Prediction of Carcass Traits of Santa Inês Lambs Finished in Tropical Pastures through Biometric Measurements.

The aim of this study was to predict carcass traits of Santa Inês lambs finished in tropical pastures by using biometric measurements. Data originated from two experiments involving 56 lambs (32 in experiment I and 24 in experiment II). In both experiments, the sheep were finished in that were finished in pastures of Panicum maximum and Brachiaria brizantha, experiment I being conducted in the rainy season and experiment II in the dry season. The following biometric measurements were recorded before slaughter: body length (BL), withers height (WH), rump height (RH), thorax width (TW), rump width (RW), chest width (CW), heart girth (HG), thigh circumference (TC), rump circumference (RC) and leg length (LL), in addition to live weight at slaughter (SW). After slaughter, hot carcass weight (HCW), cold carcass weight (CCW) and the weights of primal cuts (shoulder, neck, loin, leg and rib) were recorded. In the equations generated to predict SW, HCW and CCW, R2 ranged from 0.58 to 0.91 and the measurements of WH, TC, CW, HG and RW were the most relevant. In the equations developed to predict the weight of primal cuts, in turn, R2 ranged from 0.26 to 0.99. In these models, SW, BL, CW, TC, LL and HG explained most of the variation in the weight of primal cuts. Biometric measurements can be used to accurately and precisely predict HCW, CCW and the weight of primal cuts from the carcass of Santa Inês sheep finished in tropical pastures, since the equations presented R2 and correlation coefficient and agreement above 0.8.

Biometry and carcass characteristics of lambs supplemented in tropical grass pastures during the dry season / Biometria e características da carcaça de cordeiros suplementados em pastos de gramíneas tropicais na época seca

The objective of this study was to evaluate the biometry and carcass characteristics of finished Santa Inês crossbred sheep grazed on tropical grass pastures during the dry season. The study was carried out at the Grupo de Estudos em Forragicultura (GEFOR/UFRN), in Macaíba ­ RN, Brazil. Four forage treatments were evaluated: Brachiaria brizantha cvs. Marandu e Piatã, Panicum maximum cvs. Aruana e Massai. The 2.88 ha-area used was divided in two blocks of 1.44 ha; each one was composed of four plots corresponding to each cultivar, and each plot was subdivided into six paddocks with an area of 0.06 ha. The pastures were managed under intermittent stocking with seven days of occupation and 35 days of rest, with variable stocking rate. No significant difference was observed in the biometric measurements evaluated in the animals, except for chest width in which animals kept in Marandu pastures obtained higher values than those in the Aruana cultivar. The lowest values of average daily gain, final weight and weight at slaughter values were observed in the animals kept in Aruana cultivars. Cut weights of the shoulder, the loins, short legs/shanks and ribs were higher in the animals kept in Marandu grass and lower in those kept in the Aruana grass; however, no differences were observed for the yield of the cuts and for the biometric measurements of the carcass. The evaluated pasture cultivars did not modify the finished sheep carcasses, however, the lower forage mass from Aruana grass pastures in the dry season affected animal performance and the sheep carcass composition.

Objetivou-se avaliar a biometria e as características da carcaça de ovinos mestiços de Santa Inês terminados em pastos de gramíneas tropicais na época seca. O trabalho foi realizado no Grupo de Estudos em Forragicultura (GEFOR/UFRN), em Macaíba ­ RN, Brasil. Os tratamentos avaliados foram quatro forrageiras: Brachiaria brizantha cvs. Marandu e Piatã, Panicum maximum cvs. Aruana e Massai. A área utilizada foi de 2,88 ha dividida em dois blocos de 1,44 ha, onde cada um desses foi constituído de quatro parcelas correspondente a cada cultivar, e cada parcela subdivida em seis piquetes com área de 0,06 ha. Os pastos foram manejados sob lotação intermitente com sete dias de ocupação e 35 dias de descanso, com taxa de lotação variável. Não houve diferença significativa nas medidas biométricas avaliadas nos animais, exceto para a largura do peito, em que os animais mantidos nos pastos da cultivar Marandu obtiveram valores maiores que aqueles da cultivar Aruana. Os menores valores de ganho médio diário, peso final e peso ao abate foram observados nos animais mantidos na cultivar Aruana. Os pesos dos cortes paleta, lombo, pernil e costela foram maiores nos animais mantidos no capim-marandu e menores naqueles mantidos no capim-aruana, porém não foram observadas diferenças para o rendimento dos cortes e para as medidas biométricas na carcaça. As cultivares avaliadas não modificam as carcaças de ovinos terminados em pasto, porém a menor massa de forragem dos pastos da cultivar Aruana na época seca comprometem o desempenho animal e a composição das carcaça de ovinos.

Tillering dynamic and structural characteristics of tropical grasses under cutting management / Dinâmica de perfilhamento e características estruturais de gramíneas tropicais sob corte

This paper aimed to evaluate the dynamics of tillering, tiller density and structural characteristics of Brachiaria brizantha, Panicum maximum and Cenchrus ciliaris under a cutting regime. The utilized design was randomized blocks with six treatments (cultivars) and three replications. The evaluations were conducted from May to September 2011, with the data grouped into two periods, rainy season and beginning of the dry season. The greatest tiller population density was observed in the Massai cultivar, averaging 1,019 tillers.m-2. The tiller mortality rate was higher for Mombaça and less for Piatã cultivars. The highest values for forage mass, percentage of leaf blades and relations between green mass:dead mass were observed in Brachiaria brizantha and Panicum maximum cultivars. Panicum and Brachiaria cultivars have shown to be promising for cultivation in the transition areas between the Atlantic Forest and Caatinga biomes in Northeastern Brazil. Cenchrus cultivars are less productive in environments without restriction of abiotic factors.

Objetivou-se avaliar a dinâmica de perfilhamento, a densidade populacional de perfilhos e as características estruturais de cultivares de Brachiaria brizantha, Panicum maximum e Cenchrus ciliaris em regime de corte. O delineamento utilizado foi em blocos ao acaso com seis tratamentos (cultivares) e três repetições. As avaliações foram realizadas de maio a setembro de 2011, sendo os dados agrupados em dois períodos, águas e início da seca. A maior densidade populacional de perfilhos foi observada na cultivar Massai com média de 1019 perfilhos/m2. A taxa de mortalidade de perfilhos foi maior na cultivar Mombaça e menor na Piatã. Os maiores valores para massa de forragem, percentual de lâminas foliares e relações entre massa verde:massa morta foram observados nas cultivares de Brachiaria brizantha e Panicum maximum. As cultivares de Panicum e Brachiaria se mostraram promissoras à utilização em áreas de transição entre os biomas de Mata Atlântica e Caatinga na Região Nordeste do Brasil. As cultivares de Cenchrus são menos produtivas em ambientes sem restrição de fatores abióticos.

Ingestive behavior of sheep in Panicum and Brachiaria pastures in dry season / Comportamento ingestivo de ovinos em pastos de Panicum E Brachiaria na época seca

The ingestive behavior of sheep supplemented with concentrate in Brachiaria brizantha and Panicum maximum pastures were evaluated during the dry season. Twenty four male sheep of ½ Santa Inês x ½ undefined breed genotypes were used. The treatments were four feeds of cultivar grasses: B. brizantha cvs. Marandu and Piatã, P. maximum cvs. Massai and Aruana. The ingestive behavior of the animals was recorded during two periods of 24 hours. The grazing time, rumination, idleness (minutes day-1), bite rate (bites minute-1), and the frequency of the animals activities in relation to defecation, urination and search for water, concentrated and mineral salt were observed. There was interaction between time of the day and evaluated cultivars based on the grazing time and bite rate response. Sheep grazing on marandu-grass showed higher grazing time between 11 am to 4 pm (257 minutes), compared to animals grazing on aruana-grass (217 minutes). The bite rate was higher for sheep on massai-grass between 11 am to 4 pm (34.32 bits minute- 1). There was no grass effect for idleness and rumination, which can highlight the similarity of chemistry characterization and high percentage of structural components in evaluated pastures. The structural limitations and feed mass composition in the dry season caused effects on the ingestive behavior of idleness and bite rate of supplemented sheep in Brachiaria and Panicum pastures.

Avaliou-se o comportamento ingestivo de ovinos, suplementados com concentrado, em pastos de Brachiaria brizantha e Panicum maximum durante a época seca. Foram utilizados 24 animais, machos inteiros do genótipo ½Santa Inês x ½ sem padrão racial definido. Os tratamentos corresponderam a quatro cultivares de gramíneas forrageiras, sendo B. brizantha cultivares. Marandu e Piatã e P. maximum cultivares. Massai e Aruana. O comportamento ingestivo dos animais foi registrado durante dois períodos de 24 horas. Observou-se o tempo de pastejo, ruminação, ócio (minutos/dia), taxa de bocados (bocados/minuto) e a frequência dos animais em relação à defecação, micção e busca pela água, concentrado e suplemento mineral. Houve interação entre o período do dia e as cultivares avaliadas sobre as respostas de tempo de pastejo e taxa de bocado. Os animais sob pastejo no capim-marandu apresentaram maior tempo de pastejo no período de 11-16h (257 minutos) em relação aos animais do capim-aruana (217 minutos). A taxa de bocados foi maior para os animais do grupo do capim-massai no período 11-16h (34,32 bocados/minuto). Não houve efeito de tratamento para as variáveis de ócio e ruminação, o que pode evidenciar a semelhança da caracterização química e elevada porcentagem de constituintes estruturais nos pastos avaliados. As limitações estruturais, de composição e massa de forragem na época seca provocam efeitos sobre as variáveis de comportamento ingestivo de ovinos suplementados em pastos de Brachiaria e Panicum.

Características morfogênicas e acúmulo de forragem de gramíneas forrageiras sob corte / Accumulation of forage and morphogenic responses in forage grass by cutting

Objetivou-se avaliar e as características morfogênicas e o acúmulo de forragem de três gêneros de gramíneas, Brachiaria, Panicum e Cenchrus em regime de corte. O delineamento utilizado foi em blocos ao acaso com parcelas subdivididas. Houve efeito de interação entre cultivar e época de avaliação para a taxa de aparecimento de folhas, alongamento de colmos, duração de vida das folhas e senescência de folhas. As cultivares Áridus e Biloela (Cenchrus) apresentaram os menores Filocronos, seguidos da cultivar Piatã (B. brizantha). A taxa de alongamento de folhas e seu comprimento final foram maiores no período das chuvas, para todas as cultivares. As cultivares Massai e Mombaça apresentaram os maiores comprimentos de folha, mas os menores números de folhas vivas por perfilho. As cultivares Áridus e Biloela as menores taxas de acúmulo de lâminas foliares em relação ás demais. O maior fluxo de tecidos observado no gênero Cenchrus, não foi suficiente para superar a maior de produtividade das cultivares dos gêneros Panicum e Brachiaria.

This study aimed to evaluate the accumulation of forage and the morphogenesis of three genera Brachiaria, Cenchrus and Panicum in cutting regime. The experimental design was a randomized block with three replicates and six treatments. After each cut were evaluated for forage production, appearance and elongation rates of leaves and stem final leaf length, number of green leaves, leaf life span, rate of senescence of leaves. For herbage accumulation rate was higher in the cv. Xaraes, which is more than double the cumulative cv. Aridus, the lowest rate among cultivars. As for leaf appearance rate and leaf elongation was higher in the rainy season only for cultivars Aridus Biloela and the other showed no difference between the evaluation periods. Cultivars Aridus, Biloela and Piata obtained the highest number of leaves per tiller, differing from Mombaça, Massai and Xaraes that showed the lowest values. The lower values of leaf life span were found in the rainy season to cultivate Aridus, Biloela and Mombaça. Except Aridus, which showed a higher rate of senescence of leaves in the rainy season, others grasses did not differ between the evaluation periods. We conclude that the highest rates of leaf appearance and number of green leaves found on the cultivars of the genus Cenchrus, were not enough to overcome the greatest potential for producing forage cultivars of the genera Panicum and Brachiaria. The grasses tested showed potential for use in the Northeast, but were influenced by seasons, mainly due to a decrease in rainfall.