Further studies of hexoestrol implantation of Blackface wether lambs

1. In the summer of 1958, 15 mg. of hexoestrol was administered to Blackface wether lambs in one of the following ways; 5 mg. before weaning followed by two 5 mg. tablets at weaning, three 5 mg. tablets at weaning, and thirdly a single 15 mg. tablet at weaning. In a further series of experiments in 1959 the effect of both raising the pre-weaning implantation to 10 mg., and the total hexoestrol dosage to 20 mg. was studied.2. Suckled lambs implanted with 5 mg. of hexoestrol at the milk clip gained significantly more in live-weight (18%) up to weaning in 1958 than did untreated lambs; in 1959 the difference was only 11%.3. Between weaning and the end of the trial all treatments with the exception of that in which hexoestrol dosage was raised to 20 mg. showed a very highly significant increase in live-weight gain over untreated lambs, the increases ranging from 26 % to 54%.4. In neither year was the overall gain in live-weight from pre-weaning to the end of the trial significantly increased by implanting part of the hexoestrol dose prior to weaning.5. Live-weight gain of the lambs was not significantly increased when three 5 mg. tablets of hexoestrol replaced a single 15 mg. tablet.6. The implanting of lambs with 20 mg. hexoestrol failed to give a response superior to that obtained with 15 mg. hexoestrol.7. Each group of lambs receiving hexoestrol treatment showed an increased average carcass weight.

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The effect of hexoestrol on nitrogen retention of lambs and on ration digestibility

Proceedings of the British Society of Animal Production ◽

10.1017/s0369852100001871 ◽

1958 ◽

Vol 1958 ◽

pp. 13-17 ◽

Cited By ~ 4

Author(s):

T. R. Preston ◽

V. Rochanasaroj ◽

Isoline Gee

Keyword(s):

Weight Gain ◽

Major Part ◽

Growth Response ◽

Nitrogen Retention ◽

Live Weight ◽

Experimental Period ◽

Feeding Period ◽

Subcutaneous Implantation ◽

Live Weight Gain ◽

Series Of Experiments

It is now widely accepted that the subcutaneous implantation of stilboestrol or hexoestrol increases the rate of live-weight gain in lambs and cattle. In sheep it is generally considered that for a feeding period of up to 12 weeks a single implantation of hormone produces an adequate growth response. Perry et al.(1951), Stephens & Thompson (1952) and Bell et al.(1954) reported no advantage from repeated implantations during the experimental period. In a series of experiments at this Institute (Preston & Gee, 1957a) it has been noticed that the major part of the increased weight gain takes place during the first six weeks after hexoestrol implantation.

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The influence of formaldehyde application at ensiling and of supplementation with urea or maize starch on the utilization by calves of ryegrass and red clover silages

Animal Science ◽

10.1017/s0003356100010412 ◽

1983 ◽

Vol 36 (3) ◽

pp. 371-381 ◽

Cited By ~ 1

Author(s):

A. G. Kaiser ◽

D. F. Osbourn ◽

P. England

Keyword(s):

Organic Matter ◽

Weight Gain ◽

Formic Acid ◽

Dry Matter ◽

Nitrogen Retention ◽

Live Weight ◽

Red Clover ◽

Carcass Weight ◽

Live Weight Gain ◽

Formaldehyde Treatment

ABSTRACTPrimary growths of perennial ryegrass and red clover were ensiled with formic acid (2 1/t fresh crop), o an equal quantity of formic acid together with formaldehyde (46 or 49 g/kg crude protein in the ryegrass or red clover respectively). The four silages were offered ad libitum to 12 groups, each of five British Friesian steer calves, either alone or with urea or maize starch supplements at 18·4 or 185·2 g/kg total dry-matter intake respectively.Digestible organic matter and digestible energy intake, live-weight gain, carcass weight, nitrogen retention and all digestibility measurements were higher on the ryegrass silages than on the red clover silages. However, dry-matter intake was higher on the red clover silages.Formaldehyde treatment reduced lactic and total acid content, and protein degradation in the silages. It also increased intake, live-weight gain and nitrogen retention on ryegrass but not on red clover, the effect being greater when the urea supplement was given. Digestibility measurements were depressed by formaldehyde treatment, although cellulose digestibility was only depressed in the ryegrass silage.Supplementation with starch depressed silage intake and nitrogen and cellulose digestibility, but increased dry matter, organic matter and energy digestibilities, digestible organic matter and digestible energy intakes, live-weight gain and carcass weight. The positive intake, live-weight gain and carcass weight responses were greater on the silages treated with formic acid, while the digestibility and the live-weight gain responses were greater on the red clover silages. Starch supplementation did not improve nitrogen retention.The different animal production responses to formaldehyde treatment on the ryegrass and red clover silages are discussed.

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A note on the progressive carcass-weight changes of fattening store lambs

Animal Science ◽

10.1017/s0003356100034929 ◽

1973 ◽

Vol 16 (1) ◽

pp. 95-98 ◽

Cited By ~ 1

Author(s):

W. Rutter

Keyword(s):

Weight Gain ◽

Dry Matter ◽

Live Weight ◽

Carcass Weight ◽

Dry Matter Intake ◽

Weight Changes ◽

Live Weight Gain ◽

Ad Libitum

SUMMARYTwo experiments involving the sequential slaughter of intensively fattened store lambs were each carried out over a period of 12 weeks. In the first experiment the lambs were offered a concentrate diet ad libitum. In the second experiment they were offered swede turnips ad libitum with a limited amount of concentrates.In each experiment, similar groups of lambs were slaughtered at equal intervals in order to measure progressive changes in live weight, carcass weight and dry-matter intake. Carcass-weight gain as a proportion of live-weight gain was found to be 74% in the first experiment and 86% in the second experiment.

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Effects of clover in the diet of grazed lambs on production and carcass composition

Animal Science ◽

10.1017/s0003356100006863 ◽

1993 ◽

Vol 57 (2) ◽

pp. 253-261 ◽

Cited By ~ 6

Author(s):

J. E. Vipond ◽

G. Swift ◽

R. C. Noble ◽

G. Horgan

Keyword(s):

Fatty Acid Composition ◽

Fatty Acid ◽

Weight Gain ◽

Acid Composition ◽

Live Weight ◽

Carcass Composition ◽

Carcass Weight ◽

Live Weight Gain ◽

Protein Retention ◽

Tissue Lipids

AbstractThe effect of grazing clover on ewes and lambs was studied using nitrogen-fertilized grass (G) and grass/white clover pastures (GC) containing proportionately 0·18 clover. Carcasses of lambs grazed on GC were significantly heavier than carcasses of lambs grazed on G pastures. An interaction with weaning occurred. Carcasses from lambs grazed on GC for 53 days post weaning were 2·3 kg heavier (F < 0·01) but lambs slaughtered at weaning had similar carcass weights. Diet had no effect on relative joint components of carcasses. The effect of clover in the diet on carcass weight was attributed to higher levels of protein retention.Analysis of the fatty acid composition of intramuscular and subcutaneous and perirenal lipids indicated small but significant effects of diet. Lean tissue lipids of lambs grazing clover showed significant increases in C18:2 and reduced C20: 5 fatty acids. In tissue fats there were small increases in C14:0, C16:0 and C18:2 with reduced C18:1 content.Twin suckled lambs grazing GC for 94 days from turn-out in early April showed increased live-weight gain over lambs on G of 336 v. 287 g/day (s.e.d. 84; P < 0.001). Post weaning live-weight gain of lambs was 173 and 221 g/day on G and GC respectively. Sward height was maintained at 5.18 and 5.24 (s.e.d. 0.075) cm on G and GC paddocks by adjusting ewe numbers. GC pastures carried proportionately 0.82 of the stock on G pastures but output of lamb was similar at 1289 and 1247 kg/ha for G and GC respectively.Results showed that the production penalty of lower stocking rate associated with grass/clover v. grass fertilized with 190 kg nitrogen per ha was ameliorated by higher lamb live-weight gain and carcass weight without change in joint composition or nutritionally significant change in fatty acid composition of carcass tissues.

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Hexoestrol implantation of steers fattened at pasture II. Effects on empty weight, carcass weight and carcass quality

Animal Science ◽

10.1017/s0003356100037946 ◽

1964 ◽

Vol 6 (1) ◽

pp. 57-71 ◽

Cited By ~ 3

Author(s):

F. E. Alder ◽

J. C. Tayler ◽

J. E. Rudman

Keyword(s):

Weight Gain ◽

Live Weight ◽

Carcass Weight ◽

Carcass Quality ◽

Live Weight Gain ◽

Herbage Intake ◽

Winter Grazing

The first paper of this series (Alder, Tayler and Rudman, 1964) described experiments carried out over 4 years on the effects of hexoestrol on live-weight gain and herbage intake in grazing steers. The 52 steers used weighed between 750 and 1,100 lb. initially and included four pairs of twins. The experiments lasted between 55 and 124 days and involved both summer and winter grazing. This paper is concerned with observations made on the animals after slaughter.

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Beef production from silage 2. The performance of beef cattle given silages of either perennial ryegrass or red clover

Animal Science ◽

10.1017/s0003356100024934 ◽

1981 ◽

Vol 32 (2) ◽

pp. 149-153 ◽

Cited By ~ 20

Author(s):

C. Thomas ◽

B. G. Gibbs ◽

J. C. Tayler

Keyword(s):

Weight Gain ◽

Perennial Ryegrass ◽

Dry Matter ◽

Live Weight ◽

Red Clover ◽

Live Weight Gain ◽

Primary Growth ◽

Significant Difference ◽

The Difference ◽

Rate Of Decline

ABSTRACT1. A primary growth of perennial ryegrass was cut on 8 to 11 May (early) or on 12 June (late) for comparison with the primary growth of a tetraploid red clover, which was cut either on 1 or 2 June (early) or on 28 June (late). The crops were ensiled, after wilting for about 4h, with the addition of formic acid at 2·21/t fresh crop. The silages were given ad libitum alone or with rolled barley at 11·5 g dry matter per kg live weight to 40 British Friesian steers initially 3 months old and 108 kg live weight.2. On average there was no significant difference in digestibility between perennial ryegrass and red clover. However, the rate of decline in digestibility with time was greater with perennial ryegrass than with red clover.3. Calves given silage of red clover as the sole feed ate more dry matter and grew faster than calves given grass silage (P <0·001) but supplementation with barley reduced the intake of red clover silage to a greater extent than that of perennial ryegrass silage. Barley supplementation increased live-weight gain of calves given perennial ryegrass from 0·32 to 0·83 kg/day and that of calves given red clover from 0·63 to 0·99 kg/day (interaction P <0·05). The results did not indicate a higher net efficiency of utilization of the legume. Date of cut had no significant effect on dry-matter intake but earlier cutting resulted in an increase in live-weight gain from a mean of 0·61 to 0·77 kg/day (P <0·001).4. The results show that high rates of live-weight gain (0·74 kg/day) can be achieved by calves given silage of red clover and that earlier cutting of herbage for silage does not always result in higher intakes of dry matter. Supplementation of silages with barley can reduce markedly the difference in intake and live-weight gain apparent when the silages are given as sole feeds.

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The effects of oral and implanted hydroxyzine on growth, endocrine and carcass characteristics of lambs

Animal Science ◽

10.1017/s0003356100033729 ◽

1961 ◽

Vol 3 (1) ◽

pp. 9-17 ◽

Cited By ~ 1

Author(s):

T. R. Preston ◽

Euphemia B. Charleson ◽

N. A. MacLeod ◽

G. D. Rosen ◽

J. Vernon

Keyword(s):

Weight Gain ◽

Adrenal Glands ◽

Carcass Characteristics ◽

Live Weight ◽

High Energy ◽

Mean Value ◽

Carcass Weight ◽

Live Weight Gain ◽

Creep Feed ◽

Daily Rate

1. The results of four experiments on the effects of oral and implanted hydroxyzine on lambs are reported.2. The effect of hydroxyzine on daily rate of live-weight gain ranged from +7·8% to −6·2% improvement with a mean value of +2·3%.3. Lambs receiving hydroxyzine in the creep feed manifested significantly higher killing-out percentages and lower thyroid weights than the controls. Pituitary weights were not affected by hydroxyzine.4. In an experiment on individually-penned, weaned wethers, given a high energy diet, hydroxyzine by either route did not affect live-weight gain but significantly increased killing-out percentage, rate of gain of carcass weight and fat deposition in certain tissues. Hydroxyzine did not affect the fresh weights of the pituitary, thyroid and adrenal glands or the weights of the teats.

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The efficiency of beef production in terms of carcass-weight increase as influenced by the ration concentration and the age of steers

The Journal of Agricultural Science ◽

10.1017/s0021859600013782 ◽

1963 ◽

Vol 61 (1) ◽

pp. 127-134 ◽

Cited By ~ 3

Author(s):

H. C. Luitingh

Keyword(s):

Weight Gain ◽

Live Weight ◽

Efficiency Index ◽

Carcass Weight ◽

Weight Increase ◽

Control Group ◽

Beef Steers ◽

Differential Growth ◽

Live Weight Gain ◽

Image Position

The carcass-weight increase of beef steers of various ages receiving fattening rations of different roughage: concentrate ratios was calculated by making use of the average dressing percentage of a control group slaughtered at the beginning of the experiment.It is shown that, in terms of t.d.n./100 lb. carcass-weight increase, which is probably the more accurate measure of efficiency, the 2-year-olds were better feed converters than the calves. When the criterion was t.d.n./100 lb. live-weight increase the calves were superior. Ration B (1 concentrates: 1 roughage) was utilized most efficiently in terms of calculated carcass-weight increase, followed in a descending order by the high-concentrate ration C and the high-roughage ration (ration A).The relationship of live-weight increase to carcass- weight increase as calculated is discussed. The proportion of live-weight gain laid down as carcass varied with age, growth rate and type of ration. This percentage variation ranged from 57% in slow-growing calves to 81% in fast-growing 3-year-olds. On the average, calves converted 61% of their live-weight gain into saleable carcass, the 2-year-olds 70·8% and the 3-year-olds 75·9%. The steers on the A (high roughage) ration converted 65·7% of live-weight gain into carcass, those on the C (high concentrate) ration 71·5% and those on the B (1 concentrate: 1 roughage) 69·2%. Reasons for these differences are discussed in terms of so-called differential growth.The live weights and carcass weights of steers were plotted and the regression equationwhere Yis carcass weight and X is live weight, was derived. The correlation coefficient r = 0·98 and the slope of the curve indicated that for an increase of 1% in the live weight of the steers, the carcass weight increased by 1·13%.Several methods of expressing ‘efficiency of the fattening’ were applied to the data and the results are discussed. The methods were unanimous in selecting the steers on the B ration as the most efficient followed by those on ration C and the poorest were those on the A ration. Methods based on live-weight increase showed the calves, but those based on carcass-weight increase the 2-yearolds, as the most efficient. Results obtained by applying the Efficiency Quotient and Efficiency Index suggested that the older animals wero the more efficient. They differed from all other methods since these indicated that efficiency declined with age.Efficiency values calculated by different formulae vary and no efficiency index has yet been evolved that will embrace all the variable factors which may have an influence on the efficiency of growth and fattening.

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Efficiency of food utilization and carcass characteristics of steers marketed at different weights

Animal Science ◽

10.1017/s0003356100025356 ◽

1985 ◽

Vol 40 (2) ◽

pp. 251-258 ◽

Cited By ~ 1

Author(s):

R. Hironaka ◽

B. H. Sonntag ◽

G. C. Kozub

Keyword(s):

Weight Gain ◽

High Weight ◽

Carcass Characteristics ◽

Live Weight ◽

Carcass Weight ◽

Backfat Thickness ◽

Food Utilization ◽

Live Weight Gain ◽

Slaughter Weight ◽

Ad Libitum

ABSTRACTHereford and Charolais x Hereford steer calves were given an all-concentrate diet ad libitum. The Hereford steer calves were marketed at about 400, 440 and 475 kg live weight. The Charolais x Hereford steer calves were marketed at about 525, 570 and 610 kg. For each kg increase in slaughter weight of Hereford steers, the digestible energy required per unit live weight gain increased by 0·024 (s.e. 0·009) MJ, the killing-out proportion increased by 0·22 (s.e. 0·08) g/kg, and the backfat thickness by 0·004 (s.e. 0·002) cm. The area of m. longissimus increased by 0·245 (s.e. 0·037) cm2 and 0·139 (s.e. 0·048) cm2 for Hereford and Charolais X Hereford steers, respectively, for each kg increase in carcass weight. Among Hereford steers, mean backfat thickness as indicated by carcass grade scores (score of 1 to 4 as backfat increases) at the two lowest slaughter weights were similar and lower than scores at the high weight. Among Charolais X Hereford steers, the carcass grade was not influenced by slaughter weight. Slaughtering Hereford and Charolais x Hereford steers at light weights does not ensure that all the carcasses will be lean when the cattle are given a high concentrate diet to appetite from weaning to slaughter.

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