Heavier Carcasses Research Articles

Effects of the level and duration of feeding restriction on carcass components of broilers

Abstract. The effects of the restriction of the advised daily feed intake (ADFI) during 1 or 2 weeks on broiler body weight (BW) and carcass composition were studied. A total of 150 1-day-old male broilers (Ross-308) were randomly allotted to a control and four experimental treatments with three replicates per treatment. Broilers were subjected to a feeding restriction equal to 75 and 50 % of ADFI, either for a 7- or a 14-day period, between the 7th and 14th and 7th and 21th day of age, respectively. The BW and carcass composition were determined on day 42. From the findings, neither of the two levels of restriction nor the two time intervals had significant effects (P > 0.05) on the BW or breast and leg weight and proportion, liver and most of the body components. However, the feeding treatments show a tendency (P = 0.078) to influence the BW, with birds fed 75 % of ADFI for 14 day being heavier than the control group. For eviscerated carcass weight, an effect (P = 0.002) was observed, with birds fed 75 % of ADFI for 14 day having heavier carcasses (P < 0.05) than those in control group. The abdominal fat, both with regard to weight and proportion, was slightly influenced by dietary treatments (P > 0.05). From our results, it can be concluded that the applied feeding restrictions have a neutral or slightly beneficial effect on broiler growth traits and carcass composition.

Effects of Duroc Breeding Lines on Carcass Composition and Meat Quality.

This study was performed to investigate the carcass composition and pork quality of Duroc breeding lines in Korea. A total of 200 Duroc pigs were used, and those were originated from four different great-grandparent (GGP) breeding stock farms (L1: N farm, L2: W farm, L3: S farm, L4: R farm). The carcasses of pigs from these farms were collected, and meat quality traits were evaluated. L1 and L2 had smaller carcass weights and thin backfat, whereas L3 and L4 had heavy carcass weights and thick backfat. L3 and L4 had higher contents of fat and protein than L1 and L2. For the meat quality characteristics, L1, L2, and L4 had higher pH values than L3. In addition, L4 had higher water holding capacity than the other lines. L4 had the highest sensory evaluation scores with regard to both juiciness and flavor. Consequently, the study results indicate that pork quality information from domestic Duroc breeding stock lines could be used to effectively improve pork quality in Korea.

Effect of graded levels of lablab (Lablab purpureus L. Sweet) hay on carcass characteristics of red sokoto goats fed maize stover basal diet

An experiment was conducted to investigate the effect of feeding varying levels of lablab hay on carcass characteristics of Red Sokoto bucks. Twenty (20) male, non castrate Red Sokoto bucks of average initial weight range of 9.30-11.87± 0.1kg, were used for the experiment. They were randomly assigned to five treatment diets containing lablab hay at 0, 25, 50, 75 and 100% levels of inclusion, respectively. The bucks were individually pen-fed with the concentrate diets at 2% body weight in a Randomized Complete Block Design for a period of 90 days, before they were slaughtered. Results revealed that a 50% inclusion level of lablab hay in the diet led to 79% higher (P<0.05) dressed weight compared to the control diet (35%). The length of small intestine increased by 51% (P<0.05) at 100% level of inclusion of lablab hay compared to the control diet (25%). Also, there was a 45% increase (P<0.05) in the head weight of the bucks at 75% level of lablab hay inclusion. Similarly, including lablab hay at 100% in the diet led to 55% decrease (P<0.05) in the abdominal fat content compared to the control diet. Generally, lablab hay inclusion in the diet of Red Sokoto bucks led to increased (P<0.05) weight of other prime cuts and organs. It was therefore concluded that lablab hay is a potential feed supplement for Red Sokoto bucks under smallholder systems and should be adopted by the farmers for better performance, heavier carcass weight and lean meat production in Nigeria.Key words: Carcass, diet, goats, lablab, Nigeria

Genetic parameters for carcass weight, conformation and fat in five beef cattle breeds

Profitability of beef production can be increased by genetically improving carcass traits. To construct breeding value evaluations for carcass traits, breed-specific genetic parameters were estimated for carcass weight, carcass conformation and carcass fat in five beef cattle breeds in Finland (Hereford, Aberdeen Angus, Simmental, Charolais and Limousin). Conformation and fat were visually scored using the EUROP carcass classification. Each breed was separately analyzed using a multitrait animal model. A total of 6879–19 539 animals per breed had phenotypes. For the five breeds, heritabilities were moderate for carcass weight (h2=0.39 to 0.48, s.e.=0.02 to 0.04) and slightly lower for conformation (h2=0.30 to 0.44, s.e.=0.02 to 0.04) and carcass fat (h2=0.29 to 0.44, s.e.=0.02 to 0.04). The genetic correlation between carcass weight and conformation was favorable in all breeds (rG=0.37 to 0.53, s.e.=0.04 to 0.05), heavy carcasses being genetically more conformed. The phenotypic correlation between carcass weight and carcass fat was moderately positive in all breeds (rP=0.21 to 0.32), implying that increasing carcass weight was related to increasing fat levels. The respective genetic correlation was the strongest in Hereford (rG=0.28, s.e.=0.05) and Angus (rG=0.15, s.e.=0.05), the two small body-sized British breeds with the lowest conformation and the highest fat level. The correlation was weaker in the other breeds (rG=0.08 to 0.14). For Hereford, Angus and Simmental, more conformed carcasses were phenotypically fatter (rP=0.11 to 0.15), but the respective genetic correlations were close to zero (rG=−0.05 to 0.04). In contrast, in the two large body-sized and muscular French breeds, the genetic correlation between conformation and fat was negative and the phenotypic correlation was close to zero or negative (Charolais: rG=−0.18, s.e.=0.06, rP=0.02; Limousin: rG=−0.56, s.e.=0.04, rP=−0.13). The results indicate genetic variation for the genetic improvement of the carcass traits, favorable correlations for the simultaneous improvement of carcass weight and conformation in all breeds, and breed differences in the correlations of carcass fat.

Growth and Carcass Traits of Three Portuguese Autochthonous Chicken Breeds: Amarela, Preta Lusitânica and Pedrês Portuguesa

The purpose of this study was to estimate the growth curve parameters and carcass traits yields of three Portuguese autochthonous chicken breeds, Amarela (AM), Preta Lusitânica (PL) and Pedrês Portuguesa (PP). Birds (198) were individually weighed at pre-established time intervals (6682 records) and the study period lasted 30 months. The growth data were fitted to a mixed nonlinear model based on the Gompertz growth function. Fixed effects were breed, sex, lot, temperature and photoperiod. The adult weight estimated for males (females) were 2851.3 (1951.6) g for AM, 3047.5 (2147.7) g for PL, and 3243.7 (2344.0) g for PP, respectively. The males (females) estimated maximum daily growth were 22.7 (18.1) g at 77 (69) days for AM, 20.7 (17.5) g at 79 (72) days for PL, and 18.1 (16.3) g at 82 (74) days for PP, respectively. Within breed the males were heavier than females at 365 days but with lower maturity rates. Yields of carcass and noble meat pieces were evaluated on data collected from 10 males of each breed, sacrificed at 240 days. Traditionally, these breeds are commercialised whole and again the PP had the heaviest carcass with the highest yield. Growth of these autochthonous breeds after 240 days was minimal and may justify the decrease of the traditional slaughter age of approximately one year, in order to increase profitability. Establishing special market niches will also be a valuable complement for the rural economy of Portugal and an important contribution to the conservation of this genetic heritage.

Factors influencing the priority of access to food and their effects on the carcass traits for Japanese Black (Wagyu) cattle

The factors influencing the priority of access to food and the effects of the priority of access to food on their carcass traits were analyzed for Japanese Black (Wagyu) cattle in a semi-intensive fattening production system. The records of 96 clinically healthy steers and heifers were analyzed. The calves at ∼3 to 4 months of age were allocated to pens with four animals per pen; all four animals in the same pen were of the same sex and of similar body size. The ranking of the animals’ priority of access to food (1st, 2nd, 3rd and 4th), which was determined by the farm manager, was used as an indicator of social dominance in the present study. Four models including sire line, maternal grandsire line and the difference in the animals’ birth dates as fixed effects were used to analyze factors influencing the priority of access to food. Ranking was represented by ordinal scores (highest=4, lowest=1) in Model 1, and the binary scores were assigned in Model 2 (highest=1; 2nd, 3rd and 4th=0), Model 3 (1st and 2nd=1; 3rd and 4th=0) and Model 4 (1st, 2nd and 3rd=1; lowest=0). The results showed that the difference in the animals’ birth dates had a significant effect on the establishment of the priority of access to food in Model 3 (P<0.05), suggesting that animals born earlier may become more dominant in the pen. The maternal grandsire line tended to affect the social rank score in Models 2 and 3 (P<0.10). Our results indicated that the maternal grandsire line may affect the temperament of calves through their mothers’ genetic performance and thereby more aggressive calves may be more dominant and have higher priority of access to food. On the other hand, there was a significant effect of the priority of access to food on beef marbling score (BMS; P<0.05), and the priority of access to food also tended to influence the carcass weight (P=0.09). The highest BMS was observed for animals with the first rank of the priority of access to food (P<0.05), and the higher-ranking animals had the tendency to be heavier carcass than the lower-ranking animals. Our findings emphasized the importance of information about the priority of access to food determined by farmers’ own observation on implementing best management practices in small-scaled semi-intensive beef cattle production systems.

Fattening performance, metabolic indicators, and muscle composition of bulls fed fiber-rich versus starch-plus-lipid-rich concentrate diets.

The aim of this study was to compare the responses in fattening performance and meat composition for high-concentrate diets rich in either starch and lipids (especially omega-3 fatty acids) or fibrous by-products. A total of 140 Charolais bulls (initially 319 ± 27 kg BW) were allocated to 3 high-concentrate diets and were fattened for up to 18 mo. The diet treatments included concentrate mixtures rich in either fiber (FR; n = 56) or starch plus linseed (diets SL and SLR; n = 56 and n = 28, respectively) and barley straw. The concentrate mix was offered ad libitum in SL and FR diets but was kept isoenergetic to the FR diet in the SLR diet. Bulls were weighed every 15 d. Feed intake was measured daily. Carcass composition was assessed for all animals slaughtered at 699 ± 65 kg BW. Meat nutritional quality traits (e.g., fat content and fatty acid composition focusing on n-6 and n-3 polyunsaturated fatty acids) were measured on the longissimus thoracis, rectus abdominis, and semitendinosus muscles. Metabolic enzyme activity (phosphofructokinase, lactate dehydrogenase, and cytochrome-c oxidase) was measured on these muscles and on liver. The SL diet bulls had greater fattening performance, BW gain (P = 0.006), and efficiency for growth (P = 0.025) at an energy intake similar to that of FR diet bulls. They also had heavier carcasses with a greater proportion of fat. However, liver samples showed no difference in specific metabolic activity. Compared to bulls fed the SL diet, bulls fed SLR consumed 15% less energy and had lower BW gain (P < 0.001) but were slightly more efficient for growth (P = 0.010). They had lower carcass weight but a greater muscle-to-fat ratio. Compared to bulls fed the FR diet, SLR bulls had lower than planned NEg intake and lower BW gain but did not have differences in body composition. Compared to the FR diet, the SL diet led to a greater omega-3 fatty acid content because of a greater supply of dietary linoleic acid, especially in lean muscle.

Effects of beef production system on animal performance and carcass characteristics.

The objective of this study was to evaluate conventional (CONV) and natural (NAT) beef production systems from annual pasture through finishing through grazing. Beef steers (n=180, initial BW=250±19 kg) were assigned randomly to 2 treatments in the pasture phase. Steers were implanted with 40 mg of trenbolone acetate (TBA), 8 mg estradiol, and 29 mg tylosin tartrate (CONV), or received no implant (NAT). Steers on the 2 treatments grazed wheat or cereal rye for 109 d. Conventional steers had an 18.5% improvement in ADG (1.22 vs. 1.03 kg/d, P<0.01) and a heavier final BW (385 vs. 366 kg, P<0.01) compared with NAT steers. Following the pasture phase, steers (n=160 steers, 5 steers/pen, 8 pens/treatment) were assigned to a 2×2 factorial in the feedlot phase. Production system (NAT vs. CONV) was maintained from the pasture phase, and the second factor was 7 vs. 12% low-quality roughage (DM basis, LOW vs. HIGH). During finishing, CONV steers were given 120 mg of TBA and 24 mg estradiol at processing, fed monensin and tylosin, and fed zilpaterol hydrochloride for the last 20 d of the experiment. There were no program×roughage level interactions (P>0.07). The CONV steers ate 6.9% more feed (11.8 vs. 11.0 kg/d, P<0.01), gained 28.4% faster (1.90 vs. 1.48 kg/d, P<0.01), and were 24.2% more efficient (0.164 vs. 0.132, P<0.01) compared with NAT steers. The LOW steers had greater G:F (0.153 vs. 0.144, P<0.01) compared with HIGH steers. There was a 28.3% improvement in estimated carcass weight gain (1.36 vs. 1.06 kg/d), 18.6% improvement in carcass efficiency (0.115 vs. 0.097, P<0.01), and 21.6% improvement (1.52 vs. 1.25 Mcal/kg, P<0.01) in calculated dietary NEg for CONV compared with NAT steers. Hot carcass weight was increased by 62 kg (424 vs. 362 kg, P<0.01) and LM area was increased by 16.9 cm2 (100.9 vs. 84.0 cm2, P<0.01), decreasing USDA yield grade (YG, 3.09 vs. 3.54, P<0.01) for CONV steers compared with NAT steers. Natural steers had a greater percentage of carcasses in the upper 2/3 of USDA Choice grade (48.7 vs. 18.7%, P<0.01), a greater percentage of YG 4 and 5 carcasses (25.4 vs. 9.3%, P<0.01), and a greater percentage of abscessed livers (39.6 vs. 10.5%, P<0.01) compared with CONV steers. The results show that CONV production results in more rapid and efficient production that resulted in heavier carcasses with superior YG and desirable quality grades with both roughage levels.

The Influence of Season and Sex on the Carcass Yield of Common Warthog (Phacochoerus africanus)

The carcass yield and dress out percentage of the common warthog (Phacochoerus africanus) was investigated as influenced by season and sex. Season did not have a significant impact on carcass weight (P = 0.64) and dress out percentages (P = 0.28) of adult warthogs (n = 46). Males (n = 21) had heavier carcasses (35.24 kg ± 2.59) than females (n = 25) (27 kg ± 0.96) (P = 0.03) and had a higher dress out percentage (57.14% ± 0.91) than females (52.14% ± 0.91) (P < 0.01). Due to the imbalance in sampled populations age was not included as a variable in the final analyses. Warthogs have a favourable carcass yield and can be utilized for commercial game meat production.

Comparison of water buffalo (Bubalus bubalis) with crossbred and purebred Brahman cattle for growth performance on savannah and slaughter traits at four ages in Venezuela

Males (n = 132) of water buffalo (Buffalo), Brahman crossbred and purebred cattle (Brahman) were born, raised, weaned, castrated (half of the animals at 7 months) and fattened on the same grazing savannahs, and then slaughtered at four different ages (7, 17, 19 and 24 months) to compare growth and slaughter traits and examine post-weaning castration effects. Buffalo showed consistently faster weight gains and heavier carcasses but had lower dressing percentages than Brahman cattle due to higher proportions of hide, head, and red and white viscera at each age (P &lt; 0.05). Additionally, Buffalo had abundant fat cover distribution, and whiter subcutaneous fat than Brahman (P &lt; 0.05), this resulted in a higher proportion of Buffalo carcasses that graded in the second quality Venezuelan grade ‘A’ (P &lt; 0.05). Regardless of species, bulls had higher average daily gain and liveweight than steers (P &lt; 0.05); however, no differences were detected in carcass weight and dressing percentages (P &gt; 0.05). Also, at the same weight steers produced carcasses with thicker back fat, more abundant fat cover distribution and whiter fat than bulls (P &lt; 0.05). With respect to age groups, there were concomitant increases in slaughter weight, carcass weight, and dressing percentage as age increased (P &lt; 0.01). As age advanced, carcasses had a more convex leg profile, abundant fat cover, thicker back fat, higher marbling and greater REA (P &lt; 0.05). Based on the observed growth and carcass traits, Buffalo offer a promising alternative for meat production under savannah feeding production systems.

Finishing feedlot lambs in enriched pens using feeder ramps and straw and its influence on behavior and physiological welfare indicators

Abstract Sixty lambs were placed in enriched (EE) or conventional (CO) pens (3 pens per treatment or 10 lambs per pen), in which the EE pens had a wooden platform with ramps giving access to a concentrate hopper, straw as bedding and forage, and a further ramp for play. The CO pen was barren without any enrichment. The general behavior of the lambs and the use of space were similar for both treatments; however, CO lambs developed significantly more stereotypies ( P ≤ 0.05). The EE lambs resolved a T-maze more quickly ( P ≤ 0.05), and their physiological adaptation response to the feedlot environment was more efficient. The CO lambs mobilized more body reserves and had lower levels of immunity (i.e., increased nonesterified fatty acid and neutrophil/lymphocyte ratio, respectively, P ≤ 0.05) than EE lambs at the end of the fattening period, which indicates chronic stress, probably associated with the barren environment. The EE lambs had a higher ( P ≤ 0.05) average daily gain, heavier carcasses and higher fattening scores, as well as lower pH ult . This study shows that enrichment can improve the welfare of feedlot lambs by reducing stereotypies and enhancing the physiological adaptation response to a novel environment.

Association of carcass weight with quality and functional properties of beef from Hanwoo steers

The association of carcass weight with quality and functional properties of Hanwoo (Korean native cattle) beef was investigated. The carcasses of 250 Hanwoo steers were categorised into light (&lt;375 kg; n = 74), medium (375–425 kg; n = 76) and heavy (&gt;425 kg; n = 100) groups and were evaluated for back fat thickness, rib eye area, and beef marbling score 24 h postmortem using the Korean carcass grading system. Rib eye area, back fat thickness, and marbling score significantly increased (P &lt; 0.05) with increasing carcass weight. However, marbling score and intramuscular fat content showed only a little increase (P &lt; 0.05) beyond a limit of 375 kg. Inosine-5′-monophosphate concentration was significantly higher (P &lt; 0.05) in medium and heavy carcasses. Carnosine concentration was significantly higher in medium carcasses. Total saturated fatty acid content and n-6 : n-3 ratio decreased as carcass weight increased (P &lt; 0.05). Medium and heavy carcasses had significantly higher (P &lt; 0.05) scores for sensory quality parameters. Overall, medium carcasses of Hanwoo displayed optimal sensory and health benefits while minimising the economic disadvantages of growing cattle to heavier weights.

Body chemical composition, tissue deposition rates and gain composition of young Nellore cattle selected for postweaning weight

Empty body and carcass chemical composition were determined in 67 Nellore bulls from Selection Nellore (NeS) and Control Nellore (NeC) herds of an animal breeding program for growth, slaughtered at 570 days of average age, after 100 days of feedlot. Selection Nellore animals had, respectively, 360 and 430 kg of initial and slaughter body weight, and NeC animals had 318 and 373 kg for the same traits. Animals were slaughtered and empty body composition was determined by chemical analysis of the components blood, hide, head and feet, viscera and carcass. Tissue deposition rates and gain chemical composition were also determined based on gains estimated by comparative slaughter technique. Significant differences were detected between NeS and NeC animals for slaughter body weight, empty body weight, empty body gain rate, and contents of water, protein, ash and retained energy in empty body, showing that selected animals had greater body sizes and growth rates. There were no significant differences in fat contents in empty body and carcass, suggesting that selected animals had higher growth rates as compared with the control, and were slaughtered with good body and carcass fat contents in the same feedlot time. Control Nellore animals showed a 10% higher gain in fat percentage than NeS in the period. This shows that the growth of bone and muscle ceased earlier and NeC group accumulated more fat. Animals selected for growth have heavier carcasses and greater tissue deposition rates with proportional composition similar to unselected animals.

Effect of enriched housing on welfare, production performance and meat quality in finishing lambs: The use of feeder ramps

This study analyses the effect of environmental enrichment on the welfare, productive traits and meat quality of lambs housed in feedlots. Sixty lambs were placed in enriched (EE) or conventional (CO) pens (3 pens for each treatment, 10lambs/pen) where EE had a wooden platform with ramps that provided access to a concentrate hopper, cereal straw as bedding and forage, and one play ramp. The CO pen was barren, similar to commercial feedlots. The physiological adaptation response of EE lambs was more efficient than CO, since the latter mobilised more body reserves (i.e., increased NEFA, P<0.05), and had lower levels of immunity (i.e., increased N/L, P<0.05), which indicate chronic stress, probably associated with the barren environment. The EE lambs had a higher (P<0.05) average daily gain, with heavier carcasses and higher fattening scores, as well as lower pHult, higher L* and b* values, and lower values of texture (P<0.05).

Factors influencing the occurrence of high ultimate pH in three muscles of lamb carcasses in Australia

Chilled lamb meat exported from Australia has, on occasions, been rejected by importing countries due to greening, after only 6 weeks of storage time. Greening is known to be more prevalent in high ultimate pH (pHu) beef meat (&gt;5.9). There are few data available for lamb carcasses in Australia on the occurrence of high pHu meat, which may have an impact on the understanding and control of quality and greening during storage. The aim of this project was to determine the prevalence of, and influencing factors for, high pHu meat in a range of muscle types in lamb carcasses in Australia. Muscle pHu data were collected from a total of 1614 carcasses from 78 lots at four lamb processing plants in Victoria and New South Wales in autumn and spring of 2013. The pHu of the knuckle (rectus femoris), rack (longissimus) and blade (infraspinatus) was measured and data on carcass and lot characteristics were recorded. Data were subjected to restricted maximum likelihood and generalised linear mixed model analysis. The mean pHu of the knuckle, rack and shoulder were 6.06, 5.79 and 6.12 respectively, and the main factors influencing muscle pHu and occurrence of dark-cutting were breed, season, electrical stimulation and carcass weight. Merino lambs had a higher pHu in the blade and knuckle than did other breeds (P &lt; 0.05, P &lt; 0.01 respectively). Lambs processed in autumn had a higher predicted pHu in the blade and knuckle and a higher percentage dark-cutting (DC; pHu &gt;6.0) for those muscles, than did those processed in spring (P &lt; 0.05). Carcasses that had been electrically stimulated had a higher %DC and a higher pHu in all three muscles (P &lt; 0.05). Carcass weight had a significant effect on the pHu of all three muscles (P &lt; 0.001), with heavier carcasses having a lower pHu and lower %DC. The pHu of the rack was not a reliable predictor for the pHu in other muscles of the lamb carcass. In conclusion, the high occurrence of DC in the muscles, particularly the blade and knuckle, suggests that these muscles may be at risk for producing greening in the vacuum bag during storage.

Effect of breed, grazing system and concentrate supplementation on fattening performance, carcass value and meat quality of steers

Abstract. The aim of the study was to test the influence of breed, grazing system and concentrate level on fattening performance, carcass value and meat quality of steers.Ninety-six German Simmental and German Holstein steers were fattened using two different grazing systems: continuous grazing system (CGS) and rotational grazing system (RGS). They were supplemented with medium (M) or low (L) concentrate levels. The trial period involved 22 months divided into four phases: phase 1 (indoor), 2 (grazing), 3 (indoor vs. outdoor) and 4 (grazing). In phases 1 and 3 the animals were offered grass silage ad libitum. All animals were supplied with concentrate during phase 1. In phases 3 and 4 the animals were supplied with M or L. Group M consumed a total of 275 kg and group L 191 kg concentrate per steer.German Simmental steers were significantly superior in all essential parameters of the fattening performance and the carcass value (e.g. final weight: 631 kg vs. 608 kg). German Holstein steers showed better meat quality (intramuscular fat content, tenderness, meat colour) than German Simmental steers. The impact of the grazing system was only for a few parameters (carcass weight, dressing percentage and fat colour). The CGS showed higher grazing yield and higher content of nutrients than the RGS, as a consequence, CGS steers presented heavier carcass weight than RGS steers. Concentrate levels had no effects on the evaluated parameters.

Effect of pre-slaughter weight and sex on commercial meat cut yields of Iberian pigs

It is very important for the Iberian swine industry to determine the optimum slaughter weight. Therefore, predicting the weights and yields of valuable meat cuts (ham, foreleg and loin) at a given pre-slaughter live weight may be very useful for management decisions. Also, sex differences in prime-cut yields should be elucidated. For this study, 300 extensively reared Iberian pigs (castrated males and females) were slaughtered at live weight (LW) ranging from 125 to 200 kg. At the packing plant, carcass and meat cuts were weighed, and meat cut yields were recorded. Increasing LW class was associated with heavier carcass and meat cuts, but also with lower carcass and prime-cut yields. Males were heavier, but females had higher carcass yield. Nevertheless, males were superior to females in the case of foreleg weight and yield and combined prime-cut yield. Sex differences within each LW class were consistent. Results suggest that in Iberian pig weight gain during finishing in extensive systems is mostly based on fat cover deposition, and also that males, despite castration, have a greater front leg development than females.

RECEITA DOS CORTES SECUNDÁRIOS DA CARCAÇA DE MACHOS NELORE NÃO CASTRADOS ABATIDOS COM DIFERENTES PESOS E DENTIÇÕES

The objective of this work was to assess the income of deboning secondary cuts from non-castrated Nellore carcasses, slaughtered with different weights and dentition. Fourty animals with average initial weight at feedlot of 350 kg were used. The animals were divided into four groups: animals with 0 and two teeth, with carcass weight up to 238,0 kg (young and light carcass); 2-teeth animals with carcass weight ranging from 238,1 to 258,0 kg (young and medium carcass); 2-teeth animals with carcass weight above 258 kg (young and heavy carcass) and animals with four or six teeth, regardless of carcass weight (adults). The animals were confined and fed a diet calculated to achieve a weight gain of 1.2 kg/day. The study showed that carcasses of young animals show similarity in yields of most deboned cuts among weight classes and the four or six-teeth (adults) males were similar to young and medium animals and lower to young with heavy carcasses in some boneless cuts. We concluded that deboning primary cuts into secondary cuts represent considerable aggregation value to industry, emphasizing the efficiency of flank deboning process. KEYWORDS: Bos indicus ; debone; industrial yield; slaughterhouses; slaughter weights.

CARACTERÍSTICAS DE CARCAÇA E RECEITA INDUSTRIAL COM CORTES PRIMÁRIOS DA CARCAÇA DE MACHOS NELORE ABATIDOS COM DIFERENTES PESOS

The objective of this study was to evaluate the commercial cuts income and to study the carcass characteristics of non-castrated Nellore males slaughtered at different weights. Forty Nellore males with initial average weight of 350 kg were used. The animals were divided into four groups: animals with 0 and two teeth, with carcass weight up to238,0 kg (young and light carcass); 2-teeth animals with carcass weight ranging from 238,1 to 258,0 kg (young and medium carcass); 2-teeth animals with carcass weight above 258 kg (young and heavy carcass) and animals with four or six teeth, regardless of carcass weight (adults). After 84 days of feedlot, the animals were slaughtered in a commercial abattoir. There was no difference for carcass fat characteristics and meat marbling, as well as for commercial cuts percentages, hot carcass weight and yield. Income analysis showed that, depending on the wholesale price differences of the primary cuts of the carcass, studies on cattle breeding should seek to increase the conformation and hindquarter percentage, provided they meet the minimum finishing degree required by the abattoirs. KEYWORDS: commercial cuts; fatness level; industrial break-even point; non-castrated males; slaughter weight.

Production, carcass and meat quality traits of Hereford, Charolais and Hereford×Charolais bulls offered grass silage-grain-based rations and slaughtered at high carcass weights

The objective of the experiment was to study performance and meat quality aspects of pure-bred Hereford (Hf) and Charolais (Ch) bulls and Hf×Ch cross-bred bulls offered grass silage-grain-based rations and raised to heavy carcass weights (CWs). The average slaughter age for all breeds was 565 days and the mean CWs for Hf, Hf×Ch and Ch bulls were 414, 476 and 507 kg, respectively. The Ch bulls tended to achieve higher weight gains, produce less fat and had a higher percentage of valuable cuts in comparison with Hf bulls. Breed group had no significant effects on the beef flavour of Musculus longissimus lumborum, but tenderness and juiciness were better in the meat of Hf bulls than that of Ch bulls. The cross-bred Hf×Ch bulls produced heavier and better conformed carcasses compared to pure Hf bulls which indicate that this type of cross-breeding can enhance beef production under the conditions studied.