Steer Average Daily Gain Research Articles

485 Impact of annual and perennial forage systems on forage biomass and quality, steer performance, and enteric methane emissions

Abstract Beef producers require forage options that provide adequate yield and high nutritive value, optimizing the production and sustainability of grazing operations. Few multiple year studies within Canada compare novel perennial and annual grass legume blends under grazing. This study evaluated the effects of perennial and annual forage systems on forage biomass and quality, grazing animal performance, and enteric emissions. Forage treatments included 1) AC Success hybrid bromegrass (Bromus riparius Rehm. × Bromus inermis Leyss.) + PS3006 alfalfa (Medicago sativa L.; HBG-ALF), 2) AC Armada meadow bromegrass (Bromus riparius Rehm.) + AAC Mountainview sainfoin (Onobrychis viciifolia Scop.; MBG-SF), 3) AC Hazlet fall rye (Secale cereale L.) + Frosty berseem clover (Trifolium alexandrinum L.; FR-CLOV), and 4) Winfred forage brassica (Brassica oleracea L.× Brassica rapa L.) + Gorilla forage brassica (Brassica napus L.) + 4010 pea (Pisum sativum L.) + CDC Austenson barley (Hordeum vulgare L.; BR-PE-BRAS). Yearling beef steers [n = 120, body weight (BW) = 397 ± 10 kg] were randomly allocated to 1 of 4 replicated (n = 3) forage systems for an average of 65 d grazing period amongst the 12 paddocks. Dry matter yield (DMY) was similar (P = 0.33) between BR-PE-BRAS (2,170 kg/ha) and HBG-ALF (1938 kg/ha), which were greater (P < 0.0001) than both MBG-SF (1030 kg/ha) and FR-CLOV (700 kg/ha) systems. Total digestible nutrient content (TDN) of FR-CLOV (63.6%) and BR-PEA-BRASS (62.0%) was greater (P < 0.0001) than both MBG-SF (51.7%) and HBG-ALF (49.3%) forages. Crude protein (CP) was greatest in FR-CLOV (15.2% P = 0.0012) intermediate in BR-PEA-BRASS (10.0%) and HBG-ALF (8.5%), and least in MBG-SF (6.6%). Steer performance was greatest when grazing HBG-ALF (87 kg/ha) paddocks, which was similar (P = 0.31) to FR-CLOV (62 kg/ha) and similar (P = 0.10) MBG-SF (51 kg/ha), but greater (P = 0.01) than BAR-PEA-BRASS (26 kg/ha). Enteric methane concentration from steers was the least when grazing BR-PE-BRAS (19.7g/kg DMI), followed by FR-CLOV (22.4g/kg DMI), MBG-SF (23.4g/kg DMI) and finally HBG-ALF (28.1g/kg DMI). In summary, BR-PE-BRAS and HBG-ALF forage systems provided the greatest DMY, while steer average daily gain (ADG) grazing HBG-ALF forage outperformed steers on BR-PE-BRAS paddocks. Forage energy and protein was greater in annual forage systems FR-CLOV and BR-PE-BRAS, compared with perennial forage systems. Enteric methane levels were the lowest in the steers grazing BR-PE-BRAS forage.

Does adding legumes to tall fescue pastures before stockpiling improve productivity and animal performance?

AbstractThe rising prices of N fertilizer led to exploring cost‐saving efforts, such as intercropping cool‐ or warm‐season legumes serving as alternative sources of N for managing fall‐stockpiled tall fescue [Schedonorus arundinaceus (Schreb.) Dumort.; TF]. We aimed to evaluate red clover (Trifolium pratense L.; RC) and sunn hemp (Crotalaria juncea L.; SH) mixed with TF as alternative sources of N for stockpiling TF to increase productivity and animal performance. The experiment was conducted in Crossville, TN, in 2020 and 2021 and consisted of TF pastures mixed with RC (TRC) or SH (TSH), and TF fertilized with urea (TU). The experiment was divided into two periods: the pre‐grazing period (stockpiling) (April–October) and the grazing period (October–December). After the stockpiling period, Black Angus beef (Bos taurus) steers were used for the grazing period. The study evaluated the botanical composition, herbage mass (HM), nutritive value, steer average daily gain (ADG), and net returns (NR). The TRC pastures had a greater proportion of legumes compared to TSH plots in May, October, November, and December of both years. There were no differences among treatments for the total HM and nutritive value in 2020; however, in 2021, TU had greater HM at the beginning of the grazing period and greater average crude protein values compared to the other treatments. In both years, there were no differences among treatments for ADG or NR. Therefore, producers can make the same profit considering the beef steer price and the cost of conventional and alternative N sources.

89 Improving cattle grazing efficiency with multi-functional cover crops

Abstract Grazing cool-season cover crops provides a sustainable way of extending the grazing season and reducing the impact row-crop farming systems on the environment. Cover crops promote soil health; however, the impacts of grazing cover crops on soil health in the Southeast are not well understood. The objective of the current study was to determine the effects of different cover crop mixtures on a cotton (Gossypium hirsutum)-peanut (Arachis hypogaea) cropping system. The experiment consisted of 18 paddocks, planted in mixtures of grass [‘Coker’ oat (Avena sativa)], grass + legume [‘Dixie’ crimson clover (Trifolium incarnatum)], or grass + legume + brassica [(‘T-raptor’ brassica (Brassica napus × B. rapa)] planted at the Wiregrass Research and Extension Center (Headland, AL). Paddocks were randomly allocated to grazed or not grazed (n = 3). Grazed paddocks were grazed with yearling beef steers (266 ± 44 kg) using the put and take method to maintain a forage alloance of 1 kg DM per kg BW. Forage samples were collected every 2 wk, for biomass, botanical compositions, and nutritive value. Paddocks were grazed from 17 Jan – 22 Mar 2023 (65 d) and steer BW were taken at the beginning and end of the grazing season for calculation of average daily gain Data were analyzed using Proc Glimmix of SAS 9.4 (SAS Institute, Cary, NC) with forage sampling date considered a repeated measure. No difference in steer average daily gain was detected among grazed treatments (1.5 kg/d; P > 0.44). Cover crop (forage) biomass was also not different among all grazed and ungrazed treatments (1,097 kg DM/ha; P = 0.56). According to the results, grazing cool-season annual cover crops may reduce the supplementation required to maintain cattle through the winter months in the Southeast.

Supplementing a Bacillus-based probiotic to high-risk stocker cattle.

This experiment evaluated the performance, health, and physiological responses of high-risk steers receiving a Bacillus-based probiotic during a 90-d grazing period. A total of 240 Angus-influenced steers were used in this experiment that was replicated over 2 yr (120 steers/year). Each year, steers were obtained from an auction yard and transported to the experimental facility (120 km). Steer body weight (BW) was recorded at arrival (day -1), and this value was averaged with BW recorded on day 0 to represent the initial BW (236.6±1.5kg). On day 0, steers were ranked by BW and allocated to 1 of 12 pastures with stockpiled native grass (4-ha pastures; 10 steers/pasture). Pastures were randomly assigned to receive daily supplementation with dried distillers' grains at 1% of BW containing either: 1) Bacillus subtilis + B. licheniformis probiotic (BOV; 2g/steer daily of Bovacillus; Novonesis, Horsholm, Denmark) or 2) no feed additive (CON). Cattle received treatments from days 0 to 90, in addition to free-choice access to water and mineral + vitamin mix without ionophore. Steers were assessed for bovine respiratory disease (BRD) signs daily. Blood samples were collected and full BW was recorded on days 0, 14, 28, 56, and 90. Shrunk BW was recorded on day 91 after 16h of feed and water restriction, and a 4% pencil shrink was used to calculate the final BW. Average daily gain (ADG) was calculated based on initial and final BW. No treatment effects were detected (P ≥ 0.73) for steer final BW and ADG. A treatment × day interaction was detected (P ≤ 0.05) for plasma haptoglobin concentration, which was greater for CON steers on days 14 and 28 (P ≤ 0.02). Incidence of BRD signs did not differ (P = 0.97) between treatments (51.7% and 51.3% for BOV and CON, respectively; SEM = 7.70). However, steer mortality + removals for health complications were greater (P = 0.01) in CON compared to BOV (0.00% vs. 5.04%, respectively; SEM = 1.41). Supplementing BOV improved (P ≤ 0.04) total pasture-based liveweight change (643 vs. 502kg/pasture, respectively; SEM = 45) and final pasture-based total liveweight (3,007 vs. 2,869kg/pasture, respectively; SEM = 46). Collectively, supplementation with a probiotic based on B. subtilis and B. licheniformis to high-risk stocker cattle did not alleviate the incidence of BRD signs nor improved ADG, but decreased acute-phase protein response, reduced steer mortality + removal, and increased pasture-based productivity during a 90-d grazing period.

Interaction of Sweet Bran inclusion and corn processing method in beef finishing diets.

The study objective was to determine the effects of corn processing method and Sweet Bran (Cargill, Blair, NE) inclusion in beef finishing diets on performance and carcass characteristics. Four hundred and eighty crossbred yearling steers (363 ± 15kg) were assigned to a 2 × 3 factorial arrangement of treatments, consisting of two corn processing methods, steam-flaked corn (SFC) or a high-moisture corn: dry-rolled corn blend (HMC: DRC), and three inclusions of Sweet Bran (0%, 20%, or 40% of diet dry matter). Data were analyzed using the MIXED procedure of SAS as a generalized block design with pen as the experimental unit and block as a fixed effect. Dry matter intake increased linearly as Sweet Bran increased in the diet, regardless of corn processing method (P < 0.01). A corn processing × Sweet Bran interaction (P < 0.01) was observed for feed efficiency (G:F), average daily gain (ADG), and hot carcass weight (HCW). The G:F of steers fed SFC did not change with increasing Sweet Bran concentrations (P = 0.19) and the G:F of SFC-fed steers was 12.4% greater than those fed HMC:DRC without Sweet Bran, but was only 5.3% greater when Sweet Bran was included at 40% (P = 0.04). The ADG of steers increased linearly with increasing concentration of Sweet Bran in both SFC and HMC:DRC-based diets. However, the interaction occurred (P < 0.01) because ADG increased at a greater rate in HMC:DRC-based diets (1.93 to 2.21kg/d for 0% and 40% Sweet Bran, respectively) compared to SFC-based diets (2.18 to 2.27kg/d for 0% and 40% Sweet Bran, respectively;). Accordingly, while the ADG of steers fed SFC was 13% greater than steers fed HMC:DRC without Sweet Bran (P < 0.01), there was no difference in ADG due to corn processing method at 40% Sweet Bran (P = 0.30). In SFC-based diets, HCW tended to increase from 446 to 455kg as Sweet Bran increased (P = 0.06). In HMC: DRC-based diets, HCW linearly increased from 421 to 449kg (P < 0.01), resulting in similar HCW at 40% Sweet Bran (P = 0.28). These data suggest HMC:DRC-based diets are more competitive with SFC-based diets due to similar gains and more similar feed efficiencies when Sweet Bran is fed.

A complex mineral additive for feeding of steers of Black-and-White breed

The need for minerals is so high that without their additional introduction into the ration it is impossible to ensure the normal growth and development of young animals. The purpose of the research was the use of diff erent doses of a complex mineral additive in the rations of steers in diff erent rearing periods. The research was carried out on steers of Black-and-White breed under the conditions of LLC “Sever” in the Kurtamyshsky district of the Kurgan region. The possibilities of increasing the productivity of steers with the use of a complex mineral additive including 11 mineral components that compensate for the rations of steers for phosphorus, magnesium, manganese, copper, zinc, cobalt and selenium, which contributes to an increase in live weight and average daily gain of steers. It was found as a result of the conducted studies that feeding the complex mineral additive when rearing of steers together with the main ration in the age period of 6–9 months contributed to a greater increase in live weight by 2,38 and 5,22 kg per head. The average daily gain in live weight of steers during this period in the 1st and 2nd experimental groups was higher by 4,22 and 8,87 %, compared with herdmates of the control group. The live weight of the control group steers at the age of 12 months was 306,25 kg, in the experimental groups 311,40 and 324,10 kg, the superiority was 5,15 and 17,85 kg (p &lt; 0,05). The average daily gain in live weight during the rearing period of 9–12 months in the experimental groups of steers was higher than 3,15 and 14,39 % compared with the steers of the control group.

8 Impact of Increasing Level of Milk Production on Cow and Calf Performance in the Nebraska Sandhills

Abstract Selection for increased milk production across the United States has resulted in variable cow and calf productivity responses. The calf growth response variability may be due to the relationship between calf milk and forage intake, which nursing and grazing behavior may help explain. The objectives of this study were to determine the impact of increasing level of milk production on cow body weight (BW), body condition score (BCS), reproductive performance, calf growth, nursing, and grazing behaviors in the Nebraska Sandhills. In a 2-yr study, data were collected on 118 mature crossbred cow-calf pairs from March- and May-calving herds. On approximately 30, 60, 90, 120, and 210 d postpartum, individual cow 24-h milk yield was estimated through weigh-suckle-weigh techniques. Cow BW and BCS were collected 14 d prior to calving, weekly from d 30 through breeding, and at weaning. Calf BW was recorded at each milking. Calf nursing and grazing behaviors were determined during 3-wk periods at EARLY (65.4 ± 10.0 d) and LATE (162 ± 22.3 d) lactation using high frequency (1 hz) global positioning system (GPS) data collected with neck collars. Milk area under the curve values were calculated to determine total milk production during lactation for each cow and all response variables were analyzed using linear regression analysis. Cow BW, BW change, and reproductive performance were not (P &amp;gt; 0.12) associated with total milk production, except for a tendency (P = 0.09) for lower BW at breeding with increased milk production. At weaning, cow BCS was negatively associated (P = 0.02) with increasing milk production but was not associated at any other physiological stage. Calf percent of time spent grazing was not affected (P = 0.33) by increasing dam milk production. However, percent of time nursing exhibited a tendency (P = 0.10) to decrease with increasing dam milk production. Pre-weaning calf BW was positively associated (P &amp;lt; 0.01) with increased milk production at each weigh date. A positive association of calf average daily gain (ADG) with increasing dam milk production was observed (P &amp;lt; 0.04) from birth to age 120 d with only a tendency (P = 0.09) for a positive association observed from age 120 d to weaning. However, steer ADG in the finishing phase was not associated (P = 0.63) with level of dam milk production. In this study and environmental conditions, increasing milk production had a positive increase in calf growth during the pre-weaning phase without any negative impact reproduction.

Beef Steer Performance on Irrigated Monoculture Legume Pastures Compared with Grass- and Concentrate-Fed Steers.

Simple SummaryMost U.S. beef calves are finished on grain-based rations, but a small proportion are finished on grass-dominated pastures. A number of temperate perennial legumes thrive when cultivated under irrigation in the U.S. Mountain West, including alfalfa, sainfoin, birdsfoot trefoil and cicer milkvetch. With the exception of alfalfa, these are non-bloating legumes, and all have fiber and non-fiber carbohydrate concentrations more similar to feedlot rations than to grass. This 3-year study was undertaken to compare the average daily gain of steer calves on monoculture legume pastures to the gain of calves on concentrate diets; in the final year, a grass pasture treatment was added. Gains of calves on birdsfoot trefoil pastures were two-thirds to three-quarters that of concentrate-fed calves; gains on cicer milkvetch pastures were about half that of concentrate-fed calves, and gains on grass pasture were about one-third that of concentrate-fed calves. The elevated gains of birdsfoot trefoil-fed calves compared with grass-fed calves were likely due to greater intake combined with the presence of a condensed tannin that precipitates excess plant protein in the rumen but does not interfere with post-ruminal digestion. Perennial legume pastures are a sustainable alternative to feedlot finishing for western U.S. beef producers.Fall- or spring-born steers grazed monoculture irrigated birdsfoot trefoil (BFT; Lotus corniculatus L.) or cicer milkvetch (CMV; Astragalus cicer L.) pastures for approximately 12 weeks for 3 years and were compared with steers on concentrate diets. In the 3rd year, an irrigated meadow bromegrass (MBG; Bromus biebersteinii Roem. and Schult.) pasture treatment was added for further comparison. Steer average daily gain (ADG) was 1.31, 0.94, 0.83 and 0.69 kg d−1 on concentrate, ‘Norcen’ BFT, ‘Oberhaunstadter’ BFT, and ‘Monarch’ CMV diets, respectively; ADG on grass pastures was 0.43 kg d−1. The ADG on the concentrate diet was greater than ADG on legume or grass pastures, ADG was greater on BFT than CMV in every year (p < 0.03), and ADG on BFT was greater than ADG on grass (p < 0.03). The rate constant of gas production of an in vitro rumen fermentation demonstrated a slower rate of microbial digestion for CMV than for BFT. The elevated ADG on BFT pastures may be due to greater non-fiber carbohydrate (NFC) concentration and reduced neutral detergent fiber (NDF) concentration combined with condensed tannins that protect proteins in the rumen but do not impede protein digestion in the abomasum and intestines.

Vegetation and Animal Performance Responses to Stocking Density Grazing Systems in Nebraska Sandhills Meadows

Management-intensive grazing, which is proposed to increase forage and animal productivity and maintain soil integrity and biodiversity, is seen as an alternative to meet 21st century agricultural and environmental challenges. The purpose of this study was to test the hypothesis that high levels of trampling of standing vegetation associated with mob grazing (a.k.a., ultrahigh stocking density) leads to increased plant diversity and productivity. A long-term experiment was established on a subirrigated meadow in the Nebraska Sandhills as a complete block design comparing three grazing treatments applied annually during the growing season for 8 consecutive yr (2010−2017): 120-pasture rotation with one grazing cycle (mob; 225 000 kg live weight ha−1), four-pasture rotation with one grazing cycle (4PR1; 7 000 kg live weight ha−1), and four-pasture rotation with two grazing cycles (4PR2; 5 000 kg live weight ha−1). All treatments were set at a moderate stocking rate (7.4 animal unit months ha−1) using yearling steers. Percentage trampling, plant production, species composition, and steer weight gain were estimated annually. We applied linear mixed-effect models to account for year and treatment effect on the response variables. Percentage trampling on mob pastures ranged from 40% to 55% over the 8 yr of the study, nearly double that of the 4PR1 and 4PR2 pastures. We observed that mob grazing had no overall effect on plant species composition, aboveground production, and root growth relative to low stocking densities. Average daily gain of steers in the mob pastures was less than gain of steers in 4PR2 pastures in all years, with intermediate weight gains for the 4PR1 steers. Overall, stocking density did not appear to be a driver of plant composition and productivity in rotationally grazed pastures on subirrigated meadows in the Nebraska Sandhills.

102 Effects of Cattle Removal Date on Forage Production and Steer Performance in Grazed Cover Crops

Abstract Grazing of cool-season cover crops has been shown to be a viable tool in extending the grazing season while mitigating environmental risks associated with row crop farming systems. Grazing cover crops is not novel, but most information available on this practice focuses on soil health as opposed to forage production and animal performance. The objective was to evaluate the effects of cattle removal date on steer performance, forage yield, and forage quality. Twelve 1.2-ha pastures were established in a forage mix consisting of ‘Cosaque’ oats (Avena strigose), ‘FL401’ cereal rye (Secale cereale), ‘AU Sunrise’ crimson clover (Trifolium incarnatum), and ‘T-raptor’ brassica (Brassica napus ×B. rapa) and randomly allocated to be grazed through either mid-February (FEB), mid-March (MAR), or mid-April (APR) with an un-grazed control (CON). Three tester steers were randomly placed in each paddock with the exception of CON and allowed ad libitum grazing. Animals were weighed every 30 d for determination of average daily gain (ADG). Forage was harvested bi-weekly and analyzed for average yield, NDF, ADF, and CP. All data were analyzed using MIXED procedure of SAS version 9.4 (SAS Inst., Cary, NC). The following data represents the first three years of a four-year project. Differences in yield were detected between CON and FEB (3,913 vs. 2,398 kg/ha; P &amp;lt; 0.001), CON and MAR (3,913 vs. 1,908 kg/ha; P &amp;lt; 0.001), and CON and APR (3,913 vs. 2,126 kg/ha; P &amp;lt; 0.001). A difference in CP was detected between MAR and CON (13.36% vs. 11.78%; P &amp;lt; 0.02). No differences were detected for ADG (1.2 kg/day, P = 0.56), NDF (52.48%, P = 0.99), or ADF (30.82%, P = 0.4) among treatments. These results indicate that grazing will reduce forage yield, but removal date of cattle will not further affect forage yield or steer average daily gain.

Dietary inclusion of ruminally protected linseed oil as a means to mitigate heat and slaughter-induced stress in feedlot cattle.

There is evidence of a relationship between increased energy intake and the development of metabolic inflammation and insulin resistance (IR), and between the aforementioned metabolic state and impaired tolerance to heat stress. Based on the anti-inflammatory properties and mitigating effects on IR and stress of n-3 polyunsaturated fatty acids (n-3 PUFA), an experiment was performed to evaluate the effect of n-3 PUFA supplementation to feedlot-finished steers during summer on animal performance, physiological and biochemical variables associated with glucose metabolism, heat and preslaughter-induced stress, and meat quality. A total of 48 Angus steers (388±2kg) were fed one of three corn-based finishing diets containing (dry matter basis) 0% added oil (CON; negative control), or 1.90% of sunflower oil-calcium salt (SUN; positive control), or 1.92% of linseed oil-calcium salt (LIN). There was a trend (P = 0.08) for greater dry matter intake (DMI) and greater (P = 0.02) average daily gain (ADG) in LIN-fed animals compared with the average between those that received the CON or SUN diets, whereas no differences (P ≥ 0.34) were observed between the latter. No other performance, physiological, or carcass variables were affected (P ≥ 0.12) by treatment. Blood glucose and insulin were similar (P ≥ 0.14), though the homeostatic model assessment (HOMA) which gauges IR tended (P = 0.06) to be reduced for LIN-fed animals compared with the average between those that received the CON or SUN diets. Blood insulin and HOMA increased linearly (P ≤ 0.01) with days on feed. An interaction between the study phase (feeding period or slaughter) and treatment was observed (P ≤ 0.05) for glucose and cortisol. While the magnitude of glucose increase (P < 0.01) from the end of the feeding period to slaughter was greater for CON- and SUN-fed animals compared with LIN-fed ones, cortisol increased (P < 0.05) only in animals that received CON or SUN diets. Meat quality attributes were not affected (P ≥ 0.16) by treatment. The concentration of n-3 PUFA was greater (P < 0.01) and n-6:n-3 ratio was lesser (P < 0.01) in meat from LIN-fed animals compared with that resulting from the average between the animals that received the negative (CON) or positive (SUN) control diets. Results suggest that n-3 PUFA supplementation mitigated metabolic alterations associated with IR and preslaughter-related stress. It may have also improved tolerance to heat, resulting in greater DMI and ADG of steers fed a high-energy diet during summer. Results also indicate that glucose metabolism and heat stress tolerance worsen with time when feeding concentrate-based diets.

PSIV-8 Effect of pre-grazing herbage mass, post-grazing sward height and finishing diet on performance of late-maturing beef steers

Abstract Grazing sward structure can influence animal performance in forage-only and forage plus concentrate-based production systems. The objective was to determine the effects of pre-grazing herbage mass (PGHM), post-grazing sward height (PGSH) and indoor finishing diet on performance of weaned, spring-born beef steers. Steers (n = 96, ca. 12 months of age, 396 ± 20.1 kg) previously fed grass silage only over the first winter, were assigned to one of twelve grazing groups, balanced for live weight. Grazing groups were randomly assigned to a two PGHM (1500 or 2500 kg DM/ha) × two PGSH (4 or 6 cm) factorial arrangement of treatments (n = 3 groups/treatment). Steers rotationally grazed Lolium perenne-dominant swards (not mechanically topped) for 222 days. Steers were then accommodated indoors and offered grass silage only (SO) or grass silage + 3.8 kg concentrate DM/head daily (SC) for a 146 day finishing period. Data were analysed using the mixed procedure of SAS with terms for PGHM, PGSH, finishing diet and their interactions in the model. Grazed herbage intake was unaffected by PGHM but was greater for PGSH-6 than PGSH-4 (6.94 vs. 6.18 kg DM/day; P &amp;lt; 0.001). Steer average daily gain at pasture was greater for PGHM-1500 than PGHM-2500 (0.65 vs. 0.60 kg; P &amp;lt; 0.05) and for PGSH-6 than PGSH-4 (0.70 vs. 0.55 kg; P &amp;lt; 0.001). After indoor finishing, carcass weight was unaffected by PGHM, but was heavier for PGSH-6 than PGSH-4 (386 vs. 367 kg; P &amp;lt; 0.01); carcass traits were unaffected by PGHM or PGSH. Carcasses were heavier (+43 kg), fatter (P &amp;lt; 0.001) and more conformed (P &amp;lt; 0.01) for SC than SO. In conclusion, both PGHM-2500 and PGSH-4 restricted animal growth at pasture; however, following an indoor finishing period, carcass weight did not differ between PGHM, but was heavier for PGSH-6 than PGSH-4.

PSXIII-17 Supplementing organic-complexed or inorganic Co, Cu, Mn, and Zn to beef cows during gestation: post-weaning responses of offspring reared as replacement heifers or feeder cattle

Abstract Beef cows and their progeny were used to evaluate the effects of supplementing organic-complexed or inorganic Co, Cu, Mn, and Zn during gestation: on offspring reared as replacement heifers or feeder cattle. Non-lactating, pregnant beef cows (n = 190) were ranked by parity, pregnancy type, body weight (BW) and body condition score (BCS), at 117 ± 2.2 d of gestation (d 0) and assigned to receive a supplement containing: 1) sulfate sources of Cu, Co, Mn, and Zn (INR; n = 95) or 2) an organic complexed source of Cu, Mn, Co, and Zn (AAC; Availa®4; Zinpro Corporation, Eden Prairie, MN; n = 95). From d 0 to calving, cows were maintained in a single pasture and individually offered treatments three times a week. Calves were weaned at 6 mo of age (d 367) and preconditioned for 45-d. Heifer puberty status was verified weekly (d 437 to d 619) based on plasma progesterone concentrations. Steer calves were shipped to a commercial feedlot on d 493, where they were managed as a single group until slaughter (d 724). Plasma cortisol concentration was greater (P = 0.05) in AAC calves at weaning but tended to be less (P = 0.10) on d 370 compared with INR calves. Mean plasma haptoglobin concentration was greater (P = 0.03) in INR vs. AAC calves during preconditioning, and no treatment effects were noted (P = 0.76) for preconditioning average daily gain (ADG). Puberty attainment was hastened in AAC heifers during the experiment (treatment × day; P &amp;lt; 0.01), despite similar (P = 0.39) ADG between treatments from d 412 to 620. No treatment effects were detected (P ≥ 0.24) for steer ADG from d 412 until slaughter, nor for carcass quality traits. Therefore, supplementing Co, Cu, Zn, and Mn as organic complexed instead of sulfate sources to beef cows during the last 5 mo of gestation did not improve performance of steer progeny until slaughter, but hastened puberty attainment in female progeny reared as replacement heifers.

Supplementing organic-complexed or inorganic Co, Cu, Mn, and Zn to beef cows during gestation: postweaning responses of offspring reared as replacement heifers or feeder cattle.

One hundred and ninety nonlactating, pregnant beef cows (¾ Bos taurus and ¼ Bos indicus; 138 multiparous and 52 primiparous) were assigned to this experiment at 117 ± 2.2 d of gestation (day 0). Cows were ranked by parity, pregnancy type (artificial insemination = 102, natural service = 88), body weight (BW) and body condition score, and assigned to receive a supplement containing: (1) sulfate sources of Cu, Co, Mn, and Zn (INR; n = 95) or (2) an organic complexed source of Cu, Mn, Co, and Zn (AAC; Availa4; Zinpro Corporation, Eden Prairie, MN; n = 95). The INR and AAC provided the same daily amount of Cu, Co, Mn, and Zn, based on 7 g of the AAC source. From day 0 to calving, cows were maintained in a single pasture and segregated 3 times weekly into 1 of 24 individual feeding pens to receive treatments. Calves were weaned on day 367 (200 ± 2 d of age), managed as a single group for a 45-d preconditioning period (days 367 to 412), and transferred to a single oat (Avena sativa L.) pasture on day 412. Heifer calves were moved to an adjacent oat pasture on day 437, where they remained until day 620. Heifer puberty status was verified weekly (days 437 to 619) based on plasma progesterone concentrations. Steer calves were shipped to a commercial feedlot on day 493, where they were managed as a single group until slaughter (day 724). Plasma cortisol concentration was greater (P = 0.05) in AAC calves at weaning but tended to be less (P = 0.10) on day 370 compared with INR calves. Mean plasma haptoglobin concentration was greater (P = 0.03) in INR vs. AAC calves during preconditioning, and no treatment effects were noted (P = 0.76) for preconditioning average daily gain (ADG). Puberty attainment was hastened in AAC heifers during the experiment (treatment × day; P < 0.01), despite similar (P = 0.39) ADG between treatments from days 412 to 620. Expression of myogenin mRNA in the longissimus muscle was greater (P = 0.05) in INR vs. AAC heifers on day 584. No treatment effects were detected (P ≥ 0.24) for steer ADG from day 412 until slaughter, nor for carcass quality traits. Hepatic mRNA expression of metallothionein 1A was greater (P = 0.02) in INR vs. AAC steers on day 586. In summary, supplementing Co, Cu, Zn, and Mn as organic complexed instead of sulfate sources to beef cows during the last 5 mo of gestation did not improve performance and physiological responses of the steer progeny until slaughter, but hastened puberty attainment in the female progeny reared as replacement heifers.

Forage production and steer performance in fertilized smooth bromegrass and smooth bromegrass–legume pastures

AbstractSmooth bromegrass is a commonly used cool‐season pasture grass that responds favorably to annual spring fertilization, but annual fertilizer applications require annual inputs of both time and expense. This study was conducted to determine if interseeding legumes into established smooth bromegrass pasture is a viable alternative to spring fertilization. Steers (Bos taurus) were rotationally grazed in either fertilized smooth bromegrass pastures or smooth bromegrass pastures interseeded with legumes. Data were collected on forage production, forage available at the beginning of each grazing rotation, steer weight gain, and the number of grazing days. Total forage production for the growing season was not different between the pasture types, but fertilized pasture had greater available forage early in the growing season and interseeded pasture had greater forage production late in the growing season. Season‐long average daily gain of steers was not different between pasture types, but daily gains were greater in interseeded pasture late in the growing season and may be linked to proportionally greater abundance of legumes late in the season. Beef production ac–1 was higher in interseeded pastures, largely due to increased days of grazing. We found that interseeding legumes into established pasture can be a viable alternative to annual spring fertilization and may outperform fertilized pasture depending on the metric and growing conditions.

Stocking rate impacts performance and economics of grazing beef steers on mixed-grass prairies of the Southern Great Plains.

Stocking rate is a fundamental management factor that has major impacts on animal performance, profitability, and long-term sustainability of native range ecosystems. This research was conducted to determine the effects of stocking rate on performance and economics of growing steers grazing a mixed-grass prairie on a rolling upland red shale ecological site at the Marvin Klemme Range Research Station (35° 25′ N 99° 3′ W). The recommended sustainable stocking rate at this location is suggested to be 25 animal unit days (AUD)/ha. Steers [n = 836, initial body weight (BW) ± SD = 216 ± 11.7 kg] grazed at seven stocking rates ranging from 4.13 ha/steer to 1.83 ha/steer over a 7-yr period, from 1990 to 1996, with year considered the random replication. During the experimental period, overall climatic conditions were favorable for forage production with average growing season precipitation of 118% of the long-term average over the 7-yr experiment, and only 1 yr (1994 with only 57% of the long-term average) with growing season precipitation substantially less than the long-term average. Over the entire summer grazing season, average daily gain (ADG) decreased linearly (P < 0.01) with increasing stocking rate, such that for each additional hectare available per steer ADG increased by 0.05 kg/d (R2 = 0.88). Contrary to ADG, BW gain per hectare over the grazing season increased linearly (P < 0.01) with increasing stocking rate, as stocking rate increased from 4.13 ha/steer to 1.83 ha/steer BW gain per hectare doubled from 33.1 kg/ha to 66.8 kg/ha, respectively. With land costs included in the economic analysis, net return per hectare increased linearly (P < 0.01) from $13 [U.S. Dollars [USD]) at the 4.13 ha/steer to $52/ha at the 1.83 ha/steer. For each additional hectare per steer, net return was reduced by $15.80 (USD)/steer and $15.70 (USD)/ha. In favorable climatic conditions, such as during this 7-yr experiment, economically optimal stocking rates can be more than doubled compared with the stocking rate recommended by the United States Department of Agriculture (USDA) Soil Conservation Service. Increasing stocking rates decrease individual animal performance but maximize BW gain per hectare, which leads to the increasing economic returns observed. Research is needed to determine the long-term implications of these stocking rates during unfavorable growing conditions and setting stocking rates based on seasonal weather patterns and extended weather outlook predictions.

Expeller-pressed and solvent-extracted Pongamia seedcake as a protein supplement for cattle consuming a basal diet of forage

Three studies were conducted evaluating expeller-pressed (EKC) or solvent-extracted (SKC) Pongamia seedcake (PSC) as protein supplements for beef cattle. To determine palatability, EKC or SKC were mixed with wheat middlings (WM) at 200, 400, or 600 g/kg, and offered to seven steers in a 7 × 7 Latin square. Solvent-extracted PSC was more palatable than EKC, and could be included at up to 400 g/kg of supplement without negatively affecting consumption; EKC could be included at 200 g/kg without significantly decreasing extent or rate of consumption compared to control. However, inclusion of both EKC and SKC resulted in linear (P < 0.01) decreases in both extent and rate of consumption. To determine nutrient utilization/N balance, five treatments consisting of a control (no supplement, NOSUPP) and four isonitrogenous levels of supplementation (100 mg of N/kg BW) 0 g/kg of the supplement as PSC (0PSC), 400 g/kg of the supplement as SKC (400SKC), 200 g/kg of the supplement as EKC (200EKC), and 400 g/kg (400EKC) of the supplement as EKC, were dosed ruminally into five ruminally cannulated steers in a 5 × 5 Latin square. Steers were fed low-quality hay (62 g of CP/kg DM) to determine the effects of source and level of PSC on forage utilization. Forage DM intake was not different (P > 0.05) between 200EKC (4.71 kg/d) or 400SKC (4.88 kg/d), but both were less (P < 0.05) than 0 PSC (6.12 kg/d). Infusion of 400EKC resulted in the least forage intake (3.57 kg/d) which was less than (P < 0.05) NOSUPP (5.25 kg/d). Nitrogen retention for all PSC-containing supplements was less (P < 0.05) than 0 PSC, but was more (P < 0.05) than NOSUPP for 200EKC and 400SKC. In the long-term feeding study, fifteen steers, five per treatment, were assigned to either a positive control (0PSC), 200 g/kg EKC (200EKC), or 200 g/kg of supplement SKC (200SKC) supplement for 126 days to determine the long-term effects of feeding PSC. Supplementation with 0PSC resulted in greater (P < 0.05) total OM intake (6.79 kg/d) compared to 200EKC and 200SKC (5.69 and 5.42 kg/d). Average daily gain of steers on either PSC supplement was significantly lower (P < 0.05) than that of control steers (0.60 kg/d), but similar between the two PSC groups (0.39 and 0.38 kg/d for 200EKC and 200SKC, respectively). Additional research is required to full elucidate the components of PSC that negatively effect beef cattle performance and to determine the effectiveness of possible mitigation strategies.

Pre-transit vitamin C injection improves post-transit performance of beef steers

Although cattle can synthesize vitamin C (VC) endogenously, stress may increase VC requirements above the biosynthetic threshold and warrant supplementation. This study investigated the effects of a VC injection delivered before or after a long-distance transit event on blood parameters and feedlot performance of beef steers. Fifty-two days prior to trial initiation, 90 newly weaned, Angus-based steers from a single source were transported to Ames, IA, USA. On day 0, 72 steers (356 ± 17 kg) were blocked by BW and randomly assigned to intramuscular injection treatments (24 steers/treatment): saline injection pre- and post-transit (CON), VC (Vet One, Boise, ID, USA; 5 g sodium ascorbate/steer) injection pre-transit and saline injection post-transit (PRE) or saline injection pre-transit and VC injection post-transit (POST). Following pre-transit treatment injections, steers were transported on a commercial livestock trailer for approximately 18 h (1675 km). Post-transit (day 1), steers were sorted into pens with one GrowSafe bunk/pen (4 pens/treatment; 6 steers/pen). Steers were weighed on day 0, 1, 7, 30, 31, 56 and 57. Blood was collected from 3 steers/pen on day 0, 1, 2 and 7; liver biopsies were performed on the same 3 steers/pen on day 2. Data were analyzed as a randomized complete block design (experimental unit = steer; fixed effects = treatment and block) and blood parameters were analyzed as repeated measures. A pre-transit VC injection improved steer average daily gain from day 7 to 31 (P= 0.05) and overall (day 1 to 57; P= 0.02), resulting in greater BW for PRE-steers on day 30/31 (P= 0.03) and a tendency for greater final BW (day 56/57; P= 0.07). Steers that received VC pre- or post-transit had greater DM intake from day 31 to 57 (P= 0.01) and overall (P= 0.02) v. CON-steers. Plasma ascorbate concentrations were greatest for PRE-steers on day 1 and POST-steers on day 2 (treatment × day; P< 0.01). No interaction or treatment effects were observed for other blood parameters (P≥ 0.21). Plasma ferric-reducing antioxidant potential and malondialdehyde concentrations decreased post-transit (day; P< 0.01), while serum non-esterified fatty acids and haptoglobin concentrations increased post-transit (day; P< 0.01). In general, blood parameters returned to pre-transit values by day 7. Pre-transit administration of injectable VC to beef steers mitigated the decline in plasma ascorbate concentrations and resulted in superior feedlot performance compared to post-transit administration.

Effect of High Potency Growth Implants on Average Daily Gain of Grass-Fattened Steers.

Simple SummaryImproving efficiency in beef cattle production requires the adoption of technologies that are low cost but high in return. High potency growth-promoting implants (HGPs) are widely used under feedlot conditions but there are few reports of their use under grazing conditions. We conducted a trial to assess whether the use of high potency HGPs have advantages for grass-finished cattle. Our results were similar to those reported for feedlot cattle, showing that the quality of the pastures was good enough to take advantage of the HGP technology, generating a marginal income that justifies the use of technology under grazing conditions.High potency growth promoter implants (HGPs) are widely used under feedlot conditions but there are few reports under grazing conditions. The study’s goal was to assess the effect of HGPs on the average daily gain of steers fattened in pastures. A total of 57 crossbreed steers (Hereford × Angus)—initial body weight = 356.65 kg ± 5.04 (SEM)—were randomly allocated to one of three groups: Control without HGP (n = 19), Synovex group (n = 17), and Revalor group (n = 21). The fattening period was 67 days using paddocks of Lolium perenne L. and Trifolium repens L. Body weight was recorded three times in the period. The data were analyzed using an analysis of covariance with a level of significance of 5%. The average daily gain (ADG) (1.55 ± 0.07 and 1.48 ± 0.09 kg/d) and the total weight gain (103.4 ± 4.9 and 99.2 ± 5.8 kg) were similar for Revalor and Synovex, respectively (p > 0.05). Moreover, HGP groups showed higher ADG and total weight gain (p < 0.01) than the control group (ADG = 0.93 ± 0.08 kg/d and a total weight gain of 62.2 ± 5.2 kg). Final body weights were 527.8 ± 8.5 kg and 512.2 ± 9.9 kg for Revalor and Synovex, respectively; and 479.9 ± 10.1 kg for Control. In conclusion, grazing-finished steers showed better performance when high potency HGPs were used, improving the ADG and final live body weight, generating a marginal income that justifies the use of the technology under grazing conditions

Substituting hammermilled Juniperus spp. for chopped alfalfa hay in steer feedlot diets: Growth performance and blood serum chemistry

A completely randomized design study with two feeding periods was used to evaluate the effects of substituting hammermilled Juniperus spp. for chopped alfalfa in growing steer diets. Steers (n = 44; initial body weight, BW = 343 kg) were fed in a Calan gate system (4 feeders/pen; 11 pens) for 112 days. During Period 1 (days 0 to 69), steers were fed 70% concentrate diets that only differed in roughage composition (juniper replaced 0, 33, 66 or 100% of the alfalfa portion; 0JUN, 33JUN, 66JUN, or 100JUN, respectively). In Period 2 (days 70 to 112), steers were transitioned to a common 90% concentrate diet. During Period 1, treatment × day interactions (P < 0.001) were observed for steer BW, average daily gain (ADG), and gain-to-feed ratio (G:F). Within all days, other than day 0, BW linearly decreased (P ≤ 0.01) as the percentage of juniper increased in the diet. When averaged across Period 1 (treatment × day, P = 0.64), DMI linearly decreased (P < 0.001) as juniper increased. Steer ADG linearly decreased (P ≤ 0.005) between days 0 to 14 and d 28 to 42, tended to linearly decrease (P = 0.09) between d 14 to 28, and tended to quadratically decrease (P = 0.07) between days 42 to 56. Steer G:F linearly decreased (P < 0.001) between days 0 to 14 and quadratically decreased (P = 0.02) between days 42 to 56. During Period 2, treatment × day interactions (P ≤ 0.04) were observed for steer BW, DMI, ADG, and G:F. No differences (P ≥ 0.13) within day were observed for steer DMI, but ADG increased linearly (P < 0.001) between days 84 to 98 and tended to increase quadratically (P = 0.07) between days 98 to 112 with prior juniper inclusion level. Steer G:F increased linearly (P = 0.001) and quadratically (P = 0.02) between days 84 to 98 and days 98 to 112, respectively, with prior juniper inclusion level. Overall, serum chemistry did not indicate negative health issues. Collectively, results suggested that while juniper has less dietary energy, replacing 33% of the alfalfa with juniper did not negatively affect steer growth performance and should be considered. Using up to 30% juniper in the diet did not negatively affect animal health; however, under the conditions of this study, supplemental protein would be required when juniper completely replaced alfalfa.