Meat Breeds Research Articles

Characteristics of the wool produced by ewes raised for meat production

The objective of this study was to evaluate the characteristics of wool produced by ewes of different genetic groups, ages, and reproductive statuses. A total of 115 ewes, of the following genetic groups, were used: 10 Corriedale, 37 Hampshire Down, 26 1/2 Hampshire Down + 1/2 Corriedale, 24 1/2 Ile de France + 1/2 Corriedale, and 18 1/2 Suffolk + 1/2 Corriedale. Age was determined by the number of permanent incisors, ranging from four teeth to eight teeth. Ewes were further classified by their reproductive status into: lambed, having reared one lamb; and not-lambed. Hampshire and half-blood Suffolk ewes were heavier (53.2 and 52.7 kg, respectively), while Corriedale animals were lighter (40.1 kg). Older ewes and not-lambed ewes were heavier as well. Fleece weight was higher for the Corriedale and its crossbred ewes (average of 2.9 kg). Genetic group did not affect yield after scouring (61.6%). Ewe age, reproductive status, and year of evaluation did not affect greasy fleece weight or yield. Fiber diameter and number of crimps were not affected by any tested variables, with mean values of 29.8 μm and 5.8 crimps per centimeter, respectively. Staple length was influenced only by genetic group, in which the Hampshire ewes showed the shortest staple (6.2 cm). In general, the character was classified as good to regular, and the worst was found in the Hampshire. That genetic group grew rough wool, while the others were rated as slightly soft to rough. All genetic groups presented wools with some medullation. The majority of the samples were classified from Cruza 1 to Cruza 3 in all five groups and, for quality, the majority of the samples were rated as Good. Wool produced by meat breeds presents variations of quantity and quality that should be considered by producers and industry.

Proximate Composition, and l-Carnitine and Betaine Contents in Meat from Korean Indigenous Chicken.

This study investigated the proximate composition and l-carnitine and betaine content of meats from 5 lines of Korean indigenous chicken (KIC) for developing highly nutritious meat breeds with health benefits from the bioactive compounds such as l-carnitine and betaine in meat. In addition, the relevance of gender (male and female) and meat type (breast and thigh meat) was examined. A total of 595 F1 progeny (black [B], grey-brown [G], red-brown [R], white [W], and yellow-brown [Y]) from 70 full-sib families were used. The moisture, protein, fat, and ash contents of the meats were significantly affected by line, gender, and meat type (p<0.05). The males in line G and females in line B showed the highest protein and the lowest fat content of the meats. l-carnitine and betaine content showed effects of meat type, line, and gender (p<0.05). The highest l-carnitine content was found in breast and thigh meats from line Y in both genders. The breast meat from line G and the thigh meat from line R had the highest betaine content in males. The female breast and thigh meats showed the highest betaine content in line R. These data could be valuable for establishing selection strategies for developing highly nutritious chicken meat breeds in Korea.

How do introgression events shape the partitioning of diversity among breeds: a case study in sheep.

BackgroundFrom domestication to the current pattern of differentiation, domestic species have been influenced by reticulate evolution with multiple events of migration, introgression, and isolation; this has resulted in a very large number of breeds. In order to manage these breeds and their genetic diversity, one must know the current genetic structure of the populations and the relationships among these. This paper presents the results of a genetic diversity analysis on an almost exhaustive sample of the sheep breeds reared in France. Molecular characterization was performed with a set of 21 microsatellite markers on a collection of 49 breeds that include five breed types: meat, hardy meat, dairy, high prolificacy and patrimonial breeds.ResultsValues of expected heterozygosity ranged from 0.48 to 0.76 depending on the breed, with specialized meat breeds exhibiting the lowest values. Neighbor-Net, multidimensional analysis or clustering approaches revealed a clear differentiation of the meat breeds compared to the other breed types. Moreover, the group that clustered meat breeds included all the breeds that originated from the United Kingdom (UK) and those that originated from crossbreeding between UK breeds and French local breeds. We also highlighted old genetic introgression events that were related to the diffusion of Merino rams to improve wool production. As a result of these introgression events, especially that regarding the UK breeds, the breeds that were clustered in the ‘meat type cluster’ exhibited the lowest contribution to total diversity. That means that similar allelic combinations could be observed in different breeds of this group.ConclusionsThe genetic differentiation pattern of the sheep breeds reared in France results from a combination of factors, i.e. geographical origin, historic gene flow, and breed use. The Merino influence is weaker than that of UK breeds, which is consistent with how sheep use changed radically at the end of 19th century when wool-producing animals (Merino-like) were replaced by meat-producing breeds. These results are highly relevant to monitor and manage the genetic diversity of sheep and can be used to set priorities in conservation programs when needed.Electronic supplementary materialThe online version of this article (doi:10.1186/s12711-015-0131-7) contains supplementary material, which is available to authorized users.

Биоэкология и эпизоотология эймериоза молодняка кур мясо-яичного направления продуктивности

Отечественными и зарубежными учеными отмечается факт неблагополучия птицеводческих хозяйств, практикующих напольное содержание птиц, по паразитарным болезням, особенно по эймериозу. Технология выращивания и подготовка птичника к посадке цыплят не выдерживает принципа «пусто-занято», продолжительность профилактического перерыва, а способы дезинфекции сводятся к механической очистке помещений и однократному применению 2 % раствора каустической соды. Технологически птица размещается в одном отделении, где кур содержат в широкогабаритных птичниках емкостью по 5 тыс. голов. Куры содержатся как на глубокой подстилке, так и на постоянно сменяемой. В неблагополучных приусадебных птицеводческих хозяйствах Кабардино-Балкарии при напольном выращивании цыплят породы кучинская юбилейная средняя экстенсинвазированность эймериями 5 видов (Eimeria tenella, E. maxima, E. necatrix, E. acervulina, E. brunetti) в весенний период составляет 67 %, в летний — 62 %, в осенний — 86 %, что следует учитывать при составлении планов диагностики и организации мер борьбы с эймериозами птиц. Полученные результаты статистически обрабатывали с определением их значимости с применением программы «Биометрия». На зараженность цыплят эймериями (E. tenella, E. maxima, E. necatrix, E. acervulina, E. brunetti) определенное влияние оказывает технология выращивания птиц. Так, если технологический цикл выращивания бройлеров осуществляется за 37 – 42 суток, то цыплят мясо-яичной породы выращивают до 100 – 110 дней. Этот факт обуславливает многократное увеличение вероятности заражения ооцистами эймерий цыплят как 1 – 3-, так и 4 – 8-месячного возраста через помет.

Investigation of food meat value obtained from bull-calves of Polissya meat breed with different types of higher nervous activity

Meat productivity of cattle is formed by wide range of morphological, biological, physiological characteristics, which depend on the species, genotype of animals, environmental conditions, type of higher nervous activity, diet and usefulness is measured by such indicators as the cost of feed per unit increase; body weight, absolute and relative growth rates, carcass yield, meat quality. Therefore, the study of biochemical processes in fattening bull-calves of Polissya meat breed, depending on the type of higher nervous activity and the effect of feeding feed additive Mikrolipovit on the main indicators of metabolism and meat productivity is extremely important.The increase in the above parameters and urea indicates the enhancement of protein metabolism in calves, glucose, carbohydrate metabolism and total lipids resulting in increased meat productivity, improved slaughter performance and meat quality characteristics. Based on the data content and the ratio of essential nutrients, biological value of meat its technological properties must be concluded that the meat of calves of different types of higher nervous activity, characterized by optimum chemical composition and high usefulness protein that is fully consistent needs of consumers.Maximizing productivity of fattening bull-calves, compared to other research groups, found in animals such as inert strong equilibrium type of higher nervous activity (3rd group).

Effects of behavioral reactivity on production and reproduction traits in Dorper sheep breed

Abstract The aim of the current research was to evaluate the effects of behavioral reactivity on production and reproduction performance in Dorper sheep, a meat breed. Temperament of animals was subjectively evaluated using a 5-point scoring system at weighing, during which sheep spent 30 seconds on the scale. The heritability of temperament was low (0.10 ± 0.03). Estimated phenotypic ( r p ) and genetic ( r g ) correlations between temperament and litter size in ewes were negative and negligible ( P > 0.05) at −0.06 ± 0.18 and −0.08 ± 0.09, respectively. Significant genetic correlations were found between lamb temperament and preweaning growth rate ( r g = −0.44 ± 0.07, P ≤ 0.05) and postweaning growth till the age of 120 days ( r g = −0.52 ± 0.08, P ≤ 0.05). Significant genetic correlations were found between lamb temperament and growth rates during their first 3 months of age. As a result, selection for calm temperaments should translate to increased growth rates of lambs. Negative correlations between temperament and production traits, both in ewes and lambs, suggested that selection against animals that are highly reactive to improve welfare and ease of handling would not have detrimental impacts on productivity.

Survival in crossbred lambs: Breed and heterosis effects.

The objective of this study was to estimate genetic and nongenetic effects affecting survival in crossbred lambs during 3 time periods: through 1 d of age ( = 7,933), 2 to 30 d of age ( = 5,370), and 2 to 60 d of age ( = 5,216) in a population being upgraded to the dairy breeds of East Friesian and Lacaune in which lambs were artificially reared on milk replacer. Survival was analyzed for lambs born in 14 yr from 1998 to 2011 using pedigree information from 14,339 animals born in 23 yr from 1989 to 2011. Date of death, sex, age of the dam, birth type, month and year of birth, and breed composition were recorded, and the proportion of retained heterosis was calculated for each animal. Lambs were crossbreds of 2 or more breeds with 14 breeds represented in the population. Due to low mean genetic contribution of the 12 nondairy breeds, they were placed into 2 groups: meat breeds (Hampshire, Suffolk, and Texel) and maternal breeds (Romanov, Finnsheep, Dorset, Targhee, Rambouillet, Polypay, Katahdin, Arcott Rideau, and Commercial). The proportion of individual retained heterosis was positively associated ( < 0.05) with lamb survival from 2 to 30 and from 2 to 60 d of age. The predicted increase in survival of F lambs compared to purebred lambs was +8.8 and +14.6%, respectively. Predicted survival of meat breed lambs and maternal breed lambs was greater ( ≤ 0.01) than Lacaune lambs during all 3 periods. Predicted survival of East Friesian lambs was consistently lower ( ≤ 0.01) than meat breed and maternal breed lambs during all periods. The predicted survival of East Friesian lambs was numerically greater but not significantly different from Lacaune lambs. There was a lower ( < 0.01) survival of females compared to males through 1 d of age (-5.6%), but females had higher ( < 0.01) survival than males in the other 2 periods (2 to 30 d = +3.3% and 2 to 60 d = +6.0%). Through 1 d of age, lambs of triplet and greater birth types had lower ( < 0.01) survival than single lambs (-6.2%), and lambs from 1-yr-old dams had lower ( < 0.01) survival than lambs from 2-yr-old dams (+4.5%). Estimates of heritability of lamb survival were 0.14 (SE = 0.03), 0.03 (SE = 0.04), and 0.06 (SE = 0.03) for the 3 time periods, respectively. An increase in the proportion of individual retained heterosis was the most important genetic factor associated with increased lamb survival in this study.

Design of a DNA panel for genomic studies in Russian cattle breeds

A panel of 96 DNA samples (Russian Cattle Genomic Diversity Panel 1.0 or RCGDP 1.0) characterizing the breadth of genetic diversity in popular Russian cattle breeds was designed. The panel contains from four to eight animals from each of 11 dairy and six dairy-meat and meat breeds. The main criterion for inclusion of individual animals in the panel was that they had, according to the pedigree data, the greatest number of unrelated haploid genomes. The resulting panel of 96 animals was estimated to contain 186.1 unshared haploid genomes and was expected to allow a 95% probability of detecting alleles with a frequency greater than 0.016 in the group. This is comparable to the USDA MARC Beef Cattle Diversity Panel version 2.1. Analysis of three SNPs in the Galloway, Hereford, Grey Ukrainian and Black Pied breeds showed no significant differences in the allele frequencies between the animals in the panel and in the herds. Thus, the designed DNA panel may be useful for SNP selection in the genetic analysis of economically important traits, for identification of purebred and hybrid animals, and, probably, for tentative estimation of allele frequencies in the populations.

Mechanick� kvalita ku�e ovc� plemene Texel a jeho kr�encu

High quality leather of small ruminants is a valuable raw material for various industrial sectors. Sheep breeding system was significantly re-oriented and focused on meat breeds in the Czech Republic during last 15 years. Therefore, the objective of work was to evaluate effect of Texel blood share and body part on selected quality traits of sheep leather as an additional product of its breeding. A total of 10 leathers of purebred Texel lambs (T100) and 10 leathers of Merino x Texel crossbred (T50) were analysed. The basic indicators of leather quality namely leather thickness (LT, mm), yield strength (YS, μm), tensile strength (TS, MPa), and breaking point (BP, μm) were measured and evaluated in relation to selected factors. LT of cross-breds with 50% share of Texel blood was by 0.1616 (P < 0.001) mm thicker than in pure-bred Texel lambs. Body part of leather significantly (P < 0.05-0.01) affected all characteristics evaluated except BP. Hypothesis stated was confirmed and initial results documented necessity of more detailed further research focusing on leather quality of meat breeds of sheep.

Histological characteristics of glandular and muscular stomach of plimutrok roosters in postembryonic ontogenesis

We studied the histological structure of the glandular and muscular stomach in the Cornish and Plymouth roosters meat breeds. The major elements in the research was found that the intensive development of membranes goiter observed up to 155 days of age, followed by a gradual decrease in growth of up to 420 days. Also it was established correlation between the average male body weight and the thickness of the mucous membrane of the crop.

Cholesterol Content and Fatty Acids Composition of Mangalitsa Pork Meat

The aim of this study was to examine variability in cholesterol content and fatty acid composition in musculuslongissimus (MLLT) of various genotypes of pigs. Out of 30 male castrated animals used in the trial, 20 were Mangalitsa pigs (Swallow Belly - SBM and White - WM) while 10 were of the Swedish Landrace breed – SL. The representative of pig meat breeds, SL had significantly less cholesterol in MLLT compared to SBM and WM pigs. The total monounsaturated fatty acids (MUFA) and unsaturated fatty acids (USFA) content was higher in SBM and WM than in SL pigs (p< 0.001).

Carcass measurements, non-carcass components and cut production of local Brazilian Pantaneiro sheep and crossbreeds of Texel and Santa Inês with Pantaneiro

This study aimed to assess and compare the non-carcass components, carcass measurements and meat cut production of Pantaneiro (P) sheep and their Texel (TP) and Santa Inês (SIP) crossbreds. Ninety-six lambs, of which 51 were male and 45 were female, with a mean weaning weight of 15.21±1.25kg and age of 78±13 days were slaughtered at 32kg of body weight. TP lambs had greater leg compactness and weight and percentage of pelt, whereas genotypes (G) P and SIP had higher carcass depth. P and SIP females had weights omental fat percentages that were superior to the other animals, whereas SIP females had higher mesenteric fat. TP males had higher production of white viscera. There was no effect of sex, G or interaction for production and percentage of all meat cuts. Pantaneiro lambs and their crosses with meat breeds could be useful in meat production systems under Savannah environmental conditions.

Anthelmintic resistance in ovine gastrointestinal nematodes in inland southern Queensland.

To establish the prevalence of anthelmintic resistance in ovine gastrointestinal nematodes in southern Queensland. An observational parasitological study using the faecal egg count reduction test. Sheep farms (n = 20) enrolled in this study met the twin criteria of using worm testing for drench decisions and having concerns about anthelmintic efficacy. On each farm, 105 sheep were randomly allocated to one of six treatment groups or an untreated control group. Faecal samples were collected on day 0 and days 10-14 for worm egg counts and larval differentiation. Single- and multi-combination anthelmintics, persistent and non-persistent, oral liquid or capsule, pour-on and injectable formulations were tested. Monepantel was not tested. Farmers also responded to a questionnaire on drenching practices. Haemonchus contortus was the predominant species. Efficacy <95% was recorded on 85% of farms for one or more anthelmintics and on 10% of farms for six anthelmintics. No resistance was identified on three farms. The 4-way combination product was efficacious (n = 4 farms). Napthalophos resistance was detected on one farm only. Resistance to levamisole (42% of farms), moxidectin injection (50% of farms) and the closantel/abamectin combination (67% of farms) was identified. Moxidectin oral was efficacious against Trichostrongylus colubriformis, which was predominant on only one farm. Of the farms tested, 55% ran meat breeds, 60% dosed more than the recommended dose rate and 70% always, mostly or when possible practised a 'drench and move' strategy. This level of anthelmintic resistance in southern Queensland will severely compromise worm control and force increased use of monepantel.

Determination of the novel genetic variants of goat STAT5A gene and their effects on body measurement traits in two Chinese native breeds

Signal transducer and activator of transcription 5A (STAT5A), previously known as mammary gland factor (MGF), belongs to the prolactin/JAK2/STAT5 pathway, and plays an important role in growth and development, milking, and lipid accumulation in mammals. The aim of this study was to identify novel genetic variants of the goat STAT5A gene, as well as to test the possible effects of these variants on body measurement traits in the Xinong Saanen dairy goat (XNSN, milking breed) and the Hainan black goat (HNBG, meat breed) that thrive in Northwest China and Southeast China, respectively, which concurrently need improvement in terms of growth. Three novel single nucleotide polymorphisms (SNPs) (IVS1+254C>T, SNP1; Tyr90Tyr, SNP2; and IVS3+303T>C, SNP3) within the goat STAT5A gene were identified in intron 1, exon 2, and intron 3, respectively, as well as a documented SNP (Pro268Pro, SNP4) was also detected in exon 7. These SNPs were genotyped using the amplification created restriction site-polymerase chain reaction-restriction fragment length polymorphism (aCRS-PCR-RFLP) and polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) methods; their minor allelic frequencies varied from 0.079 (SNP4) to 0.372 (SNP2) in the HNBG breed as well as from 0 (SNP1) to 0.362 (SNP4) in the XNSN breed, respectively. The PIC values of these loci varied from 0 to 0.358. Haplotype analysis uncovered only 8 haplotypes; the major haplotypes were Hap1 (CCCC), Hap2 (CCTC), and Hap4 (CTTC). During linkage disequilibrium analysis, only SNP1 and SNP3 loci showed strong linkage (r2=0.999) in the HNBG breed. Statistical analyses indicated that only the known variant (SNP4, Pro268Pro) was significantly associated with body measurement traits in the two breeds when analyzed separately or in combination (P<0.05 or P<0.01), implying that this SNP significantly affected goat body measurement traits. Therefore, the STAT5A gene is a candidate gene affecting goat body measurement traits and could contribute to goat breeding improvement programs through marker-assisted selection (MAS).

Preliminary Researches Regarding the Conservation of Endangered Local Cattle to be Abandoned and the Achieving of Meat Hybrids Throughout the Hybridization with Romanian Breeds

Abstract Studies were performed on first generation meat hybrids, from the Bălţată cu Negru Românească (BNR) dairy cattle, into four experimental groups of five animals /group, in relation to meat bulls breeds from which the frozen semen material used for cows artificial insemination, respectively: Group E1- Limousine (Li), E2 - Aberdeen Angus (AA), E3 - Blue Blanch Belgian (BBB) and E4 - Charolaise (CH). The hybrids obtained from the experimental groups were observed in terms of dynamic growth and development through biometric measurements and periodic weightings 3 months intervals until 12 months of age. Average Daily Gain (ADG) recorded different variations in report to age and breed: at six months old, between 418.52 ± 60.97 g (Group E3 -BBB) and 486.67 ± 108.66 g (Group E2 - AA), at 12 months old, between 997.22 g (Group E2 - AA) and 1311.11 g (Group E3 -BBB). Slaughter rate at 12 months showed variations in relation to breed and thermal regime, so in hot regime the values ranged between 56.62 % (BNR x AA) and 60.60 % (BNR x BBB) and in cold regime (to 24 hours) between 55.68 % (BNR x AA) and 59.73 % (BNR x BBB). Carcasses development indicators had values in most cases in favor of BNR x AA hybrids than BNR x BBB hybrids, with significant differences (P ≤ 0.01) regarding the width index (201.43 cm to 175.84 cm) and pulp development index (129.27 cm to 110.64 cm). From results analysis it can be concluded that in dangered local cattle, to be abandoned because of productive reform or not relevant point of view of milk production can be used in first generation for hybridization with meat breeds in obtaining meat hybrids with morphological features, slaughter rate and carcass structure from superior quality categories than the maternal breed.

VLIV ZVOLENÝCH FAKTORŮ NA SÍLU SVALOVÝCH VLÁKEN PODLE POHLAVNÍ PŘÍSLUŠNOSTI JATEČNÉHO SKOTU

The aim of this study was to evaluate the muscle fibre diameter of bulls (n = 136), heifers (n = 38) and steers (n = 18). The influence of age at slaughter, weight at slaughter, net daily weight gain, SEUROP meatiness and SEUROP fatness on the muscle fibre diameter was observed. The group of animals included Czech Red Pied and its crossbreeds (F1) with the specialized meat breeds (Charolais and Galloway), further crossbreeds of hybrid bulls. Bulls were slaughtered at an average age of 587 days and average weight of 610 kg. The average age of heifers was 644 days and average weight at slaughter was 550 kg. The highest average age was that of steers (689 days) and they were fattened to the average weight of 610 kg. The sample of musculus longissimus lumborum et thoracis (m.l.th.) was used for the ana­ly­ses. The results showed that the muscle fibres were stronger in diameter in the negatively selected (culled) heifers (p &gt; 0.01) as compared to the category of bulls and steers. Apart from sex we also analysed the effect of age at slaughter of the individual animal categories on the fibre diameter. We discovered that the diameter of the fibre increased with age. The fibre diameter of bulls of up to 530 days of age was 37.86 µm and at the age of more than 601 days it was 39.81 µm. The diameter of the muscle fibres was also affected by the pre-slaughter weight. At lower weights the fibres of all categories of cattle were finer. Of growth factors affecting the fibre diameter we selected the net weight gain which is the general indicator of the life-long growth intensity and carcass yield. The fibre diameter in bulls and steers increased insignificantly (p &gt; 0.05) with increasing net weight gains. We also analysed the effect of the SEUROP classification of cattle carcasses and discovered a stronger correlation between the dia­me­ter of muscle fibres and meatiness compared to the classification of fatness of the carcasses.

Whole grain diet for Feedlot Lambs

For a lamb feedlot system became competitive it is essential that an equilibrate nutrition and functional feeding management happens naturally. Therefore, this experiment has the objective to evaluate the efficiency of whole corn grain diet on lambs performance and carcass quality parameters and ruminal papillae development. During the experiment twenty Dorper/Santa Inêscrossbred lambs were used, divided randomly in two treatments: control diet and whole grain diet. The experimental design was completely randomized design and data analysis done by SISVAR using the Tukey test at 5% of probability. No statistical differences were observed on the characteristics evaluated for performance and carcass as well as the length and width of ruminal papillae. The composition of the diet together with the weight gain potential of the lambs can explain the good average daily weight gain of 0.284kg. The initial body condition average was 2.1 (thin) and improved at the end of the trial period achieving3.15 (normal). Carcass yield reached 46.24%, the results is between the range ideal for specialty meat breeds ranging from 40 to 50%. The carcass conformation, fat cover conformation and the thickness of subcutaneous fat found can be classified as medians. Also there was no difference in the characteristics of ruminal papillae. Thus, it is concluded that the use of whole grain diet did not influence the characteristics evaluated; and the choice of diet should be made with regard to profitability, simplicity of use and availability of forage in feedlot.

Effectiveness of homogeneous and heterogeneous selection of Kazakh meat and wool sheep breed for conformational and constitutional type under conditions of the Zailiiskii Altai piedmont zone

The author presents the results of homogeneous (broad-bodied x broad-bodied constitutional type) and heterogeneous (broad-bodied x slender-bodied) variants of selecting Kazakh meat and wool sheep breed. Broad-bodied animals have greater vitality and better adaptive qualities to conditions of their breeding zone, in connection with which they have a higher level of productivity compared to slender-bodied animals. Selection of sheep for conformational and constitutional type will allow predicting the level of productivity of animals at an early age.

The effect of sex and genotype on growth performance, feed efficiency, and carcass traits of local sheep group Pantaneiro and Texel or Santa Inês crossbred finished on feedlot.

This study aimed to assess and compare the growth performance, feed efficiency, and carcass traits of Pantaneiro sheep and their Texel and Santa Inês crossbreds. Ninety-six lambs, fifty-one males, and forty-five females, with a mean weaning weight of 15.21 ± 1.25kg and 78 ± 13days of age, were slaughtered at a 32-kg body weight. The results showed better production efficiency from males compared with females. Texel-crossed lambs had a better growth performance than the other genotypes. The Texel × Pantaneiro lambs were more efficient with a better feedlot performance, higher ribeye muscle area, and better carcass characteristics with an adequate amount of fat cover. Pantaneiro lambs and their crosses with meat breeds could be useful in meat production systems under Savanna environmental conditions.

Carcass composition of Namaqua Afrikaner, Dorper and SA Mutton Merino ram lambs reared under extensive conditions

This study evaluated the differences in the muscle-fat-bone yield of Namaqua Afrikaner (NA), Dorper (D) and SA Mutton Merino (SAMM) ram lambs. The breeds constituted an indigenous, hardy and late maturing, fat-tailed breed (NA), an early maturing, commercial meat breed (D) and a late maturing commercial dual-purpose breed (SAMM). Lambs were slaughtered at 35 (± 8) days post weaning. Carcasses were cooled for 24 h, separated into retail cuts (leg, loin, rib, and shoulder), weighed and deboned. Meat and fat were separated after deboning and weighed to calculate the muscle-fat-bone yield per cut. Least-square means were computed for the respective breeds, using slaughter age as covariate. Results for percentage meat indicate that, with exception of the rib, retail cuts from the NA breed contained a lower percentage of meat than D and SAMM breeds, particularly in the valuable loin and leg cuts. The shoulder of the NA had a lower percentage meat than that of the D. The percentage fat in retail cuts did not differ between breeds for any of the cuts. In comparison with both D and SAMM, NA contained a higher percentage bone in all cuts. Dorper and SAMM carcasses did not differ in terms of the percentage of bone, fat or muscle for any of the retail cuts. The lower meat yield, particularly in the more expensive loin and leg of the NA, when compared to the commercial meat breed (D) could make the former less preferred for meat production. However, the NA compared more favourably than the dual-purpose SAMM. Differences in carcass composition could be attributed to the fact that the NA is an unimproved and late maturing sheep breed.