Effect of zeranol implantation on body weight changes in zebu crossbred cattle grazing tropical pasture

Nine experiments on the effect upon bodyweight change of subcutaneous ear implantation of 36 mg zeranol in 605 Bos indicus crossbred cattle were conducted. Bullocks aged 3 to 4 years, steers aged 18 months and entire heifers aged 18 to 30 months were used over the period January to August, 1980. They were grazed on 6 commercial farms in tropical northern Australia. Seven of the experiments examined the results of single implantation after the initial 60 to 97 days. Growth rates of untreated cattle in the January to May period ranged from 0.43 kg/day over 97 days in heifers to 1.07 kg/day in bullocks. Bodyweight gains attributed to zeranol ranged from 1.8 kg (4.3% increase) over 97 days in heifers (NS) to 22.3 kg (28.9% increase) over 90 days in 18 month-old steers (P < 0.01). The significant bodyweight responses to zeranol treatment in all 5 experiments involving older 3-to 4-year-old bullocks have not been previously reported. Hot dressed weights of the zeranol-treated bullocks were significantly heavier than the untreated controls and dressing percentages were similar. Increases in bodyweight attributable to implantation with zeranol yielded 50 to 54% saleable carcase weight. Single-, repeat-, and non-implanted treatments were compared over 186 days from January to August. Both zeranol treatments significantly out-performed the controls (P < 0.05), and the repeat-implanted bullocks gained 9.2 kg more than the single-implanted bullocks (P<0.10) in spite of bodyweight tosses recorded in the 3 treatments over the final 105 days. In 2 experiments bullocks implanted once in January/February were weighed in August to monitor compensatory bodyweight changes after April/May. The cattle retained 72.4% and 92.6% of the original bodyweight advantage attributed to zeranol treatment, depending upon whether they lost or gained in bodyweight respectively during the April/May to August period. The commercial relevance of these results is discussed and suggestions are made for further work.     

Production, parasitological and carcase evaluation studies in steers exposed to trichostrongyle infection and treated with a morantel bolus or fenbendazole in two consecutive grazing seasons

Friesian steers were exposed to natural trichostrongyle infection and left untreated (controls) or treated with either a morantel sustained release bolus or fenbendazole at two week intervals (clean) in each of two consecutive grazing seasons. In the second grazing season the mean liveweight gains of the clean, morantel treated and control groups of cattle over 152 days were 105, 131 and 109 kg respectively (morantel treated greater than clean, control P less than 0.02). The cattle were slaughtered following an indoor fattening period. The dressed carcase weight, killing out percentage and related carcase measurements were superior in the treated groups. Eighty per cent of the clean and morantel treated cattle graded satisfactorily and qualified for subsidy payment whereas less than 30 per cent of the control cattle were successful. Rib joint analyses showed significantly lower total weight, eye muscle weight and area together with a higher bone content in control cattle.     

Growth response of steer calves treated with zeranol, oestradiol 17β or progesterone-oestradiol benzoate implants before and after weaning

This experiment compared the growth response of untreated steer calves with those given a long acting oestradiol-silicone rubber implant or implants of zeranol or oestradiol-progesterone pellets either singly, or repeated after 79 days. The experiment extended through the 6 weeks prior to weaning at 8 months of age, 5 weeks of grazing oat stubble and a 16-week finishing phase on a feedlot. The oestradiol-silicone rubber implant was the only product to significantly increase weight gains compared to controls (0.69 vs 0.52 kg/head/day, 18.2% advantage) in the pre-weaning phase. All anabolic agents produced higher weight gains ranging from increases of 0.16 to 0.19 kg/head/day (18.2-21.6%) above controls in the first 60 days of the feedlot phase. Responses did not differ significantly among the products and were the same whether or not steers had been previously implanted. Lower planes of nutrition in the late suckling and post-weaning periods were accompanied by smaller and non-significant responses to both the short acting anabolics, zeranol and oestrogen-progesterone, compared to the increased weight gains of steers given oestradiol-silicone rubber implants. Implanting with oestradiol in a silicone rubber matrix resulted in similar increases in weight gain both before and during the feedlot phase. This may have been due to the implant maintaining a continuously high level of circulating anabolic agent for the 190 days of the experiment.     

Effect of a single dry season anthelmintic treatment of N'Dama cattle on communal pastures in The Gambia

The effect of a single anthelmintic treatment of cattle during the early dry season was studied. One hundred and sixty-six N'Dama cattle, 1–3 years old, were selected from five herds. There were 65 males and 101 females divided into two groups of 83 animals each. One group was treated with fenbendazole at 7.5 mg/kg body weight by mouth in November 1992; the other group remained as the untreated control. At monthly intervals from November 1992 to April 1993, each animal was weighed and the number of eggs/g of faeces (epg) was determined. The infective larvae (L3) were examined following culture of pooled samples from each group of animals. In April 1993, 6 animals (3 treated and 3 controls) from the herds under study were necropsied. The difference in the weight gains (4.6 kg) of the two groups was highly significant (p<0.0001). The difference in the weight gains and the epg between the treated and control groups was influenced by the age of the animals. Of the treated animals, one contained no nematodes, one contained only 25Oesophagostomum radiatum, and the third contained 25Cooperia L4. The three untreated animals were all infected. It was concluded that the treatment in early dry season, with an anthelmintic effective against both adults and larvae, led to a significant reduction in egg counts, to elimination of adults and hypobiotic larvae and, consequently, to an increase in the body weight gain by the treated animals.     

Weight gain in steer and heifer calves treated with zeranol or oestradiol 17 beta

Male and female Hereford and Hereford cross beef calves between 2.5 and 4.5 months of age were implanted with 36 mg zeranol, 24 mg oestradiol 17 beta or left untreated, and then weighed every 4 to 5 weeks. Calves treated with zeranol or oestradiol 17 beta gained 9.6 kg (8.2%) and 12.9 kg (11.0%) more weight respectively than untreated calves. Steer calves gained more weight than heifer calves. There was no response to either growth promotant in heifers or in zeranol-treated steers beyond 35 days after implantation, and the only significant further gains in the next 31 days were made by steers treated with oestradiol 17 beta. After this time growth of treated and control calves was similar. The lack of a continued response to the growth promotants was not associated with significantly lower growth rates in any weighing interval.     

The vitamin A requirement and the vitamin A status of growing cattle. 2. Studies of fattening cattle

Three long time individual feeding experiments (greater than 258 days) with 48 beef cattle each (dairy breed and beef breed, 50% each) were carried out in order to measure the influence of various vitamin A supply (0, 2,500, 5,000 and 10,000 IU vitamin A per 100 kg body weight and day) on fattening and slaughtering performance, vitamin A concentration of liver and serum as well as carotene concentration of serum. The bulls consumed corn silage (experiments 1 and 2; 9.4 and 18.3 mg carotene per kg dry matter) or NaOH-treated and pelleted straw (experiment 3; no carotene). The roughages were supplemented with 2 (exp. 1 and 2) and 3 kg (exp. 3) concentrate per day. The vitamin A supply of corn silage diet did not significantly influence the dry matter intake (exp. 1: means: 6.95; 6.91 to 7.05; exp. 2: means: 6.54; 6.53 to 6.54 kg dry matter per animal and day) and the daily weight gain of bulls (exp. 1: means: 1076; 1028 to 1157; exp. 2: means: 1058; 1041 to 1057 g per animal). The bulls consumed 8.87 kg dry matter per day, the daily weight gain amounted to 1030 g per animal and day in experiment 3. The bulls of unsupplemented group reduced feed intake and weight gain after 150 days, an additional vitamin A supply was necessary. At the end of experiments 1 and 2 the liver vitamin A concentration of unsupplemented groups amounted to 38.8 and 65.9 mumol/kg, it increased after vitamin A supply (up to 153.4 mumol/kg). Feeding of pelleted straw effected a liver vitamin A concentration lower than 10 mumol/kg except the group supplemented with 10,000 IU vitamin A per 100 kg body weight and day (35.7 mumol per kg fresh matter of liver). The vitamin A concentration of blood is unsuitable for evaluation of vitamin A status of cattle. The carotene content of feeds and level of vitamin A supply determined the carotene concentration of blood. Recommendations for a suitable vitamin A supply of ration of growing cattle were given depending on body weight and type of diet.     

The effect of time of implanting zeranol on the growth of suckling steer calves

Three groups of beef steer calves were implanted in 1983 with 36 mg of zeranol at 2 months or 4.5 months age or at both these ages, and their growth rates were compared with an untreated group. At approximately 8 months age in December the 3 implanted groups were heavier than the control group by 14.6 kg (P less than 0.05), 23.4 kg and 22.1 kg (P less than 0.01). At peak animal weights recorded in March the differences were 18.7 kg (P less than 0.05), 31.3 kg and 31.0 kg (P less than 0.01). In June 1984, following loss of weight by the steers, differences between the implanted groups and the control groups had declined to 7.7 kg (P greater than 0.05), 19.4 kg (P less than 0.01) and 21.1 kg (P less than 0.001), differences similar to those recorded approximately 3 months after implantation. It is concluded that higher weight gains resulted from implanting suckling calves at 4.5 months of age, than by implanting calves at 2 months of age, and that implanting suckling calves twice is unlikely to be any better than implanting them once at 3 to 6 months age. Part of the maximal response can be lost if steers subsequently lose weight.     

Effects of parenteral administration of doramectin or a combination of ivermectin and clorsulon on control of gastrointestinal nematode and liver fluke infections and on growth performance in cattle

OBJECTIVE: To compare effects of an injectable doramectin preparation with those of an injectable ivermectin-clorsulon preparation on control of gastrointestinal nematodes and liver flukes and on growth performance in cattle. DESIGN: Randomized complete block design. ANIMALS: 60 crossbred calves. PROCEDURES: Calves (20/treatment group) were treated with doramectin or ivermectin-clorsulon or were not treated. Fecal samples were collected for nematode and Fasciola hepatica egg counts on day 0 and for up to 140 days after treatment. Cattle were weighed before treatment and at 28-day intervals until day 140. RESULTS: From day 7 through day 49, nematode egg counts for calves treated with doramectin or with ivermectin-clorsulon were significantly lower than those for untreated control calves. As the study progressed beyond day 56, the percentages of cattle with fluke eggs in their feces increased, but differences in regard to these percentages were not detected among the 3 groups. Average daily gain for the doramectin-treated cattle (0.79 kg/d [1.74 lb/d]) was significantly greater than that for the cattle treated with ivermectin-clorsuIon (0.71 kg/d [1.56 lb/d]); values for both groups were significantly greater than that for the control cattle (0.62 kg/d [1.37 lb/d]). CONCLUSIONS AND CLINICAL RELEVANCE: Results suggest that doramectin had a greater impact on subclinical gastrointestinal tract parasitism in calves, as demonstrated by growth performance, than did ivermectin-clorsulon. In the Gulf Coast region of the United States, spring-born nursing beef calves may have minimal grazing exposure to F hepatica during the peak fluke transmission period; therefore, mature fluke burdens may be negligible at the beginning of the fall season.     

Rumen fermentation and liveweight gain in beef cattle treated with monensin and grazing lush forage

Objective To determine the prevalence of subacute rumen acidosis (SARA) in beef cattle grazing lush pasture and the effect of monensin on reducing SARA and improving animal performance. Design Commercial Angus and Murray Grey steers received a monensin slow‐release capsule (n = 19) or remained untreated (n = 19). Cattle grazed an oats crop or tetraploid ryegrass pasture for a total of 91 days. Rumen fluid pH, volatile fatty acids (VFA) and lactic acid concentrations and body weight data were collected prior to treatment and again 28, 56 and 91 days after treatment. Changes in measures over time were analysed using mixed model repeated measures analysis. Differences in average daily gain between treatment groups were determined. Results The prevalence of SARA was low during the study, with only one animal satisfying criteria for SARA at one time point. Cattle treated with monensin capsules were 11.9 kg heavier at the completion of the study compared with untreated controls (414.5 ± 3.88 kg vs 402.6 ± 4.03 kg, P = 0.04). Rumen VFA and L‐ and D‐lactate levels did not differ between cattle treated with monensin and untreated cattle. However, the ratio of propionate to acetate plus two times butyrate was higher (P < 0.001) when cattle were treated with monensin. Conclusions Subacute rumen acidosis was not consistently detected under the conditions of the study. The higher body weight of cattle treated with monensin may have been due to improved energy utilisation of the pasture, indicated by increased propionate proportions in the rumen, rather than prevention of SARA.     

Transient enhancement of the serum antibody response to Brucella abortus strain 19 in cattle treated with levamisole

Two experiments were done on 57 steers. These cattle were allotted to 8 groups (4 groups/experiment) and vaccinated with 1 to 3 X 10(9) colony-forming units of Brucella abortus strain 19. Cattle in 3 of the 4 groups/experiment were given 6 mg of levamisole/kg, subcutaneously, either at the time of vaccination (day 0), 7 days later, or at both times. Serum antibody titers to B abortus were measured sequentially for 28 days in experiment 1 and for 56 days in experiment 2, using the card test, Rivanol test, complement-fixation test, fluorometric immunoassay, and an enzyme-linked immunosorbent assay. In general, the highest mean antibody titers, as determined by all serologic tests, occurred in steers treated with levamisole at 7 days after vaccination or in those treated at the time of vaccination and 7 days later. By the card test on day 56, there was a significantly (P less than 0.05) greater number of seropositive cattle among those given levamisole 7 days after seropositive cattle among those given strain 19 alone. Simultaneous administration of strain 19 and levamisole did not alter antibody responses to B abortus.     

Field efficacy of flumethrin pour-on against Psoroptes ovis in cattle.

The field efficacy of pour-on formulation of flumethrin 1 per cent was assessed in cattle naturally infested with Psoroptes ovis. In a finishing unit, 18 infested animals were selected, left untreated for one month and examined twice to monitor the progress of the infestation. They were treated twice 10 days apart with a pour-on formulation of flumethrin 1 per cent (2 mg/kg bodyweight). Skin samples were collected from the animals on days 0, 7, 14, 28 and 42 and examined for the presence of live mites. The clinical condition of the cattle was evaluated at the beginning and at the end of the trial using a standardised chart. Bodyweights were recorded on days -32, 0, 28 and 50. In addition the 65 cows in a calving unit were given the same treatment regimen and its efficacy was evaluated on days 0, 7, 14 and 28 in 11 P ovis infested animals. On the day of treatment most of the infested animals had a severe pyodermatitis. From day 7 onwards no live mites were found in the treated animals and there was a marked clinical improvement. The percentage efficacy on day 28 was 100 per cent in both units. In the finishing animals treatment was associated with a marked improvement in daily weight gains between day 0 and day 28.     

Effect of moxidectin against natural infestation of the cattle tick Boophilus microplus (Acarina: Ixodidae) in the Mexican tropics

The study was divided in to two trials and carried out in a ranch in eastern Yucatan state, Mexico. In the first trial, two groups of 15 BostaurusxBosindicus heifers, 6-12 month of age and naturally infested with Boophilus microplus ticks were used. Heifers in Group 1 were treated with a 1% injectable formulation of moxidectin at the dose of 0.20mg/kg body weight by subcutaneous injection. The other group remained as untreated controls. Number of immature and engorging female ticks were assessed on days 0, 7, 14, 21, 28 and 35 post-treatment (PT). The efficacy of moxidectin on adult ticks from day 7 to 28 PT was greater than 95%. The efficacy decreased to 74.9% by day 35. In the second trial, animals in Group 1 were treated with the moxidectin product as before, while cattle in Group 2 were treated according to the routine procedure for the control of ticks on that property (125 g/l amitraz as a dip). Treatment of all cattle was repeated four times at intervals of 28 days. The efficacy of the experimental moxidectin treatment was similar to that of the routine amitraz treatment, i.e., greater than 99%.     

Effect of ivermectin on performance of beef cattle on Georgia pastures

A total of 469 cows and calves from 2 herds, each on 6 pastures, was used to evaluate the anthelmintic efficacy and animal-performance benefits of ivermectin given subcutaneously at a dosage of 200 micrograms/kg to nursing beef calves and their dams during a grazing season. Pastures were paired across the 2 herds. Three pasture groups from 1 herd were randomly assigned to either a nonmedicated control or to a medicated group. Treatment assignments were reversed in the other herd. The control groups comprised 110 cows and 108 calves, whereas 127 cows and 124 calves were treated with ivermectin (200 micrograms/kg). The cows were treated once, in late spring, and the calves were treated twice, once in late spring and again in midsummer. Cattle from one herd were weighed on days - 12, 21, 49, 77 (day of 2nd treatment for calves), and 105, and the other herd was weighed on days - 6, 23, 57, 86 (day of 2nd treatment for calves), and 113. Rectal fecal samples for nematode egg counts were obtained from approximately 25% of the cattle in each pasture on weighing days; usually, the same cattle were sampled each time. Calves treated with ivermectin gained (P less than 0.05) more weight than control calves up to the 2nd treatment date and up to the termination of the study. There was no significant difference between treated and control cows, with regard to weight gain over either interval. Treated calves had fewer positive fecal egg counts (P less than 0.01) and passed fewer eggs (P less than 0.05) after both treatments than did control calves. There were no differences in either number of eggs or number of negative cows between treatment groups. Adverse reactions attributable to treatment were not seen.     

饲喂复合化学处理稻草和甲醛处理精料对生长奶牛的影响

初始体重为 2 0 0kg的黑白花奶牛育成牛分别采食东北羊草 +青贮 +混合精料(A组 ) ,未处理稻草颗粒 +青贮 +混合精料 (B组 ) ,处理稻草颗粒 +青贮 +混合料 (C组 ) ,处理稻草颗粒 +混合料和处理稻草颗粒 +甲醛处理混合精料 (E组 ) 5组日粮 ,每组1 0头牛 ,试验期 6 1d ,混合精料和甲醛处理混合精料定量供给 ,每天每头 1 .74kgDM ,玉米青贮也定量供给 ,每天每头 0 .98kgDM ,其余粗饲料自由采食 ,东北羊草 ,未处理稻草颗粒 ,以及C组 ,D组和E组的处理稻草颗粒的采食量分别为 2 .81 ,3 .84,4.1 4,5.1 5和4.98kgDM/(头·d) ,A ,B ,C ,D和E组育成牛平均日增重分别为 797,82 9,90 5,898和91 5g/(头·d) ,其中C ,D和E组的日增重无显著差异 (P >0 .0 5) ,但显著高于A和B组 ;饲料 (kgDM) /增重 (kg)比在各组之间无显著差异 ,用复合化学处理稻草颗粒可完全代替育成牛日粮中的东北羊草和青贮 ,且完全可以保证育成牛的生长发育。但精饲料中的豆饼和玉米经甲醛处理对生长牛的生产性能没有明显影响。     

Hormone secretory patterns, pituitary characteristics and selected blood metabolites in feedlot steers implanted with growth stimulants

Twelve Charolais-crossbred steers (256 kg) received one of three treatments: nonimplanted controls (C), implanted initially and at 84 days with 36 mg zeranol (Ralgro, R) and implanted initially and at 84 days with 200 mg of progesterone and 20 mg of estradiol benzoate (Synovex-S,S). All steers were fed a corn-based diet (calculated metabolizable energy 2.89 Mcal/kg dry matter) ad libitum. In a parallel comparative slaughter trial, rates of empty body protein accretion were increased 14% in R and 24% in S steers (P less than .01). R and S steers in the present study had heavier pituitary weights (P less than .001), more pituitary growth hormone content (P less than .04) and more pituitary weight/unit live weight (P less than .05) than did C steers. Cattle implanted with R or S exhibited an increased growth hormone (GH) secretory response to a pituitary challenge with thyrotropin releasing hormone (TRH). Plasma insulin profiles were not significantly altered, but tended to be greater for steers given implants. Overall 9-hr GH secretory profiles were not affected by implantation. Plasma urea N at 94 days post-implantation was decreased (P less than .01) by implantation. Plasma glucose was increased (P less than .04) at both 94 and 199 days in R and S vs C steers. Overall mean and total (integrated area) plasma GH, as well as secretory profile components (baseline mean, amplitude of secretory spikes) were negatively correlated with body weight and size on days 94 and 199. Overall mean, baseline and integrated area of plasma insulin on days 94 and 199 were positively related to body weight and size. Thus positive protein anabolic growth responses from implantation (parallel comparative slaughter trial) were coupled with increased pituitary GH content and little change in circulating plasma GH concentrations between implanted and control steers. This may suggest that changes in tissue sensitivity, an increased plasma clearance rate of GH and/or a direct effect on target tissues may be involved in the improved growth performance of cattle implanted with R or S.     

Energy requirements of young female cattle. 5. Energy intake and energy expenditure

From 6 experiments dealing with the development of young female cattle, partly from calf to calving, 660 metabolism periods were evaluated as to energy intake, live weight gain (LWG) and energy expenditure. Growth intensity was deliberately regulated through energy intake. In the experiment with the highest growth rate the average LWG was greater than 850 g/animal and day and in the experiment with the lowest growth rate at about 550 g/animal and day. Energy expenditure increased from 15 MJ net energy fatcattle/kg LWG at a live weight of 50 kg to 50-80 MJ NEFcattle/kg LWG in clear dependence on growth intensity. Comparative examinations of energy intake and energy requirement, estimated with equations forming the basis of recommendations for the energy supply of young female cattle in the framework of the GDR system of feed evaluation, lead to the conclusion that a new concept of identifying the energy requirement of young female cattle has to be developed.     

Radioimmunoassay of the anabolic agent zeranol. II. Zeranol concentrations in urine of sheep and cattle implanted with zeranol (Ralgro)

A radioimmunoassay for zeranol has been validated and used to measure the concentration of zeranol in the urine of sheep and cattle treated with zeranol (Ralgro). The assay uses an antibody raised against zeranol-16-carboxy-propyl ether conjugated to human serum albumin. In sheep and cattle urine the limits of detection were approximately 2 ng/ml and 2.5 ng/ml, respectively. In two trials 13 sheep were implanted with 12 mg zeranol at the base of the ear. The mean maximum concentrations of zeranol observed in urine were 45 ng/ml (Trial I) on day 35 and 90 ng/ml (Trial II) on day 56, and had declined to 26 ng/ml 42 days after implantation (Trial I) and 11.7 ng/ml 70 days after implantation (Trial II). In four cattle implanted with 36 mg zeranol the concentrations of zeranol in urine reached a mean maximum concentration of 13.5 ng/ml 22 days after implantation and had declined to 2.9 ng/ml 69 days after implantation.     

氨化秸秆与棉籽饼补充对育肥黄牛生产性能的影响研究

试验以氨化秸秆作为基础日粮,分别进行1、2、3和4公斤,4种不同水平的棉籽饼补充,并以氨化秸秆日粮组作为对照,探讨育肥黄牛的生产性能。4种补充水平日增重分别为602.4克、702.7克、838克和940.8克,而对照组日增重为255.6克。试验结果表明:在以氨化秸秆为基础日粮的饲喂体系中,用棉籽饼作为精料补充是可行的。从秸秆利用率、日增重及生产成本分析认为,每天补饲1～2公斤棉籽饼的日粮配合有较大的经济效益,且适合目前农村养牛生产水平,因而具有较大的推广价值。     

The therapeutic efficacy and prophylactic activity of doramectin against Dictyocaulus viviparus in cattle

SUMMARY Three groups of 8, 4-month-old male Jersey or Jersey-cross calves were infected with 2400 Dictyocaulus viviparus L₃ larvae and either left untreated or injected subcutaneously with 200 μg/kg doramectin 5 or 25 days after infection (DAI). Lungworms were found in all untreated cattle (geometric mean = 49) at necropsy 39 or 40 DAI. None was found in any of the treated cattle. In a second experiment, groups of 6, 8-month-old calves were untreated or injected with 200 μg/kg doramectin 28, 21 or 14 days before each calf was challenged with 2700 D viviparus larvae. Lungworms were recovered at necropsy 32 to 34 DAI. The geometric mean worm burden in the untreated cattle was 550. This was reduced by 100%, 99.5% and 94.1% in calves treated with doramectin 14, 21 or 28 days, respectively, before infection. It was concluded that doramectin is a highly effective anthelmintic against D viviparus adult or L₄ infections of cattle, and that reinfection of treated cattle will be significantly reduced for at least 28 days after treatment.     

Low quality roughages for steers grazing wheat pasture. I. Effect on weight gains and bloat

The effect of feeding low quality roughages (LQR) on live and carcass weight gains and the incidence and severity of bloat of stocker cattle grazed on wheat pasture was evaluated in a 3 yr study. One hundred eighty-five steer calves (172 kg mean initial weight) grazed clean-tilled wheat pasture and were either fed no LQR or had ad libitum access to wheat straw (WS) or sorghum-Sudan hay (SS). Grazing periods were (I) fall grazing, (II) winter grazing, (III) period of lush spring growth of wheat forage and (IV) period of advancing forage maturity and declining quality. Mean dry matter (DM), crude protein and acid detergent fiber (ADF) content (percentage of DM) of wheat forage averaged across years ranged, respectively, from 23.8 to 33.0, 19.8 to 26.4 and 21.5 to 27.7. Mean daily consumption (kg DM/head) of WS and SS by steers ranged from .076 to .100 and .199 to .248, respectively. Live and carcass weight gains of steers during Periods I through III (i.e., the usual wheat pasture grazing period) were not influenced (P greater than .05) by treatments. Carcass weight gains were about 74% of live weight gains. Bloat was observed only during the last 2 wk of Period III of the first year. The incidence (steer days of bloat) and severity (bloat score) of control, WS- and SS-fed steers were 9.5 and 1.2, .5 and .5 and 2.0 and 1.0, and were not different (P greater than .05) among treatments. Intake of WS and SS [g/body weight (BW).75kg] during Periods I to III was, respectively, only about 5 and 12% of roughage intakes (i.e., 37.5 g/BW.75kg) reported in the literature to "effectively control" or aid the prevention of bloat. It seems unlikely that LQR consumed to amounts similar to those of this study would control bloat of stocker cattle on wheat pasture.