Cattlemen's Day, 2004

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Open Access
Relationship of total iron content in beef to flavor attributes
(Kansas State University. Agricultural Experiment Station and Cooperative Extension Service, 2010-08-04T13:50:08Z) Grobbel, J.P.; Dikeman, Michael E.; Milliken, George A.; Yancey, E.J.; jgrobbel; mdikeman; milliken
The objective of our study was to evaluate the relationships among total iron content, myoglobin/total iron ratio, hemoglobin/total iron ratio, and flavor attributes in beef top sirloin, shoulder clod, and tenderloin muscles. Top sirloin (n=74), shoulder clod (n=68), and tenderloin (n=73) muscles from A or B maturity carcasses that were either USDA Slight or USDA Small marbling and of either normal pH (<5.7) or high pH (>6.0) were vacuum packaged, aged 35 days at 35ºF, and stored at -4ºF until analysis. A well trained, flavorprofile sensory panel determined flavor attributes on charbroiled steaks. Flavor attributes included beef flavor identification, bloody/serumy, brown roasted, livery, metallic, rancid, and sour. Concentrations of myoglobin and hemoglobin were determined by using high-pressure liquid chromatography. Total iron concentration was determined by using an atomic absorption spectrophotometer. The shoulder clod had greater total iron (P<0.05) than the top sirloin or tenderloin. Livery flavor increased (P<0.05) and beef flavor identification and brown roasted flavor decreased (P<0.05) in the top sirloin as total iron increased. Compared with the top sirloin and shoulder clod, the tenderloin had lower (P<0.05) myoglobin/total iron ratios and greater (P<0.05) hemoglobin/total iron ratios. At medium and high myoglobin/total iron ratios, samples with Slight marbling had more (P<0.05) livery flavor. At low myoglobin/total iron ratios, A-maturity samples had more (P<0.05) rancid off-flavor than B maturity samples. There were no relationships between hemoglobin/total iron ratios and flavor attributes. Total iron may contribute to livery flavor in the top sirloin, but total iron is not a reliable indicator of livery flavor.
Open Access
Effect of castration time on feedlot performance, carcass characteristics, and beef tenderness
(Kansas State University. Agricultural Experiment Station and Cooperative Extension Service, 2010-08-04T13:49:57Z) Homm, J.W.; Marston, T.T.; Brethour, J.R.; Unruh, John A.; junruh
Crossbred Angus calves (n=120) were randomly assigned to early-castrated, early-castrated plus implant, and late-castrated treatment groups. After weaning, calves were placed on feed at the Western Kansas Agricultural Research Station in Hays, Kansas, for finishing. On-feed weights and final weights were similar among treatments. During the first 132 days on feed, the steers castrated early and implanted had a lower average daily gain than early- and late-castration treatments. Early castrates tended (P=0.08) to have a lower feed-to-gain ratio for the first 132 days on feed. Hot carcass weight, internal fat, and marbling scores were not affected by treatment. Carcasses from steers castrated late had less backfat, larger ribeye areas, and lesser yield grades (greater cutability) than carcasses from steers castrated early, with or without an implant. Carcasses from steers castrated early and implanted had a greater percentage grading USDA choice (60%) than did carcasses from steers castrated early (45%) or late (41%). Warner-Bratzler shear force and sensory-panel traits were similar for all treatment groups.
Open Access
Relationship of Warner-Bratzler shear force and trained sensory panel tenderness of strip loin steaks cooked to 131 and 158°F
(Kansas State University. Agricultural Experiment Station and Cooperative Extension Service, 2010-08-04T13:46:21Z) Stephens, J.W.; Obuz, E.; Grobbel, J.P.; Dikeman, Michael E.; mdikeman; jgrobbel
In a previous study, eighteen strip loins from USDA Select and premium Choice carcasses were cooked on a Magikitch’n® belt grill to determine tenderness at nine different endpoint temperatures. That study revealed that optimum Warner-Bratzler shear force (WBSF) values occurred in strip loin steaks cooked to 131°F, but current WBSF protocol requires steaks to be cooked to 158°F. Therefore, trials employing trained sensory panels (TSP) were conducted to determine the relationship of WBSF with TSP tenderness from steaks cooked to 131 and 158°F on the belt grill. As expected, panelists found steaks cooked to 131°F more tender than those cooked to 158°F. The relationship of WBSF with TSP ratings for tenderness was not significant (P>0.05) when both steaks were cooked to 158°F. When both steaks were cooked to 131°F, however, there was a moderate relationship (r = -0.52) of WBSF with TSP tenderness. The relationship of WBSF from steaks cooked to 131°F with TSP ratings for tenderness from steaks cooked to 158°F was the strongest (r = -0.66). More research is needed to determine the feasibility of cooking steaks to 131°F, rather than 158°F, to improve WBSF determination.
Open Access
Endpoint temperature, cooking method, and marbling degree have different effects on Warner-Bratzler shear force of beef strip loin, bottom round, and brisket muscles
(Kansas State University. Agricultural Experiment Station and Cooperative Extension Service, 2010-08-04T13:46:10Z) Obuz, E.; Stephens, J.W.; Grobbel, J.P.; Loughin, T.M.; Dikeman, Michael E.; mdikeman; jgrobbel; loughin
Our objective was to determine the effects of endpoint temperature, cooking method, and marbling on Warner-Bratzler shear force (WBSF; an objective method for determining tenderness) of three beef muscles. Eighteen subprimals of a muscle containing low content of connective tissue, longissimus lumborum (strip loin), and two muscles containing a high content of connective tissue, biceps femoris (bottom round) and deep pectoralis (brisket), were selected from USDA Select and Choice (Certified Angus Beef) carcasses. After 14 days of aging, subprimals were frozen, fabricated into steaks, and stored frozen until cooking. Steaks were assigned to one of two cooking methods, the Magikitch’n® electric belt grill (a rapid conduction method) or a water bath (a slower, convection method); and one of nine endpoint cooking temperatures, 104, 113, 122, 131, 140, 149, 158, 167, or 176°F. According to WBSF results, optimum tenderness for the strip loin occurred around 131°F. Higher marbling protected tenderness at higher endpoint temperatures. Tenderness increased in bottom round and brisket muscles as endpoint temperature increased from 104 to 140°F, then tenderness decreased as endpoint temperature rose from 149 to 176°F. Endpoint temperature was the only significant factor affecting bottom round tenderness. Steaks cooked in the water bath had higher WBSF and, therefore, were less tender than those cooked on the belt grill. This was true for both the strip loin and brisket. The effect of increasing endpoint temperature on WBSF of the strip loin was different than for the bottom round and brisket.
Open Access
Fffect of freezing the beef Longissimus muscle on Warner-Bratzler shear force
(Kansas State University. Agricultural Experiment Station and Cooperative Extension Service, 2010-08-04T13:45:59Z) Homm, J.W.; Unruh, John A.; junruh
Seventy-two ribeye rolls (IMPS 112) were used to compare Warner-Bratzler shear force (WBSF) from fresh steaks and previously frozen steaks. Ribeye rolls were aged (32ºF) in vacuum-packaged bags for 14 days postmortem and fabricated into 1-inch thick longissimus muscle (ribeye) steaks. Steaks from each ribeye roll were either cooked fresh (158ºF) or stored at –20ºF before they were thawed and cooked for WBSF determination. Sensory panel determinations were also conducted on steaks stored frozen before cooking. Previously frozen steaks had lesser WBSF values (were more tender) than fresh (not previously frozen) steaks. Sensory panel attributes of myofibrillar tenderness, connective tissue amount, and overall tenderness were negatively correlated with WBSF for both fresh (r = –0.54, –0.53, and –0.58) and frozen (r = –0.63, –0.56, and –0.62) steaks, respectively. The WBSF of fresh steaks was also correlated (r = 0.48) with the WBSF of frozen steaks.
Open Access
Effects of round bale feeding sites on soil fecal bacteria and nutrient concentrations
(Kansas State University. Agricultural Experiment Station and Cooperative Extension Service, 2010-08-03T17:56:31Z) Lenehan, N.A.; Marston, T.T.; Christian, Michael L.; Marchin, G.L.; DeRouchey, Joel M.; jderouch; gmarchin
An experiment was conducted over seven months (January to July 2003) to evaluate fecal bacteria and nutrient concentrations in soil surrounding round bale feeders at winter feeding sites. Six-inch soil samples were taken each month from a total of ten feeding sites, at distances of 10, 40, 70, and 100 feet from each feeder. Soil samples were taken before (January) livestock access to the sites, during (February, March, and April) the feeding period, and after (May, June, and July) cattle had been removed from the sites. Results indicate that fecal bacteria concentrations increased over the duration of feeding period and were greatest at close proximity to round bale feeders. The data suggest that environmental contamination due to fecal bacteria in the soil can occur up to 100 feet from the feeding site. For soil nutrients, the greatest increase generally occurred at 10 feet from the feeders, with few differences thereafter.
Open Access
Evaluation of ExpressTM 5-PHM and Titanium® 5-PHM Bac®-1 on high-risk receiving steers
(Kansas State University. Agricultural Experiment Station and Cooperative Extension Service, 2010-08-03T17:56:17Z) Epp, M.P.; Hollis, Larry C.; Barnhardt, B.B.; Blasi, Dale A.; mepp; dblasi; lhollis
One backgrounding field study was conducted at two locations to compare the health and performance of high-risk receiving steers given an ExpressTM 5-Pasteurella Haemolytica- Multocida (PHM) vaccine or a Titanium® 5-PHM Bac®-1 vaccine. At one location, calves given the Titanium 5-PHM vaccination had fewer first and second repulls (P<0.05). At the other location, calves given the Express 5-PHM vaccination had fewer initial pulls for respiratory disease and more hospital pen days at initial pull (P<0.05) than those given Titanium 5-PHM. No differences were measured at either location for mortality and average daily gain.
Open Access
Steroid hormone profiles and brain monoamine oxidase type A (MAO-A) activity of buller steers
(Kansas State University. Agricultural Experiment Station and Cooperative Extension Service, 2010-08-03T17:56:06Z) Epp, M.P.; Blasi, Dale A.; Johnson, B.J.; Kayser, J.P.; Grieger, David M.; mepp; dblasi; dgrieger
A grazing/feedlot field study was conducted to evaluate the steroid hormone profile and brain monoamine oxidase type A (MAOA) activity of steers exhibiting characteristics attributed to the Buller Steer Syndrome in a feedlot environment. Differences of serum progesterone, testosterone, and estrogen were found in bullers at different phases of production. Brain MAO-A activity was greater in bullers than in non-bulling steers. This study suggests that MAO-A activity, under potential influence of steroidal hormones in the steer brain, may be a plausible mechanism that induces Buller Steer Syndrome.
Open Access
In vitro evaluation of fibrolytic enzymes to increase digestion of fibrous feedstuffs
(Kansas State University. Agricultural Experiment Station and Cooperative Extension Service, 2010-08-03T17:55:56Z) Elwakeel, E.A.; Johnson, B.J.; Titgemeyer, Evan C.; etitgeme
Fermentations were conducted to identify enzyme activities and amounts that would optimize digestion of high-fiber feed ingredients (soybean hulls, alfalfa, corn silage, and corn gluten feed). In general, adding enzymes increased in vitro dry matter disappearance, but total volatile fatty acid concentrations were not improved by enzyme treatments. The response to enzymes was similar across substrate, suggesting that substrate specificity of the enzymes is not important. The most effective enzyme preparation had greater cellulase activity than the other enzyme preparations, suggesting that cellulase might be the most important enzymatic activity for improving digestion of fibrous feedstuffs.
Open Access
Grazing cattle on winter cereal pasture on the sandy soils of south-central Kansas
(Kansas State University. Agricultural Experiment Station and Cooperative Extension Service, 2010-08-03T17:55:37Z) Martin, Victor L.; Hale, R.; vmartin
Rye, wheat, and triticale pasture were evaluated during the winters of 2000-01, 2001-02, and 2002-03 for their ability to increase cattle weight from late fall through mid-spring. Large-scale studies were conducted on two 80-acre sites divided into either 25- or 40-acre pastures. Cattle at these sites were stocked at one head per acre, with an average initial weight between 500 and 550 lb. At the Sandyland Experiment Field, small-scale studies were conducted by using the same winter cereals for forage, but at greater stocking rates, ranging from two to three head per acre. Supplemental feeding, as necessary, included summer annual forage hay, prairie hay, and grain consisting of wheat middlings and processed grain sorghum. Winter cereals were planted at 100 lb/acre in September of each year. Rye provided the best pasture in terms of cattle weight gain and needed the least supplemental feeding. Wheat was next in producing pounds of beef, and triticale produced less gain than either rye or wheat. These data suggest that rye and wheat were able to support greater stocking rates than triticale.
Open Access
Influence of fall protein supplementation with a self-fed liquid supplement on performance of beef cows grazing tallgrassprairie range
(Kansas State University. Agricultural Experiment Station and Cooperative Extension Service, 2010-08-03T17:55:25Z) Llewellyn, Donald A.; Gray, B.T.; Marston, T.T.; Bandyk, C.A.
We evaluated the effect of providing a liquid, high-protein supplement during the fall grazing period on beef cow and calf performance. Mature, pregnant, spring-calving cows (n=122) grazing native range were assigned to supplementation treatments. All calves were weaned on October 15. Control cows received no fall supplementation and then were handfed a dry supplement (40% crude protein; as fed basis) from December 17 until calving. Supplemented cows were either allowed access to a liquid protein supplement (40% crude protein; as-fed basis) approximately 2 months before weaning until calving (fall supplementation from August 14 to December 17) or from weaning until calving (fall supplementation from October 15 to December 17). Supplement intake of the control cows from December 17 until calving was adjusted to match the estimated supplement intake of the liquid-fed groups and was prorated and fed 3 days/week. Supplementation was terminated upon calving, at which time all cows were treated similarly. Provision of liquid supplement during the fall increased cow body weight and body condition in the post-weaning period. However, cows not supplemented during the fall phase were able to overcome their lesser previous nutrition when they were suitably supplemented during the winter phase. The pre-weaning rate of gain of calves was not affected by fall supplementation. Calves produced by cows receiving no fall supplementation gained more weight from birth to the start of the summer grazing season. Subsequent pregnancy rate was not affected by fall supplementation.
Open Access
Night feeding to reduce bird predation in feedlots
(Kansas State University. Agricultural Experiment Station and Cooperative Extension Service, 2010-08-03T17:55:13Z) Greenquist, M.A.; Sindt, J.J.; Kessen, T.J.; Loe, E.R.; Montgomery, Sean P.; Sulpizio, M.J.; Drouillard, James S.; Lee, Charles D.; jdrouill; clee
During times of heavy infestations by birds, feedlots can have 25 to 30% increases in feed usage, thereby resulting in large economic losses. Because starlings, blackbirds, grackles, and other avian pests normally feed during daylight hours, we hypothesized that feeding cattle at night would minimize feed contamination and feed loss due to bird infestation. Crossbred beef heifers (n=96; 770 lb) were used to evaluate the effects of feeding at night on performance and carcass characteristics. Heifers were fed for 107 days during the months of November to March, when large bird populations were observed. Feed was delivered once daily at approximately 10:00 a.m. for heifers with continuous access to feed and 30 minutes before dusk for heifers that had access to feed only at night. Feed calls for heifers fed at night were managed so that no feed remained in the bunk at dawn, whereas the control heifers were allowed ad libitum access to feed. Daily feed deliveries per animal (21.51 vs. 18.15 lb for heifers fed continuously or only at night, respectively) were decreased by 16% (P<0.01) when cattle were provided access to feed only at night, but daily gain was not different. Feed efficiency was improved by 14% (P=0.05) with night time feeding, but carcass weights and dressing percentage remained similar. Overall, feeding cattle only during hours of darkness yielded similar growth performance compared to cattle fed continuously. However, feed efficiency was improved substantially, which we attribute to reduced theft by birds.
Open Access
Effect of corn endosperm type and corn containing the Cry1F protein on performance of beef heifers fed finishing diets based on steam-flaked corn
(Kansas State University. Agricultural Experiment Station and Cooperative Extension Service, 2010-08-03T17:53:37Z) Sindt, J.J.; Loe, E.R.; Kessen, T.J.; Sulpizio, M.J.; Montgomery, Sean P.; Owens, F.N.; Drouillard, James S.; jdrouill
Eighty beef heifers (initial body weight = 795 ± 18 lb) were individually fed finishing diets based on steam-flaked corn for 118 days. Dietary treatments consisted of corn hybrids containing vitreous (HARD), opaque (SOFT), or intermediate (INT) types of corn endosperm. Within the HARD endosperm type, a transgenic hybrid (HARD-GMO) containing the Herculex I Cry1F protein was compared with its nontransgenic, conventional (HARDCONV) counterpart. Dry matter intake, average daily gain, and gain efficiencies were similar among treatments. Likewise, hot carcass weight, dressing percentage, and ribeye area were unaffected by dietary treatment. Heifers fed HARD-CONV were fatter than heifers fed HARD-GMO, having fewer (P<0.01) USDA Yield Grade 1 and 2 carcasses. In this experiment, feeding flaked corn finishing diets that contained different endosperm types did not alter performance or carcass characteristics. Feeding heifers HARD-GMO compared with HARD-CONV corn resulted in similar performance, although heifers fed HARD-CONV had higher USDA Yield Grades, perhaps because of greater starch availability of HARD-CONV flaked corn than HARD-GMO corn.
Open Access
Addition of estradiol cypionate and (or) calf removal to a modified MGA + CO-Synch protocol for fixed-time artifical insemination of beef cows
(Kansas State University. Agricultural Experiment Station and Cooperative Extension Service, 2010-08-03T17:53:26Z) Johnson, Sandra K.; Harmoney, Keith R.; Stevenson, Jeffrey S.; sandyj; jss; kharmone
A study was conducted in 735 suckled beef cows to determine if synchronization of ovulation could be improved with estradiol cypionate (ECP) and(or) 48-hour calf removal in a modified MGA + CO-Synch protocol. All cows were fed melengestrol acetate (MGA) (0.5 mg/cow) daily for 14 days (days -32 to - 19 of the experiment) and received an injection of gonadotropin-releasing hormone (GnRH) on d -7, an injection of prostaglandin F2α (PGF) on day 0, and received a fixed–time artificial insemination (AI) at 72 hours after PGF. Treatments were applied in a 2 x 2 factorial arrangement. Calves either remained with cows (suckled) or were removed for 48 hours, beginning 24 hours after PGF and continuing until after the fixed-time AI (calf removal). Cows received either ECP at 24 hours after PGF or received GnRH concurrent with the fixed-time AI. AI pregnancy rates were similar for cows receiving ECP (48%) or GnRH (45%). Cycling status influenced the response to calf removal. Noncycling cows whose calves were removed had greater AI pregnancy rates than suckled cows, 37% vs. 27%, respectively. When calves were not removed, GnRH given at fixed-timed AI resulted in pregnancy rates similar to ECP and did not require additional handling of the cows. In the herd of mature cows with body condition scores near 5 and that had calved 75 to 80 days before the time of AI, the MGA + CO-Synch system used in this study produced AI pregnancy rates of 50% or better without heat detection.
Open Access
Estrus synchronization of suckled beef cows by using GnRH, prostaglandin F2α (PGF), and progesterone (CIDR): a multi-location study
(Kansas State University. Agricultural Experiment Station and Cooperative Extension Service, 2010-08-03T17:53:05Z) Larson, J.E.; Lamb, G.C.; Stevenson, Jeffrey S.; Marston, T.W.; Johnson, Sandra K.; Day, M.L.; Geary, T.W.; Kesler, D.J.; DeJarnette, J.M.; Schrick, F.N.; Areseneau, J.D.; jss; sandyj
Our objectives were to determine whether a fixed-time artificial insemination (TAI) protocol could yield pregnancy rates similar to a protocol requiring detection of estrus and whether inclusion of a CIDR (a vaginal insert containing progesterone) in protocols using gonadotropin-releasing hormone (GnRH) and prostaglandin F2α (PGF) would enhance fertility. Postpartum suckled beef cows (n = 2,630) from 14 locations were assigned randomly to each of five estrus-synchronization protocols using PGF with GnRH and(or) a CIDR. Protocols were Control, CO-Synch, COSynch+ CIDR, Hybrid-Synch, and Hybrid-Synch+CIDR. The percentage of cows cycling at the initiation of estrus synchronization was 66.8%, the percentage of cycling cows ranging from 38 to 90% among locations. Overall pregnancy among locations ranged from 39% to 67%. Pregnancy rates were greatest for the Hybrid-Synch+CIDR (57.9%) treatment, although not significantly different from the CO-Synch+CIDR (53.6%) and Hybrid-Synch (53.0%) treatments, but greater than the Control (52.3%) and CO-Synch (43.4%), which yielded the poorest pregnancy rates. Overall, the Hybrid-Synch+CIDR protocol (AI after detected estrus for 3 days, and then a clean-up TAI) achieved the greatest pregnancy rates, but CO-Synch+CIDR is a reliable, fixed-time AI protocol that gives producers the option to eliminate
Open Access
Near infrared spectroscopy as a potential method to detect bovine respiratory disease
(Kansas State University. Agricultural Experiment Station and Cooperative Extension Service, 2010-08-03T17:52:49Z) Fox, J.T.; Spire, M.F.
Bovine respiratory disease continues to be the leading cause of illness and death loss from weaning through finishing. There is no objective method to evaluate a live animal’s severity of sickness or their response to treatment. A pilot study was conducted at a commercial feedyard to evaluate the ability of near infrared spectroscopy to differentiate between cattle identified as healthy and those identified as having undifferentiated Bovine Respiratory Disease (BRD). At processing, 215 randomly selected 900 lb heifers were evaluated to determine tissue oxygen saturation (StO2) levels. Mean ranks of the StO2 values were 176.86 ± 5.50. One hundred cattle pulled for clinical signs of bovine respiratory disease were evaluated in the hospital. Animals were classified as: 1st pull, 2nd pull, and 3rd pull on the basis of clinical observations. First-pull animals were those having no previous history of being treated for respiratory disease and having signs of BRD, with rectal temperature at or above 104°F. Second pulls and 3rd pulls were those animals failing to respond to either a first treatment or a second treatment for BRD as evidenced by no improvement in clinical appearance or by rectal temperature remaining above 104°F. Mean StO2 ranks were 110.42 ± 11.29, 120.08 ± 14.48, and 132.83 ± 19.00 for 1st, 2nd, and 3rd pulls, respectively. A significant difference was found between the rank of the StO2 values in cattle at processing and those classified as 1st, 2nd, or 3rd pulls (P<0.05). No difference was found between the three pull classifications. Results provide the basis for further research in the evaluation of BRD with near infrared spectroscopy.
Open Access
Effects of early weaning on performance of cow/calf pairs
(Kansas State University. Agricultural Experiment Station and Cooperative Extension Service, 2010-08-03T17:52:38Z) Koch, E.A.; Christopher, J.A.; Marston, T.T.; Breiner, Ryan M.; Unruh, John A.; rbreiner; junruh
Commercial cow/calf pairs (Angus based, n=103) were used to determine the effect of calf weaning age on cow body weight and body condition score (scale=1 to 9) and calf performance in terms of subcutaneous fat and marbling deposition. Only cows with male progeny (steers, n=52; bulls, n=51) were used in this study. Treatments were: 1) early-weaned bulls, 2) early-weaned steers, 3) traditionally weaned bulls, and 4) traditionally weaned steers. Cow/calf pairs grazed pastures at four different locations. Calving began February 1, 2003, and ended in early April. In the early-weaned treatment group, calves were weaned June 25, with an average age of 115 days. In the late-weaned treatment group, calves were weaned October 6, with an average age of 218 days. The data indicate that the cows in the early-weaned treatment group gained 121 lb more weight (P<0.0001), had 0.13 inches more external backfat (P<0.0001), and had an average body condition score 1.2 greater (P<.0001) than their late-weaned counterparts. All steer calves were implanted before they entered the feedlot. Early weaning and subsequent feedlot placement produced heavier calves at approximately nine months of age. Ultrasound technology indicated that early-weaned calves had greater backfat and marbling scores 26 days after feedlot placement than did traditionally weaned calves. However, the early–weaned bulls had less backfat at a similar average weight to their steer contemporaries.
Open Access
Feedlot performance and carcass traits of serially slaughtered finishing heifers
(Kansas State University. Agricultural Experiment Station and Cooperative Extension Service, 2010-08-03T17:52:28Z) Hale, R.L.; Bishop, G.L.; Brethour, J.R.; Marston, T.T.
Two experiments were conducted at the KSU Agricultural Research Center, Hays, Kansas, to measure feedlot gain and carcass traits of serially slaughtered, yearling crossbred heifers. In Exp. 1, 159 heifers averaging 792 lbs were randomly assigned to one of four slaughter groups, and slaughtered at 21-day intervals beginning at 92 days on feed. In Exp. 2, 181 heifers averaging 759 lbs were randomly assigned to one of four slaughter groups, and slaughtered at intervals of 19, 23 and 21 day, respectively, starting at 127 days. In both experiments, final weight, gain, and carcass weight increased with days on feed. Heifers did not gain body weight between 134 and 155 days on feed in Exp. 1, but heifers continued to gain body weight through 190 days on feed in Exp. 2. Despite having a lighter starting weight, final body weights and hot carcass weights were greater for heifers in Exp. 2 than in Exp. 1 because they had more time on feed. Ribeye area increased with time, although the ratio of ribeye area to carcass weight decreased over time. Increases in backfat and kidney, pelvic, and heart fat suggest that carcass gain increases in fat content over time. Yield grade and marbling scores also increased with each successive slaughter group. Quality grade improved with more days on feed in Exp. 1. Carcass quality was, however, hampered by significantly increased carcass maturity in Exp. 2. Although it is not well defined, the greatest increase in carcass fat deposition seemed to occur between 92 and 113 days on feed in Exp. 1, whereas the increases in carcass fat seemed to increase continually between 127 and 188 days on feed in Exp. 2.
Open Access
Effects of Lactobacillus acidophilus and Propionibacterium freudenreichii on growth performance and carcass characteristics of finishing beef cattle
(Kansas State University. Agricultural Experiment Station and Cooperative Extension Service, 2010-08-03T17:52:16Z) Greenquist, M.A.; Dicke, B.; Erickson, G.E.; Klopfenstein, T.J.; Drouillard, James S.; jdrouill
There have been contradicting reports of the efficacy of direct-fed microbials in finishing cattle diets. Some researchers have observed improvements in daily gain and feed efficiency when direct-fed microbials are included in finishing diets, whereas others have reported no differences in dry matter intake or ruminal and blood pH. Many of these studies have been conducted on a relatively small scale and used few animals per pen compared with that of typical commercial feedlot operations. In our study, yearling crossbred beef steers and heifers (n=3,539; 796 lb body weight) were used in an experiment conducted at a commercial feedlot operation to characterize growth performance and carcass characteristics associated with the supplementation of direct-fed microbials (Lactobacillus acidophilus and Propionibacterium freudenreichii) in finishing cattle diets. Including direct-fed microbials in the diet throughout a 122-day finishing period had no measurable impact on growth performance or carcass characteristics of finishing cattle.
Open Access
Growth performance and carcass characteristics of finishing beef steers implanted with component TE-S or component TE-S with Tylan
(Kansas State University. Agricultural Experiment Station and Cooperative Extension Service, 2010-08-03T17:52:04Z) Dicke, B.; Erickson, G.E.; Klopfenstein, T.J.; Botts, R.T.; Anderson, P.T.; Depenbusch, Brandon E.; Drouillard, James S.; bdepenbu; jdrouill
Component TE-S and Component TE-S with Tylan growth-promoting implants were compared in an experiment conducted at a commercial feedlot operation (Ward Feed Yard; Larned, Kansas) to evaluate effects on growth performance and carcass characteristics. Crossbred steers (n=1843; 827 lb body weight) were implanted with either Component TE-S or Component TE-S with Tylan and were fed a finishing ration based on steam-flaked corn for an average of 116 days before slaughter. Cattle were assigned randomly to the implant treatments at processing and were allotted to 12 pens, containing an average of 154 steers each. No differences were detected in dry matter intake (P=0.18), average daily gain (P=0.41), or feed efficiency (P=0.59) of cattle administered the different implants. Component TE-S with Tylan produced fewer (P<0.05) buller steers. Cattle implanted with Component TE-S with Tylan were more heavily conditioned than cattle implanted with Component TE-S. Cattle with the implant including Tylan had a greater percentage of USDA Choice or Prime carcasses (P=0.11) and a greater percentage of USDA Yield Grade 4 carcasses (P=0.03). Component TE-S with Tylan also tended to produce fewer (P=0.12) USDA Yield Grade 1 carcasses compared with cattle implanted with Component TE-S. Total carcass value was also greater for the Component TE-S with Tylan cattle, as calculated by either a muscle-based or quality-based marketing grid. Inclusion of a pellet of the antibiotic Tylan within Component TE-S implants seems to result in modest changes in carcass fattening, as well as significant reductions in the incidence of buller activity among feedlot steers.