In a series of indoor and outdoor experiments with young sheep, feed supplements having different protein content were investigated. The supplements were chosen as those likely to elicit different Protein:Energy (P/E) ratios in the nutrients absorbed by the animal. The objective was to identify and characterize those that would support faster growth rate, bigger and leaner carcass production for the meat market, in different seasons in Southern Victoria, Australia (35-37° South, 141-143° East). Throughout, the GrazFeed model provided a reference system chosen for prediction of performance, with which the results of grazing experiments could be compete. / Supplementary feeding experiments were undertaken in the field (Experiments 1 and 4) in seasonal periods in which the pasture base found to poorly support high growth rates of weaned lambs. These experiments were supported by nutritional studies in pens (Experiments 2, 3 and 5) and supplement effects were evaluated in terms not only of liveweight but carcase and meat characteristics. Supplements used were evaluated and selected for use in further experiments on the basis that they would provide additional metabolisable energy but also would differ in the amount and nature of the crude protein they supplied and thus deliver different balances of absorbed nutrients, in particularly different P:E ratios. / Fish meal, with a high content of rumen undegradable protein of high biological value was used in each of these experiments to provide a test of the hypothesis that slow ruminal degradation and additional protein digested in the small intestine can influence animal response. In Experiment 1 and the related pen Experiment 2, comparing a lower to a higher P (CP%):E(MJ/kg) ratio feeds (barley, 12:13 P:E ratio) to (fishmeal / lucerne meal, 1/2 w/w, 35:10 P:E ratio), barley resulted in higher fat and lower protein amounts deposited as carcass components (P<0.01). The animals consuming extra protein were larger, leaner and became more uniform as a flock in terms of the range in LW and fat content at slaughter than those provided with supplements that are classed as energy feeds. / In Experiment 3 a range of alternative protein rich feeds and composite supplements was assembled that are cheaper and more readily available than fishmeal, with the idea that different patterns of ruminal degradation, intra-ruminal N availability and amounts of RUP could be created that would be beneficial in terms of the overall animal response. The paths of rumen protein degradability was determined with nylon bag techniques, and this was used to select feeds for investigation in a field and indoor experiments, Experiments 4 and 5. / In Experiment 4, grazing animals supplemented with lupines; (P:E 32:12), fishmeal / wheat bran 1/2 w/w (P:E 35:12) and formaldehyde treatment protected sunflower meal / wheat bran 1/2 w/w (P:E 24:11) responded poorly to the supplements where quality and quantity of pasture was such that unsupplemented growth rates were predicted to be poor by the decision support model, GrazFeed. In this and the supporting pen Experiment 5, the liveweight gain, final weight and dressing percentage of all supplemented lambs were significantly better than those of control (grazing only) animals (P<0.05). High and low commencing LW animals responded to protein supplements differently when these were fed at 1% BW with ad libitum medium quality roughage diet in indoor conditions. The heavier subgroup of fish meal / wheat bran (P:E 35:12) animals were significantly fatter than the heavy subgroup of wheat bran (P:E 17:10) animals (P<0.001). Lighter subgroup of animals were leaner and became more uniform (less variable) in weight and composition as a flock. Both the heavy and the light liveweight subgroups of fish meal grew faster but were fatter at slaughter than any other sub-groups. Lightest lambs fed bran grew from 26 to 36 kg in 10 weeks and had the most suitable carcase with the lowest priced supplement tested in the experiment. / Though protein supplementation had a positive effect on lamb performance; the advantage of high RUP was not consistent or always statistically significant. Compared to the alternative protein rich feeds, fish meal showed no cost effective advantage. The consequence of this current or possible future market conditions for feeding strategies for high quality lamb production are considered.

Thesis (MSc Food Sc)--Stellenbosch University, 2002. / ENGLISH ABSTRACT: Please refer to fulltext for abstract. / AFRIKAANSE OPSOMMING: Sien asb volteks vir opsomming

The aim of this thesis was to evaluate the influence of the addition of linseed oil to pregnant and lactating ewes to rearing of lambs. For more conclusive results ewes were divided into groups that received linseed oil (for testing) and the group without the constituents of linseed oil in the diet (control). Effect of linseed oil was demonstrated in ewes blood analysis. Analysis of blood parameters were monitored three - cholesterol, triglycerides and lipase. Physiological levels of cholesterol in sheep is 1,7 mmol.l-1. Before the test was observed in ewes cholesterol levels from 1,6 to 2,2 mmol.l-1 and after the test in the range from 1,3 to 1-9 mmol.l-1. Cholesterol after the test decreased in both the test and the control group. Natural levels of triglycerides in ewes is 0.8 mmol.l-1. In our case, the TAG content was below this threshold. Before the test from 0,18 to 0,22 mmol.l-1 after the test from 0.08 to 0.19 mmol.l-1. In test and control groups after the test content triglycerides decreased. After the test, reducing the content of the lipase in the test group and an increase of the content of the control group. Lambs of control and test group ewes were compared on the following criteria: average daily gain (higher increases should control group lambs), weight in control days, the chemical composition of meat - nitrogen, protein and fats. The normal composition of lamb meat: 21 % crude protein, 4,75 % fat and 1,1 % ash. In our case, the content of the NL test group 22,3 % and 21,8 % of the control group, the fat content of the test group and the control 6,5 % and 5,4 %, ash content in the test group and the control 1,23 % and 1,25 %. Further monitoring criteria: weight in carcass weight (between groups) and analysis of blood (cholesterol, triglycerides and lipase) - no difference between test and control lambs.

Made available in DSpace on 2014-06-11T19:33:31Z (GMT). No. of bitstreams: 0 Previous issue date: 2013-02-01Bitstream added on 2014-06-13T19:04:33Z : No. of bitstreams: 1 almeida_fa_dr_jabo.pdf: 679987 bytes, checksum: 9a78d8170ed736b585bc4728c0152d0c (MD5) / Este trabalho teve como objetivo avaliar aspectos qualitativos da carne de cordeiros in natura, relacionados ao pH, cor, maciez, capacidade de retenção de água, perdas de peso por cocção, composição centesimal, colesterol, perfil de ácidos graxos e concentração de vitamina E (α-tocoferol), assim como a qualidade sensorial de hambúrguer e linguiça provenientes dos cortes menos nobres da carcaça de cordeiros Ile de France. O experimento foi desenvolvido na Faculdade de Ciências Agrárias e Veterinárias (FCAV) da Universidade Estadual Paulista (Unesp), Câmpus de Jaboticabal, SP. Foram avaliados 32 cordeiros Ile de France, machos não castrados, dos 15 aos 32 kg ± 200g de peso corporal, que foram divididos nos seguintes tratamentos: C – cana-de-açúcar (var. IAC 86-2480) + concentrado; CG – cana-de-açúcar + concentrado com grãos de girassol; CE – cana-de-açúcar + concentrado com 1000 mg vitamina E/kg de matéria seca (MS) da dieta; CGE – cana-de-açúcar + concentrado com grãos de girassol e 1000 mg vitamina E/kg de MS da dieta. O delineamento experimental foi o inteiramente casualizado em esquema fatorial 2 x 2 (com ou sem grãos de girassol e com ou sem 1000 mg de vitamina E/Kg de MS da dieta). Para a análise sensorial da carne ovina o delineamento experimental utilizado foi o inteiramente casualizado, com 2 tratamentos (sem grãos de girassol e sem vitamina E e com grãos de girassol e vitamina E). A carne dos animais que foram alimentados com grãos de girassol teve menor a* (intensidade de vermelho) e oxidação lipídica e a carne dos que receberam grãos de girassol e vitamina E teve maior concentração de vitamina E. A dieta não influenciou na composição centesimal e na análise sensorial da carne. A inclusão dos grãos de girassol melhorou o perfil de ácidos graxos aumentando a quantidade do ácido vacênico, do linoleico... / The aim of this study was to evaluate the pH, color, tenderness, water retention capacity, cooking loss, chemical composition, cholesterol, fatty acid profile and the concentration of vitamin E (α-tocopherol), as well as the sensory analysis of hamburger and sausage from the less noble cuts of carcasses of Ile de France lambs. The experiment was conducted at the College of Agriculture and Veterinary Sciences (FCAV), Universidade Estadual Paulista (Unesp), Jaboticabal, SP. Thirty two Ile de France lambs were evaluated, non-castrated males, with an average of body weight from15 to 32 kg ± 200 g. The animals were divided into the following treatments: S – sugarcane (var. IAC 86-2480) + concentrate; SS - sugarcane + concentrate with sunflower seeds; SE - sugarcane + concentrate with 1000 mg vitamin E/kg of dry matter (DM) of the diet; SSE - sugarcane + concentrate with sunflower seeds and 1000 mg vitamin E/kg of DM of the diet. A completely randomized design was used, in a factorial scheme 2x2 (with or without sunflower seeds and with or without 1000mg vitamin E/kg of DM of the diet). A completely randomized design was used for the sensory analysis of the meat composed by 2 treatments (without sunflower seeds and vitamin E and with sunflower seeds and vitamin E). Meat from animals that were fed sunflower seeds had lower a* (redness) and lipid oxidation and the meat form animals that received sunflower seeds and vitamin E had a higher concentration of vitamin E. The diet did not affect the chemical composition and sensory evaluation of meat. The inclusion of sunflower seeds improved fatty acid profile by increasing the amount of vaccenic acid, linoleic and the conjugated linoleic acid (CLA). The hamburgers from meat of animals fed sunflower seeds and vitamin E had lower shear force and lipid oxidation... (Complete abstract click electronic access below)

Orientador: Américo Garcia da Silva Sobrinho / Banca: Alda Lúcia Gomes Monteiro / Banca: Iraídes Ferreira Furucho Garcia / Banca: Gustavo Rezende Siqueira / Banca: Eliana Gertrudes Macedo Lemos / Resumo: Este trabalho teve como objetivo avaliar aspectos qualitativos da carne de cordeiros in natura, relacionados ao pH, cor, maciez, capacidade de retenção de água, perdas de peso por cocção, composição centesimal, colesterol, perfil de ácidos graxos e concentração de vitamina E (α-tocoferol), assim como a qualidade sensorial de hambúrguer e linguiça provenientes dos cortes menos nobres da carcaça de cordeiros Ile de France. O experimento foi desenvolvido na Faculdade de Ciências Agrárias e Veterinárias (FCAV) da Universidade Estadual Paulista (Unesp), Câmpus de Jaboticabal, SP. Foram avaliados 32 cordeiros Ile de France, machos não castrados, dos 15 aos 32 kg ± 200g de peso corporal, que foram divididos nos seguintes tratamentos: C - cana-de-açúcar (var. IAC 86-2480) + concentrado; CG - cana-de-açúcar + concentrado com grãos de girassol; CE - cana-de-açúcar + concentrado com 1000 mg vitamina E/kg de matéria seca (MS) da dieta; CGE - cana-de-açúcar + concentrado com grãos de girassol e 1000 mg vitamina E/kg de MS da dieta. O delineamento experimental foi o inteiramente casualizado em esquema fatorial 2 x 2 (com ou sem grãos de girassol e com ou sem 1000 mg de vitamina E/Kg de MS da dieta). Para a análise sensorial da carne ovina o delineamento experimental utilizado foi o inteiramente casualizado, com 2 tratamentos (sem grãos de girassol e sem vitamina E e com grãos de girassol e vitamina E). A carne dos animais que foram alimentados com grãos de girassol teve menor a* (intensidade de vermelho) e oxidação lipídica e a carne dos que receberam grãos de girassol e vitamina E teve maior concentração de vitamina E. A dieta não influenciou na composição centesimal e na análise sensorial da carne. A inclusão dos grãos de girassol melhorou o perfil de ácidos graxos aumentando a quantidade do ácido vacênico, do linoleico... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: The aim of this study was to evaluate the pH, color, tenderness, water retention capacity, cooking loss, chemical composition, cholesterol, fatty acid profile and the concentration of vitamin E (α-tocopherol), as well as the sensory analysis of hamburger and sausage from the less noble cuts of carcasses of Ile de France lambs. The experiment was conducted at the College of Agriculture and Veterinary Sciences (FCAV), Universidade Estadual Paulista (Unesp), Jaboticabal, SP. Thirty two Ile de France lambs were evaluated, non-castrated males, with an average of body weight from15 to 32 kg ± 200 g. The animals were divided into the following treatments: S - sugarcane (var. IAC 86-2480) + concentrate; SS - sugarcane + concentrate with sunflower seeds; SE - sugarcane + concentrate with 1000 mg vitamin E/kg of dry matter (DM) of the diet; SSE - sugarcane + concentrate with sunflower seeds and 1000 mg vitamin E/kg of DM of the diet. A completely randomized design was used, in a factorial scheme 2x2 (with or without sunflower seeds and with or without 1000mg vitamin E/kg of DM of the diet). A completely randomized design was used for the sensory analysis of the meat composed by 2 treatments (without sunflower seeds and vitamin E and with sunflower seeds and vitamin E). Meat from animals that were fed sunflower seeds had lower a* (redness) and lipid oxidation and the meat form animals that received sunflower seeds and vitamin E had a higher concentration of vitamin E. The diet did not affect the chemical composition and sensory evaluation of meat. The inclusion of sunflower seeds improved fatty acid profile by increasing the amount of vaccenic acid, linoleic and the conjugated linoleic acid (CLA). The hamburgers from meat of animals fed sunflower seeds and vitamin E had lower shear force and lipid oxidation... (Complete abstract click electronic access below) / Doutor

Conselho Nacional de Desenvolvimento CientÃfico e TecnolÃgico / A carne ovina à um produto altamente rico em proteÃnas, com baixo teor de gordura e muito valorizado no mercado internacional. PorÃm, vÃrios fatores responsÃveis pela caracterizaÃÃo da qualidade da carne contribuem para a baixa popularidade desse produto no paÃs, tais como operaÃÃes de prà e pÃs-abate mal realizadas, abate de animais velhos, manejo inadequado, tÃcnicas precÃrias de manuseio pÃs-abate, entre outros. Dessa forma, a pesquisa teve por objetivo avaliar a qualidade funcional e sensorial da carne ovina produzida e comercializada no Estado do Cearà a fim de detectar e melhorar as condiÃÃes que afetam a qualidade das carnes. No experimento, utilizou-se 6 animais provenientes de cinco procedÃncias do Estado do Cearà (P1- TauÃ, P2- Sobral, P3- QuixadÃ, P4- Caridade e P5- criatÃrio experimental da UFC), totalizando 30 cordeiros que variaram de seis meses a 1 ano de idade. ApÃs o abate, as carcaÃas permaneceram durante 24 horas em cÃmara fria a 0ÂC. Em seguida, foram divididas longitudinalmente em duas meia-carcaÃas. De cada animal, utilizaram-se os cortes paleta e perna da meia-carcaÃa direita e os dois lombos. As peÃas foram dessossadas e retiradas porÃÃes dos mÃsculos para cada anÃlise. As peÃas musculares foram embaladas em filmes de nylon-polietileno, seladas a vÃcuo e mantidas em congelamento atà a realizaÃÃo das anÃlises de pH, capacidade de retenÃÃo de Ãgua (CRA), perdas de peso por cocÃÃo (PPC), forÃa de cisalhamento (FC), cor medido pelos parÃmetros L*, a*, b*, H* e C*, composiÃÃo centesimal e anÃlise sensorial dos atributos de cor, sabor, maciez, suculÃncia e aceitaÃÃo global. Os valores de pH obtidos nas diferentes procedÃncias apresentaram diferenÃa significativa, sendo que a carne da procedÃncia P3 apresentou maior pH. Com relaÃÃo as propriedades CRA e PPC, houve significÃncia estatÃstica devida tanto aos cortes como Ãs procedÃncias estudadas, sendo que a procedÃncia P5 se destacou com maiores valores para as duas variÃveis. A FC nÃo apresentou significÃncia estatÃstica para as diferentes procedÃncias. No entanto, para as variÃveis da anÃlise de cor, a procedÃncia P5 apresentou valores de L*, a*, b*, H* e C* significativamente maiores que as demais procedÃncias. Com relaÃÃo à composiÃÃo centesimal, apenas o conteÃdo de cinzas na carne nÃo apresentou diferenÃas significativas entre as procedÃncias. Quanto à aceitaÃÃo sensorial, as procedÃncias P5 e P4 se destacaram em todos os atributos analisados (cor, sabor, maciez, suculÃncia e aceitaÃÃo global), ou seja, a criaÃÃo de ovinos em confinamento pode influenciar a aceitaÃÃo do produto pelos consumidores, uma vez que esse tipo de sistema gera animais em melhores condiÃÃes no momento do abate, o que determina a qualidade final da carne. Quanto à atitude de consumo, a procedÃncia P5 apresentou maior aceitaÃÃo e menor rejeiÃÃo, indicando essa como a mais aceita entre os provadores. / Lamb meat is rich in protein, low in fat content and highly valued in the international market. However, several factors responsible for the characterization of the meat quality contribute to a low popularity of this product in the local market. Among them the slaughter operations performed poorly, inadequate management of the animals and poor techniques of post-slaughter handling. Thus, the study aimed to evaluate the functional and sensory quality of lamb produced and marketed in the State of Cearà to detect conditions that affect the quality of the meat. In this experiment, six animals from five different locations of the State of Cearà (P1 - Taua, P2 - Sobral, P3 - QuixadÃ, P4 - Caridade and P5 - UFC) were used, totaling 30 lambs ranging from six months to one year of age. After slaughter, carcasses remained for 24 hours in cold storage at 0ÂC. They were then divided longitudinally into two half-carcasses. From each animal, were used the shoulder and the leg cuts from the right half carcass and the loins from the two half carcasses. The pieces were removed, bonned and the muscles separated for analysis. The muscle pieces were packed in nylon-polyethylene film, vacuum sealed and kept frozen until the realization of the following meat analysis: pH, water holding capacity (WHC), cooking loss (CL), shear force (SF), color, chemical composition and sensory analysis of color, flavor, tenderness, juiciness and overall acceptance. The meat pH values obtained from different locations showed significant differences, with P3 showing higher values than the other meats. Regarding the CRA and PPC analysis, statistical significance was observed for both the type of cut and the location of the animals where P5 showed the highest values for both variables. SF values were not different for the different locations of the animals. However, for the variables of color analysis, the results for P5 showed values for L*, a*, b*, H* and C* significantly higher than those for the other locations. With respect to meat composition, only the ashes were not significantly different among the locations. As for the meat sensory the animals from P5 and P4 performed better than those from the other locations in all the attributes evaluated (color, flavor, tenderness, juiciness and overall acceptance). Raising sheep in confinement may influence product acceptance by consumers, since this type of system produces animals with appropriate condition at slaughter, which influences the final quality of the meat. The attitude of the consumers related to the meat from P5 showed greater acceptance and less rejection of the meat.

This study aimed to evaluate the quantitative carcass traits and physicochemical meat of Santa Inês lambs slaughtered at 2.0; 3.0 and 4.0 mm of backfat thickness, assessed by ultrasound in Longissimus dorsi.Twenty-four lambs, male, unneutered, with approximately 100 days of age and live weight of 22.7 ± 3.75 kg were used. The experimental design was completely randomized design with three treatments and eight replications.Lambs were confined, fed pelleted complete ration designed to gain 0.300 kg / day. Assessments by ultrasound in Longissimus dorsi between the 12th and 13th ribs and weighed every 14 days were performed.Lambs as they reaching the predetermined thickness of fat were slaughtered. The right half carcasses were five commercial cuts: neck, shoulder, ribs, loin and leg. The cuts were dissected into subcutaneous and intermuscular fat, muscle, bones and waste.Significant differences (P <0.05) on the weight of the shoulder and leg, with the highest average obtained by lambs slaughtered at 4.0 mm of fat thickness were observed.There was no effect of fat thickness for dressing of cuts. The percentages of retail cuts of muscles did not differ (P> 0.05) between treatments. Lambs slaughtered at 3.0 and 4.0 mm differed (P <0.05) for the percentage of total fat in the palette.Lambs slaughtered at 2.0 mm showed a higher percentage of bone in loin. The leg muscularity lambs slaughtered at 2.0 mm was lower (0.34) compared to that of lambs slaughtered at 3.0 and 4.0 mm of fat thickness. No difference (P> 0.05) was observed in muscle: bone and muscle: fat between treatments. Samples of Longissimus dorsi muscle were used for physical and chemical characteristics. The initial pH (pH0h) did not differ (P> 0.05) between treatments, with average value of 6.24. For the pH measured at 24 hours after slaughter (pH24h), differences (P <0.05) were observed for the treatment with 4.0 mm thickness of subcutaneous fat. Meat of lambs slaughtered at 3.0 and 4.0 mm thick fat had higher lightness (L *). The softness (2.21 kgf / cm 2) and weight loss by cooking (13.90%) of meat were not affected by the thickness of subcutaneous fat. No significant differences (P> 0.05) for moisture content (74.39%) and crude protein (22.10%) were observed.For contents of total lipids of the flesh significant differences (P <0.05) were observed between lambs slaughtered at 2.0 mm and lambs with 3.0 and 4.0 mm thickness of subcutaneous fat. The regional composition of the carcass and tissue cuts, as well as the rate of muscle were influenced by the thickness of subcutaneous fat.Physical and chemical characteristics of meat from Santa Ines lambs were changed, however, remained in the range considered acceptable for sheep meat. Is recommended to the slaughter of lambs with 3.0 mm thick subcutaneous fat remained for 33 days unless and similar weight to lambs slaughtered at 4.0 mm thick subcutaneous fat. / Objetivou-se avaliar as características quantitativas da carcaça e físico-químicas da carne de cordeiros Santa Inês abatidos com 2,0; 3,0 e 4,0 mm de espessura de gordura subcutânea, avaliadas por ultrassonografia no Longissimus dorsi. Foram utilizados 24 cordeiros, machos, não castrados, com aproximadamente 100 dias de idade e peso vivo de 22,7± 3,75 kg. O delineamento experimental adotado foi o inteiramente casualizado, com três tratamentos e oito repetições. Os cordeiros permaneceram confinados, recebendo ração completa peletizada, elaborada para ganho de 0,300 kg/dia. Foram realizadas avaliações por ultrassonografia no Longissimus dorsi entre a 12ª e 13ª costelas e pesagens a cada 14 dias. Os cordeiros foram abatidos à medida que atingiam a espessura de gordura pré-determinada. A meia carcaça direita foi seccionada em cinco cortes comerciais: pescoço, paleta, costilhar, lombo e perna. Os cortes foram dissecados em gordura subcutânea e intermuscular, músculos, ossos e resíduos. Foram observadas diferenças significativas (P<0,05) sobre o peso da paleta e perna, sendo as maiores médias obtidas pelo cordeiros abatidos com 4,0 mm de espessura de gordura subcutânea. Não houve efeito da espessura de gordura para os rendimentos dos cortes. As porcentagens de músculos dos cortes comerciais não diferiram (P>0,05) entre os tratamentos. Cordeiros abatidos com 3,0 e 4,0 mm diferiram (P<0,05) para a porcentagem de gordura total da paleta. Os cordeiros abatidos com 2,0 mm apresentaram maior percentual de ossos no lombo. A musculosidade da perna nos cordeiros abatidos com 2,0 mm foi menor (0,34), quando comparada à dos cordeiros abatidos com 3,0 e 4,0 mm de espessura de gordura. Não foi observada diferença (P>0,05) na relação músculo:osso e músculo:gordura entre os tratamentos. Para as características físico-químicas foram utilizadas amostras do músculo Longissimus dorsi. O pH inicial (pH0h) não diferiu (P>0,05) entre os tratamentos, apresentando valor médio de 6,24. Para o pH medido às 24 horas após ao abate (pH24h), foram observadas diferenças (P<0,05) para o tratamento com 4,0 mm de espessura de gordura subcutânea. As carnes dos cordeiros abatidos com 3,0 e 4,0 mm de espessura de gordura apresentaram maior índice de luminosidade (L*). A maciez (2,21 kgf/cm2) e perda de peso por cocção (13,90%) da carne não foram afetadas pelas espessuras de gordura subcutânea. Não foram verificadas diferenças significativas (P>0,05) para os teores de umidade (74,39%) e proteína bruta (22,10%). Para os teores de lipídeos totais da carne foram observadas diferenças significativas (P<0,05) entre os cordeiros abatidos com 2,0 mm e os cordeiros com 3,0 e 4,0 mm de espessura de gordura subcutânea. A composição regional da carcaça e tecidual dos cortes, assim como o índice de músculo foram influenciadas pela espessura de gordura subcutânea. Características físicas e químicas da carne de cordeiros Santa Inês foram alteradas, no entanto, permaneceram na faixa considerada aceitável para carne ovina. Recomenda-se o abate de cordeiros com 3,0 mm de espessura de gordura subcutânea por permanecerem 33 dias a menos e peso semelhantes aos cordeiros abatidos com 4,0 mm de espessura gordura subcutânea.

M.S.

Thesis (MScAgric)--Stellenbosch University, 2008. / ENGLISH ABSTRACT: The aim of this study was to investigate the effect of South African production system (feedlot {FL-} or free-range {FR-}) and gender (ewes, rams or castrates) on growth and carcass characteristics of Dorper sheep. Male lambs (castrates and rams) grew twice as fast as ewes (P<0.05) under FL-conditions while much smaller differences were observed between gender groups in FR-lambs. FL-lambs produced heavier carcasses (P=0.0003) with higher dressing percentages (P<0.05) and greater carcass fatness levels (P<0.052) than FR- lambs. No differences attributable to production system were found on meat tenderness (as indicated by Warner Bratzler shear force strength) and on the intramuscular lipid concentration. In contrast, sensory evaluation results suggested that meat from FL-lambs was juicier and more tender than meat from FR-lambs. The sensory panel could not distinguish between FL and FR meat as far as the attributes of aroma and flavour were concerned. Cholesterol results indicated that for intermuscular fat, higher cholesterol levels were observed for FL-lambs than for FR-lambs. The level of palmitic acid (C16:0) was significantly higher (P=0.0375) in the Longissimus dorsi (LD) muscles of FL-lambs. For intramuscular fat from the Biceps femoris (BF) muscle, g-linolenic acid (C18:3n-6) was higher (P<0.0001) in FL- lambs. Results for intramuscular BF further indicated that ram lambs had the highest (P=0.0019) palmitic acid (C16:0) and sum of TUFA (P=0.0014), castrates had the highest (P=0.0260) α-linolenic acid (C18:3n-3) and g-linolenic acid (C18:3n-6), while ewe lambs had the highest (P=0.0014) SFA concentrations. Linoleic acid (C18:2n-6c) was significantly higher (P=0.0067) in the subcutaneous fat of FL-lambs while FR-lambs had more linolenic acid (C18:3n-3). For the kidney fat, FR-feeding increased (P < 0.05) stearic (C18:0), linolelaidic (C18:2n-6t), α-linolenic (C18:3n-3) and homo-g-linolenic acid (C20:3n-6) percentages. Conversely, linoleic acid (C18:2n-6c) was increased (P=0.0372) by FL-feeding. For the intermuscular fat, FR-lambs had higher linolenic acid (C18:3n-3) and SFA (P=0.0113 and P=0.0341) compared to FL-lambs. On the other hand, the sum of TUFA for the intermuscular fat was higher (P=0.0341) in FL-lambs compared to FR-lambs. Results from the study imply that the consumer may not necessarily be able to discern between meat from FR- or FL-lambs, although they may possibly discriminate against the increase in visible fatness of FL-lambs. No clear advantage of production system in terms of human health could be demonstrated as far as the proximate chemical composition and the fatty acid composition of the meat was concerned. The faster growth and the associated shorter production cycle of FL-lambs could be an advantage under certain production systems. However, it needs to be weighed against the cost of concentrate feeding and the preference consumers are likely to develop for lamb produced in natural environments. / AFRIKAANSE OPSOMMING: Die doel van die studie was om Suid Afrikaanse produksiestelsel (voerkraal {VK-} of veld {VD}) en geslag (ooie, hamels of ramme) op die groeivermoë en karkaseienskappe van die Dorperskape te bepaal. Manlike lammers (ramme and hamels) het twee keer vinniger (P<0.05) as ooilammers onder VK-toestande gegroei, terwyl kleiner verskille tussen geslagsgroepe by VD-diere waargeneem is. VK-lammers het swaarder karkasse (P=0.0003), hoër uitslagpersentasies (P<0.05) en meer karkas vet (P<0.052) as VD -lammers vertoon. Geen verskille as gevolg van produksiestelsel is op die sagtheid van vleis (soos aangedui deur Warner-Bratzler skeurkragwaardes) en die binnespierse vetinhoud gevind nie. Daarenteen het sensoriese analises aangedui dat vleis van VK-lammers sappiger en sagter as vleis van VD- lammers was. Die sensoriese paneel kon nie verskille aangaande die aroma en geur van vleis tussen VK- en VD-vleis onderskei nie. Cholesterolvlakke was hoër vir VK-lammers as by VD-lammers. Die vlak van palmitiese suur (C16:0) was hoër (P=0.0375) in die Longissimus dorsi (LD) spier van VK-lammers. Vir binnespierse vet van die Biceps femoris (BF) spier was g-linoleniese suur (C18:3n-6) hoër (P<0.0001) in VK-lammers. Resultate vir binnespierse vet van die BF spier het verder bewys dat ramlammers die hoogste (P=0.0019) palmitiese suur (C16:0) and totale onversadigde vetsure (P = 0.0014) getoon het, hamels die hoogste (P=0.0260) α-linoleniese suur (C18:3n-3) en g-linolenese suur (C18:3n-6) getoon het terwyl ooilammers die hoogste (P=0.0014) versadigde vetsuurvlakke getoon het. Linoliese suur (C18:2n-6c) was hoër (P=0.0067) in die onderhuidse vet van VK-lammers terwyl VD-lammers meer linoliese suur (C18:3n-3) gehad het. Resultate vir niervet het getoon dat VD-voeding die persentasies van steariese (C18:0), linoleladiese (C18:2n-6t), α-linoleniese (C18:3n-3) and homo-g-linoleniese suur (C20:3n-6) verhoog (P<0.05) het relatief tot VK-voeding. Linoliese suur (C18:2n-6c) is deur VK-voeding verhoog (P=0.0372). Vir intermuskulêre vet het VD-lammers hoër linoleniese suur (C18:3n-3) en versadigde vetsure (P=0.0113 en P=0.0341) as VK-lammers gehad. Die totale onversadigde vetsure vir tussenspiere vet was hoër (P=0.0341) in VK-lammers in vergelyking met VD-lammers. Resultate van hierdie studie dui daarop dat verbruikers nie noodwendig tussen vleis van VD- en VK-lammers sal onderskei nie, alhoewel hulle dalk teen die sigbaar vetter vleis van VK-lammers kan diskrimineer. Geen definitiewe voordeel in terme van menslike gesondheid kon op grond van die chemiese samestelling van die vleis bevestig word nie. Vinniger groei van VK-lammers, en die korter produksiesiklus wat daarmee verband hou, mag onder sekere produksie stelsels ʼn voordeel wees. Die voordeel moet teen die hoër koste van VK-voeding en die voorkeur van verbruikers vir lam produksie in natuurlike omgewing opgeweeg word.

Made available in DSpace on 2014-06-11T19:33:33Z (GMT). No. of bitstreams: 0 Previous issue date: 2008-12-03Bitstream added on 2014-06-13T18:45:24Z : No. of bitstreams: 1 leao_ag_dr_jabo.pdf: 521620 bytes, checksum: b7a5bff297fc0e40402517dee2f40fe5 (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / Com o objetivo de avaliar as características nutricionais, estruturais, físico-químicas e sensoriais da carne de cordeiros terminados em confinamento com dietas contendo cana-de-açúcar ou silagem de milho em duas relações volumoso: concentrado, 60:40 ou 40:60, utilizou-se 32 cordeiros Ile de France, não castrados, com 15 kg de peso corporal. Os animais foram confinados em baias individuais e abatidos aos 32 kg. A carne dos cordeiros teve 74,55% de umidade, 19,61% de proteína bruta, 1,04% de cinzas e 51,28 mg/100g de colesterol, sendo o teor de extrato etéreo, maior na dos alimentados com dietas contendo silagem de milho (3,97%) e na dos que receberam alimentação mais concentrada (4,02%). Os ácidos graxos em maior concentração na carne dos cordeiros foram: mirístico (4,18%), palmítico (26,41%), esteárico (17,09%), oléico (37,93%) e linolênico (4,00%). A carne dos alimentados com dietas contendo cana-de-açúcar teve maiores teores dos ácidos cáprico (0,47) e araquidônico (4,17), e menores dos palmitoléico (2,02) e linolênico (0,25). A carne dos cordeiros alimentados com maior quantidade de cana-de-açúcar (60%) teve também maiores teores dos ácidos pentadecanóico (0,68), heptadecanóico (2,13) e eicosadienóico (1,34), sendo estes reduzidos quando a cana-de-açúcar foi utilizada em menor quantidade. Com relação às características estruturais da carne dos cordeiros, as dietas não alteraram a freqüência das fibras SO, FOG e FG, entretanto, aquelas contendo 60% de concentrado, propiciaram maior diâmetro, área e área total relativa das mesmas. Quanto ao tipo de músculos, a freqüência das fibras SO e FG foi maior no Triceps brachii, e a das fibras FOG, maior no Longissimus lumborum. O músculo Triceps brachii teve para todos os tipos de fibras musculares, maiores áreas e diâmetros do que o Longissimus lumborum. Independentemente da dieta... / With the aim to evaluate nutritional, structural, physic-chemical and sensorial characteristics of meat of lambs finished on feedlot with diets containing sugar cane or corn silage on two roughage:concentrate ratios, 60:40 or 40:60, it was used 32 Ile de France lambs, non castrated, with 15kg of corporal weight. The animals were confined on individual stalls and were slaughtered at 32 kg of corporal weight. Lamb meat had 74.55% of moisture, 19.61% of crude protein, 1.04% of ash and 51.28 mg/100g of cholesterol, being ethereal extract content, highest on meat of lambs fed up with diets containing corn silage (3.97%) and on those of animals that received more concentrate food (4,02%). The fatty acids on highest concentration in lamb meat were: miristic (4.18%), palmitic (26.41%), stearic (17.09%), oleic (37.93%) and linoleic (4.00%). The meat of lambs fed up with diets containing sugar cane (60%) had higher contents of capric (0.47) and arachidonic (4.17) acids, and lower contents of palmitoleic (2.02) and linoleic (0.25) acids. The meat of lambs fed up with higher quantity of sugar cane (60%) had higher contents of pentadecanoic (0.68), heptadecanoic (2.13) and eicosadienoic (1.34) acids too. These acids were reduced when sugar cane was used on lower quantity. In relation to meat structural characteristics, diets didn’t change frequency of SO, FOG and FG fibers. However, those containing 60% of concentrate propitiated larger diameter, area and total area relative at the same. About muscle type, frequency of SO and FG fibers was higher on Triceps brachii, and frequency of FOG fibers was higher on Longissimus lumborum. For all muscle fiber types, Triceps brachii muscle had areas and diameters larger than Longissimus lumborum. Independently of diet and evaluated muscle, the contents of total and soluble collagen of meat not differed, with average values of 2.45 and 0.30 mg/g... (Complete abstract click electronic access below)