Gerry L. Kuhl

Implant strategies for finishing calves

Two hundred-sixteen Angus and Angus-cross steer calves (690 lb) were used in a 129day finishing study to evaluate different implant strategies, including an experimental new implant for feedlot cattle that contains 28 mg of estradiol benzoate and 200 mg of trenbolone acetate (EBTBA). Treatments were 1) nonimplanted control, 2) implanted and reimplanted with Synovex-Sfi, 3) single initial implant with EBTBA, 4) single initial implant with Revalor-Sfi, 5) implanted with Synovex-S and reimplanted with EBTBA, and 6) implanted and reimplanted with EBTBA. Initial implants and reimplants were administered on day 0 and 63, respectively. All implant treatments increased feed intake, slaughter and carcass weights, and rate and efficiency of gain. Compared with other implant treatments, the use of EBTBA as a reimplant treatment (trts 5 and 6) resulted in improved (P<.08) rate and efficiency of gain and heavier carcass weights (P<.07). However, only 58.3% of cattle in trts 5 and 6 graded Choice vs. 86.1% for controls and 80.6% for steers implanted twice with Synovex-S (P<.07). Carcasses were more masculine (P<.07) for steers in trts 5 and 6 than for nonimplanted controls, steers implanted with Revalor-S, and steers implanted twice with Synovex-S. Performance of steers implanted once with EBTBA did not differ from that of steers implanted once with Revalor-S or twice with Synovex-S, but carcasses were more masculine (P<.07) for EBTBA vs. Revalor-S steers. Implant treatment did not affect meat tenderness, as measured by Warner-Bratzler shear force determinations. Single EBTBA or Revalor-S implants resulted in performance and carcass traits similar to those resulting from implanting twice with Synovex-S.

Wheat middlings in roughage-based or limit-fed, high-concentrate diets for growing calves

A 101-day growing study was conducted to evaluate the growth performance of beef heifers fed wheat middlings in traditional fullfed, sorghum silage-based rations and in limit-fed, high-concentrate rations. Diets were formulated without wheat middlings or with wheat middlings replacing 33, 67, or 100% of rolled corn plus soybean meal. Daily gains decreased linearly (P<.01) with increasing levels of wheat middlings in the roughage-based diets because of lower feed intake (P<.10), but feed efficiency was not affected (P>.30). For the limit-fed diets, heifer daily gains decreased linearly (P<.01) as the proportion of wheat middlings in the diet increased, resulting in a linear reduction (P<.01) in feed efficiency. Wheat middlings can be utilized effectively as the predominant energy/protein source for growing cattle, though their nutritional and economic value, relative to corn and soybean meal, may be different for roughagebased and limit-fed diets.

Influence of implanting grazing steers with Ralgro® or Synovex-S® followed by Synovex® Plus™ or a Ralgro®/Synovex® Plus™ reimplant program in the feedlot on pasture/finishing performance and carcass merit

In an 84-day pasture/132-day finishing study using 480 crossbred steers (675 lb), Ralgro® increased (P<.05) pasture gains 9.3% compared to nonimplanted controls. Gains of Synovex-S®-implanted steers were intermediate. Pasture treatments were split into two finishing-phase implant treatments: Synovex® PlusTM or initial Ralgro with a Synovex Plus reimplant on day 56. No interactions occurred between pasture and finishing implants with respect to finishing performance or carcass traits. Steers on the Synovex Plus treatment gained 11.7% faster and 7.9% more efficiently (P<.01) during the first 56 days of the finishing phase than the Ralgro-implanted steers. However , when those steers were reimplanted with Synovex Plus, they gained 22.2% faster and 21.1% more efficiently (P<.01) during the last 76 days. Over the entire 132-day finishing phase, the feedlot reimplant program improved rate (4.0%; P<.06) and efficiency (7.5%; P<.01) of gain compared to Synovex Plus alone. Overall , gains and intakes during the finishing phase were similar for all pasture implant treatments. However, control pasture steers were 4.5% more efficient (P<.08) than Ralgro and Synovex steers during the finishing phase. Neither pasture or finishing implant treatment influenced carcass traits. This study indicates that implanting during grazing may reduce feed efficiency during the finishing phase, especially when a feedlot reimplant program is not used. However, this finding disagrees with several previous research studies where pasture implantation had no effect on feedlot performance.

Effects of added fat, degradable intake protein, and ruminally-protected choline in diets of finishing steers

This report is brought to you for free and open access by New Prairie Press. It has been accepted for inclusion in Kansas Agricultural Experiment Station Research Reports by an authorized administrator of New Prairie Press. Copyright 1998 Kansas State University Agricultural Experiment Station and Cooperative Extension Service.

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.

Effects of Finaplix®, Synovex-S® and Ralgro® implants, singularly or in combinations, on performance, carcass traits and longissimus palatability of Holstein steers

This report is brought to you for free and open access by New Prairie Press. It has been accepted for inclusion in Kansas Agricultural Experiment Station Research Reports by an authorized administrator of New Prairie Press. Copyright 1990 Kansas State University Agricultural Experiment Station and Cooperative Extension Service.

Timing of trenbolone acetate implants on performance, carcass characteristics, and beef quality of finishing steer calves

Angus and Angus-cross calves (632 lb) were utilized in a finishing study to evaluate the effects of implanting with estradiol and progesterone (Synovex-S®) and(or) trenbolone acetate (Finaplix®) on performance of finishing steers. Over the entire finishing period (117 d), implanted steers had higher (P<.05) daily gains and were more efficient than nonimplanted steers. Carcasses from implanted cattle had heavier (P<.05) hot weights and larger (P<.05) ribeye areas. Steers implanted with Finaplix had larger (P<.05) ribeye areas than those implanted with Synovex only. Marbling scores and quality grades were not affected by implant treatments. Rib (9-10-11) sections from implanted steers were heavier (P<.05) as a result of both heavier (P<.05) bone and soft tissue weights. However, no differences in percentages of protein, fat, and moisture were detected by proximate analysis of the soft tissue. Concomitant use of Finaplix with Synovex-S did not affect performance of Angus and Anguscrossed steer calves.

Effect of Terramycin® and Bovatec® in free-choice mineral mixtures on gains of heifers grazing native grass

This report is brought to you for free and open access by New Prairie Press. It has been accepted for inclusion in Kansas Agricultural Experiment Station Research Reports by an authorized administrator of New Prairie Press. Copyright 1987 Kansas State University Agricultural Experiment Station and Cooperative Extension Service.

Implant comparisons for finishing steers

This report is brought to you for free and open access by New Prairie Press. It has been accepted for inclusion in Kansas Agricultural Experiment Station Research Reports by an authorized administrator of New Prairie Press. Copyright 1984 Kansas State University Agricultural Experiment Station and Cooperative Extension Service.

Toxicity problems with ammoniated dry roughages

In two trials conducted at the Fort Hays Experiment Station, symptoms of toxicity (hyperexcitability, circling, convulsions, death) were observed in several newborn calves (l to 14 days of age) nursing cows consuming ammoniated forage sorghum hay. None of these symptoms was observed in calves nursing cows consuming untreated hay. No toxicity symptoms were observed in the cows on any treatment. However, several instances of similar symptoms in cattle consuming ammoniated forages have been reported in growing calves and adult cattle in Kansas, Texas, California, and Kentucky. The primary forages involved in these incidents were forage sorghum, hybrid sudan, cereal grain, brome, and fescue hays. To date, no problems have been reported with ammoniated wheat straw or other Poor quality forages. Analyses of the treated forages associated with several of these toxicity incidents have shown relatively high levels of imidazole compounds-chemicals with convulsive properties previously implicated in toxicity with ammoniated molasses.