The Alpharma Beef Cattle Nutrition Symposium titled “Enhancing beef production efficiency with new knowledge and technologies: Building the bridges for future collaboration” was held at the Joint Annual Meeting of the American Society of Animal Science and the American Dairy Science Association, July 9 to 14, 2011, New Orleans, LA. Future research in animal science will require a more comprehensive understanding of the interactions between more than one traditional area of training and research. This symposium addressed the current status and potentially novel interactions among beef cattle nutrition and other related disciplines. Research funding opportunities have increasingly required applications to address multidisciplinary approaches to solve intricate systems biology research questions. The development of interdisciplinary teams can provide a collaborative approach to research and outreach that may allow issues or questions that are vital to stakeholder interests to be better addressed than the traditional, single discipline approach. Future development and implementation of ruminant research will need to include this interdisciplinary model in the initial formulation. In this symposium, experts in several areas discussed and identified future areas for multidisciplinary interaction and development of integrated research programs to address complex and novel areas of investigation to help in the process of building the bridges for future collaboration. Integration of research programs can help provide increased allocation of resources that can assist with developing solutions to large scale biological questions. Current advancements in ruminal biochemistry must be placed in context within existing paradigms of conventional nutritional research. Physiology, genomics, and endocrinology can help address these interactions as well as application of emerging technologies and novel techniques to beef cattle nutrition. The relationship of traditional beef cattle nutrition research to a more integrated model of research, required by areas such as fetal programming, can be best approached by the integrated research model discussed.

The Alpharma Beef Cattle Nutrition symposium was held at the joint annual meeting of the American Society of Animal Science, the American Dairy Science Association, and the Canadian Society of Animal Science in Montreal, Quebec, Canada, July 12 to 16, 2009. The symposium was organized to discuss the increased incorporation, challenges, and management options when alternative energy sources are incorporated into high-energy diets for finishing beef cattle. Much of the dietary energy in feedlot diets for beef cattle has and continues to originate from the inclusion of corn grain. However, as the more traditional sources of energy for cattle are being diverted to supply substrates for other purposes (e. g., ethanol production), feedlot diet formulation must adapt. Concurrently, price volatility of grain sources, increases in cost per unit of energy, and locally availability of coproducts affect the formulation of high-energy feedlot diets for finishing cattle. These challenges to the continued use of traditional high-energy feedlot diets for beef cattle have compelled the beef cattle feeding industry to identify and utilize a greater array of coproducts from other production systems as alternative energy sources in feedlot diets. Incorporation of alternative energy sources presents opportunities and challenges to diet formulation, determination of feed energy content, practical feed delivery and utilization, beef cattle performance, digestive physiology, and carcass characteristics. Owens et al. (2010) reviewed the impact of feedstuff nutrient composition on digestibility and energy supply for cattle. The variability of the chemical composition in feed ingredients is a major issue in feedlot diet formulation and predication of cattle performance. The ability to identify and adapt to the variation in chemical composition can have great economic importance. Crude fiber appears to most closely estimate TDN and metabolic fecal loss of OM associated with a variety of feedstuffs. Crude fiber content of feedstuffs may exert an adverse effect on apparent digestibility of other nutrients that could have a greater nutritional impact than the energy derived from fiber digestion itself. The influence of fiber, as well as other feed components, on the metabolic fecal loss of OM, total energy expenditure, influence on digestibility, and utilization in cattle warrants further investigation. The review by Owens et al. (2010) portended the importance of the discussion about the incorporation of coproducts into diets of feedlot cattle. Berger and Singh (2010) described evolutions in the processing methods of corn and the resulting coproducts. Innovative technologies are being utilized in ethanol production facilities that fractionate the corn or distillers dried grains with solubles (DDGS) or both for recovering additional coproducts, alter the nutritional composition of DDGS, and reduce the volume of DDGS. Corn components including the germ, pericarp fiber, endosperm fiber, and oil are used as sources for other coproducts or directly as ingredients in animal feeds. The modification of the DDGS chemical composition has important implications for the formulation of high-energy feedlot diets and the resulting cattle performance. Feedlot research reviewed in Berger and Singh (2010) indicated that new DDGS can replace corn in feedlot diets and still maintain or improve beef cattle performance and carcass characteristics. Wet coproducts other than corn-based products are an important component of many high-energy feedlot diets. Wet coproducts fed to beef cattle include those from the fruit, vegetable, juice, and brewing industries. Quantitatively, potato (Solanum tuberosum) may be the most important because of the estimated 4.3 million t of coproduct produced (Nelson, 2010). The incorporation of potato coproducts into beef cattle diets is contingent Alpharma Beef Cattle Nutrition Symposium: Alternative energy sources for beef cattle finishing diets

The objective of this study was to evaluate the effect of growth implants on the carcass characteristics and tenderness of steers and heifers with different genetic potentials for growth, lean meat yield production, and marbling. Two experiments were conducted. Experiment 1 evaluated Angus steers sired by bulls with high EPD for retail product yield or marbling. Implant treatment was imposed randomly within sire groups. Loins (Institutional Meat Purchasing Specifications 180) were collected from each carcass and cut into three 2.54-cm steaks aged for 7, 14 and 21 d to evaluate tenderness. The second experiment evaluated steers and heifers of British and Continental breed descent. Steers and heifers were slaughtered after 120 d on feed. Loin sections were collected, and one 2.54-cm steak aged 7 d was used for tenderness analysis. When implants were used in Angus steers, HCW and LM area increased, whereas internal fat and marbling decreased (P < 0.01). In Angus steers, sire type did not affect shear force values of steaks; however, implant use significantly increased shear force values (P < 0.01). Carcasses from cattle of Continental breed descent were significantly heavier than carcasses of British breed descent with larger LM area, slightly less fat, and a reduced yield grade (P < 0.01). Also, steer carcasses were heavier than heifer carcasses with larger LM (P < 0.05), but no effect of sex on fat depth, internal fat, yield grade or marbling was observed. No significant interactions were seen between growth implant and breed or between growth implant and sex for shear force values. Shear force values were significantly less for steaks from steers and heifers of British decent compared with steers and heifers of Continental descent (P < 0.01). Steaks from implanted steers and heifers had significantly (P < 0.01) greater shear force values than steaks from steers and heifers not implanted. Use of growth implants in growing cattle resulted in significantly heavier carcass weights, larger LM area, and reduced internal fat. However, implant use also reduced the amount of marbling along with contributing to reduced tenderness. Complicating the tenderness issue is the increased shear force values reported for heifers as well as steers of Continental breed descent. Use of implants may contribute to tenderness variability because of different animal responses to implants.

Willow Creek' forage winter wheat (Triticum aestivum L.) (Reg. No. CV-1032, PI 655073) was released by the Montana Agricultural Experiment Station. Awnletted cereal forages are widely used for hay production on integrated crop- livestock operations in the Northern Great Plains. Five awnletted winter wheat accessions were evaluated for forage characteristics in 1996 and 1997, and Willow Creek was selected directly from PI 306505. Willow Creek was evaluated in replicated trials for forage yield and quality, grain yield, and agronomic characteristics from 1998 through 2008. Willow Creek is an awnletted winter wheat cultivar with good performance as an annual hay crop under irrigated or rainfed conditions in Montana and Wyoming. This cultivar has excellent winterhardiness and is tall and late-maturing. Willow Creek has good forage quality characteristics suitable for use by livestock in winter maintenance diets.

Reproduction is the most important factor to profitability of the cow herd when compared with other economically important traits, such as growth and carcass characteristics. By increasing the proportion of heifers calving at two yr of age, producers can increase the revenue and selection intensity of their herds. Therefore, the primary objective of this project was to estimate breed effects and heterosis values for heifer pregnancy. Reproductive records collected on 651 purebred and crossbred commercial beef females, comprised of Hereford, Simmental, and Tarentaise, from Montana State University's Northern Agricultural Research Center in Havre, Montana were analyzed as a binary trait. Females were born from 1976 to 1995. Data included calving records on two- and three-yr-old cows. Heifer Pregnancy was defined as a success if her first calving record was at two yr of age, but a failure if her first calving record was at three yr of age. Heifer pregnancy was able to be defined this way because young cows in this herd were not culled unless they were open for two consecutive years. Comparison of direct genetic effects showed that Simmental females were the most likely and Hereford females were the least likely to calve at two yr of age with Tarentaise being intermediate to the other two breeds. Comparison of maternal genetic effects showed that females out of Tarentaise dams were the most likely and females out of Hereford dams were the least likely to calve at two yr of age with no estimation on females out of Simmental dams. Comparison of paternal genetic effects showed that females out of Tarentaise sires were most likely and females out of Simmental sires were least likely with females out of Hereford sires being intermediate. Heterosis was estimated to be -2.79%, -0.52%, and 9.56% for direct, maternal and paternal heterosis, respectively, which is a favorable response that indicates that crossbreeding will increase the proportion of females calving at two yr of age. age.

Rebreeding a first calf heifer to produce her second calf at 3 yr of age can be challenging for beef producers. Heifers generally require more recovery time following their first calf which may delay the onset of estrus to a point beyond the normal breeding season. In an effort to improve heifer rebreeding, data on beef cows at 2 and 3 yr of age were analyzed to determine if rebreeding of first calf heifers is under any degree of genetic control. Records on 399 females born from 1976 - 2001 were analyzed to determine genetic parameters for probability of rebreeding. Animals included in the analysis were the Line 4 Herefords which are maintained at Montana State University's Northern Agricultural Research Center in Havre, Montana. Young cows in this herd were only culled if they were open, so any cow calving at 2 yr of age, but not at 3 yr of age was considered to fail at rebreeding. Overall, 69.9% of females were successful in breeding back to produce a calf at 3 yr of age. To estimate the genetic parameters associated with this trait, data were analyzed using MTDFREML with year of birth as a categorical fixed effect and percentage of individual inbreeding fit as a linear and quadratic covariate. On the observed scale, heritability was estimated to be 0.14 (0.12). Converting the observed trait to the underlying scale produced a heritability estimate for rebreeding of 0.24. Probability of rebreeding to produce a second calf at three yr of age has a genetic component and selection against females who fail to rebreed should result in a positive genetic response.

Eighty crossbred steers (average initial weight 392 kg) were used to compare the feedlot performance, nutrient digestibility, and grain energy content of 4 finishing rations based on: corn, or 'Valier,' 'Haxby,' and 'H3' barley. Grain was dry rolled prior to being fed and diets were formulated to be isocaloric (2.07 Mcal/kg NEm and 1.40 Mcal/kg NEg) and isonitrogenous (2.0% N). Diets were formulated (DM basis) to contain 80% grain, 6% straw, 3% soybean oil, and 11% vitamin/mineral supplement. Steers were weighed at the beginning and end of the 106-d study, and diet, ort, and fecal samples were collected on d 25, 53, 81, and 106. Acid insoluble ash was used as an internal marker to estimate fecal output and calculate apparent nutrient digestibility. Steers were slaughtered when 70% were visually estimated to grade Choice and carcass measurements were collected after a 24- h chill. Weight and carcass data were analyzed using the GLM procedure of SAS with pen as the experimental unit. Intake and digestibility data were analyzed as repeated measures using PROC MIXED with pen as the experimental unit. Average daily gain (P = 0.25) and G:F (P = 0.12) did not differ between treatments, averaging 1.8 kg/d and 15.5 kg gain/100 kg feed, respectively. Carcass characteristics did not differ (P > 0.13) between steers fed corn, H3, Haxby, or Valier. Starch intake was greatest (P = 0.0001) by steers fed corn, intermediate by steers fed Haxby and Valier, and lowest by steers fed H3; however, there was no difference (P > 0.12) in DM or N intake between diets. Dry matter digestibility tended to be lower (P = 0.11) for Valier and H3 diets compared to the corn diet. Digestibility of ADF was greater (P = 0.01) for the corn diet than the barley diets. Corn grain had higher (P < 0.06) NEm and NEg content than H3 and Haxby, while Valier had NEm and NEg content similar to corn and H3 but higher than Haxby. Differences in grain energy content, starch intake, and DM digestibility did not affect steer weight gains or carcass characteristics.

Angus crossbred steers were assigned randomly to one of four finishing diets based on corn, Chinook, Logan, or H3 barley. Steers were harvested and after a 72-h chill, carcass quality and yield grade data were collected. Beef ribs were removed from 72 carcasses for further analysis. Ribs were aged in vacuum bag at 2 °C for 14 days. After aging three adjacent steaks (3.18 cm) were removed to determine color stability, tenderness, proximate analysis and pH. Diets fed to steers had no effect on quality and yield grade or tenderness of beef steaks. Steaks from steers fed Logan barley variety were significantly less red at 10 days of storage (Hunter a* = 24.06) than steaks from steers fed the other barley varieties (Chinook a* = 26.4; H3 a* = 28.05) or corn (a* = 26.14). Identification of barley varieties that affect color stability could result in designing diets specifically for improved color and increase the use of barley as a finishing grain.

Records for 1971 calves produced in the Line 4 Hereford herd at the Northern Agricultural Research Center (NARC) in Havre, Montana from 1976 to 2004 were analyzed to determine the current status of this closed herd. From 1976 to 1995, selection in this line was performed using an index of adjusted yearling weight minus 3.2 times adjusted birth weight. Since 1995, selection has been based on single trait selection for scrotal circumference. Records available across the majority of years included birth weight, weaning weight, weaning wither height, and weaning condition score. The average inbreeding coefficient for calves born in 2004 was 36.4%. Genetic parameters for all traits were analyzed using a univariate model. Estimates of direct heritability (and associated s.e.) were 0.51 (0.09), 0.21 (0.07), 0.28 (0.11), and 0.24 (0.09) for birth weight, weaning weight, weaning wither height, and weaning condition score, respectively. Estimates of maternal heritability were 0.08 (0.04), 0.09 (0.06), 0.13 (0.07), and 0.09 (0.07), respectively. The estimate of the direct-maternal genetic correlation was non-significant for most traits with estimates of 0.15 (0.26), -0.12 (0.35), -0.52 (0.22), and -0.48 (0.29), respectively. The proportion of variance due to maternal permanent environmental effects was only significant for weaning weight and weaning condition score with estimates of 0.30 (0.05) and 0.14 (0.04), respectively. Birth weight direct breeding value (DBV), maternal breeding value (MBV), and phenotypic trends were estimated to be -0.005, -0.004, and -0.034 kg/yr, respectively. Weaning weight trends were estimated to be +0.289, +0.082, and +0.276 kg/yr, respectively. Weaning wither height trends were +0.025, +0.010, and -0.130 cm/yr, respectively. Weaning condition score trends were +0.0061, - 0.0002, and +0.0040 score/yr. Trends for these traits are relatively flat for the period of time studied.

Barley management options were evaluated by varying seed band width, population densities, and harvest endpoint under dryland conditions using commercial air drill technology. The trial was established in the spring under dryland conditions as a randomized complete block (r=6) with a factorial arrangement of treatments and was conducted for three years (2001, 2002 and 2003). Plots were 15.24 m by 3.04 m consisting of ten rows on 30.5 cm centers. Treatments consisted of cultivar ('Harrington' and 'Haybet'), bandwidth (narrow, 12.5 cm and wide, 19.3 cm), and population rate (140, 184 and 226 seeds/m -2 ). The initial forage cut (EARLY) was taken at soft dough, while the late (LATE) cut was seven days later. Data were analyzed using the GLM procedure in SAS. Altering the bandwidth in which the seed is placed (NARROW versus WIDE) did not affect yield, plant height or forage quality (P>0.05). Nitrate-N for the EARLY harvest was reduced 15% (P = 0.0019; NARR = 0.105% and WIDE = 0.090%). LATE harvest nitrate-N was reduced 22% (NARR = 0.092% and WIDE = 0.071%). At the highest population (226 seeds/m -2 ) DM yield was increased both for the EARLY and LATE harvest (P < 0.05). WIDE seed configuration for increasing population rates for both the EARLY and LATE harvest have a significant negative linear relationship for nitrate-N concentration (P = 0.0611 and P = 0.0378, respectively). Narrow seed configuration for increasing population rates for both the EARLY and LATE harvest have a significant quadratic relationship (P = 0.0243 and P = 0.0330, respectively). This quadratic relationship indicates that the potentially worst scenario to harvest barley forage is at the moderate seed rate in a narrow seed configuration. It appears forage quality can be altered by manipulating management options associated with seed placement and populations using air drill technology. Nitrate-N was reduced 15 and 22% by planting the seed in a wide versus a narrow row configuration. Increasing populations employing a wide bandwidth configuration decreased nitrate-N significantly as population increased, however nitrate-N levels were highest at the moderate seeding rate in the narrow row configuration.

This study evaluated the effect of barley varieties in the diets of finishing steers on carcass composition, fat, and lean color and the fatty acid profile of subcutaneous fat. Crossbred steers (391 kg initial BW) were assigned randomly to one of five finishing diets composed primarily of corn (n = 9), Morex barley (n = 9), Steptoe barley, (n = 9), or two experimental barley varieties SM3 (n = 9) and SM5 (n = 9). Grains were cracked prior to feeding. Diets were formulated (DM basis) to be isonitrogenous (2.24% N) and isocaloric (2.01 Mcal/kg NEm, and 1.35 Mcal/kg NEg). Steers were slaughtered according to industry-accepted procedures when it was visually estimated that 70% of carcasses would grade USDA Choice. After a 24-h chill at 4degreesC, carcass quality and yield grade data were collected by trained, experienced university personnel. Objective color (L*, a*, and b*) of both the LM and subcutaneous fat were measured, and samples of subcutaneous fat were removed from the 10th- to 12th-rib region for fatty acid analysis. Diet did not affect hot carcass weight (P = 0.15), fat thickness (P = 0.58), LM area (P = 0.57), percentage of internal fat (P = 0.52), yield grade (P = 0.96), marbling (P = 0.73), or quality grade (P = 0.10). However, the LM from steers fed diets formulated with Morex and SM5 barley varieties tended to be lighter (higher L* values, P = 0.08) than the LM from steers fed the corn-based diet. Additionally, fat from steers fed corn tended to be more yellow (higher Hunter b* values, P = 0.09) than fat from steers fed barley-based diets. Although grain source had only minimal effects on the fatty acid composition of subcutaneous fat samples, pentadecanoic acid (15:0) was greater (P < 0.05) in fat from steers fed SM3 and Steptoe barley varieties than in fat from steers fed corn. Stearic acid (18:0) concentrations were higher (P < 0.05) in fat samples from steers fed corn than in those fed the experimental barley lines (SM3 and SM5). Conversely, fat samples from steers fed Steptoe and SM5 barley had greater (P < 0.05) gadoleic acid (20:1) concentrations than fat from steers fed corn or Morex variety. Although the variety/line of barley included in the finishing diet may affect LM and fat color, grain-source (barley vs. corn) had little effect on beef carcass quality and yield grades and did not greatly alter the fatty acid composition of subcutaneous fat.