Simmental Steers Research Articles

Effect of exogenous glucoamylase inclusion on in vitro fermentation and growth performance of feedlot steers fed a dry-rolled corn-based diet.

The objective was to evaluate the effect of adding an exogenous glucoamylase (GA) enzyme from the fungus Trichoderma reesei on in vitro fermentation, growth performance, and carcass characteristics of feedlot steers fed a dry-rolled corn (DRC)-based diet. Experiment 1 evaluated three levels of added enzyme (0, 0.24, and 0.72 GA enzyme units) and two corn particle sizes (CPS; 2 and 4 mm) in a factorial arrangement using a 7 h in vitro batch culture fermentation. Addition of GA increased (P < 0.01) in vitro dry matter disappearance by 13% and decreased final pH (P < 0.01). Molar proportion of propionate increased with GA inclusion (P < 0.01). A smaller CPS increased (P < 0.01) in vitro dry matter disappearance and total volatile fatty acid and decreased final pH (P < 0.01). A smaller CPS also decreased (P < 0.01) the molar proportion of acetate and increased (P < 0.01) the molar proportion of butyrate. In experiment 2, Angus × Simmental steers (n = 105; initial body weight [BW] = 329 ± 38 kg) were used to evaluate the inclusion of an exogenous GA on growth performance and carcass characteristics. Steers were fed a basal diet consisting of 60% DRC, 17.5% modified distillers grains with solubles, 12.5% corn silage, and 10% dry supplement on a dry matter basis for 136 d. Steers were blocked by weight and allotted to pens. Pens were randomly assigned to one of three treatments (5 pens/treatment): diet with no GA (CON), low inclusion of GA (122 enzyme units/kg dry matter [DM]; LGA), or high inclusion of GA (183 enzyme units/kg DM; HGA). Inclusion of GA did not affect (P ≥ 0.23) final BW, dry matter intake (DMI), or average daily gain (ADG) for the 136-d feeding period. Feed conversion was affected (P = 0.02) by treatment with steers fed HGA having ~8% greater G:F compared with LGA and CON. Treatment did not affect (P = 0.32) fecal starch. Inclusion of GA did not affect (P ≥ 0.19) carcass traits including hot carcass weight, 12th rib fat thickness, yield grade, longissimus muscle area, or marbling score. Overall, results suggest inclusion of exogenous GA enzyme increased in vitro dry matter disappearance in batch culture and improved feed conversion in steers fed 183 enzyme units/kg DM during the finishing phase.

Beef productivity of steers of Simmental breed of different constitutional types

In order to ensure the growth of beef production, it is necessary to rationally use all available reserves and, fi rst of all, the allocation of intra-breed types and lines that ensure the improvement of herds and breeds of animals with high genetic potential under specifi c natural conditions. Therefore when breeding cattle of dual purposes breeds important role should be attached to the selection of animals of diff erent lines, body types, related groups that provide high fattening, and beef indicators with good adaptive traits. In relation with the above, it has been considered relevant to study the formation of beef productivity of steers of diff erent exterior and constitutional intra-breed types of Simmental breed with the determination of the energy and biological value of products under intensive rearing. As well as the infl uence of feeding conditions and maintenance of young animals of Simmental breed, taking into account the exterior and constitutional type, on the formation of live weight in the postnatal period, with a comparative assessment of the growth intensity depending on the body type. As a result of the research, the association between the live weight and the weight of the most active internal organs: heart, lungs, kidneys, which characterize the level and nature of metabolic processes that have a positive eff ect on the formation of beef productivity of experimental Simmental steers of domestic selection depending on the exterior and constitutional types. It has been found that to increase the production of high-quality beef, it is advisable to intensively rear Simmental steers of medium and compact types up to 18 months of age with a live weight of 460,2–517,8 kg, a carcass weight of 252,3–282,4 kg, a slaughter yield of 58,1–59,4 % and expenditures of feed of 3,7–4,0 thousand tons of EFU per 1 head.

243 Effects of rubber matting on cattle performance and carcass characteristics in slatted facilities

Abstract The objective was to determine effects of interlocking rubber floor matting in slatted indoor cattle feeding facilities on cattle performance and carcass characteristics. In experiment 1, Fall-born Angus x Simmental steers (N = 206; BW = 228 ± 34 kg) were blocked by weight and assigned to 32 pens. Pens were randomly assigned to 1 of 4 treatments: new Max Grip Animat matting (MG), new Animat Pebble matting (PEB), old Animat Pebble matting (OLD), and no matting/concrete slating (CONC). Steers were fed a common diet for 209 d with an average stocking density of 3.70 m2 per steer. Final BW was affected (P = 0.02) by treatment with PEB steers being the heaviest, MG and CONC were intermediate, and OLD was the lightest. Treatment affected (P &amp;lt; 0.01) ADG with PEB steers being greatest, MG and CONC were intermediate, and OLD was the least. Flooring treatment did not affect overall dry matter intake (P = 0.16) or G:F (P = 0.94). Flooring treatment did not affect (P ≥ 0.19) any carcass traits. In experiment 2, Fall-born Angus x Simmental steers (N = 189; BW = 352 ± 43 kg) were blocked by weight and assigned to 21 pens. Pens were randomly assigned to 1 of 3 treatments: new Animat Pebble matting (PEB2), old Animat Pebble matting (OLD2), or no matting/concrete slating (CON2). Steers were fed a common diet for 112 d with an average stocking density of 2.64 m2 per steer. After 112 days on feed, flooring treatment did not affect (P ≥ 0.30) BW or ADG. There were no treatment differences (P = 0.13) observed for overall DMI at d 112. Overall, results suggest new rubber matting in slatted indoor cattle feeding facilities improved ADG during a 209 d trial.

228 Effect of exogenous glucoamylase inclusion on in vitro digestion and feedlot cattle performance

Abstract The objective was to evaluate the effect of adding an exogenous glucoamylase (GA) enzyme to a finishing diet on in vitro digestion and performance of feedlot cattle. Experiment 1 evaluated 3 levels of added enzyme (0, 0.24, and 0.72 GA enzyme units) and 2 corn particle sizes (2 and 4 mm) in a 7 h in vitro batch culture fermentation. No interactions were observed (P &amp;gt; 0.10). Addition of GA increased (P &amp;lt; 0.01) in vitro dry matter disappearance by 9%. A smaller corn particle increased (P &amp;lt; 0.01) in vitro dry matter disappearance by 11%. In Experiment 2, Angus × Simmental steers (N = 105; BW = 340 ± 39 kg) were blocked by weight and assigned to 15 pens. Pens were randomly assigned to one of 3 treatments: control (CON) diet with no added enzymes, low inclusion of GA (122 enzyme units/kg DM; LGA), or high inclusion of GA (183 enzyme units/kg DM; HGA). Steers were fed a basal diet consisting of 60% dry rolled corn, 17.5% modified distillers grains with solubles, 12.5% corn silage, and 10% of a corn-based supplement on a DM basis for 139 d. Inclusion of GA did not affect (P ≥ 0.24) final BW, DMI, or ADG overall for the 136 d feeding period. Steers fed HGA had increased (P = 0.02) G:F compared with LGA and CON with least square means of 0.213, 0.194, and 0.197, respectively. Inclusion of GA did not affect (P ≥ 0.19) carcass traits including HCW, 12th rib fat thickness, yield grade, longissimus muscle area, or marbling score. Overall, results suggest inclusion of exogenous glucoamylase enzyme increased in vitro dry matter disappearance in batch culture and improved feed conversion of the finishing diet fed to feedlot steers at 0.381 g enzyme protein/kg DM.

PSXI-19 Investigating the Relationship Between Temperament and Performance Traits in Feedlot Cattle

Abstract Temperament in cattle, is defined as behavioral changes in response to humans or changes in the environment, and has been associated with reduced feed efficiency, reduced growth rate, and poor feedlot health. The objective of the study was to determine if temperament affected the performance, growth and health of feedlot cattle. One-hundred and thirty-one Angus x Simmental steers from a single ranch were sampled at a commercial feedlot in Chappell, NE. Blood samples for metabolite analysis, exit velocity, and blood lactate concentration for temperament classification were collected in addition to feedlot performance data and carcass quality measurements. The GLM and LSM procedures of SAS (SAS 9.4, 2014) were used to evaluate differences between temperament classifications. Pearson correlations were calculated between temperament and performance variables. Steers were divided into three exit velocity classifications, with fast animals (n = 27) having exit velocity greater than one standard deviation from the mean and slow animals (n = 26) having exit velocities lower than one standard deviation from the mean. Feed intake and behavior was monitored for 42 days with GrowSafe feed bunks and average daily gain, dry matter intake and residual feed intake calculated. There were significant differences between the temperament classifications of fast, medium and slow for both exit velocity and blood lactate (P &amp;lt; 0.0001), indicating there was a difference in responses from the classifications. Exit velocity had no effect on any of the growth parameters measured. There was a significant positive correlation between exit velocity and blood lactate (P &amp;lt; 0.0001). RFI was significantly correlated with exit velocity (P = 0. 051) and blood lactate (P &amp;lt; 0.05). This suggests that animals with higher RFI or less efficient animals had more flighty temperaments as determined by blood lactate and exit velocity.

Balancing the dietary ratio of nitrogen to sulfur by adding inorganic sulfur improves nitrogen retention and consequently decreases urine nitrous oxide emissions in steers

Two consecutive trials were carried out to study the effects of dietary supplementation with inorganic sulfur (S) on nitrogen (N) metabolism and nitrous oxide (N2O) emissions of urine from steers. In Trial 1, six castrated Simmental steers [449 ± 19 kg liveweight (LW)] were used as the experimental animals. Three levels of Na2SO4, i.e., 0 (control), 20 and 40 g/d were added to a basal ration [S content 1.15 g/kg dry matter (DM)] as experimental treatments. The animals and the treatments were randomly assigned to a replicated 3 × 3 Latin square design. Each experimental period included 15 days for adaptation and 5 consecutive days for sampling. The results of Trial 1 indicated that dietary supplementation with Na2SO4 linearly decreased the urinary excretions of N (P = 0.05) and urea (P = 0.03), and linearly increased rumen microbial N flow (P = 0.04), and tended to increase N retention rate (P = 0.06) in a linear manner. Supplementing Na2SO4 also linearly increased the excretions of fecal S (P = 0.02), urinary S (P < 0.01), urinary sulfate (P < 0.01) and S retention (P = 0.01). S retention rate was not influenced by Na2SO4 supplementation. Sulfate was undetectable in feces at a limit of 20 mg/kg DM. In Trial 2, the N2O emissions of the urine samples from Trial 1 were measured using the static incubation technique. The N2O-N emissions of steer urine applied to soil linearly decreased with increasing addition of Na2SO4 in the diet. Urinary sulfate did not affect the N2O-N emissions of steer urine. In conclusion, dietary supplementation with Na2SO4 at 20 g/d was effective for balancing the dietary N/S ratio, obtaining an ideal N retention rate in steers and decreasing the N2O emissions from steer urine.

Use of feed additives “Valopro” and “Ruprokol” to increase the energy of growth and meat productivity of simmental steers

The article assesses the growth, development and meat productivity of Simmental bulls during the growing period when the feed additives “Valopro” and “Ruprokol” are included in the ration. For experience in intensive growing conditions on the basis of the industrial complex LLC Agropark-Razvilnoye, Rostov Region, in September 2019, two groups of 10-month-old calves of Simmental breed were formed. In the experimental group, the calves were fed in feed compound “Valopro” at the rate of 20 grams and “Ruprokol” - 50 grams per head per day. Gobies of control feed additives were not received. In the experimental group, over 80 days of growing, an average of 9.15 kg was consumed, and in the control group, 8.9 kg of dry matter per head per day. The absolute growth of young animals fed a diet with feed additives was 26 kg higher during the accounting period. The use of fodder additives in the feeding of bull calves made it possible at the age of 13 months to obtain a live weight of 439 kg, one kilogram of which contains 403 g of muscle tissue and 429 g of edible carcass elements. The introduction of feed additives helped to reduce feed costs per 1 kg of gain in live weight by 18%, to obtain 1600-1700 g of daily gain and provide additional profit.

Effect of calcium oxide and soybean hull addition to feedlot diets containing dried distillers grains and corn stover on steer performance, carcass characteristics, and digestibility.

The objective of this study was to determine the effect of soybean hulls (SBH) and/or calcium oxide (CaO) on rumen pH, digestibility, and performance of steers fed diets containing dried distillers grains with solubles (DDGS). In experiment 1, Angus × Simmental steers (n = 112, body weight [BW] = 364 ± 7.8 kg) were allotted to 1 of 4 diets arranged as a 2 × 2 factorial and placed in 16 pens (7 steers/pen, 4 pens/treatment, and 28 steers/treatment). Factors were SBH (0% or 30% of diet dry matter [DM]) and CaO (0% or 1%) inclusion. Basal diets contained 20% corn stover, 30% DDGS, and 4% supplement. Diets with SBH contained 14.1% or 15.0% corn and diets without SBH contained 43.9% or 44.8% corn. In experiment two, four steers (BW = 510 ± 9.8 kg) were allotted to a 4 × 4 Latin square (21 d periods) to determine the effects of CaO and SBH on ruminal pH, volatile fatty acid (VFA), nutrient digestibility, and digestion kinetics. Statistical analyses were conducted using the MIXED procedure of SAS. In experiment 1, BW did not differ among treatments (P ≥ 0.46). Overall carcass-adjusted gain did not differ due to SBH or CaO inclusion (P ≥ 0.13); however, there was an interaction (P = 0.01) where CaO improved gain in steers fed no SBH, but not in steers fed SBH. Steers fed SBH consumed more DM than steers not fed SBH (P = 0.02) and an interaction tended to occur (P = 0.06) where CaO increased dry matter intake in steers fed no SBH, but not in steers fed SBH. Calcium oxide increased hot carcass weight and yield grade (interaction; P ≤ 0.04) and tended to increase fat thickness (interaction; P = 0.08) in steers fed no SBH, but not in steers fed SBH. Dressing percentage, longissimus muscle area, % kidney, pelvic, heart fat, and marbling score did not differ among treatments (P ≥ 0.14). Total VFA concentrations were greater with SBH inclusion and with CaO addition (P < 0.01). Digestibility of DM, neutral detergent fiber (NDF), and acid detergent fiber (ADF) was greater with CaO addition (P ≤ 0.04) and NDF and ADF digestibility were greater with SBH inclusion (P < 0.001). Inclusion of SBH did not affect (P ≥ 0.26) rate of digestion (kd) or passage (kp). Addition of CaO tended to increase mean retention time (P = 0.09). An interaction between SBH inclusion and CaO addition occurred for kd (P = 0.01), where CaO increased kd in steers fed SBH, but decreased kd when steers were fed no SBH. Total N excretion tended to be lower with SBH inclusion and CaO addition (P = 0.07). In conclusion, CaO enhances performance of cattle fed corn, DDGS, and corn stover diets, but not when corn is partially replaced by a fiber-based energy feed.

In vitro degradability of corn silage and Leymus chinensis silage and evaluation of their mixed ratios on performance, digestion and serum parameters in beef cattle.

This study investigated the degradability of corn silage (CS) and Leymus chinensis silage (LS) in vitro, and evaluated the effect of various ratios on growth performance, digestion and serum parameters in beef cattle. A 72-hr bath culture trial was performed to evaluate degradability and rumen fermentation characteristics of CS, LS and their combinations [67:33, 33:67, dry matter (DM) basis]. Forty Simmental steers, averaging 441.46±4.45kg of body weight (BW), were randomly allocated into four dietary treatments for 120-d period. Diets were given as total mixed rations with a forage-to-concentrate ratio of 60:40 and CS:LS ratios of 100:0, 67:33, 33:67 and 0:100 (DM basis). The in vitro trial showed that DM and neutral detergent fibre (NDF) degradability decreased linearly as LS proportion increased, whereas CP degradability increased linearly. Additionally, increased acid detergent fibre (ADF) degradability was detected at 48hr of incubation. Increasing the proportion of LS increased rumen liquor pH and decreased volatile fatty acid linearly including acetate, propionate and butyrate, whereas the ammonia-N increased linearly at 12 and 72hr of incubation. With increasing LS ratio, final BW, average daily gain and feed conversion ratio of steers decreased linearly, whereas DMI was not affected. Additionally, apparent digestibility of DM, organic matter, NDF and ADF linearly and quadratically decreased while ether extract apparent digestibility decreased linearly, and CP apparent digestibility was not affected. Serum glucose and urea nitrogen linearly and quadratically decreased while glutamic-pyruvic transaminase activity linearly decreased as the proportion of LS increased. Other serum parameters including total triglycerides, total cholesterol, total protein, albumin and glutamic-oxalacetic transaminease were not affected. Overall, enhancing ratio of LS caused inferior DM and NDF degradability but improved CP degradability in the combinations of LS and CS. A CS:LS ratio of 67:33 resulted in the best growth performance and nutrient utilization in steers.

Effects of soybean lecithin supplementation on growth performance, serum metabolites, ruminal fermentation and microbial flora of beef steers

This study was aimed to estimate the effect of soy lecithin (SL) on growth performance, serum metabolites, rumen fermentation and microbial flora in Simmental steers. Sixty Simmental steers were randomly assigned to four treatments: control (C), S1 (TMR with 10 g/kg (DM) SL), S2 (TMR with 20 g/kg (DM) SL) and S3 (TMR with 40 g/kg (DM) SL).The ADG of steers fed 10 g/kg, 20 g/kg and 40 g/kg SL was 8.6%, 22.5% and 9.4% higher than that control group, respectively (P<0.001), while FCR decreased quadratically (P<0.001) by increasing the SL level, and the lowest FCR was achieved for steers fed 20 g/kg SL. There was a linear decrease in the ruminal pH value yet a quadratic increase in acetate and total VFAs concentration by increasing the SL supplementation (P<0.001). The serum concentrations of CHO, TG, HDL, FAS and HLS concentrations showed a linear increase by increasing the SL supplementation (P<0.05). The rumen bacterial community of five phyla (Bacteroidetes, Firmicutes, Proteobacteria, Spirochaetae and Actinobacteria) and genera (Prevotella, Bacteroidales_BS11_gut, Prevotellaceae_UGG-033, Rikenellacese_RC and Coprostanoligenes) that were most abundant in the rumen microbial flora was not affected by SL supplementation (P>0.05), while some ruminal bacterial with lower abundance showed a linear decrease by increasing the SL supplementation. Therefore, SL supplementation improved growth performance and increased ruminal VFA yields of Simmental steers with no inhibitory effect on the dominant ruminal bacterial. Based on the results of growth performance, the recommended amount of SL supplement is 20 g/kg DM for beef steers.

Beef traits of steers of Simmental breed and its crossbreds with Holstein breed

Scientists from different countries have accumulated a lot of material on the beef productivity of young animals obtained from crossbreeding Simmental cows with sires of Holstein breed. The purpose of the research was to study the growth dynamics and beef productivity of steers of Simmental breed and its crossbreds with Holstein breed, as well as the possibility of making a profit from the production of beef. During the period of rearing the experimental animals have been housed at the complex with loose housing barn. During the experiment the steers have consumed 3649,5 EFU and 393 kg of digestible protein. Under the same environments of feeding and housing, the expenditures of feed per 1 kg of gain in the group of Simmental steers amounted to 8,32 EFU, which were by 0,17–0,60 EFU less than in the groups of crossbred steers. In the entire period of rearing purebred Simmental animals grew more intensively, which exceeded at 18 months of age half-blooded Holstein breed analogues by 16,5 kg, 3/4-blooded – by 25,0 kg (P &lt; 0,01) and 7/8-blooded – by 30,2 kg (P &lt; 0,001). The study of meat productivity has shown that Simmental steers surpassed their herdmates of Holstein breed by 10,0–24,8 kg in terms of carcass weight, and their meat weight was higher than that of crossbred animals by 8,4–21,9 kg (P &lt; 0,01–0,001). The conversion rate of feed protein to meat products has shown that Simmental steers were by 0,27–1,05 % more efficient at converting feed protein into meat products compared to crossbred herdmates, and the differences in metabolic energy conversion were by 3,9–5,86 % more. The study of the effectiveness of beef production by steers of different genotypes has shown the advantage of Simmental steers. The profit of the group of Simmental steers made up 8998 Rub that was higher by 2011 Rub than in group of half-blooded Holstein breed steers, and with the group of 3/4-blooded the difference was 2795 Rub and 7/8-blooded steers – 3190 Rub.

Effect of feeding a low-vitamin A diet on carcass and production characteristics of steers with a high or low propensity for marbling

Our research group demonstrated that vitamin A restriction affected meat quality of Angus cross and Simmental steers. Therefore, the aim of this study is to highlight the genotype variations in response to dietary vitamin A levels. Commercial Angus and Simmental steers (n = 32 per breed; initial BW = 337.2 ± 5.9 kg; ~8 months of age) were fed a low-vitamin A (LVA) (1017 IU/kg DM) backgrounding diet for 95 days to reduce hepatic vitamin A stores. During finishing, steers were randomly assigned to treatments in a 2 × 2 factorial arrangement of genotype × dietary vitamin A concentration. The LVA treatment was a finishing diet with no supplemental vitamin A (723 IU vitamin A/kg DM); the control (CON) was the LVA diet plus supplementation with 2200 IU vitamin A/kg DM. Blood samples were collected at three time points throughout the study to analyze serum retinol concentration. At the completion of finishing, steers were slaughtered at a commercial abattoir. Meat characteristics assessed were intramuscular fat concentration, color, Warner-Bratzler shear force, cook loss and pH. Camera image analysis was used for determination of marbling, 12th rib back fat and longissimus muscle area (LMA). The LVA steers had lower (P < 0.001) serum retinol concentration than CON steers. The LVA treatment resulted in greater (P = 0.03) average daily gain than the CON treatment, 1.52 and 1.44 ± 0.03 kg/day, respectively; however, there was no effect of treatment on final BW, DM intake or feed efficiency. Cooking loss and yield grade were greater and LMA was smaller in LVA steers (P < 0.05). There was an interaction between breed and treatment for marbling score (P = 0.01) and percentage of carcasses grading United States Department of Agriculture (USDA) Prime (P = 0.02). For Angus steers, LVA treatment resulted in a 16% greater marbling score than CON (683 and 570 ± 40, respectively) and 27% of LVA Angus steers graded USDA Prime compared with 0% for CON. Conversely, there was no difference in marbling score or USDA Quality Grades between LVA and CON for Simmental steers. In conclusion, feeding a LVA diet during finishing increased marbling in Angus but not in Simmental steers. Reducing the vitamin A level of finishing diets fed to cattle with a high propensity to marble, such as Angus, has the potential to increase economically important traits such as marbling and quality grade without negatively impacting gain : feed or yield grade.

Effect of Feeding a Low Vitamin a Diet to Beef Steers on Calpain 1 Activation during Meat Aging

ObjectivesThe objective of the study was to determine if a vitamin A deficient diet during beef finishing influences calpain 1 activation during meat aging.Materials and MethodsSixty-four steers of approximately 7 mo of age were subjected to a 14-d acclimation period followed by a 95-d growing period on a low vitamin A diet (1017 IU vitamin A/kg DM) designed to deplete liver vitamin A stores. Steers were assigned to a randomized complete blocked design with a 2 × 2 arrangement of treatments (breed: commercial Angus, n = 32, and purebred Simmental, n = 32; and a Low Vitamin A diet or a control diet). The low Vitamin A (LVA) treatment was a finishing diet with no supplemental vitamin A (723 IU vitamin A/kg DM). The control (CON) treatment was the LVA diet plus supplementation with 2200 IU vitamin A/kg DM for a total of 2923 IU vitamin A/kg DM. Serum retinol concentrations were monitored at the beginning and end of treatment. Upon completion of finishing, steers were slaughtered in two groups at a commercial plant. After fabrication, boneless strip loins (IMPS 180) were collected and transported to NDSU. Samples (approximately 40 g) were collected from the anterior portion of the strip loin on d-2 and d-7 of aging and immediately frozen. Protein was extracted from meat samples in fractionation buffers to yield sarcoplasmic and myofibrillar portions, separated by SDS-PAGE, and transferred to PVDF membranes. Immunoblot analysis was done using anti-desmin (d-2 and d-7) and anti-calpain 1 (d-2) antibodies, and results were visualized and documented. A pooled control was run on all membranes and set to a value of one for normalizing results. All experimental data were analyzed using the Proc Mixed procedure of SAS with breed of steers, dietary treatments, their interaction and slaughter date used as a fixed effect.ResultsCalpain 1 autolysis in the sarcoplasmic protein fraction of the d-2 aged loin samples were not affected by treatment or breed. The myofibrillar protein fraction from Angus loins had greater (P = 0.02) accumulation of the 76 kDa calpain 1 autolysis product than that from the Simmental loins; the myofibrillar fraction of the loins from the LVA treatment tended (P = 0.07) to have more 76 kDa calpain 1 autolysis product than that from the CON. There were not any differences (P &gt; 0.19) in the 80 kDa calpain 1 band or the 78 kDa calpain 1 intermediate autolysis product in the myofibrillar fraction. There was a treatment by breed interaction (P = 0.01) for desmin in the d-7 aged loins where Angus loins from the CON treatment had less accumulation of the 46 kDa band than Angus loins on the LVA treatment and Simmental loins from either treatment.ConclusionVitamin A restriction increased protein proteolysis in Angus but not in Simmental steers. The increased calpain 1 autolysis in Angus vs. Simmental, regardless of Vitamin A treatment, indicates a genetic difference that may be the driver for the increased protein degradation in steers a restricted vitamin A diet.

Effect of ruminally protected arginine and lysine supplementation on serum amino acids, performance, and carcass traits of feedlot steers1.

One hundred twenty Angus × Simmental steers [322 ± 4.8 kg initial body weight (BW)] were blocked by BW and randomly allocated to 4 treatments arranged as a 2 × 2 factorial to evaluate the effects of supplemental arginine (none or 63 g/d of a 15.6% metabolizable arginine), supplemental lysine (none or 40 g/d of a 25% metabolizable lysine), and their interaction on performance and carcass composition of feedlot steers during a 170-d feeding period. The basal diet [dry matter (DM) basis] contained 52% dry-rolled corn, 22% dried distillers grains with solubles, 20% corn silage, and 6% vitamin-mineral supplement. Lysine balance was estimated to be -10.3 to -10.8 g for diets that did not contain supplemental lysine, and arginine supply was estimated to be +9.7 g for diets that did not contain supplemental arginine during period 1 (days 0 to 87). Lysine and arginine supplies met or exceeded requirements in period 2 (days 88 to 170). Rumen-protected arginine and lysine were top dressed daily until slaughter at a common BW (622 ± 5.5 kg). Data were analyzed using the MIXED procedure of SAS. Body weight, average daily gain, and DM intake were not affected (P ≥ 0.14) by arginine or lysine supplementation. However, lysine increased gain:feed (P = 0.05) during period 1. Lysine decreased serum urea nitrogen (P = 0.03) on day 87, increased (P = 0.01) longissimus muscle (LM) area, decreased (P ≤ 0.01) fat thickness and yield grade, and tended (P = 0.06) to increase moisture content of LM steaks. There tended to be an interaction for moisture content of steaks (P = 0.09), where arginine supplementation increased moisture content to a greater extent in steaks from cattle supplemented with lysine compared with steaks from cattle not fed supplemental lysine. Arginine tended to increase the proportion of Choice grade carcasses (P = 0.09) but did not change lipid content of steaks (P = 0.59). Arginine tended to decrease serum glutamate (P = 0.09) and lysine (P = 0.07) after 87 d of feeding. In conclusion, supplemental rumen-protected arginine and lysine did not improve performance, but lysine can increase carcass muscle and leanness, and although arginine did not increase lipid content of steaks, it may favorably shift carcasses to a greater quality grade.

Global DNA Methylation in the Limbic System of Cattle.

To elucidate the extent to which DNA methylation varies across multiple tissues in the brain and between animals, we have quantified global DNA methylation in tissues comprising the limbic system for six Red Angus x Simmental steers. Global DNA methylation was measured in nine regions of the bovine brain: amygdala, the bed nucleus of the stria terminalis, cingulate gyrus, dorsal raphe, hippocampus, hypothalamus, nucleus accumbens, periaqueductal gray and prefrontal cortex. DNA methylation varies among animals for each tissue type and varies among tissue types for each animal. The highest amounts of DNA methylation were found in the amygdala, cingulate gyrus and dorsal raphe, while the bed nucleus of the stria terminalis, nucleus accumbens and periaqueductal gray had the lowest amounts of DNA methylation. A heatmap sorted by k-means clustering was generated to graphically display percent DNA methylation in relation to tissue type and animal number. This is the first study to report measures of DNA methylation in the limbic system of the bovine brain and can be used to inform the cattle genomics community of expected variation in cattle brain methylation.

Polymorphisms of the &amp;lt;i&amp;gt;ASIP&amp;lt;/i&amp;gt; gene and the haplotype are associated with fat deposition traits and fatty acid composition in Chinese Simmental steers

Unlike specific expression in the skin of wild mice, the agouti signaling protein (ASIP) is expressed widely in the tissue of cattle, including adipose and muscle tissue. Hence, it has been suggested that ASIP plays a role in bovine fat metabolism. An inserted L1-BT element was recently identified upstream of the ASIP locus which led to an ectopic expression of ASIP mRNA in cattle. In this study, we detected the indel of the L1-BT element at g. nt and three SNPs in introns of the ASIP gene (g. A G, g. A T, and g. 4805A T) in a Chinese Simmental steer population. The association analysis between variants of ASIP and economic traits showed that the homozygous genotype of L1-BT element insertion, AA genotype of g. A G, and AT genotype of g. 4805A T were significantly correlated with carcass and fat-related traits, such as live weight and back fat thickness. Moreover, three haplotypes (H1: AT; H2: AA; H3: GT) were identified by linkage disequilibrium analysis and formed six combined genotypes. Results indicated that Chinese Simmental steers with an H1H2 combined genotype had a higher measured value of fat-deposition-related traits (), including thickness of back fat and percentage of carcass fat coverage, but a lower content of linoleic acid and -linolenic acid (). Individuals of an H3H3 combination had a lower marbling score, perirenal fat weight, and carcass weight (). This suggests that these three SNPs and two combined haplotypes might be molecular markers for beef cattle breeding selection.

Dressing percentage and the differential between live weight and carcass weight in cattle are influenced by both genetic and non-genetic factors1.

The objective of the present study was to quantify the genetic and non-genetic contributors to variability in both carcass dressing percentage and dressing difference (i.e., the difference between carcass weight and live weight immediately prior to slaughter) in young animals and cows. The datasets contained 18,479 young animals from 653 herds, and 2,887 cows from 665 herds. Live weight records within 7 d of slaughter and associated carcass weight were available for all animals. Association analyses were undertaken using linear mixed models with fixed effects for the model of young animals consisting of animal breed, days between the date of last recorded live weight and slaughter date, heterosis and recombination loss coefficients, dam parity, a 3-way interaction between whether the animal originated in a dairy or beef herd, animal sex, and age at slaughter, as well as a 2-way interaction between calendar year of slaughter and month of slaughter; contemporary group was included as a random effect. Fixed effects in the cow model were cow breed, the number of days between the date of last recorded live weight and slaughter date, heterosis and recombination loss coefficients, the number of days postcalving, parity of the cow, and a 2-way interaction between calendar year of slaughter and month of slaughter; contemporary group was included as a random effect. The mean dressing percentage (phenotypic standard deviation in parentheses) and dressing difference in young animals were 55.86% (3.21%) and 280.03 kg (41.44 kg), respectively. Steers had the heaviest dressing difference at 34.18 and 60.44 kg heavier than a 16-mo old bull and 22-mo old heifer, respectively. Dressing difference for 30-mo old Simmental steers (breed with heaviest dressing difference) was 41.66 kg heavier than 30-mo old Belgian Blue steers (breed with lightest dressing difference). The heritability of dressing percentage (0.48) and dressing difference (0.35) in young animals was relatively similar to each other, in contrast to dressing percentage (0.08) in cows which was considerably lower than dressing difference (0.28). Considerable genetic variability existed in dressing difference amongst young animals (genetic standard deviation of 15.03 kg), despite the near unity genetic correlation (0.93) between carcass weight and live weight. This therefore indicates that genetic selection for increased saleable product can be achieved by selecting for increased carcass weight while concurrently selecting for lighter animals although the opportunity is limited by the strong part-whole relationships that exists between carcass weight, live weight, and dressing difference.

BEAF QUALITY OF PURE-BRED AND CROSS-BRED BEEF CATTLE OF SIBERIA

The paper presents requirements to high-quality beef in terms of its general view, biochemical composition, taste and nutritional properties. The parameters which determine the taste, aroma, juiciness, tenderness of meat, as well as the strength and richness of the broth are given. Quality of beef obtained from animals of different beef breeds and their hybrids was assessed. Meat quality of the Hereford breed is higher than that of other most common breeds by the main parameters. The effect of the cow class on the meatproductivity of the young Hereford bulls was experimentally established. They were superior to animals of the control group in pre-slaughter weight by 25 kg (6.4%), slaughter weight - by 15.4 kg (7.5%), relative mass of flesh - by 7.8 kg, half-carcass weight - by 8.1 kg (7.6%). At the age of 20 months Hereford x Simmental steers of the 1st generation and heifers of the 3rd generation were characterized by high quality meat. Depending on housing conditions (with an area of 3.5 m 2 per head), the Kazakh-white-headed x Simmental steers of the 1st generation were in the lead in terms of meat quality. When fattened at the site, the Kazakh-white-headed x young Simmental bulls and heifers of the 1st generation were superior. The positive effect of semen production of Australian stud bulls on meat marbling of Siberian analogues (6 points) was experimentally proven. A new accelerated method of taking a sample of meat for research is described. In this method probes are taken from four easily accessible large muscles: m. supraspinatus, longissimus dorsi, m. iliopsoas (fillet), m. semimembranosus. Their biochemical composition is determined, after which the quality composition of carcass flesh is defined by a special formula with allowance for correction factors.

Effect of Feeding a Low Vitamin a Diet to Beef Steers on Calpain 1 Activation during Meat Aging

ObjectivesThe objective of the study was to determine if a vitamin A deficient diet during beef finishing influences calpain 1 activation during meat aging.Materials and MethodsSixty-four steers of approximately 7 mo of age were subjected to a 14-d acclimation period followed by a 95-d growing period on a low vitamin A diet (1017 IU vitamin A/kg DM) designed to deplete liver vitamin A stores. Steers were assigned to a randomized complete blocked design with a 2 × 2 arrangement of treatments (breed: commercial Angus, n = 32, and purebred Simmental, n = 32; and a Low Vitamin A diet or a control diet). The low Vitamin A (LVA) treatment was a finishing diet with no supplemental vitamin A (723 IU vitamin A/kg DM). The control (CON) treatment was the LVA diet plus supplementation with 2200 IU vitamin A/kg DM for a total of 2923 IU vitamin A/kg DM. Serum retinol concentrations were monitored at the beginning and end of treatment. Upon completion of finishing, steers were slaughtered in two groups at a commercial plant. After fabrication, boneless strip loins (IMPS 180) were collected and transported to NDSU. Samples (approximately 40 g) were collected from the anterior portion of the strip loin on d-2 and d-7 of aging and immediately frozen. Protein was extracted from meat samples in fractionation buffers to yield sarcoplasmic and myofibrillar portions, separated by SDS-PAGE, and transferred to PVDF membranes. Immunoblot analysis was done using anti-desmin (d-2 and d-7) and anti-calpain 1 (d-2) antibodies, and results were visualized and documented. A pooled control was run on all membranes and set to a value of one for normalizing results. All experimental data were analyzed using the Proc Mixed procedure of SAS with breed of steers, dietary treatments, their interaction and slaughter date used as a fixed effect.ResultsCalpain 1 autolysis in the sarcoplasmic protein fraction of the d-2 aged loin samples were not affected by treatment or breed. The myofibrillar protein fraction from Angus loins had greater (P = 0.02) accumulation of the 76 kDa calpain 1 autolysis product than that from the Simmental loins; the myofibrillar fraction of the loins from the LVA treatment tended (P = 0.07) to have more 76 kDa calpain 1 autolysis product than that from the CON. There were not any differences (P > 0.19) in the 80 kDa calpain 1 band or the 78 kDa calpain 1 intermediate autolysis product in the myofibrillar fraction. There was a treatment by breed interaction (P = 0.01) for desmin in the d-7 aged loins where Angus loins from the CON treatment had less accumulation of the 46 kDa band than Angus loins on the LVA treatment and Simmental loins from either treatment.ConclusionVitamin A restriction increased protein proteolysis in Angus but not in Simmental steers. The increased calpain 1 autolysis in Angus vs. Simmental, regardless of Vitamin A treatment, indicates a genetic difference that may be the driver for the increased protein degradation in steers a restricted vitamin A diet.

Performance, insulin sensitivity, carcass characteristics, and fatty acid profile of beef from steers fed microalgae.

Heterotrophic production of microalgae biomass provides a consistent, high-quality source of docosahexaenoic acid (DHA; C22:6 n-3) in triglyceride oils that could be used as a ration supplement for feedlot steers to improve nutritional qualities of beef. Sixty Angus × Simmental steers (438 ± 6.4 kg) were allotted to two treatments (30 steers each, six pens, five steers/pen) to determine the effects of ForPLUS (DHA-rich microalgae Aurantiochytrium limacinum; 63.6% fat; 17.9% DHA; 30 mg/kg Sel-Plex; Alltech Inc.) on performance, insulin sensitivity, LM fatty acid composition, and meat quality. Steers were fed basal diets containing 45% corn, 30% distillers dried grains with solubles, 20% corn silage, and 5% supplement. Basal diets were formulated to contain 16.1% CP and 1.32 Mcal/kg NEg. Treatments were delivered to steers in a ground corn-based top-dress (454 g total/steer) and contained no microalgae for control steers or 100 g/steer daily of ForPLUS for microalgae steers. A glucose tolerance test (GTT) was performed 10 d prior to slaughter. Steers were slaughtered when a target pen BW of 621 kg was achieved. Fatty acid oxidation potential was determined by measuring thiobarbituric acid reactive substances (TBARS) on LM samples collected 24 h after slaughter and aged for 48 h or 21 d. Weight and BW gain did not differ during the study (P ≥ 0.13); however, steers fed microalgae remained in the feedlot seven more days compared to steers fed the control diet (111 vs. 104 d; P = 0.04). Overall DMI decreased (P = 0.002) and G:F increased during the second half of the study (P = 0.04) in steers fed microalgae compared to steers fed the control diet. Steers fed microalgae secreted less insulin (P = 0.01) and took longer to clear glucose (P = 0.01) during a 2-h GTT. Carcass traits did not differ between treatments (P ≥ 0.23). Microalgae had no effect on n-6 content (P = 0.67), but more than doubled the n-3 fatty acid percentage and the n-3:n-6 ratio of the LM (P < 0.0001). The percentage of n-3 fatty acids C20:5 and C22:6 were increased (P < 0.0001) 4-fold and 6.25-fold, respectively, by microalgae supplementation. Concentration of TBARS did not differ in LM aged for 48 h (P = 0.91); however, when aged for 21 d, steers fed microalgae tended to produce LM with greater TBARS concentration compared to steers fed the control diet (P = 0.08). In conclusion, DHA-rich microalgae decreased DMI of steers, and increased n-3 fatty acids and beef oxidation in steaks aged for 21 d.