Steer Finishing Research Articles

Effects of Supplements Differing in Fatty Acid Profile to Late Gestational Beef Cows on Steer Progeny Finishing Phase Growth Performance, Carcass Characteristics, and mRNA Expression of Myogenic and Adipogenic Genes.

Simple SummaryMaternal nutrition during late gestation affects fetal muscle and adipose tissue development, leading to persistent impacts on offspring postnatal growth and production performance. Fatty acids, especially essential fatty acids, play important roles in regulating protein and lipid metabolism. Therefore, the objective of the current study was to investigate the effects of maternal fatty acid supplementation during late gestation on beef cattle progeny finishing phase growth performance, carcass characteristics, and mRNA expression of genes involved in muscle and adipose tissue development. This study demonstrated that maternal supplementation with polyunsaturated fatty acids during late gestation increased the offspring’s feed ratio during the finishing phase. However, it had limited effects on finishing phase body weights, carcass characteristics, or relative mRNA expression in longissimus muscle and subcutaneous adipose tissue. Therefore, operations under similar systems could expect limited effects of maternal fatty acid supplementation on the growth and production performance of the finishing steers.The objective was to investigate the effects of feeding late gestational beef cows supplements differing in fatty acid profile on steer progeny finishing phase growth performance, carcass characteristics, and relative mRNA expression of myogenic and adipogenic genes. Seventy Angus-cross steers (initial body weight [BW] 273 ± 34 kg) born from dams supplemented with either 155 g DM/d EnerGII (CON, rich in palmitic and oleic acids) or 80 g DM/d Strata + 80 g DM/d Prequel (PUFA, rich in linoleic acid, eicosapentaenoic acid, and docosahexaenoic acid) for the last 77 ± 6 d prepartum were used. Longissimus muscle and subcutaneous adipose biopsies were collected to evaluate relative mRNA expression of genes related to myogenesis and adipogenesis. Steers were slaughtered at 423 ± 6 d of age. No treatment × time interaction or treatment effect (p ≥ 0.21) was detected for steer finishing phase BW, while steers from PUFA supplemented dams tended (p = 0.06) to have a greater gain to feed ratio (G:F). Neither carcass characteristics nor relative mRNA expression was different (p ≥ 0.11). In conclusion, late gestation PUFA supplementation tended to increase steer progeny finishing phase G:F, but had no effects on finishing phase BW, carcass characteristics, or relative mRNA expression during the finishing phase.

Effects of including autolyzed yeast in the finishing of feedlot steers

Functional additives, such as autolyzed yeasts, have been used to achieve greater production efficiency and animal health. These compounds are also alternatives to the use of performance-enhancing antimicrobials. The objective was to evaluate the productive performance, ingestive behavior, apparent digestibility of feed DM and the carcass characteristics of beef steers finished in feedlot receiving autolyzed yeasts in the diet. The experimental design was randomized blocks, consisting of three treatments and six repetitions, where each repetition was represented by a stall with two animals. 36 bulls, ½ Angus × ½ Nelore blood, from the same herd, with an average age of 11 months and an average body weight of ± 330 kg were used.The treatments were as follows: CON - yeast-free diet; Y4 - yeast diet (4 g animal day-1) and Y7 - yeast diet (7 g animal day-1). The product used is a functional ingredient containing the yeast Saccharomyces cerevisiae. The inclusion of autolyzed yeasts resulted in greater daily body weight gain and better feed conversion in the initial feedlot phase. The apparent digestibility of DM of diets containing autolyzed yeast was superior to the control diet, and its use did not interfere with the animal ingestive behavior. Supplementation with autolyzed yeasts at the inclusion level of 4 g day-1 promoted better results in the finishing of feedlot steers, and that the supplemented groups (4 g animal day-1 and 7 g animal day-1) achieved the same degree of carcass finishing, higher than the control group.

Effects of Maternal Supplementation with an Injectable Trace Mineral Containing Copper, Manganese, Zinc, and Selenium on Subsequent Steer Finishing Phase Performance and Carcass Characteristics.

Simple SummaryThe persistent effects of maternal nutrition on subsequent offspring health and performance have drawn great attention in both the livestock industry and human health field in recent years. Trace minerals play very important roles in nutrition and regulate many critical biological processes. Therefore, trace mineral status of the dam has the potential to influence early growth and development of the fetus, which leads to long-lasting effects on animal health and growth performance. This study demonstrated that maternal supplementation of trace minerals increased the percentage of carcasses graded as USDA Choice or greater, but maternal trace mineral injections had limited effects on finishing phase growth performance and other carcass characteristics of the offspring. Stakeholders of the cow/calf and feedlot operations should consider these results as they make decisions on maternal trace mineral administrations.The objective of this study was to investigate effects of maternal supplementation with an injectable trace mineral (Cu, Mn, Zn, and Se) on subsequent steer performance during the finishing phase. Seventy-six Angus cross steers (initial body weight 249 ± 41.5 kg) from dams administered either an injectable trace mineral (TM; Multimin 90) or sterilized physiological saline (CON) during prepartum stage were used. Individual feed intake during the finishing phase were recorded with GrowSafe feed bunks. Blood and liver biopsy samples were collected to evaluate trace mineral status. Steers were slaughtered at 413 ± 26 days of age and carcass data were obtained at a commercial abattoir. Growth performance or mineral status of the steers during the finishing phase was not affected (p ≥ 0.14) by maternal treatments. Carcass characteristics were not different (p ≥ 0.18), except steers from TM dams had greater (p = 0.05) percentage of carcasses graded as Choice or greater. In conclusion, maternal supplementation of an injectable trace mineral increased the percentage of carcasses graded as Choice or greater, other than that, maternal supplementation had limited influence on finishing phase growth performance, trace mineral status, or carcass characteristics of the subsequent steer progeny.

Fatty Acid Characterization of Beef Longissimus from Steers Finished on Fodder Beet or Traditional Winter Forages in New Zealand Compared to US Grain-Fed Beef

Fatty acids were evaluated to characterize lipid profiles of beef from 3 feeding programs: New Zealand (NZ) fodder beet (FB), NZ grass/non-FB (NFB), and United States grain. Strip loins were selected within each program based on expected eating quality focusing on marbling, ossification, and pH. Selection resulted in 6 treatments: FB high quality, FB low quality, NFB high quality, NFB low quality, US Top Choice, and US Select. Samples were aged 21 d or 35 d postmortem. A subset of 152 samples (12–13 per treatment combination) were used for fatty acid characterization. Within the polar lipid fraction, US treatments had lower monounsaturated fatty acid (MUFA) and greater polyunsaturated fatty acid (PUFA) than NZ treatments (P < 0.05). Within the neutral lipid fraction, concentrations of total neutral lipids and proportions of saturated fatty acid, MUFA, and PUFA were affected by treatment (P < 0.05). Total neutral lipids were greatest in Top Choice (P < 0.05) and greater in FB high quality than all other treatments (P < 0.05). Proportions of satu- rated fatty acid in the neutral lipid fraction were greater in NFB treatments than US treatments (P < 0.05); FB treatments were intermediate. Proportions of MUFA were greatest in Top Choice (P < 0.05). Proportions of PUFA were greatest (P < 0.05) in Select, greater in Top Choice than all NZ treatments (P < 0.05), and greater in NFB treatments than FB treatments (P < 0.05). No interactions occurred for any groups of fatty acids in either fraction ( P > 0.05), and aging did not affect fatty acid composition. Lipid profiles were impacted by finishing diet; however, most differences were between US grain-fed beef and NZ treatments—with limited differences between FB and NFB samples—when product was selected based on quality descriptors. Therefore, FB could be substituted for grass forages to sustain the NZ beef industry through winter months and limit seasonality without detrimental effects on product quality.

Grain supplementation of calves as an alternative beef production system to pasture-finished steers in Chilean Patagonia: meat quality and fatty acid composition.

Beef production in Chilean Patagonia is based on steer finishing on pastures with low nutritive value. Grain supplementation for finishing calves on pasture arises as an attractive alternative to shorten the finishing phase and improve the production efficiency of the traditional system. The aim of this study was to compare meat quality and fatty acid (FA) composition of beef from steers and calves. Forty Angus cross steers were raised on pasture and slaughtered at 18 to 20 mo of age (448 ± 31.7 kg body weight). An additional group of 10 calves from similar genetics was weaned at 9 mo of age (303 ± 8.0 kg) and subsequently supplemented with 2.5 kg corn plus 1.0 kg commercial concentrate daily while on pasture during 47 d, until they reached slaughter weight (316 ± 13.9 kg). All animals were slaughtered on the same day and the Longissimus thoracis muscle was removed from each carcass for meat quality and FA profile analysis. Hot carcass weight from calves was lighter than steers (174 ± 7.9 vs. 224 ± 17.5 kg, P ≤ 0.001). Meat from calves was lighter (higher L*) and less red (lower a*). In addition, meat from calves showed lower level of yellow pigments in subcutaneous fat (lower b*) compared with meat from steers (P ≤ 0.001). Meat from calves was more tender than meat from steers (P ≤ 0.05), although both shear force values were low and within recommendations for high consumer acceptability. Meat from both production systems showed fat content and FA profiles within dietary recommendations for a healthy diet. However, meat from calves was leaner (1.10 ± 0.29 vs. 2.00 ± 0.72% fat, P ≤ 0.001). Meat from calves showed lower percentages of saturated (P ≤ 0.05) and monounsaturated (P ≤ 0.001) FAs and higher percentages of polyunsaturated and n-3 (P ≤ 0.001) FAs and conjugated linoleic acid (total and 9c,11t-18:2 isomer, P ≤ 0.001) than meat from steers. Grain supplementation of calves on pasture can reduce the finishing period by 8 to 10 mo at the expense of lighter carcasses with similar or improved meat quality characteristics compared with the traditional finishing of steers on pasture. Implementation of the alternative production system will depend mainly on feed costs and target carcass weights for specific markets.

52 Evaluation of Production Economics and a Value of Carcasses Processed into Wholesale Cuts from Steers Finished in a Conventional System Compared to Carcasses Processed into Ground Beef from Steers Finished on a Grass-Based Systems.

52 Evaluation of Production Economics and a Value of Carcasses Processed into Wholesale Cuts from Steers Finished in a Conventional System Compared to Carcasses Processed into Ground Beef from Steers Finished on a Grass-Based Systems.

Fatty Acids Profile and Quality Attributes of Beef from Steers Finished on Legume and Grass Pasture

ObjectivesFeeding legume and grass can alter fatty acids profile and quality characteristics of pasture-finished beef. Therefore, the objective of this study was to compare finishing beef steers on mixed legume-grass pastures to feeding a high-energy supplement to grazing steers and feeding a high-concentrate diet on fat content, fatty acids profile, lipid oxidation, objective color, texture, and WBSF of beef.Materials and MethodsBritish × zebu-cross steers (n = 18) were assigned randomly to 1 of 3 dietary treatments: 1) grazing pastures comprised of oats, ryegrass, white and red clover (PAST); 2) grazing the mixed legume-grass pastures and supplementing steers (1.4% BW) with whole corn (SUPP); or 3) limit-feeding (2.8% BW) an 85% whole corn finishing diet (GRAIN). All steers were slaughtered after the 91-d feeding trial, and boneless ribeye rolls were removed from left sides 24 h of chilling, and subsequently cut into 2.54-cm-thick steaks that were individually vacuum packaged and frozen at –20°C for 20d. Analyses included proximate composition (g/100g), cholesterol (g/100g), fatty acids profile (g/100g FAME), cooking loss (%), and shear force (N), and texture profile. Five steaks were thawed and displayed at 4°C for 13 d to evaluate objective color (L*, a*, b*). TBARS (mg MDA/kg meat) were quantified on d 1, 4, 7, 10, and 13 d. Data were analyzed as a CRD. Days of display and oxidation were analyzed as repeated measures. MIXED and GLM procedures of SAS (SAS Inst. Inc., Cary, NC) were used and when significance (P ≤ 0.05) was identified by ANOVA.ResultsFinishing steers on GRAIN led to higher fat content (P = 0.002) and lower moisture values (P 0.05) among dietary treatments.No treatment effect was observed for L*, cooking loss, WBSF, and texture profile attributes, except for cohesiveness (higher from PAST and SUPP samples than for GRAIN samples, P = 0.002). Lipid oxidation was significant higher on beef from steers fed GRAIN than beef from SUPP and PAST (P < 0.001). Steaks from steers fed PAST and SUPP were redder after 10 and 13d of display than steaks from GRAIN-fed steers, and steaks from PAST and SUPP differed after 13d of display (P < 0.001). Although yellowness decreased during retail display (P < 0.001), dietary treatments did not influence b* values (P = 0.051).ConclusionBeef finished on GRAIN had higher values of n-6/n-3 ratio and increased lipid oxidation. Higher proportions of PUFA found in beef from steers finished on mixed pasture (PAST) and supplemented with corn (SUPP) did not affect lipid and color stability of beef, possibly due to natural antioxidants found in legume-grass mixtures. Dietary treatments did not influence texture, tenderness, and cholesterol values. Beef from steers finished on legume and grass pasture (PAST) showed similar attributes when compared to beef from steers finished with corn supplementation (SUPP).

Fatty Acids Profile and Quality Attributes of Beef from Steers Finished on Legume and Grass Pasture

ObjectivesFeeding legume and grass can alter fatty acids profile and quality characteristics of pasture-finished beef. Therefore, the objective of this study was to compare finishing beef steers on mixed legume-grass pastures to feeding a high-energy supplement to grazing steers and feeding a high-concentrate diet on fat content, fatty acids profile, lipid oxidation, objective color, texture, and WBSF of beef.Materials and MethodsBritish × zebu-cross steers (n = 18) were assigned randomly to 1 of 3 dietary treatments: 1) grazing pastures comprised of oats, ryegrass, white and red clover (PAST); 2) grazing the mixed legume-grass pastures and supplementing steers (1.4% BW) with whole corn (SUPP); or 3) limit-feeding (2.8% BW) an 85% whole corn finishing diet (GRAIN). All steers were slaughtered after the 91-d feeding trial, and boneless ribeye rolls were removed from left sides 24 h of chilling, and subsequently cut into 2.54-cm-thick steaks that were individually vacuum packaged and frozen at –20°C for 20d. Analyses included proximate composition (g/100g), cholesterol (g/100g), fatty acids profile (g/100g FAME), cooking loss (%), and shear force (N), and texture profile. Five steaks were thawed and displayed at 4°C for 13 d to evaluate objective color (L*, a*, b*). TBARS (mg MDA/kg meat) were quantified on d 1, 4, 7, 10, and 13 d. Data were analyzed as a CRD. Days of display and oxidation were analyzed as repeated measures. MIXED and GLM procedures of SAS (SAS Inst. Inc., Cary, NC) were used and when significance (P ≤ 0.05) was identified by ANOVA.ResultsFinishing steers on GRAIN led to higher fat content (P = 0.002) and lower moisture values (P < 0.001) when compared to PAST. Dietary treatments did not affect crude protein (P = 0.99) and cholesterol values (P = 0.13). The LT from PAST- and SUPP-fed steers had greater proportions of n-3 PUFA and 18:2cis-9, trans-11 CLA than the LT from GRAIN-fed steers; however, LT of GRAIN steers had greater (P < 0.001) n-6/n-3 ratio (8.86%) than the LT from either SUPP-fed (2.65%) or PAST-fed steers (1.91%). Although steers fed GRAIN had greater (P = 0.002) proportions of MUFA than PAST, proportions of PUFA and SFA were similar (P > 0.05) among dietary treatments.No treatment effect was observed for L*, cooking loss, WBSF, and texture profile attributes, except for cohesiveness (higher from PAST and SUPP samples than for GRAIN samples, P = 0.002). Lipid oxidation was significant higher on beef from steers fed GRAIN than beef from SUPP and PAST (P < 0.001). Steaks from steers fed PAST and SUPP were redder after 10 and 13d of display than steaks from GRAIN-fed steers, and steaks from PAST and SUPP differed after 13d of display (P < 0.001). Although yellowness decreased during retail display (P < 0.001), dietary treatments did not influence b* values (P = 0.051).ConclusionBeef finished on GRAIN had higher values of n-6/n-3 ratio and increased lipid oxidation. Higher proportions of PUFA found in beef from steers finished on mixed pasture (PAST) and supplemented with corn (SUPP) did not affect lipid and color stability of beef, possibly due to natural antioxidants found in legume-grass mixtures. Dietary treatments did not influence texture, tenderness, and cholesterol values. Beef from steers finished on legume and grass pasture (PAST) showed similar attributes when compared to beef from steers finished with corn supplementation (SUPP).

Carcass Traits of Steers Finished on Legume and Grass Pasture and in Feedlot System

Carcass Traits of Steers Finished on Legume and Grass Pasture and in Feedlot System

Beef cow prepartum supplement level and age at weaning: II. Effects of developmental programming on performance and carcass composition of steer progeny.

Objectives were to determine the interaction of prepartum dam supplement level and age at weaning on growth performance, glucose and insulin concentrations, and carcass characteristics of steers (134 steers in yr 1; 147 steers in yr 2). Mature, multiparous Angus × Simmental cows were used in a split-plot design that included 3 supplement levels (no supplement [NS], 2.16 kg·cow·d [LS], and 8.61 kg·cow·d [HS]) and 2 ages at weaning (78 ± 11 d of age [early weaned; EW] or 186 ± 11 d of age [normal weaned; NW]). Cows grazed endophyte-infected tall fescue/red clover pastures and were bunk fed supplement (70% dried distiller's grains plus solubles and 30% soybean hulls) 103 ± 11 d prepartum to 2 ± 11 d postpartum. Dam prepartum supplement level did not affect ( ≥ 0.29) finishing phase growth performance or morbidity. The percentage of steers grading Average Choice or greater was increased ( = 0.04) for steers from cows fed HS compared to the percentage of steers from cows fed NS. Early weaning increased ( < 0.01) finishing phase initial BW and final BW and reduced ( < 0.01) G:F compared to normal weaning. A year × wean interaction ( = 0.04) occurred for ADG; EW resulted in reduced ( < 0.01) ADG compared to NW in yr 2. At slaughter, EW steers had greater ( < 0.01) HCW, yield grade, and back fat than NW steers. A year × wean interaction ( ≤ 0.05) occurred for quality grade distribution; in yr 2, EW steers had a greater ( < 0.01) proportion of carcasses that graded Low Choice or greater and Average Choice or greater than carcasses from NW steers. The EW steers had greater ( ≤ 0.05) occurrence of single antibiotic treatments in yr 2 and mortality due to respiratory disease than NW steers. A trend for a year × wean interaction ( ≤ 0.07) occurred for plasma insulin concentration and insulin:glucose; EW steers had numerically greater plasma insulin concentrations and insulin:glucose than NW steers in yr 1. In conclusion, these data suggest that there is no interaction between maternal level of supplement during late gestation and age at weaning on steer finishing phase performance, glucose and insulin concentrations, and carcass yield and quality characteristics. Overfeeding supplement to the dam did not affect finishing phase growth performance but did improve quality grades of steers. Early weaning increased HCW and improved carcass quality. Both dam supplement level and age at weaning are effective strategies in increasing beef quality and are independent of each other.

Use of the correlation between input variables in estimating the risk of feedlot finishing of steers and young steers

The objective of this study was to evaluate the risk of feedlot finishing of steers (22.8 months) and young steers (15.2 months), using or not a correlation between the random input variables (data collected from 2004 to 2010) in the simulation of the Net Present Value (NPV) financial indicator. The animals were fed a diet containing roughage:concentrate ratio of 60:40 for 34 and 143 days, respectively, until they had reached a predetermined slaughter weight of 430 kg. For the NPV simulation, Latin Hypercube sampling was used, with 2000 interactions. The stochastic dominance analysis, test of differences between pairs of curves of cumulative distributions and sensitivity analysis were carried out. The NPV simulation using the correlation resulted in the best option for risk estimate. The confinement of young steers was the alternative of investment most viable than confinement of steers (NPV ≥ 0 of 80.4 vs. 62.3% in the simulation with correlation, respectively). Sensitivity analysis determined the following items had the greatest impact on the estimate of NPV: prices of fat and thin cattle, initial and final weights, diet costs, minimum rate of attractiveness and diet intake.

Performance and Carcass Quality of Forage-Fed Steers as an Alternative to Concentrate-Based Beef Production

This paper studies the performance and carcass quality of Parda de Montaña cattle under different management systems to find alternatives to concentrate feed indoor beef production. Treatments were: i) Control, with 8 bulls (216±34.3 kg initial weight; 282±45.6 days) fed concentrate and straw ad libitum during winter housing period until reaching 500 kg; ii) G-supp, with 8 steers (204±31.2 kg initial weight; 271±47.5 days) fed a total mixed ration (TMR) (50% alfalfa hay, 10% straw, 40% corn) ad libitum during winter housing period (from mid-April steers rotationally grazed on a mountain meadow supplemented with 1.8 kg dry matter corn/d until reaching 500 kg); iii) TMR, with 8 steers (200±42.5 kg initial weight; 261±39.0 days) managed as G-supp steers until mid-July, when they were housed and fed TMR ad libitum until reaching 500 kg.Control bulls had 45% greater weight gain than TMR and G-supp steers during housing period (P<0.001). In the finishing period, TMR had 31% greater weight gain than steers finished on pasture (P<0.01). At slaughter, Controls were 97-127 days younger than others (P<0.001). Steers finished on TMR had worse conformed carcasses, greater fat and fewer edible meat proportions than G-supp and Control (P<0.01). Total cost of TMR and G-supp was greater than Control, with a similar income for G-supp and Control. TMR steers were paid less because of their worse carcass quality. Hence, finishing of steers on pasture with a supplement can be a feasible alternative to fattening bulls on concentrates, depending on the relative availability and price of feedstuff.

Effects of USDA feeder cattle frame and muscle grades on stocker and feeder cattle performance and profitability

A total of 395 calves (180 ± 25 kg) were purchased from sale barns in Oklahoma and Texas in the fall of 3 consecutive years to measure the effect of USDA feeder cattle frame and muscle grades on performance and profitability. Individual purchase weight and price were recorded, and steers were assigned USDA feeder cattle grades of Large (LG), Medium (MED), or Small (SM) frame size and Number 1 or Number 2 muscle thickness by the same official USDA market graders. Steers were grazed on rye pasture and were then valued by commercial order buyers in frame and muscle grade groups. Muscle grade did not affect (P > 0.60) animal performance or profitability during the grazing phase. Grazing ADG increased linearly (P < 0.001) as frame grade increased, but purchase price was lower (P < 0.001) for SM steers than for MED and LG frame steers, respectively, resulting in greater (P < 0.001) grazing-phase net returns for SM steers. Following finishing on a high-concentrate diet, the lesser total weight gain during finishing of SM steers (P < 0.001) resulted in lesser per animal revenue. Feed and interest costs were also less (P < 0.001) and marbling score greater (P < 0.001) for SM steers, resulting in greater finishing net returns and carcass price. In a post hoc analysis in which frame and muscle grades were reassigned to cattle based on HCW and LM area, only 44% of the cattle remained in their original grade.

Silage-concentrate finishing of bulls versus silage or fresh forage finishing of steers: Effects on fatty acids and meat tenderness

The objective of this trial was to assess meat quality in terms of tenderness and fatty acid (FA) composition in M. longissimus dorsi and M. gluteus medius from bulls finished on ad lib silage-concentrates (SIL:CON) vs. steers fed ad lib silage (FF) or restricted silage and unrestricted grazing (RES-F). Warner-Brazler shear force value day 1 was lowest for the FF steers (p<0.05). Myofibril fragmentation index (MFI) values were similar after seven days of ageing, showing that ageing compensated for differences in meat tenderness associated with feeding programmes. Total monounsaturated FAs and 18:1c-9 levels were higher in the steer tissue (p<0.001). The SIL:CON bulls had higher polyunsaturated n-6 fatty acids and 18:2n-6 level (p<0.001). Polar lipid 18:2n-6 and n-6 levels were higher for FF than for RES-F steers, whereas the 18:3n-3 level was higher for RES-F than for FF steers (p<0.001). The n-6/n-3 ratio was lowest for the FF steers and highest for the SIL:CON bulls (p<0.001).

Efficiency of extruded linseed for the finishing of grass-fed steers to counteract a decline of omega-3 fatty acids in the beef

Effects of different finishing regimes with and without conventional or linseed-supplemented concentrate on growth performance and carcass composition of grass-fed steers as well as meat quality and lipid composition of the beef were investigated. Limousin × Brown Swiss and Limousin × Holstein–Friesian crossbred steers were fed on a grass-based forage-only diet up to an average live weight of 470 kg and an age of 18 months. During the following finishing period, two groups received 3 kg/day of concentrate additional to fresh grass and hay. One concentrate was a conventional cereal-based type (CC) the other contained extruded linseed (LS). Steers of these two groups were fattened to 560 kg of live weight. Two other groups further on received only grass and hay and were slaughtered either at the same average weight (G 1) or at the same age (G 2) as CC steers. The concentrate supplementation in the finishing period did not significantly increase average daily gains of the steers. The killing-out percentage was improved by CC, which was reflected in heavier hot carcasses. No other carcass quality trait was significantly affected by the different feeding regimes. The direct comparison of G 2 with CC showed a significantly higher shear force and compression energy in m. longissimus dorsi (LD) of G 2, suggesting a less tender LD, but not m. biceps femoris (BF), of the grass-fed steers. In the groups compared at the same slaughter weight, no significant differences were observed in meat colour and texture. Lower proportions of C18:3n-3 (omega-3) in total lipids and in phospholipids of LD and BF were found for CC steers compared to grass-fed steers. This effect was partly compensated for by the supplementation of linseed to the concentrate which also exerted a trend towards higher levels of conjugated linoleic acid. However, since the n-6/n-3 ratio in the beef of the CC steers was still favourably low, it remains a matter of economic calculations and marketing considerations to determine whether linseed supplementation might be a cost-efficient measure in pasture beef programs to produce meat with claimed dietetic advantages in terms of fatty acid composition.

Optimal decisions in organic beef production from steers — Effects of criterion of optimality and price changes

Organic beef production from steers demands several decisions concerning grazing strategy, feeding level in the winter and aspects as slaughter weight and length of the finishing period. A model has been developed to optimise these strategies. The objective of this study was (1) to find optimal strategies for organic beef production from steers regarding grazing strategy, feeding level in winter, finishing and slaughter in organic beef production from steer concerning economic output per time unit using a multi-level hierarchic Markov process and (2) to analyse the stability of these results by sensitivity analysis. The results showed that in general the optimal strategy only changes slightly depending on the criterion (net returns per steer versus per time unit). An optimization per time unit in some cases favours a more intensive production based on high feeding level in winter and finishing of steers as well as earlier slaughtering compared to an optimization per steer. Finishing of steers seemed not to be an optimal strategy from an economic point of view and price changes in feed, beef and premiums did not favour finishing of steers. Beef prices as well as prices for ryegrass/white clover pasture and low feeding level seemed to be the most important factors that influence net return.

Examining death loss in Kansas feedlots

This study had three primary objectives: 1) to determine if there is an annual and/or seasonal trend in percentage of death loss in Kansas feedlots; 2) to examine the difference in death loss between steers and heifers; and 3) to evaluate if "in" weight has had an effect on percentage of death loss in Kansas feedlots. The annual trend in death loss for both steers and heifers was found to be significant and positive, indicating that death loss has been increasing over the sample period. Seasonal increases in death loss were significant for early-spring closeouts for both steers and heifers. The annual trend in the difference between the death loss for steers and heifers, though not significant, was negative. There were, however, certain closeout months in which there were significant differences in the death loss of steers relative to heifers. Placement weight had a significant negative impact on death loss in heifer finishing, but no significant impact on steer finishing. Our regression analysis indicates that death loss has been increasing over the sample period, that certain closeout months tend to impact steer and heifer death loss differently, and that placement weight in heifers has had a significant impact on percentage of death loss in cattle.

Resposta econômica da terminação de novilhos em confinamento, alimentados com silagens de diferentes híbridos de sorgo (Sorghum bicolor, L. Moench)

O experimento foi conduzido com o objetivo de avaliar o resultado econômico da terminação de novilhos em confinamento, alimentados com silagens de diferentes híbridos de sorgo: AGX-213 e AG-2002 (caráter forrageiro); AGX-217 e AG-2005E (caráter duplo propósito). Utilizaram-se 48 novilhos com idade média de 19 meses e peso vivo médio inicial de 316kg. A relação volumoso:concentrado foi de 63:37, para todas as dietas testadas. O custo médio das silagens foi de 15,13; 13,53; 18,55 e 20,20 R$/t para os híbridos AGX-213, AG-2002, AGX-217 e AG-2005E, respectivamente. O ganho de peso vivo/ha estimado em função da silagem produzida/ha em dietas com relação volumoso:concentrado 63:37 foi de 1.879,9; 2.038,3; 1.609,9 e 1.912,5kg. O custo/kg de ganho de peso em R$ foi de 0,770; 0,759; 0,780 e 0,635, promovendo uma receita líquida de 432,38; 491,23; 354,18 e 698,06 R$/ha. A silagem dos híbridos forrageiros AG-2002 e AGX-213 apresenta menor custo de produção, porém a inclusão de silagem de sorgo de duplo propósito AG-2005E na dieta alimentar de novilhos em confinamento determina maior retorno econômico no sistema de produção.

Measuring Improvements in Performance of Steers and Heifers During Finishing Phases

Abstract Changes in steer and heifer finishing performance impact the relative competitiveness of the beef industry. This study examined improvements in the finishing performance of steers and heifers from January 1990 to December 1998. Data were obtained from monthly issues of the Focus on Feedlots newsletter. Steer and heifer performance were measured using ADG, feed efficiency, the rate of technological change, and the rate of change in total feeding cost. The rate of technological change measured shifts in the production frontier for steers and heifers. The rate of change in total feeding cost measured shifts in the cost frontier. ADG improved 0.99% per year for steers and 0.96% per year for heifers. Feed efficiency improved 0.60% per year for steers and 0.72% per year for heifers. The rate of technological change averaged 0.58% per year for steers and 1.01% per year for heifers. The positive rates of technological change indicated that the rate of change in BW gain was greater than the rate of change in feed fed. Total feeding cost for heifers increased by 0.63% per year. For steers, the rate of change in total feeding costs was positive, but insignificant. The higher rate of cost increase for heifers was the result of relatively large increases in BW gain for heifers during the study.

Body and carcass composition of Angus and Charolais steers as affected by age and nutrition.

The objectives of this study were to examine the effects of a low vs moderate rate of gain during the growing phase on empty body and carcass composition during finishing of Angus and Charolais steers of two ages. Forty-eight Angus and 48 Charolais steers that were either spring-born (OLDER) or fall-born (YOUNGER) were fed two diets (alfalfa pellets [CON] or cubed grass-alfalfa hay, wheat straw, cottonseed hulls, and soybean meal [RES]) for a growing period followed by a conventional feedlot period. The feedlot period started when the YOUNGER-CON steers weighed the same as the OLDER-RES steers. At that time, an interaction of age x diet occurred in empty body fat content (P < .10), whereas breed and age x diet affected carcass fat content (P < .01). OLDER-CON steers were larger (average 378 kg empty BW) and fatter than the other, smaller groups (average 222 kg). Angus carcasses were fatter than Charolais carcasses (P < .01). At the end of the finishing phase, compensating steers (OLDER-RES) had fatter carcasses than OLDER-CON steers. Empty body fat content was affected by a breed x age x diet interaction (P < .10). Allometric regressions (Y = aXb) of fat on empty BW indicated that empty body fat accretion was greater in Angus than in Charolais and in YOUNGER than in OLDER steers. A breed x age x diet interaction (P < .10) indicated that OLDER-Angus had higher fat accretive rates than YOUNGER-Angus, whereas OLDER-CON-Charolais steers deposited fat more slowly than the remaining groups. These data suggest that steers receiving feedlot diets at light weights, whether young in age or previously restricted, accumulate fat more rapidly than do larger steers. This feeding strategy may be an advantage in late-maturing types, but moderate growth through approximately 75% of slaughter weight is recommended for early-maturing types.