The muscle, fat, and bone content of Angus steer carcasses as affected by stocking rates

1964 ◽  
Vol 15 (5) ◽  
pp. 858 ◽  
Author(s):  
KW Clark ◽  
ML Dudzinski ◽  
RM Butterfield ◽  
D Bennett
Keyword(s):  
Correlation Coefficients ◽  
Subterranean Clover ◽  
Carcass Composition ◽  
Regression Equations ◽  
Stocking Rate ◽  
Bone Content ◽  
Fat Thickness ◽  
Total Fat ◽  
Multiple Correlation Coefficients ◽  
Stocking Rates

Data from the complete dissection of carcasses from a selected group of British breed cattle were used to derive regression equations for muscle, bone, and fat on the carcass variables suggested by Butteriield. These equations were used to estimate the carcass composition of 70 Angus steers which had been grazing a Phalaris tuberosa–subterranean clover pasture for 460 days. The regression equations contained data from three of these animals. Muscle was well estimated (R = 0.99) by the equation y = 9.1009–45.0288(fat thickness, cm) + 1.0686(carcass wt., lb) + 0.9240(shin muscle wt., Dg). Total bone was estimated (R = 0.99) from the equation y (total bone, g) = –1246.55 + 16.7413(shin bone wt., g) + 4.6399(carcass wt., lb). Fat estimation varied with the nutritional history of the animals. Total fat for animals never subjected to a lengthy stress period could be estimated (R = 0.96) from the equation y = 75.188 + 99.352(fat thickness, cm) + 0.4499(carcass wt., lb). The use of logarithms in the derivation of these equations generally resulted in some improvement in the multiple correlation coefficients. Values were calculated from logarithmic forms of the above equations for the muscle, fat, and bone contents of carcasses from animals which had been grazing at stocking rates of 3/8, 1/2, 5/8, 3/4 and 7/8 of a beast per acre from August 1961 to November 1962. Where the cattle had been grazing alone, both muscle and fat were significantly related to stocking rate but total bone was not. With cattle which had been grazing with sheep, only fat was significantly related to stocking rate. The use of a number of other measurements and the transformation of these variables to logarithmic form is discussed.

The use of specific gravity and its reciprocal in predicting the carcass composition of pigs slaughtered at three weights

1964 ◽  
Vol 6 (1) ◽  
pp. 97-105 ◽  
Author(s):  
J. L. Adam ◽  
W. C. Smith
Keyword(s):  
Specific Gravity ◽  
Correlation Coefficients ◽  
Live Weight ◽  
Carcass Composition ◽  
Regression Equations ◽  
Fat Tissue ◽  
Residual Variation ◽  
Bone Content ◽  
Highly Correlated ◽  
Accuracy Of Prediction

SUMMARY1. Carcass dissection data and specific gravity determinations from 76 pigs slaughtered at either 120 lb., 200 lb., or 260 lb. live-weight have been analysed to study the value of specific gravity and its reciprocal in predicting fat and lean in the carcass.2. Possible effects that the bone content of the carcass might have on the accuracy of prediction have been investigated.3. Specific gravity was highly correlated with percentage fat and lean in the half carcass. Correlation coefficients for the reciprocal were of similar magnitude but opposite in sign.4. The residual standard errors in percentage lean and fat at constant specific gravity were 1·74% and 1·72% respectively.5. The replacement of specific gravity by its reciprocal did not increase the accuracy of prediction for either lean or fat tissue expressed as a percentage of the trimmed half carcass.6. The muscle/fat ratio exerted a markedly greater influence on specific gravity than did the muscle/bone ratio. However, the inclusion of the latter ratio in equations relating specific gravity and percentage lean in the carcass, reduced the residual variation.7. Application of the pooled regression equations to independent data, obtained by the use of identical techniques, has given promising results.

The prediction of pig carcass composition from measurements of carcass density

1963 ◽  
Vol 61 (1) ◽  
pp. 9-18 ◽  
Author(s):  
D. W. Holme ◽  
W. E. Coey ◽  
K. L. Robinson
Keyword(s):  
Correlation Coefficients ◽  
Fat Content ◽  
Carcass Composition ◽  
Backfat Thickness ◽  
Regression Equations ◽  
Muscle Area ◽  
Eye Muscle ◽  
Tissue Samples ◽  
Bone Content ◽  
Pig Carcasses

1. Two cuts, the leg and the loin, were taken from the right sides of 102 pig carcasses. Their densities were determined by weighing in air and in water and the cuts were dissected into fat, muscle, bone, skin and connective tissue. Samples of the muscular and fatty tissues were taken to obtain a measure of the analytically determined fat content. The weights of each tissue were expressed as a percentage of the weight of each cut and related to density by the methods of correlation and regression. Correlation coefficients and regression equations were calculated separately for legs, loins and the composite leg plus loin for each pig and for legs and loins rogarded as 204 separate pieces of pig carcass.2. Correlations and regressions were used to relate the composition of the loin cut to three measurements of backfat thickness taken over the eye muscle at the level of the last rib, and to eye muscle area. These allowed a comparison of density and backfat thickness as measures of the fat and lean content of the loin cuts.3. There was evidence of a high degree of association between the fat or muscle contents of the cuts and the density or the reciprocal of density. In no case was the simple correlation coefficient between muscle and density or fat and density less than 0·84. The greatest standard error of estimate of any of the regressions of porcentage fat or percentage muscle on density was 3·3% fat, for the regression of percentage separable fat on the reciprocal of the density of the loin cuts. Density was found to be a better measure of the muscle or fat content of the loin cuts than eye muscle area or any of 3 measurements of backfat thickness taken over the eye muscle.4. Dissection data from 25 whole sides supported these results showing a high correlation between density and percentage fat or percentage muscle.5. There was a low correlation, r = 0·41, between percentage bone and density of 102 leg cuts. That between density and percentage bone of 25 whole sides was r = 0·47; suggesting that bone content has but a small influence on carcass density.6. It is suggested that carcass density is a better measure of carcass fatness or leanness than measurements of backfat thickness or eye muscle area.

Levels of total nitrogen and total volatile fatty acids in the rumen fluid of sheep under different grazing management systems

1967 ◽  
Vol 7 (28) ◽  
pp. 434
Author(s):  
WR McManus
Keyword(s):  
Fatty Acids ◽  
Total Nitrogen ◽  
Volatile Fatty Acids ◽  
Rumen Fluid ◽  
Subterranean Clover ◽  
Grazing Management ◽  
Stocking Rate ◽  
Continuous Grazing ◽  
Grazing System ◽  
Stocking Rates

Concentrations of total nitrogen and total volatile fatty acids in the rumen fluid of sheep grazing improved pastures were measured for ten months in a dry year on the southern tablelands of New South Wales, and the concentrations of nitrogen and volatile fatty acids (V.F.A.) were related to season, wool production, and grazing management. The observations were made during two long-term grazing management experiments. In the first experiment four groups of breeding Merino ewes grazed a Wimmera ryegrass-subterranean clover (Lolium rigidum Gaud.-Trifolium subterraneum L.) pasture. A deferred grazing system (autumn saving) of pasture management was compared with continuous grazing at stocking rate treatments equivalent to 7.0 and 3.5 ewes to the acre. In the second experiment two groups of Merino weaners grazed a Phalaris tuberosa-subterranean clover pasture at a stocking rate equivalent to 8.6 sheep to the acre. One group received a hay supplement, the other did not. In both experiments nitrogen values were low between late autumn and mid-winter and again between late spring and summer, and high in early autumn and again in spring (P<0.05). The low levels were about 55 per cent of peak autumn and spring levels in (experiment 1) and 60 per cent of peak autumn and spring levels in (experiment 2). Total V.F.A. did not vary significantly between seasons in either experiment. At the higher stocking rate the ewes had lower levels of rumen total nitrogen than at the lower stocking rate. V.F.A. did not vary consistently between stocking rates. At both stocking rates ewes on the autumn saving system of grazing management had more nitrogen in the rumen fluid during late pregnancy and early lactation than did those on the continuous grazing system (P<0.001). After the ewes had access to the saved pasture, autumn saving resulted in a higher concentration of volatile fatty acids than continuous grazing (P< 0.05). Although feeding a hay supplement benefited the weaners the concentrations of total nitrogen in the rumen fluid of the two groups of sheep were similar. There was a fairly consistent tendency for the group receiving hay to have lower concentrations of volatile fatty acids in their rumen fluid. Possible reasons for these effects are discussed.

The use of ultrasound measurement of perirenal fat thickness to estimate changes in body condition of young female rabbits

2000 ◽  
Vol 70 (3) ◽  
pp. 435-442 ◽  
Author(s):  
J. J. Pascual ◽  
F. Castella ◽  
C. Cervera ◽  
E. Blas ◽  
J. Fernández-Carmona
Keyword(s):  
Body Condition ◽  
Energy Content ◽  
Live Weight ◽  
Young Female ◽  
Ultrasound Measurement ◽  
Regression Equations ◽  
Ultrasound Measurements ◽  
Fat Thickness ◽  
Total Fat ◽  
Perirenal Fat

AbstractForty-two New-Zealand x Californian young female rabbits of 4·5 months of age were used to evaluate the use o f a computerized ultrasound system in estimating changes in body condition. In order to get a wide range of fatness, animals were randomly subjected to four food restriction regimes for 2 weeks. Female rabbits were scanned at six different back sites to estimate perirenal fat thickness, using a real-time ultrasound unit equipped with a 5·0-MHz sector probe. After scanning, all animals were weighed and slaughtered. The weights of hot carcass, cold carcass, perirenal fat, scapular fat, liver and kidneys were recorded. There was a large variation in the weight of the main fat deposits, especially for the perirenal fat (CV = 0·632), indicating its suitability for estimating changes in body condition. Ultrasound measurements of perirenal fat thickness correlated strongly with all carcass fat weight values (r= 0·692 to 0·959;P< 0·001) and the estimated carcass energy content (r= 0·777 to 0·866;P< 0·001) and seem to be more precise predictors than live weight measurements. Multiple regression equations for estimating the main fat deposit weight and estimated carcass energy content using only the live weight as an independent variable hadR2values ranging from 0·47 to 0·59. The accuracy of estimates was improved when ultrasound measurements were used in the regression model (R2values ranging from 0·81 to 0·95). Ultrasound measurement of mean perirenal fat deposit thickness at 3 cm ahead of the 2ndto 3rdlumbar vertebrae was the best predictor for perirenal fat weight (R2= 0·95;P< 0·001), total fat weight (R2= 0·93;P< 0·001) and estimated carcass energy content (R2= 0·90;P< 0·001). A validation group of 11 rabbit does was used to validate the ultrasound regression equations, showing that their mean accuracy was approximately 0·895 and 0·967 for total fat weight and estimated carcass energy content, respectively. Results suggest that ultrasound measurements of perirenal fat thickness may be an accurate method for studying changes in body condition of young female rabbits at different times.

Renovation of Yarloop subterranean clover pastures with Trikkala

1988 ◽  
Vol 28 (6) ◽  
pp. 737 ◽  
Author(s):  
DL Little ◽  
PE Beale
Keyword(s):  
Dry Matter ◽  
Plant Density ◽  
Subterranean Clover ◽  
Stocking Rate ◽  
Seed Reserves ◽  
Minimal Damage ◽  
Stocking Rates ◽  
Germinable Seed ◽  
Clover Scorch

Pastures containing the oestrogenic subterranean clover, Yarloop, were renovated and sown to Trikkala subterranean clover at the rate of 9 kg ha-1 germinable seed. The resultant pastures were continually grazed at either 7, 9 or 12 ewes ha for 6 years. Control Yarloop pastures were grazed similarly. Trikkala established at approximately 50 plants m-2 and represented 80% of all clover present in the year of sowing. Six years later Trikkala was successfully persisting at all stocking rates in terms of clover dry matter in spring (Trikkala 77%, Yarloop 23%), soil seed reserves in spring (Trikkala 450-1000 kg ha-1, Yarloop 300-450 kg ha-1) and plant density in spring (Trikkala 600-1000 plants m-2, Yarloop 200 plants m-2). Over the 6 years of the trial the proportion of Trikkala and Yarloop approached an equilibrium of 75% Trikkala to 25% Yarloop in all agronomic data collected. Compared with the control Yarloop pastures, the renovated Trikkala pastures maintained a greater clover percentage at all stocking rates. Available dry matter at the high stocking rate was consistently greater in the Yarloop pastures during winter and spring. At the low and medium stocking rates available dry matter tended to be greater in the Yarloop treatments for the first 2 years but was similar for both treatments in the latter 3 years. Clover scorch disease in the Yarloop pasture was controlled by spraying with a fungicide. Trikkala pastures were not sprayed and suffered minimal damage from the disease. Trikkala should perform better relative to Yarloop where clover scorch is a problem. It is concluded that Trikkala subterranean clover can successfully replace Yarloop subterranean clover in pastures previously dominated by Yarloop.

Studies in pasture management for the breeding ewe. I. Effects on ewe liveweights, incidence of pregnancy toxaemia, lamb birth weights, and neo-natal mortality

1968 ◽  
Vol 19 (4) ◽  
pp. 605
Author(s):  
HL Davies
Keyword(s):  
Birth Weight ◽  
Early Pregnancy ◽  
Subterranean Clover ◽  
Late Pregnancy ◽  
Stocking Rate ◽  
Pasture Management ◽  
Continuous Grazing ◽  
Natal Mortality ◽  
Stocking Rates ◽  
Pregnancy Toxaemia

Breeding ewes were run under three systems of pasture management on sown pastures (based on subterranean clover) at Canberra. The ewes lambed from mid August to late September. The three management treatments were: (i) Continuous grazing (treatment CG). (ii) Ewes were confined to one-third of the whole area available in early pregnancy, so that feed was autumn-deferred for late pregnancy (treatment DP).(iii) Ewes were confined to a portion (one-third in 1956, one-half in 1957) of the area for the whole of pregnancy in order to ensure an adequate amount of feed for lactation (treatment DL). Two stocking rates and two breeds of ram were compared (Merino and Border Leicester). Treatment DL resulted in unsatisfactory liveweight gains during pregnancy, a far higher incidence of pregnancy toxaemia, reduced lamb birth weight, and increased neo-natal mortality. At the low stocking rate there were no significant differences between treatments CG and DP. At the high stocking rate, treatment DP reduced liveweight gain in early pregnancy and ensured an adequate liveweight gain in late pregnancy. The incidence of pregnancy toxaemia was lower at the high stocking rate in 1957 on treatment DP compared with CG. At the higher stocking rate, ditocous ewes on treatment DP gained more weight in late pregnancy than those on CG or DL.

AGRICULTURAL METEOROLOGY: A STATISTICAL STUDY OF CONSERVATION OF PRECIPITATION BY SUMMER FALLOWED SOIL TANKS AT SWIFT CURRENT, SASKATCHEWAN

1940 ◽  
Vol 18c (8) ◽  
pp. 388-400 ◽  
Author(s):  
J. W. Hopkins
Keyword(s):  
Statistical Study ◽  
Correlation Coefficients ◽  
Regression Equations ◽  
Multiple Correlation ◽  
Method Of Least Squares ◽  
Arid Conditions ◽  
Multiple Correlation Coefficients ◽  
Factor Regression ◽  
Field Plots ◽  
Agricultural Meteorology

Changes in the moisture content of summer fallowed soil in tanks 15 in. in diameter and 5 ft. deep set in pits in the centre of field plots at the Dominion Experimental Station, Swift Current, Saskatchewan, which have been recorded at fairly frequent intervals during the summer months since 1922, provided two series of data, comprising observations in May and June and those in July and August. These have been analysed statistically in order to relate conservation to precipitation after making allowance for other variable factors. Five-factor regression equations, fitted by the method of Least Squares, gave multiple correlation coefficients of 0.95 and 0.96 between the computed and observed conservation in the two series. It is inferred from these equations that under average conditions a one-day rain to the amount of 0.36 in. in May-June and 0.46 in. in July-August would be required just to offset the subsequent evaporation during a 10-day period. Increased penetration and retention of the heavier rainfalls is very definitely indicated, and it is calculated that whereas on the average 66% of a one-day rain of 1 in. in May-June would still be conserved at the end of 10 days, only 30% would be retained if the same amount was received in five daily showers each of 0.20 in. The intensity as well as the total amount of precipitation is thus emphasized as a factor of prime importance in its relation to soil moisture under semi-arid conditions.

Tactical versus continuous stocking in perennial ryegrass-subterranean clover pastures grazed by sheep in south-western Victoria. 1. Stocking rates and herbage production

2001 ◽  
Vol 41 (8) ◽  
pp. 1099 ◽  
Author(s):  
R. A. Waller ◽  
P. W. G. Sale ◽  
G. R. Saul ◽  
G. A. Kearney
Keyword(s):  
Perennial Ryegrass ◽  
Dry Matter ◽  
Subterranean Clover ◽  
Trifolium Subterraneum ◽  
Stocking Rate ◽  
Soil Fertility Status ◽  
Western Victoria ◽  
Terminal Sire ◽  
Autumn And Winter ◽  
Stocking Rates

A 4-year field experiment was carried out in south-western Victoria to determine whether tactical stocking might improve perennial ryegrass (Lolium perenne L.) persistence and prime lamb production, compared with the more common practice of year-around continuous stocking. Tactical stocking consisted of variable length summer, autumn and winter rotations and continuous stocking in spring. The 2 grazing strategies were compared on 2 contrasting pastures: an upgraded pasture, sown with newer cultivars of perennial ryegrass and subterranean clover (Trifolium subterraneum L.) with 26 kg phosphorus/ha.year, and a more typical naturalised perennial ryegrass pasture receiving 6 kg phosphorus/ha.year. Paddocks were grazed by Border Leicester x Merino ewes, which were mated to a terminal sire to lamb in September. The effects of the grazing systems and pasture treatments on herbage production and stocking rate are presented in this paper. Herbage production was similar between the treatments, but tactical stocking significantly increased herbage mass during the growing season (P<0.05) compared with continuous stocking. In spring each year, the herbage mass generally exceeded 3000 kg dry matter/ha in tactically stocked paddocks and averaged 500–900 kg dry matter/ha higher than the mass on continuously stocked paddocks. This enabled the year-round stocking rate to be increased by an average of 9% over the 4 years of the experiment. We considered that the stocking rates could not be further increased, despite the higher herbage mass in spring, as stock reduced the dry herbage to a low residual mass by the opening rains in autumn. In contrast, stocking rates averaged 51% higher on the upgraded pasture compared with the typical pasture over the 4 years of the experiment. This indicates that pasture improvement and soil fertility status have a much greater impact on productivity than changes to grazing method. However, tactical stocking was able to increase the sustainability of prime lamb production on upgraded pastures in a dry summer climate, by maintaining herbage cover on the paddocks over the summer–autumn period.

Relations between stocking rate, environment and scorch disease on grazed subterranean clover pasture in Western Australia

1982 ◽  
Vol 22 (116) ◽  
pp. 182 ◽  
Author(s):  
WK Anderson ◽  
RJ Parkin ◽  
MD Dovey
Keyword(s):  
Western Australia ◽  
Chemical Control ◽  
Dry Matter ◽  
Disease Incidence ◽  
Subterranean Clover ◽  
Stocking Rate ◽  
Disease Symptoms ◽  
Sheep Production ◽  
Stocking Rates ◽  
Clover Scorch

The effects of weather on clover scorch disease caused by Kabatiella caulivora, the effects of the disease on pasture and sheep production, and the effect of sheep stocking rate (6, 8, 10 and 12 sheep/ha) on the disease were studied in a field experiment over three seasons near Albany, Western Australia. Spraying with benlate was used to control clover scorch on some treatments. Mean temperatures during the period when symptoms of the disease increased were in the range 11-17�C. Rainfall was frequent each year during the same period. The rapid increase in disease symptoms was observed when pasture dry matter on offer was approximately 2500 kg/ha. Disease symptoms decreased during a period of water stress of the pasture. Clover scorch disease had no consistent effect on pasture or animal production except that pasture dry matter on offer in spring was reduced in the unsprayed treatments at the lower stocking rates in the second two years. Higher stocking rates (10 and 12 sheep/ha) reduced the level of clover scorch symptoms without the use of chemical control with benlate. At the period of peak scorch symptoms a stocking rate of 10 sheep/ha reduced disease incidence by 20-35% compared with 6 sheep/ha in unsprayed plots. Increased sheep stocking rates are suggested as a possible alternative to chemical control or replacement of susceptible strains of subterranean clover in grazed pasture.

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