Metodologias de análise de maciez como parâmetro de qualidade de carne de bovinos de diferentes grupos genéticos e idades

O experimento foi realizado no Setor de Confinamento de Gado de Corte da Faculdade de Medicina Veterinária e Zootecnia e no Laboratório de Bioquímica de Proteínas do Instituto de Biociências. Foram utilizados animais da raça Nelore, mestiços u Aberdeen X Nelore e mestiços u Simental X Nelore, abatidos com idade entre 12 e 15 meses conforme estabelecido pelo modelo biológico superprecoce. O experimento foi conduzido em um delineamento inteiramente casualizado. O objetivo do presente estudo foi análise de componentes da maciez de novilhos superprecoces de grupos genéticos distintos. Não foi verificada diferença estatística (p>0,01) entre os grupos genéticos para a força de cisalhamento, Índice de Fragmentação Miofibrilar (MFI) e frações do colágeno, entretanto houve influência (p0,01) between genetic groups for the shear force values, Myofibrillar Fragmentation Index (MFI) and collagen, however there was influence (p<0,01) of the ageing, except for the collagen. The meat of animals slaughtered between 12 and 15 months of age showed attributes of quality independent of the genetic group and with seven days of ageing all animals had a desirable tenderness.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP

Características do crescimento animal, do tecido muscular esquelético e da maciez da carne de bovinos nelore e mestiços no modelo biológico superprecoce

Este trabalho foi conduzido com o objetivo de estudar o padrão de crescimento do tecido muscular por caracterização das fibras musculares durante o desenvolvimento animal e suas conseqüências na maciez final da carne de bovinos da raça Nelore. Foram utilizados 20 animais da raça Nelore criados no modelo biológico superprecoce. Durante o crescimento foi realizada biopsia nos animais para analisar a composição do tecido muscular no animal in vivo e sua influência na qualidade da carne postmortem. A área e diâmetro das fibras SO, FOG e FG (fibras oxidativas, oxidativas-glicolíticas e glicolíticas) apresentaram correlações (P0,05 respectivamente). Desta maneira podemos inferir que o tamanho da fibra muscular pode influenciar negativamente nas características de qualidade de carne, em especial a maciez.The present work was lead with objective to study the standard of growth of the tissue muscular by characterization of the muscular fibers during the animal development and the consequences in the final meat tenderness of bovines of Nellore breed. Twenty animals of Nellore breed had been feedlot in the superprecoce' biological model. During the growth samples were collected by biopsy in animals to analyze the composition of muscular tissue in living animal and the influence in the meat quality on the postmortem. The area and diameter of fibers SO, FOG and FG (slow oxidative, fast oxidative-glicolitic and fast glicolitic), had showed correlations (P0,05 respectively). In this way we can infer which size of muscular fiber can influence negatively in meat quality characteristics of, tenderness especially.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP

Marandu palisadegrass submitted to different sheep stocking rates: height and leaf: stem ratio

The experiment was carried out at the Sheep Experimental Farm of Federal University of Mato Grosso/Brazil, along the months of February to May 2008, during the rainy and the water-dry transition seasons. The area where the experiment were totaled 4500 m2, formed by the Marandu palisadegrass. This area was divided into 45 paddocks of 100 m2. We used 27 lambs Santa Inês (purebred) with 4 months of age and average weight of 22 kg. The lambs were grouped into nine lots of similar weights. The treatments consisted of three stocking rates, 2, 3 and 4 female lambs / paddocks, corresponding respectively to 40, 60 and 80 lambs / ha. Each treatment was represented by 15 repetitions totaling 45 plots, each representing a paddock of 100 m2. The paddocks were managed under the system of intermittent stocking with 7 days of occupation and 28 days of rest. All paddocks had the height measured in 10 points. We used the found height as a criterion for the choice of where to sample the plot residual forage mass. The cutting height was 5 cm in the ground. The samples were weighed and submitted to fractionation: leaf, stem and senescent material. We calculated the leaf: stem ratio, dividing the amount of dry residual amount of green leaves by stem + sheath. The data collected were submitted to variance and regression analysis at 5% significance level. There was a linear decrease as the stocking rate increased for leaf: stem + sheath, and the estimated values of 0.22, 0.17 and 0.11. A similar effect was also observed for the post grazing sward height, where each animal unit added to the stocking rate reduced 0.32 cm in the pasture height. The estimated values were 56.32, 49.50 and 43.34 cm, respectively for 40, 60 and 80 lambs / ha. There was higher areas excluded by the animals, being possible to display high heterogeneity kept in paddocks with lower stocking rate. Both the height of the canopy as leaf: stem ratio increased with the increase in the stocking rate

Comportamento ingestivo e desempenho de cordeiras em pastejo

O artigo não apresenta resumo em português

Capim Marandu submetido a diferentes taxas de lotação de ovinos: Altura e relação folha:colmo

O artigo não apresenta resumo em português

Tenderness charactherization of ostrich meat commercial cuts

The ostrich meat has become an interesting source of protein as well as being an alternative to red meat, because of its healthy fatty acid profile, with a high content of polyunsaturated fatty acids and low content of intramuscular fat, which arouses the interest of people who want a low animal fat diet. Ostrich meat is also appreciated by the tenderness, since it is one of the larger impact characteristics on the acceptance of a meat product for consumers. The aim of this study was to evaluate the tenderness of different ostrich meat commercial cuts and certificate that all studied cuts present tenderness acceptable by consumers. The laboratory tests were performed at the Laboratory of Biochemistry of Proteins (FMVZ), being measured shear force of seven commercial cuts of ostrich meat. The cuts were: internal thigh, external thigh, filet plan, filet out, filet small, rump and filet fan. The samples were boiled in water bath controlled by time and temperature. After chilling, fragments of 1.0 x 1.0 x 3.0 cm were removed from samples. Shear force measurements were performed using a mechanical Warner-Bratzler Shear Force equipment. The shear force means were: internal thigh (3.5 kg), external thigh (2.8 kg), filet plan (2.4 kg), filet out (1.6 kg), filet small (3.5 kg), rump (3.3 kg) and filet fan (2.0 kg). All the commercial cuts evaluated had very low values of shear force, denoting meat extremely tender. The classification of meat tenderness is based on shear force values, being values below 4.6 kg considered meat with desirable tenderness. All ostrich meat commercial cuts analyzed had shear force values lower than 4.6 kg, being classified as meat of extreme tenderness. The results found in this work allow concluding that ostrich meat can be considered tender. These findings lead us to consider the ostrich meat as an interesting alternative to red meat, in relation to tenderness and healthy fatty acid profile, being favorable for people suffering from heart disease

Caracterização da maciez de cortes comerciais de carne de avestruz

O artigo não apresenta resumo em português

Ingestive behavior and performance of female lambs under grazing

The ingestive behavior and performance of female lambs grazing on Marandu pasture submitted to different stocking rates during the rainy and transition season were evaluated. The experimental area with 4.500 m2 was divided into 45 paddocks of 100 m2 each. Twenty-seven Santa Ines female lambs (purebred) 4 months old and 22 kg of initial body weight were distributed in a completely randomized design, with nine replicates. Lambs were divided into 9 groups with the same initial weight and submitted to three stocking rates: 2, 3 and 4 lambs/paddock, which corresponded to 40, 60 and 80 lambs/ha, respectively. Each group of animals had a module of five paddocks, managed on intermittent grazing system, with 7 days of occupation and 28 d of rest. The feeding behavior of animals was assessed one day before the end of each experimental period, from 8:00 AM to 5:00 PM, observing the activities of grazing, rumination, rest and water or mineral intake at every 15 minutes. Only activity happening in the moment of observation was considered. The liveweight gain of animals was calculated by the difference between weighing dates. The average daily gain was obtained dividing the WG by the total of the experimental period days. Weight gain per area was calculated by multiplying the number of animals per hectare in each stoking rate and their respective weight gain. Increase on time of grazing and reduction on time of ruminating and resting were observed as stocking rates increased. As the activities of behavior are mutually exclusive, animals of the stocking rates of 60 and 80 animals / ha showed lower rumination and resting times when compared with the lower stocking rate. Thus, animals in the stocking rates of about 80 to 60, showed 41% reduction in resting time. We observed the existence of a negative linear effect for average daily gain. Lambs at stocking rates of 40, 60 and 80 lambs / ha had gains of 90, 67.64 and 45.62 grams per day, respectively. This is mainly due to the reduction in herbage mass and total mass of green leaf blade, caused by increasing the number of animals per paddock. It is noteworthy that the lowest daily earnings are also related to higher grazing time. The largest gain occurred in the area with 60 lambs / ha, 3.8 kg / ha / day. For the lowest and highest stocking rates, the gains for the respective areas were 3.58 and 3.45 kg / ha / day. Even with a higher number of lambs / ha, the highest stocking rate did not result in higher gain per unit area, probably due to the effect of lower gain (45.62 g / day) for the group

Efeito do colágeno na maciez da carne de bovinos de distintos grupos genéticos = Collagen effects in meat tenderness of bovines of different genetic groups

O objetivo do trabalho foi avaliar a influência do colágeno na maciez da carne de animais de diferentes grupos genéticos produzidos no sistema de produção do novilho superprecoce. Foram utilizados bezerros machos inteiros da raça Nelore, mestiços ½ Nelore x ½ Aberdeen Angus e mestiços ½ Nelore x ½ Simental. Após abate e resfriamento por 24 horas, foram retiradas amostras do músculo Longissimus dorsi, na região entre a 11a e a 13a costela, sendo que uma amostra foi congelada e as demais maturadas por 7 e 14 dias. Nãohouve diferença significativa (P>0,01) entre os grupos genéticos para a quantidade e a solubilidade de colágeno e a força de cisalhamento. A quantidade e a solubilidade do colágeno não comprometeram a maciez da carne, indiferentemente do grupo genético utilizado e do tempo postmortem, tornando vantajosa a opção de se abaterem animais jovens.The aim of work was to analyze the collagen effect in meat tenderness of animals of different genetic groups produced by very young bullock production system. Male calves Nellore purebred, ½ Nellore x ½ Aberdeen Angus and ½ Nellore x ½ Simmental crossbred were used.After slaughter and cooling for 24 hours Longissimus dorsi samples were removed, between 11th and 13th ribs, one sample was frozen and the others ageing for 7 and 14 days. There was no difference (P>0,01) between genetic groups for amount and heat soluble collagen andshear force values. The amount and solubility collagen don’t compromised the meat tenderness, indifferent of the genetic group used and postmortem period, becoming the early slaughter an advantageous option for meat production with desirable characteristics

<b>Efeito do colágeno na maciez da carne de bovinos de distintos grupos genéticos</b> - DOI: 10.4025/actascianimsci.v28i1.664

O objetivo do trabalho foi avaliar a influência do colágeno na maciez da carne de animais de diferentes grupos genéticos produzidos no sistema de produção do novilho superprecoce. Foram utilizados bezerros machos inteiros da raça Nelore, mestiços ½ Nelore x ½ Aberdeen Angus e mestiços ½ Nelore x ½ Simental. Após abate e resfriamento por 24 horas, foram retiradas amostras do músculo Longissimus dorsi, na região entre a 11a e a 13a costela, sendo que uma amostra foi congelada e as demais maturadas por 7 e 14 dias. Não houve diferença significativa (p > 0,01) entre os grupos genéticos para a quantidade e a solubilidade de colágeno e a força de cisalhamento. A quantidade e a solubilidade do colágeno não comprometeram a maciez da carne, indiferentemente do grupo genético utilizado e do tempo postmortem, tornando vantajosa a opção de se abaterem animais jovens