Growth and carcass composition of ram and wether lambs fed at two levels of nutrition

1986 ◽  
Vol 26 (3) ◽  
pp. 275 ◽  
Author(s):  
GJ Lee

This experiment examined the effects of two levels of nutrition on growth rate and fat deposition in the subcutaneous, kidney plus channel, omental and mesenteric depots of ram and wether second-cross lambs. Growth rates to slaughter were higher (P< 0.001) in lambs fed at the higher level of nutrition (170 � 5 v. 88 � 3 g/day; mean � s.e.). There was no difference in growth rates between ram and wether lambs at the levels of nutrition imposed. The level of nutrition did not influence fat depots when the comparison was made at the same carcass weight. Ram lambs had less subcutaneous fat than did wethers, the difference increasing (P = 0.06) at heavier carcass weights (1 00 v. 20 1 g increase in subcutaneous fat/kg increase in carcass weight, for rams and wethers respectively). A similar trend was evident in GR tissue depth; consequently, the distribution of fat scores of wether carcasses was closer to the high (fat) end of the range than was the distribution for ram carcasses (P < 0.05). The levels of total solvent-extractable fat in the carcass did not differ between sexes or levels of nutrition.

1980 ◽  
Vol 30 (1) ◽  
pp. 135-152 ◽  
Author(s):  
J. D. Wood ◽  
H. J. H. MacFie ◽  
R. W. Pomeroy ◽  
D. J. Twinn

ABSTRACTIn order to investigate the effects of type of breed on carcass composition, an examination was made of 361 lambs from four breeds: Clun Forest and Colbred (termed ewe breeds); and Suffolk and Hampshire (termed ram breeds). The animals were in four carcass weight groups averaging 15, 17, 19 and 21 kg.Percentage subcutaneous fat was influenced more by carcass weight than by breed, whereas both carcass weight and breed had similar effects on percentage lean. At the mean carcass weight of 18 kg, Colbreds, the leanest breed, had a similar value for percentage lean (about 57 % of carcass tissue weight) to the carcasses over all breeds weighing 15 kg; and Cluns, the fattest breed, had a similar value (about 54%) to those weighing 21 kg. Since the ram breeds were intermediate in composition between the two ewe breeds there was no effect of type of breed on carcass composition. The breed differences were related to eventual mature size and to the stage of maturity at each carcass weight, as judged by body length and bone weight measurements. However, Colbreds were bigger and leaner than published estimates of their mature weight suggested. Humerus weight was a good predictor of lean or total fat weight, explaining 83 % ofvariation when used as a predictor along with carcass weight.Type of breed had a marked effect on internal fat deposition, the ewe breeds having heavier weights of both kidney knob and channel fat (KKCF) and caul fat (omental fat) than the ram breeds; and on the length oflimb bones, the ewe breeds having longer but thinner bones than the ram breeds. The order of the relative growth of the tissues and fat depots was: subcutaneous fat > caul fat > KKCF > intermuscular fat > lean > bone. Therefore, the internal fat depots were later maturing than intermuscular fat.The percentage of prime cuts in the carcass was not affected by carcass weight. Colbreds had significantly lower values than the other breeds. Suffolks had the lowest lean to bone ratio.


1974 ◽  
Vol 82 (3) ◽  
pp. 535-547 ◽  
Author(s):  
D. M. Murray ◽  
N. M. Tulloh ◽  
W. H. Winter

SUMMARYA study was made of the effect on body composition of growing Angus steers from 300 to 440 kg at three different rates. The rates were: High (H) 0·8 kg/day, Low (L) 0·4 kg/day and High-Maintenance (HM) 0·8 kg/day followed by a period during which body weight was maintained constant.The animals were individually penned and the different growth rates were achieved by controlling intakes of a pelleted feed. Two animals (part of H treatment) were killed at 300 kg and the remaining 27 animals (nine in each treatment), were killed at common body weights of 330, 363, 400 and 440 kg.Analyses of covariance were used to compare linear regression equations representing results from each treatment. In order to do this, the logarithmic transformation of the allometric equation, y = axb, was used. As a proportion of empty body weight (EBW), hot carcass weight (HCW) was greater in both the HM and L groups than in the H group, indicating a greater offal component of EBW in the H animals. The loss in weight of the dressed carcass during storage at 2 °C for 24 h was similar in all three groups and was 0·98% of HCW. The proportions of HCW in the fore- and hind-quarters were similar in each group.At the same dissected side weight (DSW), the weight of bone was significantly greater in both the HM and L groups than in the H group indicating that bone development was related to both age and carcass weight. There were no significant differences between the groups in the proportions of either muscle or total fat. However, the proportion of kidney and channel fat in the H group was greater than in the HM and L groups and the proportion of subcutaneous fat was also greater in the H than in the L group. The amount of connective tissue in the three groups followed, in general, group differences in bone. Analyses of the dissected components of the separate fore- and hind-quarters showed that the difference between the H and L groups in the proportion of subcutaneous fat in the DSW was due to a relatively greater development of this fat in the fore-quarter of the H animals.No differences were found between treatments in the proportion of ‘expensive muscles’ relative to total side muscle (TSM). However, there were treatment effects on the proportions of TSM formed by certain groups of muscles; two examples are: the proportion of group 4 muscles (abdominal muscles) was higher and the proportion of group 6 muscles (distal muscles of the fore-leg) was lower in the H than in the L treatments. Bone weight distribution was similar in all treatments.There were differences between the H and HM groups in the relative growth ratios for all fat tissues (subcutaneous, intermuscular and kidney and channel fat) compared with total side fat. However, in the H and L groups, the relative growth ratios for corresponding fat categories were similar. The weight of kidney and channel fat in the left side of the carcass was significantly greater than in the right side of the carcass in all treatments.


1990 ◽  
Vol 30 (2) ◽  
pp. 165 ◽  
Author(s):  
DL Hopkins ◽  
KD Gilbert ◽  
KL Saunders

Summary. The growth of short scrotum and wether lambs was studied in 3 experiments over 2 years, at the Elliott Research Station in northern Tasmania. Short scrotum lambs born in winter grew significantly (P<0.05) faster than wethers from birth to slaughter at 137 days of age. For spring born, short scrotum lambs, the growth advantage was less because of the quality and quantity of pasture available during summer and autumn. Wether lambs were fatter than short scrotum lambs in all experiments, with the slope of the relationship between GR and carcass weight being 0.57 � 0.02 I! 0.42 � 0.01 mmkg (experiment 1); 1.13 � 0.1 1 v. 0.68 � 0.09 mm/kg (experiment 2); and 0.91 � 0.16 v. 0.63 � 0.08 mm/kg (experiment 3) respectively. As carcass weight increased, the difference in carcass fatness increased. There was a shift in the distribution of carcasses according to fat score, with more wether carcasses being allocated high fat scores. Testes weight in the short scrotum lambs showed considerable variation within and between experiments and in all cases the testes were located in a subcutaneous position. There was a poor relationship between testes weight and growth rate. The level of testes development in a proportion of animals indicated that the animals could be fertile.


1984 ◽  
Vol 64 (3) ◽  
pp. 631-640 ◽  
Author(s):  
S. D. M. JONES ◽  
T. D. BURGESS ◽  
K. DUPCHAK ◽  
E. POLLOCK

Forty-nine crossbred ram lambs and 62 crossbred ewe lambs were allotted at weaning (average weight 30.6 kg) to pasture (P) or concentrate (C) feeding. The number of lambs per treatment was as follows: rams, 24 P fed and 25 C fed; ewes, 31 P fed and 31 C fed. The lambs were slaughtered after 56, 72, 100 and 121 days on feed. Offal components were weighed, and the alimentary tract was emptied of digesta. One side of each carcass was broken into four cuts (leg, loin, rib, shoulder) which were further separated into fat, muscle and bone. C-fed lambs were 4.0% heavier live than P-fed lambs (P < 0.05) and ram lambs were 9.0% heavier live than ewe lambs (P < 0.05) when evaluated at a constant depth of subcutaneous fat (4.5 mm). However, P-fed lambs required an extra 21 days (P < 0.05) to reach the same fat depth as C-fed lambs. C-fed lambs had greater rib eye areas than P-fed lambs, but carcasses from all treatments had similar proportions of dissected muscle, bone and fat when evaluated at a constant proportion of subcutaneous fat. P-fed lambs had a greater proportion of their empty bodies as head and reticulo-rumen, and a lower proportion as liver and large intestine than C-fed lambs. Ram lambs had a greater proportion of their empty bodies as head, and a lower proportion as caul fat, mesenteric fat, omasum and small intestine than ewe lambs. Distribution of muscle and bone among each of the four meat cuts which were evaluated was similar for all carcasses. Sex and feeding system had only a minor effect on the distribution of the fat depots. In this study, lambs fed on pasture required 21 days longer on feed to reach the same external fatness as concentrate-fed lambs, but produced carcasses of similar composition at slightly lighter liveweights (45.3 vs. 47.1 kg). Ram and ewe lambs spent a similar time on feed to reach a similar finish, but rams were heavier live than ewes (48.2 vs. 44.2 kg). Key words: Lambs, carcass composition, offal, constant fatness


1980 ◽  
Vol 31 (3) ◽  
pp. 315-319 ◽  
Author(s):  
J. D. Wood ◽  
H. J. H. MacFie

ABSTRACTFat thickness and measurements of the m. longissimus (‘eye’ muscle) were taken at the last rib in 350 lambs' carcasses which were fully dissected. The lambs were from two ewe breeds, Clun and Colbred, and two ram breeds, Suffolk and Hampshire, and the carcass weight range was 15 to 21kg. Castrated males and females, and singles and twins, were evenly represented.Rib fat thickness (J) was a slightly more precise predictor of the weights of lean, subcutaneous fat and subcutaneous plus intermuscular fat, when used in a multiple regression equation along with carcass weight, than fat thickness directly above the greatest depth of the ‘eye’ muscle (C). Both of these were more precise predictors than ‘eye’ muscle width and depth. Accounting for breed, either by allowing for different intercepts or completely different regression lines, did increase the proportion of variation in tissue weights explained by carcass weight and J or C, but to a small and, it was considered, commercially unimportant extent. This was despite differences in conformation between the breeds, reflected in this work by smaller ‘eye’ muscles in the ewe than the ram breeds and also in maturity, which might have been expected to influence tissue, including fat, distribution.The results indicate that breed differences in partition and distribution within and between the carcass fat depots in sheep are smaller than those between the carcass and intra-abdominal fat depots.


1984 ◽  
Vol 8 ◽  
pp. 104-104
Author(s):  
B. W. Butler-Hogg

Improving the efficiency of lean meat production is a major objective of producers. With cattle and, particularly, pigs, this has resulted in an increase in the use of entire male animals but not apparently so in the sheep sector, despite similar advantages. Ram lambs have traditionally been castrated for ease of management, particularly when they are ‘stored’ during winter. However, in early maturing breeds which can be finished off grass, considerable advantages may be gained from leaving ram lambs intact.In a trial which examined growth, composition and the eating quality of meat in 15 rams and 15 ewes of the Dorset Down breed (noted for early maturity), there were clear advantages in favour of the rams. In particular, ram lambs grew 28g/day faster on average than ewes, taking 2 weeks less to achieve 35 kg live weight. At the mean carcass weight of 16.8 kg, rams contained more lean (42 g) and bone (20 g) per kg carcass weight but less subcutaneous fat (33 g), intermuscular fat (28 g) and KKCF (kidney knob and channel fat) (13 g).


1985 ◽  
Vol 65 (2) ◽  
pp. 279-293 ◽  
Author(s):  
KARIMA A. SHAHIN ◽  
R. T. BERG

Eighteen Double Muscled (DM), 18 Beef Synthetic (SY) and 18 Hereford (HE) bulls were serially slaughtered from approximately 250 to 800 kg liveweight to determine the influence of maturity type and "double muscling" on tissue growth patterns and compositional differences which were examined by using the allometric equation Y = aXb after transformation to common logarithms (log10). As liveweight (LW) increased, the proportions of total side fat (TSF) and subcutaneous fat (SCF) increased, the proportions of total side muscle (TSM) and intermuscular fat (IMF) remained relatively constant and the proportion of total side bone (TSB) decreased. Relative to LW, DM had a similar growth rate for TSM and lower growth rates for TSF, SCF and IMF than HE and SY. All breed types had similar growth rates for TSB on LW. Relative to dissected side weight (DSW) and TSB, the DM bulls had a higher growth rate for TSM than did the HE and S Y bulls. Differences existed between DM and the more normal genotypes in carcass composition. DM was characterized by a high muscle:liveweight ratio, a high proportion of muscle in the carcass, high muscle:bone and muscle:fat ratios and a low proportion of fat compared to the more normal genotypes. Objective criteria to discriminate between HE and DM were SCF, muscle:bone and TSMTMF ratios, and between SY and DM were TSB and muscle:bone ratio. Key words: Beef bulls (young), growth patterns, carcass composition, double muscling, breed type


1979 ◽  
Vol 30 (6) ◽  
pp. 1207 ◽  
Author(s):  
JM Thompson ◽  
KD Atkins ◽  
AR Gilmour

Half-carcasses of 108 wether and ewe lambs from six genotypes, slaughtered at 34, 44 and 54 kg liveweight, were dissected into subcutaneous fat, intermuscular fat, muscle, bone and connective tissue. The six genotypes were the progeny of Dorset Horn and Border Leicester rams mated to Merino, Corriedale and Border Leicester x Merino first-cross ewes. As carcass weight increased, the proportion of subcutaneous and intermuscular fat increased (b > 1 ; P < 0.05) and the proportion of muscle and bone decreased (b < 1; P < 0.05). Lambs sired by Border Leicester rams had more subcutaneous fat (12.7%), more intermuscular fat (7.6%) and more bone (5.7%) than lambs sired by Dorset Horn rams at the same carcass weight (P< 0.05). Similarly, lambs sired by Dorset Horn rams had more muscle (7.2%) than lambs sired by Border Leicester rams at the same carcass weight (P < 0.05). Breed of dam had no effect on carcass composition. Wether lambs had a greater proportion of bone (5.7%) than ewe lambs at the same carcass weight (P < 0.05). The breed of sire effect and the lack of a breed of dam effect on carcass composition, in conjunction with estimated mature weights for the breeds, suggest possible differences between sire and dam breeds in the partitioning of fat between the carcass and non-carcass depots. ____________________ *Part I, Aust. J. Agric. Res., 30: 1197 (1979).


1999 ◽  
Vol 69 (1) ◽  
pp. 81-92 ◽  
Author(s):  
A. F. Carson ◽  
B. W. Moss ◽  
R. W. J. Steen ◽  
D. J. Kilpatrick

AbstractThis study investigated the effects of the percentage of Texel or Rouge de l’Ouest (Rouge) genes in lambs (0, 50, 75 or 100%; the remainder being Greyface (Border Leicester × Scottish Blackface)) on lamb carcass characteristics and meat quality. Ewe lambs were slaughtered at 34, 40, 46 and 52 kg and ram lambs were slaughtered at 40, 46, 52 and 58 kg live weight. Dressing proportion increased (P < 0·001) by 0·53 and 0·27 g carcass weight per kg live weight for each 1% increase in Texel or Rouge genes respectively. Carcass conformation classification increased (P < 0·001) by 0·016 and 0·007 units (on a five-point scale) for each 1% increase in Texel or Rouge genes respectively. Carcass fat depth measures were reduced by Texel and Rouge genes such that at a constant fat depth end point, carcass weight could be increased by 0·029 and 0·023 kg for each 1% increase in Texel or Rouge genes. Carcass lean content increased (P < 0·001) by 0·99 and 0·27 g/kg for each 1% increase in Texel or Rouge genes. Subcutaneous fat content was reduced (P < 0·001) by 0·36 and 0·29 g/kg for each 1% increase in Texel or Rouge genes. Intermuscular fat content was reduced (P < 0·01) by 0·38 g/kg per 1% increase in Texel genes, whereas Rouge genes had no effect. Similarly, bone content was reduced (P < 0·01) by Texel genes only (0·31 g/kg per 1% increase in Texel genes). Warner-Bratzler shear force values showed a quadratic effect with increasing Texel and Rouge genes, with an initial decrease from 0 to 50% followed by an increase to 100%. Cooking loss increased (P = 0·05) as the percentage of Rouge genes in lambs increased. Increasing the percentage of Texel or Rouge genes significantly increased L* values (P < 0·01 and P < 0·05 respectively), b* values (P = 0·05 and P< 0·05 respectively) and H° values (P < 0·001).


1930 ◽  
Vol 7 (2) ◽  
pp. 165-174
Author(s):  
M. A. TAZELAAR

Linear measurements of certain appendages and the carapace of P. carcinus were made and plotted in various ways. The following conclusions were drawn: 1. The cheliped shows heterogonic growth in both male and female, but more markedly in the male, the values of k being: male 1.8 and female 1.48 2. The pereiopods in both male and female are slightly heterogonic. The relative growth rates are graded from p3 to p5, that of p3 being slightly greater than that of p5 3. Of the ordinary pereiopods the rate of growth of p1 is the smallest in the male, but the largest in the female. 4. The difference between the rates of growth of p1 and p3 in male and female is greatest where the rate of growth in the heterogonic organ, the cheliped, is most excessive in the male. 5. The growth of the 3rd maxilliped is slightly negatively heterogonic, the value of k in the male being 0.93 and in the female 0.95. Hence there seems to be a correlation between the marked heterogony in the cheliped on the growth rate of neighbouring appendages. In those immediately posterior to the cheliped the growth rate is increased and in those anterior decreased.


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