RALGRO® IMPLANTS FOR INTACT MALE CALVES

1986 ◽  
Vol 66 (2) ◽  
pp. 441-449 ◽  
Author(s):  
J. E. RICHARDS ◽  
D. N. MOWAT ◽  
J. W. WILTON

Forty-eight spring-born bulls (representing early-, medium- and late-maturing breed groups) and 30 fall-born bulls (representing medium- and late-maturing breed groups) were randomly assigned to either a control or treatment group within each breed group. Treated bull calves were initially implanted with Ralgro® at approximately 55 d of age and reimplanted every 84 d for a total of four implants. All bulls were weaned after 140 d on trial at an average age of 195 d, placed into a feedlot in pens of three or four within breed and treatment groups and gradually adjusted to a high grain ration. Bulls were slaughtered when they reached approximately 7 mm of backfat over the 12/13th ribs, determined ultrasonically. Weaning weights and daily gain to weaning were increased slightly, but not significantly, by implanting in both calving groups. Effects tended to be more pronounced with the earlier (medium) maturing breed groups. No effect of implanting on feedlot performance was observed in either the spring- or fall-born bulls. A reduction in the morbidity rate of the spring-born implanted bulls tended to occur during a period of disease outbreak shortly after weaning. Testicular weights were reduced (P < 0.05) with the use of implants in both calving groups. Scrotal circumference was decreased (P < 0.05) by implanting in the spring-born bulls only. For both of these traits, effects were also more pronounced in the early- and medium-maturing breed groups. Effects of implanting on carcass characteristics were slight. Key words: Ralgro®, bulls, live performance, carcass characteristics, testicular development

Animals ◽  
2018 ◽  
Vol 8 (12) ◽  
pp. 231 ◽  
Author(s):  
Hung Le ◽  
Quang Nguyen ◽  
Don Nguyen ◽  
Bunmi Malau-Aduli ◽  
Peter Nichols ◽  
...  

This study investigated live animal performance and carcass characteristics of Australian prime lambs fed oil based polyunsaturated fatty acid (PUFA) enriched pellets in a feedlot system. The tested hypothesis was that supplementation of lambs with a variety of dietary oil based PUFA enriched pellets would enhance growth and carcass characteristics compared with the control lambs fed only with lucerne hay. Seventy-two, 6 months old White Suffolk x Corriedale first-cross prime lambs with an average liveweight (LWT) of 35.7 ± 0.9 kg were allocated to six treatment groups in a completely randomised experimental design. The treatments were: (1) control: lucerne hay only; or lucerne hay plus wheat-based pellets infused with 50 mL/kg dry matter (DM) of oils from (2) rice bran (RBO); (3) canola (CO); (4) rumen protected (RPO); (5) flaxseed (FO) and (6) safflower (SO) dietary sources. All lambs had ad libitum access to lucerne hay and clean fresh water. Supplemented lambs were fed 1 kg of pellet/head/day for 10 weeks. Feed intake, final LWT, average daily gain (ADG), body conformation and carcass characteristics of lambs in the supplemented groups were all greater than for the control group. SO lambs had the lowest ADG of 190.3 g/day. RBO and CO treatments had the lowest feed cost per unit gain of AU$3.0/kg. Supplemented lambs had similar over the hooks (OTH) incomes that were all higher than that of the control group. This empirical evidence-based data demonstrated that supplementation of lambs with RBO and CO had comparatively lower feed costs without compromising ADG, carcass characteristics and OTH income.


1987 ◽  
Vol 67 (4) ◽  
pp. 941-949 ◽  
Author(s):  
H.-M. KUBISCH ◽  
M. MAKARECHIAN

The effects of weaning date on feedlot performance and carcass characteristics of 367 bull calves weaned 1 mo apart were compared in a 2-yr study at the University of Alberta ranch at Kinsella, Alberta. The calves belonged to three distinct breed groups. Calves were weaned either on 1 Oct. or 1 Nov., at which time they averaged 157 ± 1.5 and 189 ± 1.7 d of age, respectively. After a 4-wk postweaning adjustment period, calves in each group were fed a mixed diet containing 90% concentrate and 10% hay. During the period between the two weaning dates early-weaned calves gained more (P < 0.05) than their unweaned contemporaries, while the performance of the two groups during their respective adjustment periods was similar. The late-weaned group gained 175 g d−1 more (P < 0.05) and consumed 800 g d−1 more feed (P < 0.05) during the 140-d feedlot test while feed efficiency did not differ between the two groups. Average daily rate of gain from birth to 1 Oct. had a significant influence on feedlot gain (b = 0.42). Although late-weaned calves had a higher rate of growth during the feedlot test, their early-weaned contemporaries were 14.3 kg heavier and 7 d younger at slaughter. Significant differences in gain and carcass traits were observed between the three breed groups, but the interaction between breed group and weaning date was not significant, indicating that calves of different genetic backgrounds respond similarly to the effects of age at weaning. The results indicate that under Alberta's climatic conditions and despite lower feedlot gains, weaning calves 1 mo early is a viable alternative to the customary weaning date. Key words: Beef calves, bulls, weaning date, carcass traits


1991 ◽  
Vol 71 (1) ◽  
pp. 1-11 ◽  
Author(s):  
R. D. H. Cohen ◽  
B. D. King ◽  
P. S. W. Hunter ◽  
E. D. Janzen

In 1984–1985 and 1985–1986, groups of 136 and 127 male calves were used to assess the effects of multiple implants (Ralgro or Steeroid), castration time (early or late) and castration method (surgical or chemical) on testicular development and weight gain for 28 d following castration. Ralgro-implanted bull calves had smaller scrotal circumference (P < 0.001) and testicle weight (P < 0.001) than nonimplanted calves at early castration (59 ± 1 d), late castration (157 ± 1 d) and at slaughter (459 ± 3 d). Steeroid had no effect on testicle weight at early castration (40 ± 1 d) but reduced testicle weight (P < 0.001) at late castration (148 ± 1 d). Average daily gain (ADG) during the first 7 d postcastration was less for surgically castrated than chemically castrated calves or bulls following early castration (P < 0.05) but in the 7 d following late castration, bull calves grew faster than surgical castrates (P < 0.05) and surgical castrates grew faster than chemical castrates (P < 0.05). The ADG of calves implanted with Ralgro was greater than that of nonimplanted calves during the 28-d period following early and late castration (P < 0.05) but Steeroid had no effect (P > 0.05) on 28-d postcastration ADG. Chemical castration increased scrotal circumference at 7, 14 and 28 d postcastration (P < 0.001) but by day 56, testicular atrophy was complete in those calves that were successfully castrated. Chem-cast was an effective method of castration in young calves (< 90 kg liveweight), particularly those that had been implanted with Ralgro, but efficacy was reduced (P < 0.05) in older calves (> 150 kg liveweight). Key words: Castration, Chem-cast, Ralgro, Steeroid, testosterone, beef


1990 ◽  
Vol 70 (4) ◽  
pp. 1005-1016 ◽  
Author(s):  
J. A. NEWMAN ◽  
A. K. W. TONG ◽  
H. DOORNENBAL ◽  
T. TENNESSEN ◽  
G. H. COULTER ◽  
...  

An experiment was conducted to determine whether implantation with zeranol would reduce the aggressive behavior and probability of producing dark-cutting carcasses that characterize slaughter bulls. Thirty-six bull calves were allocated to each of four treatments – nonimplanted bulls, steers castrated at an average age of 101 d, bulls implanted with 36 mg zeranol at an average of 101, 170, 263 and 319 d of age and bulls implanted on the latter three dates only. The results reported include observations of weight gains, linear measurements, scrotal circumferences, serum testosterone concentrations, feed consumption, feed efficiency ratios and behavioral traits. Bulls exceeded steers in weight gain during a feedlot test and in body length after 140 d on feed, but neither implantation treatment significantly affected the growth of bulls. Feed consumption and conversion efficiency were lower in steers than in bulls, but were not significantly affected by implantation. Scrotal circumference measurements and serum testosterone concentrations suggested that implantation reduced testicle development during the preweaning and early postweaning periods, but that this effect diminished or disappeared during the later postweaning period. Implantation depressed aggressive and sexual activity between days 111 and 155 of the feedlot test. When evaluated at 13–14 mo of age, both implanted groups reacted to preslaughter mixing of nonfamiliar animals with equivalent head bunting to, but less mounting activity than, nonimplanted bulls. At 15–16 mo of age, however, the implanted bulls exhibited more head bunting than nonimplanted bulls, and the early implanted group exhibited fully equivalent mounting activity to nonimplanted bulls. The dark-cutting carcass condition was associated with mounting activity during preslaughter lairage. Key words: Slaughter bull, zeranol, growth, linear measurements, testicular development, behavior


1966 ◽  
Vol 46 (3) ◽  
pp. 177-180 ◽  
Author(s):  
M. Makarechian ◽  
W. E. Howell

Sera from 120 feedlot heifers were analyzed by starch gel electrophoresis to determine their transferrin types. Estimates of the possible effects of different transferrin types on gain in the feedlot and some carcass characteristics were obtained by least squares methods. Analysis of variance showed that transferrin type did not have a significant influence on gain and carcass characteristics. Gene frequencies of the different transferrin alleles, derived from a breed group of 79 Hereford heifers, arc also reported.


2019 ◽  
Vol 59 (10) ◽  
pp. 1827 ◽  
Author(s):  
Chinju Johnson ◽  
Carolyn Fitzsimmons ◽  
Marcos Colazo ◽  
Changxi Li ◽  
John Kastelic ◽  
...  

Our objective was to determine effects of genetic potential for residual feed intake (RFI) and pre-natal diet on post-natal growth and reproductive development of bulls. Twenty-five bull calves with a divergent potential for RFI were produced by mating purebred Angus heifers (60) categorised as high or low RFI and inseminated with semen from high or low RFI bulls. From 30 to 150 days of gestation, half the heifers (balanced for RFI across treatments) in each RFI category were fed to gain 0.7 or 0.5 kg/day (~100% and 75% of recommended feed intake; designated normal- and low-diet, respectively). Birthweights of bull calves (n = 25) did not differ significantly among treatment groups (P ≥ 0.1). However, there was a tendency (P &lt; 0.1) for a maternal diet*time interaction for bull weights, with bulls from low pre-natal diet fed heifers growing faster between 10 and 16 months of age than bulls from normal pre-natal diet fed heifers. Furthermore, high-RFI bulls had a larger scrotal circumference (P &lt; 0.01) and attained puberty (P &lt; 0.05) earlier than low-RFI bulls. Other testes measures, including paired testes volume, epididymal sperm reserves, daily sperm production and total sperm production, were not significantly different among treatment groups (P ≥ 0.1). High RFI bulls tended (P &lt; 0.1) to have better average sperm motility than low RFI bulls. However, sperm morphology, viability and chromatin damage were not different (P ≥ 0.1). In summary, young beef bulls with low RFI had smaller testis, delayed onset of puberty (~1.7 months) and tended to exhibit lower progressive motility compared with high RFI bulls. Pre-natal diet had no direct influence on male reproductive development, nor did it interact with RFI of bulls.


Author(s):  
Hung V. Le ◽  
Quang V. Nguyen ◽  
Don V. Nguyen ◽  
Bunmi S. Malau-Aduli ◽  
Peter D. Nichols ◽  
...  

This study investigated live animal performance and carcass characteristics of Australian prime lambs fed oil based polyunsaturated fatty acid (PUFA) enriched pellets in a feedlot system. The tested hypothesis was that supplementation of lambs with a variety of dietary oil based PUFA enriched pellets would enhance growth and carcass characteristics compared with the control lambs on lucerne only. Seventy-two, 6 months old White Suffolk x Corriedale first-cross prime lambs with an average liveweight (LWT) of 35.7 &plusmn; 0.9 kg were allocated to six treatment groups in a completely randomised experimental design. The treatments were: (1) control: lucerne hay only; or lucerne hay plus wheat-based pellets infused with 50 ml/kg DM of oils from (2) rice bran (RBO); (3) canola (CO); (4) rumen protected (RPO); (5) flaxseed (FO) and (6) safflower (SO) dietary sources. All lambs had ad libitum access to lucerne hay and clean fresh water. Supplemented lambs were fed 1kg of pellet/head/day for 10 weeks. Feed intake, final LWT, average daily gain (ADG), body conformation and carcass characteristics of lambs in the supplemented groups were all greater than for the control group. SO lambs had the lowest ADG of 190.3 g/day. RBO and CO treatments had the lowest feed cost per unit gain of AU$ 3.0/kg. Supplemented lambs had similar over the hooks (OTH) incomes that were all higher than that of the control group. This empirical evidence-based data demonstrated that supplementation of lambs with RBO and CO had comparatively lower feed costs without compromising ADG, carcass characteristics and OTH income.


1983 ◽  
Vol 37 (1) ◽  
pp. 73-80 ◽  
Author(s):  
B. D. Schanbacher ◽  
R. L. Prior ◽  
S. B. Smith

ABSTRACTFeedlot performance and carcass characteristics were examined in bulls and steers with and without a subdermal Silastic capsule containing oestradiol-17β-dipropionate. Castration and/or oestrogen treatment was imposed at approximately 8 months of age. The implants were removed 56 days before slaughter, i.e. 140 days after the trial commenced. Bulls gained more rapidly (12·9%), converted food to live-weight gain more efficiently (18·0%) and yielded leaner carcasses than did steers (P < 0·05). The oestrogenic implant elevated serum oestradiol concentrations substantially (> ninefold) over that of bulls and steers and induced a castration-response in the former. Serum luteinizing hormone, testosterone and testicular growth were suppressed (P < 0·05) during the first 140 days of the trial in bulls, but returned to normal following implant removal. This response was paralleled by a reduction in average daily gain (P < 0·05) and food: gain ratio (P < 0·10). Contrary to expectations, average daily gain and food: gain ratio were not significantly improved in implanted steers. Oestrogen treatment reduced hot carcass weight, loin eye area and quality grade in both bulls and steers; the last as a result of decreased marbling and internal fat deposition. Results of this study suggest that excessive oestrogen as provided in this study via the implant fails to improve feedlot performance and carcass merit in steers and may, in fact, diminish the inherent anabolic attributes of the intact male. Additional studies are required to understand the complex interactions of androgens and oestrogens in the regulation of body growth and composition of male cattle.


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