Alternative fall and winter feeding systems for spring calving beef cows

Could a Legume-Switchgrass Sod-Seeding System Increase Forage Productivity?

Nowadays, the lack of cattle feed, particularly green fodder, has become a key limiting factor in the agricultural economy. Switchgrass appears to offer a viable solution to the feed shortage. An improved cultivation practice might be needed to boost switchgrass forage production all season long. This study was conducted to quantify the positive effects of introducing different legume crops (vetch and pea), optimally fertilized, on the production and quality of mixed harvested switchgrass-legumes hay in late spring (May) and switchgrass hay harvested once more in early fall (September). The studied intercropping systems, independently of the legume species used, increased forage productivity (almost threefold), reaching 7.5 t ha^-1 and quality characteristics, with protein content almost rising threefold, reaching 12.5%. The aforementioned practice can assist the perennial crop (switchgrass) in providing a high hay production during the early fall harvest, even without fertilization. The overall annual economic benefit for the farmers may be increased by 90-720 € per ha, depending on the prevailing weather conditions. Overall, it may be concluded that the suggested cropping system produces a significantly higher yield of cattle feed compared to traditional monocultures, improving the agricultural economy while reducing the negative effects of modern agriculture on the environment.

Effect of stage of maturity at harvest for forage pea (Pisum sativum L.) on eating behavior, ruminal fermentation, and digestibility when fed as hay to yearling beef heifers

The objective of this study was to evaluate the stage of maturity at harvest for pea hay (Pisum sativum L., c.v. CDC Horizon) on dry matter intake (DMI), eating behavior, ruminal fermentation, and digestibility when fed to beef heifers. Pea hay was cut at EARLY (defined to occur when flat pods were on one or more nodes), MID (when seeds filled the pods at one or more nodes and the leaves were changing from green to gold), and LATE (yellow dry seeds filled pods on most or all of the nodes and the pods and leaves had a yellow color) phases, and was cured in the field and baled. Six ruminally-cannulated Speckle Park heifers were used in a replicated 3 × 3 Latin square design with three 18-d periods including 12 d for adaptation, 2 d for measurement of ruminal pool sizes, and 4 d for the collection of eating behavior, ruminal pH, ruminal digesta, and feces. For all treatments, the respective pea hay was included at 40% of the dietary DM. Stage of maturity at harvest for pea hay did not affect total DMI, pea hay DMI, or the total short-chain fatty acid concentration in ruminal fluid with averages of 8.6 kg/d, 3.2 kg/d, and 96.55 mM, respectively. The duration of time spent ruminating decreased with advancing pea hay maturity when reported as min/d, min/kg DMI, and min/kg neutral detergent fiber (NDF) (P ≤ 0.01). Mean ruminal pH also decreased with advancing pea maturity (P < 0.01). The ruminal DM and undigested NDF corrected for OM pools were not affected by stage of maturity (P ≥ 0.55) nor was the rate of digestion for NDF. However, NDF passage rate decreased by 0.21%/h with advancing pea hay maturity (P = 0.02). Apparent total tract digestibility of NDF (average = 16.30%, P = 0.41) was not affected, but starch digestibility decreased from 96.10% to 93.08% with advancing pea hay maturity (P = 0.07). Overall, stage of maturity at harvest for pea hay does not appear to affect DMI or NDF digestibililty but decreases chewing activity, apparent total tract starch digestibility, ruminal pH, and ruminal NDF passage rate.

Changes in land, feed, and manure management practices on beef operations in Canada between 2005 and 2011

The objective of this paper was to evaluate changes in management practices of beef cattle from 2005 to 2011. Large nationwide surveys of husbandry practices in the beef industry were conducted to represent management practices used in 2005 and 2011 across Canadian Ecoregions. The two surveys attempted to similarly represent operation types (cow–calf, backgrounding, and finishing) and size. Several statistically significant changes in management practices from 2005 to 2011 were observed: in non-feedlot operations, these included more operations with >50% legume in perennial forage, less N fertilization applied to forages, increased winter grazing of cows, and higher quality feed used as a supplement to grazing. In feedlots, there were more shelter structures, less feeding of grain and more of high-legume forages, and more frequent removal of manure. Several practices remained constant in the two surveys including use of covers for storing hay, frequency of harvesting forage, time of barn and feedlot cleanout, manure storage and practices relating to manure incorporation into soil. The large increase in use of winter grazing on the Prairies as well as in eastern Canada documented here is an important change in the industry that has both economic and environmental implications.

Greenhouse gas emissions of Canadian beef production in 1981 as compared with 2011

The present study compared the greenhouse gas (GHG) emissions, and breeding herd and land requirements of Canadian beef production in 1981 and 2011. In the analysis, temporal and regional differences in feed types, feeding systems, cattle categories, average daily gains and carcass weights were considered. Emissions were estimated using life-cycle assessment (cradle to farm gate), based primarily on Holos, a Canadian whole-farm emissions model. In 2011, beef production in Canada required only 71% of the breeding herd (i.e. cows, bulls, calves and replacement heifers) and 76% of the land needed to produce the same amount of liveweight for slaughter as in 1981. Compared with 1981, in 2011 the same amount of slaughter weight was produced, with a 14% decline in CH4 emissions, 15% decline in N2O emissions and a 12% decline in CO2 emissions from fossil fuel use. Enteric CH4 production accounted for 73% of total GHG emissions in both years. The estimated intensity of GHG emissions per kilogram of liveweight that left the farm was 14.0 kg CO2 equivalents for 1981 and 12.0 kg CO2 equivalents for 2011, a decline of 14%. A significant reduction in GHG intensity over the past three decades occurred as a result of increased average daily gain and slaughter weight, improved reproductive efficiency, reduced time to slaughter, increased crop yields and a shift towards high-grain diets that enabled cattle to be marketed at an earlier age. Future studies are necessary to examine the impact of beef production on other sustainability metrics, including water use, air quality, biodiversity and provision of ecosystems services.

The effects of spring versus summer calving on beef cattle economic performance in western Canada

Khakbazan, M., Durunna, O. N., Sirski, T. K., Brewin, D. G., Huang, J., Berry, N., Iwaasa, A. D., Scott, S. L., Robins, C. D., Block, H. C. and Lardner, H. A. 2015. The effects of spring versus summer calving on beef cattle economic performance in western Canada. Can. J. Anim. Sci. 95: 475–486. The choice of calving date influences the net revenue of a calving operation as it affects the number of days that calves spend in each feeding phase and when they are subsequently marketed. These two factors determine the costs, revenue, and risk (variance) of each calving system for the calving phase of a beef system. The majority of cow–calf producers in western Canada have adopted early calving (EC) in spring due to management factors. However, late calving (LC) in the summer is an alternative beef calving system associated with higher returns due to lower system costs and higher beef prices. It may offer a better match between cow nutritional requirements and pasture availability. The objective of this study was to compare the revenues and risks for a traditional EC system and an alternative LC system at three sites in western Canada. Biological and economic data from three field experimental sites in western Canada (Brandon Research Centre in Manitoba, Western Beef Development Centre in Lanigan, Saskatchewan and Semi-Arid Prairie Agriculture Research Centre in Swift Current, Saskatchewan) were used to determine the costs and benefits of the alternative beef calving system. The results showed that even though the EC has higher cost than the LC, the EC is slightly better than LC in terms of higher net revenue potential, but it comes at a greater risk due to higher revenue variances. The EC system is usually more preferable for risk-neutral producers, whereas the LC system is more preferable for risk-averse producers.

Effect of rumen degradable energy supplementation on forage utilization and performance of steers grazing stockpiled cool season perennial grass pastures

Añez-Osuna, F., Penner, G. B., Larson, K., Jefferson, P. G., Lardner, H. A. and McKinnon, J. J. 2015. Effect of rumen degradable energy supplementation on forage utilization and performance of steers grazing stockpiled cool season perennial grass pastures. Can. J. Anim. Sci. 95: 255–265. The objective of this study was to evaluate the effects of supplementing rumen degradable energy using blended by-product pellets that differed in starch and degradable fiber content on forage utilization and performance of steers grazing stockpiled cool-season perennial grass (CSPG) pastures. Forty-five yearling crossbred steers (334±23.5 kg) stratified by body weight (BW) were randomly assigned to one of nine pastures (five steers/pasture) of mature cool-season perennial grasses. Each pasture was randomly assigned (n=3) to one of three treatments: no supplement (CON); low-starch/high degradable-fibre (LSHF; 40.3% starch; 29.5% NDF) pellet and high-starch/low-degradable fibre (HSLF; 48.6% starch; 22.8% NDF) pellet, both fed daily at 0.6% of BW (DM basis). The grazing period lasted 70 d (from early-August to mid-October). Over the 70-d study, forage CP decreased from 9.9±0.82 to 6.9±0.59% of DM and digestible energy content decreased from 2.6±0.04 to 2.2±0.04 Mcal kg−1of DM. Treatment did not affect forage utilization (P=0.50; 73.4±3.15%) or forage DM intake (P=0.90; 9.0±1.54 kg d−1). Final BW and average daily gain (ADG) were not different (P>0.05) between LSHF (435±6.4 kg and 1.4±0.10 kg d−1) and HSLF (439±10.4 kg and 1.5±0.14 kg d−1) treatments. However, supplemented steers had higher (P<0.05) final BW and ADG than the control steers (402±5.6 kg and 1.0±0.09 kg d−1). These results show that unsupplemented beef steers grazing stockpiled CSPG pastures were limited in both energy and protein intake and that supplementation with by-product feed pellets formulated to supply protein and energy either as starch or degradable fibre equally improved animal performance.

Beef cattle husbandry practices across Ecoregions of Canada in 2011

Sheppard, S. C., Bittman, S., Donohoe, G., Flaten, D., Wittenberg, K. M., Small, J. A., Berthiaume, R., McAllister, T. A., Beauchemin, K. A., McKinnon, J., Amiro, B. D., MacDonald, D., Mattos, F. and Ominski, K. H. 2015. Beef cattle husbandry practices across Ecoregions of Canada in 2011. Can. J. Anim. Sci. 95: 305–321. Beef production in Canada is diverse in many dimensions with numbers of cattle per operation ranging over 10 000-fold, pasture usage from nil to 100%, and types of operations from solely cow–calf to exclusively feedlot finishing. This study summarizes management information obtained from a survey conducted in 2012 (about 2011) on 1009 beef operations in Canada. Many of the results clearly differentiate the practices in the Prairies from those in Ontario and Quebec. Compared to eastern Canada, the Prairies had earlier and shorter calving seasons, higher weaning weights, utilized more winter grazing with a variety of strategies, grew and fed more barley than corn, used more seasonal feeding areas and feedlots (and hence fewer barns), and more commonly spread manure in the fall. Many of the management practices used by cow–calf operations would have low environmental impact, including extensive use of grazing even in winter, low fertilizer inputs and feeding perennial forages with a high content of legumes. Some practices such as not covering forages or manure storage structures were common and could be changed to improve forage quality and reduce manure emissions. Most forage was harvested 3–7 d after full bloom. Earlier harvest has the potential to improve forage quality, which could reduce dependence on arable crops. Finishing operations used more housing, fed more arable-land crops and less perennial forages, and practiced little grazing. Rationale regarding the adoption of many of the management strategies was reported by the producers. For example, winter grazing was adopted primarily to reduce costs and labour, but for some it was also linked to a late calving season. Preferred sources of technical information included their own experience, farm print media, producer organisations and demonstrations at field days. The survey also identified several areas in which the industry may realize improved sustainability.

Effects of resting perennial pastures during the sensitive pre-dormancy period in western Manitoba: Pasture productivity and beef cattle performance

Durunna, O. N., Baron, V., Scott, S. L., Robins, C., Khakbazan, M. and Block, H. C. 2015. Effects of resting perennial pastures during the sensitive pre-dormancy period in western Manitoba: Pasture productivity and beef cattle performance. Can. J. Anim. Sci. 95: 129–141. The objective of this experiment was to determine whether avoiding grazing during the sensitive pre-dormancy period (ca. 6 wk prior to a dormancy-inducing frost) would improve forage production, stand quality, alfalfa persistence and animal productivity in perennial pastures. There were two pasture species (PS), alfalfa–grass (AG) or grass (G), and three grazing phases. Phase I was conventional rotational grazing of all AG and G sections. In Phase II, one half of AG and G was rotationally grazed (conventional treatment, CT) while the other half was not (rested treatment, RT). Resting AG and G in Phase II required transferring RT animals to swath-graze early-seeded cereals. In Phase III, RT animals that swath-grazed in Phase II were moved to graze the rested sections of the pastures while those that grazed the unrested sections (CT animals) were transferred to swath-graze late-seeded cereals. There was no PS (P>0.05) or rest period (P>0.13) effect on total forage yield, carrying capacity, forage disappearance and forage residues. There was no effect (P>0.13) of resting on botanical composition or yield in AG. The current study did not observe significant benefits of resting on pasture yield, botanical composition or animal performance.

The effects of spring versus summer calving on beef cattle reproductive and growth performance in western Canada

Durunna, O. N., Girardin, L. C., Scott, S. L., Robins, C., Block, H. C., Iwaasa, A. D., Khakbazan, M. and Lardner, H. A. 2014. The effects of spring versus summer calving on beef cattle reproductive and growth performance in western Canada. Can. J. Anim. Sci. 94: 259–271. The majority of beef producers in western Canada have adopted a spring calving system. Evaluating alternative calving systems such as summer calving may lead to better use of forage resources to optimize cow-calf productivity. In order to evaluate the impact of calving system on cow-calf productivity, 346 Hereford or Angus crossbred cows were used in a 3-yr research study (2007 to 2009) at Brandon, Manitoba; Swift Current, Saskatchewan and Lanigan, Saskatchewan. Cows were bred to calve from February to May (early-calving system, EC) or from May to August (late-calving system, LC). Each system was evaluated for effect on performance and reproductive efficiency. Forage yield, utilization and nutritive value were assessed. Cow body weights (BW), ultrasound measures of backfat and calf BW were evaluated at precalving, breeding and weaning. There was no difference between calving systems for pregnancy rate (P=0.13) EC (93.0%) vs. LC (95.8%); calving rate (P=0.89) EC (92.0%) vs. LC (91.7%) or proportion of calves born alive (P=0.85) EC (99.5%) vs. LC (99.6%). The average length of calving season was not different (P=0.26) between the two systems. The EC cows had greater (P=0.002) BW losses from calving to breeding but greater (P=0.001) BW gain from breeding to weaning than LC cows. Although calves born in LC had greater birth BW (P=0.003) than EC calves, calf weaning rate (P=0.01) and calf weaning BW (P<0.0001) were greater in EC. The higher weaning rate and higher weaning BW with EC has the potential to increase cow-calf productivity and may be more attractive to beef producers in western Canada.

Economic analysis and stochastic simulation of alternative beef calving and feeding systems in western Canada

Khakbazan, M., Carew, R., Scott, S. L., Chiang, P., Block, H. C., Robins, C., Durunna, O. N. and Huang, J. 2014. Economic analysis and stochastic simulation of alternative beef calving and feeding systems in western Canada. Can. J. Anim. Sci. 94: 299–311. Biological and economic data from three field-experimental sites in Manitoba (Brandon Research Centre) and Saskatchewan (Western Beef Development Centre; Semi-Arid Prairie Agriculture Research Centre) were used to determine the economic and financial benefits of alternative beef calving and feeding systems. Stochastic budgets and Monte Carlo simulation techniques were used to evaluate the profitability and risk levels of four alternative livestock beef management systems: early-calving/rapid-gain post-weaning feeding (ER), late-calving/rapid-gain post-weaning feeding (LR), early-calving/slow-gain post-weaning feeding (ES), and late-calving/slow-gain post-weaning feeding (LS). Economic budgets were constructed to evaluate the viability of different phases of beef production including backgrounding, pasture, swath grazing and finishing. Statistical analysis considered operational costs (feed, yardage, implants, medicine, labor, marketing, and other costs), price variables (fed-steer, feeder cattle, and grid pricing premiums/discounts) and steer performance measures such as average daily gain (ADG). Results from the simulation analysis revealed that late-calving systems provided higher returns for livestock producers, while rapid-feeding systems were more preferable for producers who were more risk-averse.

Effect of development system on growth and reproductive performance of beef heifers

Reproductive performance was evaluated in beef heifers born over a 2-yr period to determine the effects of target breeding weight (TBW) and development system (SYS) on growth and subsequent reproductive efficiency. Spring-born Angus heifers (253 ± 0.7 kg) were randomly allocated over 2 consecutive yr (yr 1, n = 80; yr 2, n = 96) to be developed to either 55% (350 kg) of mature BW (moderate gain, MG) or 62% (395 kg) of mature BW (high gain, HG). Each MG and HG group was further assigned to 1 of 2 replicated systems: (1) bale graze bromegrass-alfalfa round bales in field paddocks (BG) or (2) fed bromegrass-alfalfa round bales in drylot pens (DL). Heifers were fed a diet of bromegrass-alfalfa hay (56.9% TDN; 9.8% CP) and barley grain supplement (85.1% TDN; 12.3% CP). After the 202-d development period, heifers were exposed to bulls for a 63-d breeding season. Target BW × SYS interactions were not detected for any measured parameters. During the winter development period, MG heifers had lower (P = 0.01) ADG than HG heifers and MG heifers had lighter (P = 0.01) BW at breeding. The proportion of heifers attaining puberty by 14.5 mo of age was less (P = 0.05) in MG (20 ± 4%) than HG heifers (52 ± 3%). From the end of the 202-d development period to pregnancy diagnosis, ADG was greater (P = 0.04) in MG heifers than HG heifers (0.83 vs. 0.71 kg/d). First-calf pregnancy rates were 86 and 88% for MG and HG heifers, respectively (P = 0.41). Second- and third-calf pregnancy rates of cows, developed in either a MG or HG system as heifers, were not different (P = 0.74; 94.7 vs. 95.9% and 93.8 vs. 93.9%, respectively). Economic analysis revealed a $58 reduced development cost for heifers developed to 55% compared with 62% of mature BW without a loss in reproductive performance.

Effect of maturity at harvest on yield, chemical composition, and in situ degradability for annual cereals used for swath grazing

The objective of this study was to determine how harvest maturity of whole-crop cereals commonly used in swath grazing systems in western Canada affects yield, chemical composition, and in situ digestibility. We hypothesized that the increase in yield with advancing maturity would not offset the decline in digestibility and, thus, the yield of effectively degradable DM (EDDM) would decline with advanced stages of maturity. Four replicate plots of barley (Hordeum vulgare L.; cv. CDC Cowboy), millet (Panicum milliaceum; cv. Red Proso), oat (Avena sativa L., spp.; CDC Weaver), and wheat (Triticum aestivum L.; cv. 07FOR21) were grown, with a subsection in each replicate harvested at 4 different maturities: head elongation, late milk, hard dough, and fully mature. At each stage of maturity, the wet and DM yields, and chemical composition (DM, OM, NDF, crude fat, and nonfiber carbohydrates; NFC) were determined. Whole-crop samples were ground (2-mm screen) and weighed into nylon bags (pore size of 53 ± 10 µm), and duplicate incubation runs were conducted by crop type. For each incubation run, nylon bags were randomly allocated (randomized by field replication, stage of maturity, and incubation time) to 1 of 7 heifers (32 bags/heifer during each run). Degradation rates were determined using a first-order kinetic model and data were analyzed with stage of maturity as a fixed effect and plot as a random effect. The DM, OM, and NFC yields increased linearly for barley and oat (P < 0.001), and increased quadratically for millet and wheat (P ≤ 0.025). Neutral detergent fiber yield increased linearly for barley (P = 0.005) and quadratically for millet, oat, and wheat (P = 0.044). There were no changes in CP yield observed for barley, millet, or oat with advancing maturity, but there was a linear increase observed for wheat (P = 0.002). The NFC concentration increased linearly for barley, millet, and oat (P < 0.001), and quadratically for wheat (P < 0.001), whereas the EDDM concentration decreased quadratically for millet, oat, and wheat (P = 0.003). The degradation rate of NDF decreased linearly with advancing maturity (P ≤ 0.014) for millet, oat, and wheat, but was not affected for barley (P = 0.13). The yield EDDM increased linearly for barley and oat (P < 0.001), and increased quadratically for millet and wheat (P ≤ 0.025). These findings suggest that harvesting whole-crop annual cereals at the hard dough and mature stages may maximize the yield of EDDM.

Double Muscling in Cattle: Genes, Husbandry, Carcasses and Meat

Molecular biology has enabled the identification of the mechanisms whereby inactive myostatin increases skeletal muscle growth in double-muscled (DM) animals. Myostatin is a secreted growth differentiation factor belonging to the transforming growth factor-β superfamily. Mutations make the myostatin gene inactive, resulting in muscle hypertrophy. The relationship between the different characteristics of DM cattle are defined with possible consequences for livestock husbandry. The extremely high carcass yield of DM animals coincides with a reduction in the size of most vital organs. As a consequence, DM animals may be more susceptible to respiratory disease, urolithiasis, lameness, nutritional stress, heat stress and dystocia, resulting in a lower robustness. Their feed intake capacity is reduced, necessitating a diet with a greater nutrient density. The modified myofiber type is responsible for a lower capillary density, and it induces a more glycolytic metabolism. There are associated changes for the living animal and post-mortem metabolism alterations, requiring appropriate slaughter conditions to maintain a high meat quality. Intramuscular fat content is low, and it is characterized by more unsaturated fatty acids, providing healthier meat for the consumer. It may not always be easy to find a balance between the different disciplines underlying the livestock husbandry of DM animals to realize a good performance and health and meat quality.

Bioperformance evaluation of various summer pasture and winter feeding strategies for cow-calf production

Legesse, G., Small, J. A., Scott, S. L., Kebreab, E., Crow, G. H., Block, H. C., Robins, C. D., Khakbazan, M. and McCaughey, W. P. 2012. Bioperformance evaluation of various summer pasture and winter feeding strategies for cow-calf production. Can. J. Anim. Sci. 92: 89–102. Bioperformance of two summer pasture and four winter feeding cow-calf production strategies in the western Canadian Parkland was evaluated. Diet composition and animal data were collected over 5 production years. Each production year began with fixed-time artificial insemination (TAI) of cows and turnout of cow-calf pairs (n=288 yr−1 including 76 primiparous replacement cows) assigned to either alfalfa-grass (AG, n=9 paddocks) or grass (G, n=9 paddocks) pastures until weaning. Post-weaning, pregnant cows (n=240 yr−1) were assigned to either extended-grazing (EG, n=120) of dormant regrowth of perennial pastures and swathed annual crops, or one of three diets fed in a drylot (DL): hay (HY, n=40), straw/barley (SB, n=40; 70% oat straw:30% steam-rolled barley grain DM), and silage/straw (SS, n=40; 40% barley silage:60% oat straw DM). Common diets were used for all treatment groups between the weaning and winter feeding period, as well as between the pre-calving and summer grazing period. Cow and calf body weight (BW) gains were higher (P<0.05) for AG than G pasture until the third production year and the advantage diminished as the carrying capacity declined. The latter may be attributed to a lack of spring/summer moisture. Further, G pastures required more nitrogen fertilizer to achieve the same level of bioperformance as that of AG pastures in years 4 and 5. Cows in the EG treatment maintained BW better than those in the DL treatment (especially those cows receiving the SS diet) except in year 5 (P<0.05) in which drought resulted in lower body weights for cows in the EG treatment. On all treatments, cows maintained BCS that supported reproductive function; however, fertility to TAI was lowest (P<0.05) in years 4 and 5. Cows in the DL group had a 1.8 times greater risk of being culled before turnout and as a result lower (P<0.05) rates of calf survival to weaning. In conclusion, AG pastures and EG are important alternatives to further develop for cow-calf production in western Canada.