Dietary choice and grazing behaviour of sheep on spatially arranged pasture systems. 2. Wether lamb growth and carcass weight at slaughter

2017 ◽  
Vol 57 (4) ◽  
pp. 710
Author(s):  
M. C. Raeside ◽  
M. Robertson ◽  
Z. N. Nie ◽  
D. L. Partington ◽  
J. L. Jacobs ◽  
...  
Keyword(s):  
Perennial Ryegrass ◽  
Block Design ◽  
Plantago Lanceolata ◽  
Carcass Characteristics ◽  
Single Species ◽  
Carcass Weight ◽  
Eye Muscle ◽  
Internal Parasite ◽  
Dietary Choice ◽  
Condition Score

Dry matter production and nutritive characteristics of the pasture feedbase during autumn are key drivers of profitability in Australia’s prime lamb systems. An experiment was conducted to test the hypothesis that offering lambs dietary choice through spatially separated combinations of perennial ryegrass (Lolium perenne L.), plantain (Plantago lanceolata L.) and/or lucerne (Medicago sativa L.) improves the post-weaning liveweight gain, condition score (CS), pre- and post-slaughter carcass characteristics and reduces the internal parasite burdens of wether lambs finished to a slaughter weight over autumn, relative to lambs offered no dietary choice. The experiment tested seven treatments, replicated four times in a randomised complete block design with plot sizes of 1 ± 0.1 ha. The treatments were: 100% perennial ryegrass (PR), 100% plantain (PL), 100% lucerne (LU), 50 : 50 perennial ryegrass/plantain (PR + PL), 50 : 50 perennial ryegrass/lucerne (PR + LU), 50 : 50 plantain/lucerne (PL + LU) and 33 : 33 : 33 perennial ryegrass/plantain/lucerne (PR + PL + LU). Plots were grazed by weaned lambs between March and June 2011. The lambs had been born between 3 August and 7 September 2010 and were derived from either Coopworth composite dams joined to Coopworth maternal sires or from Merino dams (Toland or Centreplus bloodlines) joined to Border Leicester sires. Backgrounding the lambs on a pasture system that contained lucerne during the lactation to weaning period increased (P < 0.05) liveweight at slaughter by 8% and hot carcass weight by 10%, relative to lambs backgrounded on perennial ryegrass. Finishing lambs on the LU treatment between weaning and slaughter increased (P < 0.05) liveweight at slaughter by 11%, CS at slaughter by 0.3 units, hot carcass weight by 16%, carcass CFAT (measured over the loin) by 2.5 mm, carcass eye muscle depth by 1.1 mm and carcass GRFAT (total tissue depth at 11/12th rib, 11 cm from mid line) by 3.8 mm, relative to lambs finished on the PR treatment. Finishing lambs on LU + PR, LU + PL or LU + PR + PL did not (P > 0.05) improve any of the measured parameters, relative to finishing lambs on the LU treatment. The PL and PR treatments did not differ (P > 0.05) in liveweight at slaughter, CS at slaughter or carcass characteristics, but the PL treatment had lower (P < 0.05) liveweight gain than the PR treatment during the first 2 weeks of the experiment (39 g/day vs 330 g/day), which was later partially compensated for. Our hypothesis has not been supported given that the use of spatially arranged mixes resulted in no improvement in liveweight gain, CS, carcass characteristics or internal parasite burdens relative to the comparable single species sward.

Plantain (Plantago lanceolata L.) and perennial ryegrass (Lolium perenne L.) as pregnancy and lactation feed for ewes joined at 8 months of age

2014 ◽  
Vol 54 (8) ◽  
pp. 1023 ◽  
Author(s):  
M. C. Raeside ◽  
Z. N. Nie ◽  
M. Robertson ◽  
D. L. Partington ◽  
R. Behrendt
Keyword(s):  
Lolium Perenne ◽  
Perennial Ryegrass ◽  
Block Design ◽  
Plantago Lanceolata ◽  
Late Pregnancy ◽  
Lolium Perenne L ◽  
Condition Score ◽  
Pregnancy And Lactation ◽  
3.0 T ◽  
Western Victoria

Ewe nutrition during pregnancy and lactation is a key determinant of ewe and lamb performance. A paddock-scale field experiment in western Victoria, Australia, tested the hypothesis that grazing maiden ewes on plantain (Plantago lanceolata L.) from mid-pregnancy until lamb weaning (July 2010–January 2011) would increase ewe liveweight and condition score during this period, reduce worm egg counts, and increase lamb liveweights at birth, marking and weaning, relative to tetraploid perennial ryegrass (Lolium perenne L.), but that further increases would be achieved by offering a spatially arranged sward of plantain and perennial ryegrass. The experiment tested three treatments: plantain (PL), perennial ryegrass (PR), and a 50 : 50 (by area) spatially separated mixture of perennial ryegrass and plantain (PR + PL). Plots were ~1 ha in size arranged in a randomised complete block design with four replications. The ewes were Coopworth composites joined at 8 months of age. Feed-on-offer levels (kg DM/ha) did not differ (P > 0.05) between treatments, with 2.3–3.0 t DM/ha being available pre-grazing. Twin-bearing ewes had higher (P < 0.05) liveweights when offered PR + PL compared with PR or PL at late-pregnancy and higher (P < 0.05) liveweights than PR but not PL (P > 0.05) at lamb marking. At weaning, single-born lambs were heavier (P < 0.05) on PR than PR + PL, with the PL being intermediate. There were no other significant differences (P > 0.05). This experiment has found that feeding plantain to ewes during pregnancy and lactation, or offering ewes spatially separated mixes of plantain and perennial ryegrass, offers no clear liveweight or worm egg count improvement for ewes and lambs relative to a tetraploid perennial ryegrass under Western Victorian conditions.

Dietary choice and grazing behaviour of sheep on spatially arranged pasture systems. 1. Herbage mass, nutritive characteristics and diet selection

2017 ◽  
Vol 57 (4) ◽  
pp. 697 ◽  
Author(s):  
M. C. Raeside ◽  
M. Robertson ◽  
Z. N. Nie ◽  
D. L. Partington ◽  
J. L. Jacobs ◽  
...  
Keyword(s):  
Perennial Ryegrass ◽  
Feed Intake ◽  
Block Design ◽  
Plantago Lanceolata ◽  
Dietary Preferences ◽  
Dietary Choice ◽  
3.0 T ◽  
Livestock Productivity ◽  
Multiple Species ◽  
Grazing Behaviour

Offering livestock dietary choice through access to different pasture species enables livestock to regulate their own feed intake, select for nutrients and minerals, balance rumen health and display natural grazing and foraging behaviours, which could in turn result in increased livestock productivity. An experiment was conducted at Hamilton, Victoria, Australia, to test the hypothesis that offering lambs dietary choice through spatially separated combinations of pasture species would improve lamb performance, relative to lambs with no dietary choice. The experiment tested seven treatments, replicated four times in a randomised complete block design with plot sizes of 1 ± 0.1 ha. The treatments were: 100% perennial ryegrass (Lolium perenne L.) (PR), 100% plantain (Plantago lanceolata L.) (PL), 100% lucerne (Medicago sativa L.) (LU), 50 : 50 perennial ryegrass/plantain (PR + PL), 50 : 50 perennial ryegrass/lucerne (PR + LU), 50 : 50 plantain/lucerne (PL + LU) and 33 : 33 : 33 perennial ryegrass/plantain/lucerne (PR + PL + LU). In the multiple species swards, the pasture species were separated spatially (by area). Plots were grazed by weaned lambs between March and June 2011. Pre-grazing herbage mass during March and April were highest (P < 0.05) from the lucerne and lowest (P < 0.05) from the plantain, with lucerne producing 4.5–5.5 t DM/ha during this time, whereas the perennial ryegrass and plantain produced 3.5–3.9 t DM/ha and 2.3–3.0 t DM/ha, respectively. Herbage disappearance (calculated estimate of feed intake) was highest (P < 0.05) from the lucerne and lowest (P < 0.05) from the plantain during March and April. Leaf crude protein between the perennial ryegrass and plantain did not differ (P > 0.05) and were lower (P < 0.05) than the lucerne, but the perennial ryegrass and plantain had higher (P < 0.05) leaf on offer (kg DM/ha). Plantain leaf had higher (P < 0.05) Fe, Zn, Co, Ca and S than the perennial ryegrass leaf and higher (P < 0.05) Se, Cu, Mg, Na and Cl than the perennial ryegrass and lucerne leaf and a more negative (P < 0.05) dietary cation : anion difference. The agronomic data presented in this paper provides support for the hypothesis, with lambs showing dietary preferences between pasture species and morphological components, and forms to basis for why these preferences exist. The two subsequent papers show how offering lambs dietary choice affected the performance of male lambs to slaughter and female lambs to first joining.

scholarly journals Carcass and non-carcass component characteristics of lambs fed with cassava wastewater dregs in replacement of corn

2016 ◽  
Vol 37 (4Supl1) ◽  
pp. 2711 ◽  
Author(s):  
Daniel Barros Cardoso ◽  
Robson Magno Liberal Véras ◽  
Francisco Fernando Ramos de Carvalho ◽  
André Luiz Rodrigues Magalhães ◽  
Gustavo Araújo de Vasconcelos ◽  
...  
Keyword(s):  
Body Weight ◽  
Block Design ◽  
Carcass Characteristics ◽  
Linear Increase ◽  
Carcass Weight ◽  
Replacement Level ◽  
Randomized Block Design ◽  
Feedlot Lambs ◽  
Retail Cuts ◽  
Cassava Wastewater

The objective was to evaluate the effect of the substitution (0, 33, 66 and 100%) of corn by cassava wastewater dregs on carcass characteristics and non-carcass components of crossbred Santa Inês lambs. Forty male sheep, uncastrated with an average initial body weight of 20 ± 1.87 kg and five months of age, were used. These were housed in individual pens in a randomized block design with four treatments and ten repetitions and slaughtered after 70 days of confinement. Quadratic effect (P &lt; 0.05) was observed for the empty body weight (EBW), hot carcass weight (HCW) and cold carcass weight (CCW) and carcass compactness index (CCI), with maximum points of 36.14, 19.45, 20.20 and 0.31 kg cm-1 for the replacement level of corn for cassava wastewater dregs, 50.0, 53.84, 54.04 and 45.45% respectively. There was also an effect (P &lt; 0.05) on the weights of the rumen and “Buchada”, with maximum points of 0.909 and 6.25 kg per replacement level, 49.11 and 51.29% respectively. As for retail cuts, only the efficiency of the leg was altered (P &lt; 0.05), having a linear increase while the other variables were not affected. Cassava wastewater dregs can be used in full as an alternative food in the diet of feedlot lambs without harming the main carcass characteristics and non-carcass components.

scholarly journals PSX-29 Levels of hay and narasin inclusion on carcass characteristics and meat composition

2019 ◽  
Vol 97 (Supplement_3) ◽  
pp. 455-455
Author(s):  
Lairana A Sardinha ◽  
Daniel M Polizel ◽  
Alexandre A Miszura ◽  
Arnaldo C Limede ◽  
José P R Barroso ◽  
...  
Keyword(s):  
Body Weight ◽  
Block Design ◽  
Carcass Characteristics ◽  
Ash Content ◽  
Carcass Weight ◽  
Initial Body Weight ◽  
Composition Data ◽  
Meat Composition ◽  
Randomized Complete Block Design ◽  
Different Levels

Abstract The objective of this study was to determinate the effects of narasin on carcass characteristics of lambs fed a diet containing different levels. Forty-four lambs were allotted in a randomized complete block design, defined by initial body weight (BW), in a 2x2 factorial arrangement. The first factor was forage (coastcross hay) inclusion (10 or 20%, DM basis) and the second factor was narasin (0 or 13 ppm). The experimental diets were isonitrogenous (17.4%, DM basis). The experiment lasted 112 days. At the end of the experiment, the lambs were slaughtered to evaluate the carcass characteristics and meat composition. Data were analyzed using the MIXED procedure of SAS and the LSMEANS option was used to obtain the means. The effects were considered significant when P &lt; 0.05. There was no interaction between forage levels and narasin inclusion. The experimental diets did not affect the slaughter BW (54.8 ± 1.6 kg), hot carcass weight (29.3 ± 0.96 kg), dressing percentage (53.5 ± 0.67%) and LM area (18.8 ± 0.89 cm2). The inclusion of narasin increased 12th-rib fat (2.10 vs 2.75 mm; P &lt; 0.01) and BW thickness (16.9 vs 20.2 mm; P &lt; 0.01). The inclusion of 20% of hay decreased BW thickness (19.21 vs 17.9 mm; P = 0.03). The experimental diets did not affect the moisture (74.2 ± 0.53%) and ash content in meat (1.27 ± 0.04%). Narasin inclusion increased the fat (2.81 vs 3.62%; P &lt; 0.01) and decreased the CP (21.3 vs 20.7%; P = 0.02) in meat composition. The inclusion of 10% of hay increased the fat in meat (3.5 vs 2.9%; P = 0.03), however, did not affect the CP content. In conclusion, the narasin inclusion and levels of hay improve the carcass characteristics and change the meat composition.

scholarly journals 227 Evaluation of reimplant timing with Revalor-200 on steer performance and carcass characteristics

2019 ◽  
Vol 97 (Supplement_2) ◽  
pp. 127-128
Author(s):  
Caitlin A Coulson ◽  
Bradley M Boyd ◽  
Henry Hilscher ◽  
Brandon L Nuttelman ◽  
Grant I Crawford ◽  
...  
Keyword(s):  
Dry Matter ◽  
Block Design ◽  
Carcass Characteristics ◽  
The Other ◽  
Carcass Weight ◽  
Dry Matter Intake ◽  
Optimal Time ◽  
Trenbolone Acetate ◽  
First Derivative ◽  
Randomized Block Design

Abstract The objective of this study was to evaluate the optimal time to reimplant following an initial implant on performance and carcass characteristics when steers were fed for 180 d. Crossbred steers (n = 800; initial BW = 330 ± 25 kg) were utilized in a generalized randomized block design and assigned randomly to pen, and pen assigned randomly to one of five treatments. Treatments included 5 different days on terminal (DOT) implant (160, 120, 100, 80 or 40 DOT). All steers were given an initial implant (80 mg trenbolone acetate (TBA) + 16 mg estradiol; Revalor-IS) on d 1. Terminal implant consisted of 200 mg TBA + 20 mg estradiol (Revalor-200). Dry matter intake was the least for 40 DOT (P ≤ 0.04), with no differences between the other treatments (P ≥ 0.11). Carcass-adjusted final BW responded quadratically (P = 0.03) with 100 DOT having the greatest final BW but was not different from 120 DOT (P = 0.82). Carcass-adjusted ADG and G:F responded quadratically (P = 0.02 and P < 0.01, respectively). When solved for the first derivative, carcass-adjusted ADG and G:F were maximized at 99 and 87 DOT, respectively. However, there was less than a 2% difference in carcass-adjusted ADG and G:F between 80 and 120 DOT. Hot carcass weight responded quadratically (P = 0.03), with the greatest HCW at 100 DOT. Solving for the first derivative, HCW was optimized at 104 DOT. There were no differences in back fat, marbling, or yield grade (P ≥ 0.27). Overall, administering an initial implant followed by a terminal implant 85 to 105 d prior to harvest increased gain, efficiency, and HCW in steers when fed for 180 d. Minimal changes in performance and carcass characteristics when steers are reimplanted 80 to 120 d prior to harvest suggests flexibility in reimplanting windows.

Effects of sex and year on growth and live assessment of carcass characteristics of lambs grazing annual pastures

1991 ◽  
Vol 31 (3) ◽  
pp. 307 ◽  
Author(s):  
LP Thatcher ◽  
B Warren ◽  
PJ Nicholls
Keyword(s):  
Growth Rate ◽  
Repeated Measures ◽  
Subcutaneous Fat ◽  
Carcass Characteristics ◽  
Carcass Weight ◽  
Condition Score ◽  
Second Year ◽  
Dressing Percentage ◽  
Fat Score ◽  
Clover Content

Lambs from the Poll Dorset x (Border Leicester x Merino) cross were raised from a late lambing in 1983 (a year when pastures grew unchecked and had high clover content) and 1984 (a year with intermittent dry periods and a low clover content in pastures). Multivariate repeated measures analyses were used to compare growth rates for rams, wethers and ewes within 2 periods of growth in 1983, and 4 in 1984. In all stages rams grew significantly faster than wethers and ewes, whereas wether growth rate exceeded that of ewes in only 3 stages. In general, when pasture availability and quality was high, rams grew faster than wethers by 0.3 kg/week and ewes by 0.5 kg/week. The rams grew 0.16 kg/week faster when pasture availability was limiting for a period in winter but lost significant (P<0.01) body condition, whilst ewes maintained both weight and condition. When good quality feed was again available, rams gained more weight than wethers, as did wethers compared with ewes, while rams and wethers gained more condition than ewes. Carcass weight and fatness, measured either as indicators of fat (GR measurement or fat score) or as total subcutaneous fat, could be predicted from assessments made on live lambs. Full liveweight, sex and year explained 41% of variation in GR, 48% in fat score and 79% in subcutaneous fat. Condition score, sex and year explained 45% of variation in GR, 52% in fat score and 57% in subcutaneous fat. Full liveweight, condition score, sex and year explained 80% of the variation in subcutaneous fat, 47% in GR and 57% in fat score. An interaction of sex with full liveweight in predicting carcass weight and subcutaneous fat indicated that as carcass size increased, the sex of the lamb became an increasingly important consideration when assessing characteristics important in describing lamb carcasses. Dressing percentage decreased by 0.08/kg as liveweight increased. This result was consistent over the 2 years, with opportunities for error being assessed and eliminated in the second year. Notwithstanding that this was an unimportant loss in real terms, published information showed an increase in dressing percentage with liveweight.

scholarly journals PSXII-17 Fiber content in diets for feedlot lambs: carcass characteristics

2019 ◽  
Vol 97 (Supplement_3) ◽  
pp. 422-423
Author(s):  
Janaina S Biava ◽  
Nathalia R Eckermann ◽  
Thamires U Sturion ◽  
Daniel M Polizel ◽  
Paulo Dias Junior ◽  
...  
Keyword(s):  
Block Design ◽  
Subcutaneous Fat ◽  
Carcass Characteristics ◽  
Carcass Weight ◽  
Carcass Yield ◽  
Randomized Complete Block Design ◽  
Quadratic Response ◽  
Subcutaneous Fat Thickness ◽  
Fat Thickness ◽  
Feedlot Lambs

Abstract The objectives of this trial were to evaluate the effects of levels of fiber in high-grain diets on carcass characteristics of feedlot lambs. Fifty-eight Dorper x Santa Inês ram lambs (initial BW 20.7 ± 1.19 kg and 75 ± 10.83 d old) were assigned to a randomized complete block design. The treatments were defined by the fiber (“Coastcross” hay) content in the diets (CP: 16,12% ± 0.92): 0F: no forage diet (NDF: 10.4%); 5F: 5% of forage (NDF: 12.1%); 10F: 10% of forage (NDF: 15.0%); 15F: 15% of forage (NDF: 15.5%); 20F: 20% of forage (NDF: 20.8%) and 25F: 25% of forage (NDF: 23.5%). The experiment lasted 89 days, at the end of this time, the animals were slaughtered (169 ± 10.83 d old) to evaluate carcass characteristics. There was a quadratic response for slaughter BW (0F: 46.3; 5F: 48.1; 10F: 49.4; 15F: 50.3; 20F: 48.5; 25F: 43.3 kg; P &lt; 0.01), hot carcass weight (0F: 24.8; 5F: 25.6; 10F: 26.0; 15F: 25.7; 20F: 24.3; 25F: 21.8 kg; P = 0.01), cold carcass weight (0F: 24.3; 5F: 25.1; 10F: 25.4; 15F: 25.1; 20F: 23.8; 25F: 21.2 kg; P = 0.01) and longissimus dorsis area (0F: 16.3; 5F: 16.5; 10F: 17.4; 15F: 16.5; 20F: 16.0; 25F: 15.1 cm2; P = 0.04). There was a linear decrease in the hot carcass yield (0F: 53.0; 5F: 53.3; 10F: 52.5; 15F: 50.9; 20F: 50.1; 25F: 50.2%; P &lt; 0.01), cold carcass yield (0F: 52.0; 5F: 52.2; 10F: 51.4; 15F: 49.8; 20F: 49.0; 25F: 48.9%; P &lt; 0.01) and body wall thickness (0F: 16.2; 5F: 17.0; 10F: 16.3; 15F: 16.3; 20F: 15.1; 25F: 13.6 kg; P = 0.01). There was no effect on subcutaneous fat thickness. In conclusion, the diet with up to 5% of forage allowed higher carcass yield; however, the heavier carcasses were produced by the lambs that received 10F diet.

Growth and carcass characteristics of Wagyu-sired steers at heavy market weights following slow or rapid growth to weaning

2006 ◽  
Vol 46 (7) ◽  
pp. 951 ◽  
Author(s):  
L. M. Cafe ◽  
H. Hearnshaw ◽  
D. W. Hennessy ◽  
P. L. Greenwood
Keyword(s):  
Growth Rates ◽  
Rapid Growth ◽  
Slow Growth ◽  
Average Daily Gain ◽  
Carcass Characteristics ◽  
Carcass Weight ◽  
Muscle Area ◽  
Eye Muscle ◽  
Similar Composition ◽  
Daily Gain

Two groups of Wagyu × Hereford steers grown slowly (slow preweaning group, n = 14, mean average daily gain = 631 g/day) or rapidly (rapid preweaning group, n = 15, mean average daily gain = 979 g/day) from birth to weaning were backgrounded on improved, temperate pasture to equivalent group liveweights (543 v. 548 kg, s.e. = 8.8 kg), then finished in a feedlot for 120 days. At weaning, the slow preweaning group was 79 kg lighter than the rapid preweaning group. They required an additional 43 days of backgrounding to reach the same feedlot entry weight as the rapid preweaning group. The slow preweaning group grew more rapidly during backgrounding (630 v. 549 g/day, s.e. = 13.7 g/day) but tended to grow more slowly during feedlotting (1798 v. 1982 g/day, s.e. = 74.9 g/day) than their rapid preweaning counterparts, with overall growth rates from weaning to feedlot exit not differing between the 2 groups (rapid 763 g/day v. slow 772 g/day, s.e. = 17.5 g/day). At slaughter, following the feedlot phase, carcass weights of the 2 groups did not differ significantly (rapid 430 kg v. slow 417 kg, s.e. = 7.2 kg). There was a tendency for the steers grown slowly to weaning to have a higher dressing percentage (57.6 v. 56.6%, s.e. = 0.33%), but there were no significant differences in carcass compositional characteristics between the 2 groups. The slow preweaning steers did have a greater eye muscle area than the rapid preweaning steers (106.6 v. 98.9 cm2, s.e. = 1.87) when carcass weight was used as a covariate. These findings demonstrate that cattle grown slowly to weaning have similar composition at slaughter as those grown rapidly during the same period when backgrounded on pasture to the same feedlot entry weight. Furthermore, marbling was not adversely affected by slow growth to weaning.

Growth and carcass characteristics of crossbred and straightbred Hereford steers. II. Carcass measurements and composition

1981 ◽  
Vol 32 (1) ◽  
pp. 171 ◽  
Author(s):  
JM Thompson ◽  
R Barlow
Keyword(s):  
Subcutaneous Fat ◽  
Carcass Characteristics ◽  
Allometric Equation ◽  
The Body ◽  
The Other ◽  
Carcass Weight ◽  
Muscle Area ◽  
Eye Muscle ◽  
Fat Thickness ◽  
Breed Crosses

The effect of sire breed on the growth and development of carcass characteristics was examined in 104 steer carcasses, over the weight range of c. 300 to 600 kg liveweight. The carcasses were obtained from 28 straightbred Hereford, 27 Brahman x Hereford, 23 Simmental x Hereford and 26 Friesian x Hereford steers, which were grown on pasture and slaughtered in four groups when the Herefords weighed c. 270, 370, 470 and 570 kg liveweight. Changes in carcass characteristics with weight were examined by using the linear form of the allometric equation (log10Y = log10A+blog10X). As liveweight increased, the proportion of carcass in the body increased (b = 1.152). At the same liveweight, Brahman cross steers had heavier carcasses than the Hereford steers, which were heavier than either the Simmental or Friesian cross steers (P < 0.05). Fat thickness at the 12th-13th rib site, and kidney and channel fat weight both increased at a proportionally faster rate than carcass weight (b = 1.511 and 1 567 respectively). At the same carcass weight, Hereford and Brahman cross carcasses had a greater fat thickness than Simmental and Friesian cross carcasses (P i 0.05). Differences between sire breeds in kidney and channel fat weight were not significant (P > 0.05). C:rcass length and eye muscle area increased at a proportionally slower rate than carcass weight (b = 0.268 and 0.466 respectively). At the same carcass weight, Friesian cross carcasses were longer, and Simmental cross carcasses had a larger eye muscle area than the other breed crosses (P < 0.05). As total side weight increased, the proportions of subcutaneous and intermuscular fatAincreased (b = 1.554 and 1.535 respectively), and the proportions of muscle and bone decreased (b = 0.938 and 0.676 respectively). At the same side weight, the Hereford and Brahman cross carcasses had more subcutaneous fat than the Simmental and Friesian cross carcasses (P < 0.05). The Hereford carcasses had more intermuscular fat than the Simmental cross carcasses, which had more muscle than the other breed crosses (P < 0.05). Friesian cross carcasses had more bone than the Simmental crosses, with Brahman cross and Hereford carcasses having the least bone (P < 0.05). Brahman cross carcasses had a higher conformation score than the Simmental cross and Hereford carcasses, the Friesian cross carcasses having the lowest (P < 0.05). Samples of the M. longissimus from Brahman cross carcasses had a higher Warner-Bratzler shear force than samples from the other breed crosses (P < 0.05).

Growth and carcass characteristics of male crossbred lambs from high fecundity Booroola x Polwarth ewes: effects of litter size, castration and age

1990 ◽  
Vol 30 (3) ◽  
pp. 323 ◽  
Author(s):  
AJ Ritar ◽  
PM Williams ◽  
PJ O'May ◽  
KD Gilbert ◽  
EM Bond ◽  
...  
Keyword(s):  
Growth Rate ◽  
Litter Size ◽  
Carcass Characteristics ◽  
Multiple Birth ◽  
Eye Muscle ◽  
High Fecundity ◽  
Younger Age ◽  
Condition Score ◽  
Ram Lambs ◽  
Birth Type

Growth and carcass characteristics were obtained for 154 Border Leicester-sired male lambs, from highly fecund Booroola x Polwarth ewes, grazed on improved Tasmanian pasture and either left entire or castrated, followed by slaughter at 134, 192 or 288 days of age. Of all lambs, 15.6% were single born and 84.4% were multiple born (54.5% twins, 19.5% triplets, 8.4% quadruplets and 1.9% quintuplets). Multiples were lighter than singles at birth (3.6 v. 4.4 kg), at weaning at 78 days (21.0 v. 25.8 kg), and before slaughter at 134 days (27.5 v. 31.1 kg), 192 days (33.9 v. 36.1 kg) and 288 days (37.5 v. 42.5 kg). Similarly, carcasses were lighter and leaner, and dressing percentages were lower for multiples than for singles, but when carcass weight was included as the covariate in further analysis of carcass characteristics, there was no effect of birth type. There were no significant interactions between birth type and castration. The growth rate of ram lambs became progressively faster than wethers from weaning onwards. Liveweight differences could be detected from 134 days of age (28.8 v. 27.2 kg), but ram lamb carcasses were not heavier until 288 days (18.1 v. 16.0 kg). At 192 days, rams were leaner than wethers (condition score, 2.2 v. 2.5; GR tissue depth, 8.5 v. 11.5 mm; C-site fat depth, 3.7 v. 5.1 mm), and rams had lower dressing percentages (41.8 v. 44.0%) and larger eye muscle areas (1097 v. 1010 mm2), but carcass weights were similar (14.8 v. 14.6 kg). We conclude that the only effect of multiple birth was to delay maturation and development of lambs to reach the suitable market weight. Leaving males entire did not improve carcass weights until 288 days, which is of little benefit to Tasmanian producers where lambs are normally sold at a much younger age.

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