gestating sows in the ESF system.

Tang, S., Yu, J., Zhang, M. and Bao, E. 2013. Effects of different heat stress periods on various blood and meat quality parameters in young Arbor Acer broiler chickens. Can. J. Anim. Sci. 93: 453-460. Heat stress can influence muscle metabolism and meat quality in animals reared for food production. From a commercial perspective, understanding the mechanism of this effect is clearly necessary. The aim of this study was to investigate the effects of different heat stress periods on serum metabolites and chicken meat quality (n=120). Plasma indicators creatine kinase (CK), glutamic-pyruvic transaminase (GPT), glutamic-oxaloacetic transaminase (GOT), insulin and glucagon and meat quality (pH, expressible moisture, cooking losses, shear force values) were evaluated. Compared with controls, the concentrations of CK and GPT increased (P<0.01) after 2 and 3 h of heat stress, respectively, whereas plasma insulin and glucagon decreased after 1 and 5 h of heat stress, respectively. The immediate pH (pHi) and ultimate pH (pHu) of the pectoralis muscles decreased (P<0.01) after 1 and 2 h of exposure to heat stress, respectively. Cooking loss, expressible moisture and shear force value increased (P<0.01) after 3, 2, and 1 h of heat stress, respectively. These data indicate that elevated plasma concentrations of CK and GPT can be used as parameters for assessing the stress level to which broilers are exposed before slaughter. The preslaughter exposure of broiler chickens to heat stress can alter muscle metabolism and membrane integrity, leading to undesirable meat characteristics. Thus, a clear understanding of the mechanisms underlying these processes will contribute to the determination of prevention strategies and the avoidance of the associated economic losses.

Goumon, S., Bergeron, R., Faucitano, L., Crowe, T., Connor, M. L. and Gonyou, H. W. 2013. Effect of previous ramp exposure and regular handling on heart rate, ease of handling and behaviour of near market-weight pigs during a simulated loading. Can. J. Anim. Sci. 93: 461-470. The objective of this study was to assess whether stress response during simulated loading could be reduced by providing pigs with experience prior to the event. Two weeks before simulated loading, 160 Large White × Landrace near market-weight pigs were allocated to one of four treatments: physical training (EXERCISE), psychological training (RAMP), EXERCISE and RAMP trainings (BOTH) or no training (CON). Once training was completed, pigs were loaded into a simulated trailer compartment, and the metrics of behaviour, pig and handler's heart rates, loading time and handling difficulty were measured. During loading, heart rate was lower (P<0.05) for EXERCISE and BOTH pigs compared with RAMP and CON pigs. The numbers of touch/slap and push were lower (P<0.05 and P<0.05, respectively) for EXERCISE pigs compared with CON, RAMP and BOTH pigs, which did not differ (P>0.05). The number of balks was the lowest (P<0.05) for EXERCISE pigs, whereas there were no differences (P>0.05) between BOTH and CON or RAMP pigs. This study demonstrates that daily exercise, by itself, improves the ease of handling and reduces cardiovascular response, while it appears that previous exposure to a ramp had no beneficial effects.

da Silva, A., Dalto, D., Lozano, A., de Oliveira, E., Gavioli, D., de Oliveira, J., Jamile, Romero, N. and da Silva, C. 2013. Differences in muscle characteristics of piglets related to the sow parity. Can. J. Anim. Sci. 93: 471-475. Two hundred forty-three piglets were obtained from 81, 1st through 7th parity sows to determine the influence of sow's parity on piglets′ myogenesis. Those piglets weighing close to or equal to the average weight of their litter were sacrificed, and their semitendinosus muscles were collected to determine the secondary muscle fiber number, area and weight. The number of secondary muscle fibers was correlated with muscle weight (P<0.05; 0.39) and muscle area (P<0.001; 0.63), and muscle area and weight were also correlated (P<0.001; 0.64). Weights of piglets at birth had a correlation with number of muscle fibers (P<0.05; 0.39), muscle area (P<0.001; 0.54) and muscle weight (P<0.001; 0.73). The piglets′ birthweights and muscle weight, muscle area and muscle secondary fiber numbers increased quadratically as parity increased (R²=0.56, 0.36, 0.44, 0.64 and 0.54; P<0.05, respectively). The results of this study indicate that parity influences the pre-natal development of piglets and that the best muscle characteristics of piglets born from 3rd and 4th parity sows were responsible for their higher weight at birth.

Su, B., Wang, L., Wang, H., Shi, B., Shan, A. and Li, Y. 2013. Conjugated linoleic acid and betain prevent pork quality issues from diets containing distillers′ dried grains with solubles. Can. J. Anim. Sci. 93: 477-485. An experiment was conducted to evaluate the effects of conjugated linoleic acid (CLA) or betaine (BET) in diets containing distillers′ dried grains with solubles (DDGS) on the fatty acid profile and the shelf-life attributes of pork. Thirty-two (60±2 kg) crossed-bred barrows (Duroc×Landrace×Yorkshine) were randomly assigned to one of four diets: (1) the control diet containing no corn DDGS (control group); (2) the diet containing 30% corn DDGS (DDGS-fed group); (3) the diet containing 30% corn DDGS and 10 g kg^-1 CLA (CLA-fed group); (4) the diet containing 30% corn DDGS and 1 g kg^-1 BET (BET-fed group). Dietary DDGS decreased the proportion of saturated fatty acids (SFA) (P<0.05), and increased the proportion of unsaturated fatty acids (UFA) and polyunsaturated fatty acids (PUFA) (P<0.05) in pork with respect to the control group, whereas dietary CLA and BET decreased the proportion of PUFA and increased the proportion of SFA in pork compared with DDGS-fed group. Pork treated with DDGS alone had higher total volatile basic nitrogen (TVB-N) value (P<0.05) and thiobarbituric acid reactive substances (TBARS) value (P<0.05) with respect to the control diet during display, whereas CLA-fed group and BET-fed group had lower TVB-N concentration and TBARS value (P<0.05) in pork than DDGS-fed group. There was no significant difference of instrumental color (L*, a*, b*) between DDGS-fed group and the control group (P>0.05). However, CLA-fed and BET-fed groups maintained lower L* values and higher a* values (P<0.05), but did not affect b* values with respect to the DDGS-fed group and the control group. Results confirmed that diets containing 30% DDGS have some adverse effects on pork freshness and lipid peroxidation; However, supplementation with CLA or BET can partially reverse these effects and improve color image of pork during display.

Montanholi, Y. R., Lam, S., Peripolli, V., Vander Voort, G. and Miller, S. P. 2013. Short Communication: Associations between chemical composition and physical properties of milk and colostrum with feed efficiency in beef cows. Can. J. Anim. Sci. 93: 487-492. Lactogenesis is an energetically demanding process influencing efficiency of feed utilization. Individual energetic expenditure variation may exist in this process and could be accessed through the properties of milk and colostrum in beef cows. Properties of both secretions were analyzed for fat, protein, and lactose contents. Freezing point and somatic cell count were determined in milk and specific gravity and total solids in colostrum. Associations between feed efficiency and milk freezing point, milk lactose content, and colostrum specific gravity were noticed. This link between milk and colostrum properties with feed efficiency could be considered for the improvement of feed efficiency.

Rodríguez, D. A., Sulabo, R. C., González-Vega, J. C. and Stein, H. H. 2013. Energy concentration and phosphorus digestibility in canola, cottonseed, and sunflower products fed to growing pigs. Can. J. Anim. Sci. 93: 493-503. Many protein sources are available to the swine feed industry, but accurate data for the energy concentration and the standardized total tract digestibility (STTD) of P in these ingredients are lacking. Therefore, two experiments were conducted to determine the concentration of digestible energy (DE), metabolizable energy (ME) and the STTD of P in oilseed products. In exp. 1, 48 barrows (44.8±3.9 kg) were fed a basal diet containing 97.15% corn or seven diets containing corn and canola seed (CS), canola meal (CM), cottonseed meal (CSM), sunflower seed (SFS), sunflower meal (SFM), de-hulled sunflower meal (SFM-DH), or soybean meal (SBM). Six pigs were allotted to each treatment. Sunflower seeds contained 5492 kcal kg^-1, at least 689 kcal kg^-1 more (P<0.05) ME than all other feed ingredients. Likewise, CS (4803 kcal kg^-1) had greater (P<0.05) ME than SBM (3676 kcal kg^-1), and both CS and SBM had greater (P<0.05) ME than CM, SFM, SFM-DH, and CSM (2998, 2725, 2631, and 2459 kcal kg^-1, respectively). In exp. 2, 84 barrows (13.7±1.5 kg) were allotted to 14 diets, which contained each of the oilseed products without or with phytase, in a randomized complete block design with six pigs per dietary treatment. The STTD of P in SBM was at least 4 percentage units greater (P<0.05) than the STTD of P in the other ingredients. Adding phytase to the diets reduced fecal output of P from all ingredients and increased (P<0.05) the STTD of P for all ingredients except SFM-DH. The ME concentration in SFS and CS is greater than that of SBM and the STTD of P among these ingredients is comparable, which indicates that SFS and CS may be fed to growing pigs at the expense of SBM.

Litvak, N., Htoo, J. K. and de Lange, C. F. M. 2013. Restricting sulfur amino acid intake in growing pigs challenged with lipopolysaccharides decreases plasma protein and albumin synthesis. Can. J. Anim. Sci. 93: 505-515. Chronic subclinical levels of disease occur frequently in swine production and compromise nutrient utilization efficiency. Methionine and cysteine (M C) are involved in the pig's response to immune system stimulation (ISS), acting as substrates for the synthesis of compounds involved in the immune response, such as acute phase proteins (APP). This study was conducted to determine the impact of ISS with lipopolysaccharide (LPS) and M C intake (high vs. low; 4.0 vs. 2.2 g d^-1) on the fractional synthesis rate (FSR) of plasma albumin and fibrinogen, as well as protein in plasma and various tissues of starter pigs. Fifteen pigs (9.8±1.4 kg body weight) were allotted to one of three treatments: (1) Control (LPS- and high M C), (2) LPS and high M C, or (3) LPS and low M C. Pigs were given intramuscular injections of increasing doses of LPS 1 and 3 d before determining FSR using an intravenous infusion of a flooding dose of L-[ring-1H₅]-phenylalanine. Plasma levels of APP were not affected by the LPS challenge (P>0.10); only plasma albumin levels decreased with reduced M C intake (P=0.02). Total plasma protein FSR was increased during the LPS challenge (50.3 vs. 56.9% d^-1, SEM = 1.6; P=0.01). Albumin FSR was not affected by an LPS challenge (P>0.10), but decreased with reduced M C intake during the LPS challenge (49.5 vs. 41.9% d^-1, SEM = 1.6; P=0.005). Spleen protein FSR tended to increase during the LPS challenge (P=0.08). There were no treatment effects on protein FSR in liver, small intestine, loin or plasma fibrinogen (P>0.10). Restricting M C intake during a LPS challenge decreases albumin synthesis and tends to reduce plasma protein synthesis, implicating M C as important nutrients involved in the immune response.

Jang, Y. D. and Kim, Y. Y. 2013. Short Communication: Energy values and apparent total tract digestibility coefficients of copra meal and palm kernel meal fed to growing pigs. Can. J. Anim. Sci. 93: 517-521. To determine energy values and coefficients of apparent total tract digestibility (CATTD) of copra meal (CM) and palm kernel meal (PKM), 24 growing pigs were fed a corn-soybean meal basal diet and the basal diet replaced by 300 g kg^-1 of either CM or PKM. Copra meal had higher CATTD of gross energy (12%), dry matter (DM; 13%), neutral detergent fiber (16%), acid detergent fiber (23%), and crude fiber (79%; P<0.05) than PKM. Copra meal had a slightly higher digestible energy (DE) value than PKM (14.08 vs. 13.01 MJ kg^-1 DM; P=0.067), but metabolizable energy (ME; 13.33 vs. 12.83 MJ kg^-1 DM), net energy (7.97 vs. 7.36 MJ kg^-1 DM), and ME:DE ratio did not differ between CM and PKM. Therefore, compared with PKM, CM can be a better source of dietary energy in swine diets as evidenced by higher CATTD of energy and fiber components.

Górka, P., McKinnon, J. J. and Penner, G. B. 2013. Short Communication: Use of high-lipid by-product pellets as a partial replacement for barley grain and canola meal in finishing diets for beef steers. Can. J. Anim. Sci. 93: 523-528. The objectives were to determine the effect of the inclusion rate (0%, CON; 30%, HLP30; 60%, HLP60) of high-lipid by-product pellets (HLP) as a partial replacement for barley grain and canola meal on feed intake and growth performance of steers (n=264). Dry matter intake and gain:feed ratio were greater (P<0.01) for HLP30 and HLP60 relative to CON. This study indicates that up to 60% of the barley grain and canola meal in finishing diets for steers can be replaced with HLP, although feed efficiency may be compromised.

Holtshausen, L., Schwartzkopf-Genswein, K. S. and Beauchemin, K. A. 2013. Short Communication: Ruminal pH profile and feeding behaviour of feedlot cattle transitioning from a high-forage to a high-concentrate diet. Can. J. Anim. Sci. 93: 529-533. Sixteen ruminally cannulated cattle (384±33.9 kg) were transitioned from a high-forage to a finishing diet over 21 d using three steps ( 15% concentrate DM wk^-1). Following the initiation of each transition step, mean daily ruminal pH declined and DM intake, meal size and meal duration were reduced. Recovery time to baseline feeding behaviour increased with severity of acidosis. Changes in feeding behaviour can be indicative of sub-optimal ruminal pH conditions during dietary transition. Transition protocols such as more steps, smaller grain increments or shorter initial and longer final steps may aid in reducing the incidence of acidosis.

Stanford, K, Gibb, D. and McAllister, T. A. 2013. Evaluation of a shelf-stable direct-fed microbial for control ofEscherichia coliO157 in commercial feedlot cattle. Can. J. Anim. Sci. 93: 535-542. A direct-fed microbial (DFM) registered for use in cattle in Canada containing Lactobacillus acidophilus strain BT-1386 and a Saccharomyces cerevisiae yeast autolysate was evaluated for control of E. coli O157. Weaned calves entered the feedlot in October and November and in January were sorted into Control (12 pens with a total of 2170 calves) and DFM treatment groups (10 pens with a total of 2040 calves). Although targeted dosage of L. acidophilus was 9 log₁₀ colony forming units (CFU) head^-1 d^-1, analyses after storage at ambient temperature showed an average dose of 8.6 Log₁₀ CFU head^-1 d^-1 and demonstrated stability of DFM over the range of temperatures encountered (-32.6 to 32.9°C) during storage. Calves entering the feedlot had low prevalence (0.8%) of E. coli O157 in feces, which increased to 11.2% in January. A 47°C range in ambient temperature for that month may have stressed cattle and led to increased shedding of E. coli O157 compared with seasonal norms. Comparing hide swabs collected at initiation of DFM feeding with those at shipping for slaughter, prevalence of E. coli O157 declined (P<0.05) in cattle fed DFM, although prevalence of E. coli O157 in hide swabs from Control and DFM-treated cattle did not differ at any time. As well, numbers of E. coli O157 and prevalence of the organism in fecal pats did not differ among treatments. Colonization of calves with E. coli O157 prior to DFM feeding likely reduced efficacy of DFM in the present study. Additional information regarding timing of feeding DFM relative to interactions among organisms within the gastrointestinal tract of cattle are required to ensure consistent efficacy of DFM for pre-harvest control of E. coli O157.

This group meets yearly for one-day meetings. The 2013 meeting was sponsored by Nutreco Canada, Inc., Guelph, ON, Canada; ADM, Decatur, IL, USA; Cargill Animal Nutrition, Elk River, MN, USA; Ajinomoto Heartland, Inc., Chicago, IL, USA; Adisseo, Alpharetta, GA, USA; Lallemand Specialties, Inc., Milwaukee, WI, USA and Evonik Industries AG, Hanau, Germany. It was held on July 7 at the Hyatt Regency Indianapolis, One South Capital Avenue, Indianapolis, Indiana, USA, prior to the ADSA/ASAS Joint Annual Meeting. Summaries of the papers presented follow. Each summary has been peer reviewed and edited for clarity. The person who presented the paper is identified with an e-mail address.