No abstract

Heat stress is considered a limiting factor for sheep production. We used information from physiological characteristics linked to heat tolerance to determine whether infrared thermography temperatures were able to separate groups of animals and determine the most important variables in this differentiation. Forty-eight four-month-old male lambs from eight genetic groups were used. Physiological (rectal temperature–RT, heart rate–HR, respiratory rate–RR) and blood traits, infrared thermography temperatures, heat tolerance indices, body measurements, weight and carcass traits were measured. Statistical analyses included variance, correlations, factor, discrimination and regression. Observing the correlations between physiological characteristics (RT, RR and HR) with temperatures measured by infrared thermography, regions for further studies should include the mean temperature of flank, nose and rump. Results show that there are strong relationships between thermograph measurements and RR, RT and HR in lambs, which are suggested to be directly correlated with heat tolerance capacity of the different genetic groups evaluated in this study. The assessment of body surface temperature measured by the thermograph could be used as a noninvasive tool to assess heat tolerance of the animals.

The present study aimed to evaluate the performance, survivability and carcass traits of crossbred lambs. Data from 299 lambs born to 209 ewes were used. The dams were from a local hair breed (Santa Inês) and five breeds of sires were used: Dorper (DR), Ile de France (IF), Hampshire Down (HD), Texel (TX) and Santa Inês (SI). The lambs were weighed at birth, weaning and slaughter. Fasting body weight, skin thickness, hot and cold carcass weight, carcass yield and carcass length were measured at slaughter. Carcasses were separated into commercial cuts: neck, shoulder, rib, belly, loin and leg. Leg length and circumference were measured. Analyses of variances using MIXED procedure in SAS ® were carried out for weights and carcass traits. Factor, discriminant and canonical analysis were carried out. Mortality data of animals from birth until slaughter was analyzed using logistic regression. The HD animals had the highest mortality rate. TX lambs had similar growth rate and survivability compared to DR and IF and had better carcass traits than these genetic groups. Therefore, this breed can be used as paternal breed to crossbreeding with Santa Inês dams. Santa Inês animals did not differ in growth from birth until slaughter compared to crossbred animals, which highlights the potential of this naturalized breed for meat production. Moreover, there is a great variability inside this breed for carcass and growth traits which may undergo great improvement through selection programs.

The objective of this trial was to evaluate carcass quality in 74 Santa Ines hair ewes aged 6 to 48 months. Slaughter occurred after fasting and electroshock, followed by dissection of the jugular veins and carotid arteries. Hot carcass weight, hot carcass yield, carcass length, skin thickness, shoulder, neck, loin, belly, rib and leg weights and percentages, leg length, and girth were measured. The rib eye area, color (by CIELAB system), shear force, and cooking loss were also measured. The data were analyzed using SAS procedures for analysis of variance, regressions, correlations, and principal components. Hot carcass weight was 15.75 kg and yield was 43.65%. Younger animals had higher leg yield while yields of loin and shoulder increased as age increased. The meat was darker in older animals. As age increased, both the quantity of commercial cuts decreased and the loss of quality traits, such as color, cooking loss, and shear force, increased; therefore, slaughter should be performed before 30 months of age.

Resumo: Vários estudos têm confirmado diferenças fisiológicas entre a glândula mamária caprina e a bovina, demonstrando que devem ser realizadas adaptações para caprinos, determinando escores que melhor reflitam o verdadeiro estado sanitário da glândula mamária nesta espécie. O objetivo deste estudo foi correlacionar os resultados do Califórnia Mastitis Test (CMT), da contagem de células somáticas (CCS) e do exame bacteriológico do leite de caprinos e comparar com os padrões existentes na literatura. Foram utilizadas 23 fêmeas da raça Saanen pertencentes a Embrapa Caprinos e realizados exame clínico dos animais e teste da caneca telada, sendo que nenhum animal apresentava sintomas de mastite clínica. Posteriormente realizou-se o CMT, a coleta de leite para a contagem de células somáticas e exame microbiológico. Para a análise estatística foi utilizado o programa Assistat 7.5. Não foi observada diferença estatística significativa entre os escores 3+ e 2+ ou entre os escores 1+, traços e 0 do CMT, quando correlacionado com o exame microbiológico. A reação 3+ foi estatisticamente diferente (p<0,01) das reações 1+, traços e 0. Considerando o valor de 1120 x 10 3 céls/mL como o limite máximo de células no leite caprino, foi demonstrada diferença altamente significativa (p<0,001) entre as amostras microbiologicamente positivas e negativas. Quanto à correlação entre a CCS e o CMT, foi constatada diferença significativa (p<0,05) somente entre os escores 0 e 3+ do CMT.

-The objective of this study was to evaluate performance and biometrics of lambs fed different sources of forage. Twenty-four six-month-old Santa Inês female lambs were randomly allocated to four experimental diets and housed in individual stalls. They weighed on average 26.35±0.20 kg. The diets were coast cross hay (HAY), cassava hay (CAS), dehydrated by-product of pea crop (PEA) and saccharin (SAC). The diets were formulated with the same amount of protein and energy with fixed levels of forage (60%) and concentrate (40%). Adaptation to the diet took 7 days, with 45 days on experiment. Weights and biometric measurements were obtained every fortnight and feed intake three times a week. Rights half-carcasses were weighed and sectioned into retail cuts, rib, loin, shoulder, belly, neck and leg, which were weighed individually. Weight gain in lambs was significantly different between diets, with those fed saccharin gaining more. Overall, treatments did not significantly affect biometric measurements. There was a significant difference for feed intake and live weight at the end of the experiment. Animals fed PEA and SAC showed the best results. Average positive correlations were found between biometric measurements and live weight. Treatment PEA had heavier hot (14.36 kg) and cold (14.01 kg) carcass weights than the other groups. Hot carcass kill-out was higher for animals fed PEA as well as ham weight, belly, neck and heart girth. The weight of the abdominal viscera (%) for lambs fed CAS was greater than those fed SAC and PEA. The weights of the thoracic viscera as well as the liver, for lambs fed PEA were higher. The by-product of pea yielded best results, followed by saccharin, and can replace traditional forage sources in the region, providing similar results in terms of cuts and body components. These could be an alternative for feeding sheep in the dry season. The substitution of forages using by-product of pea and saccharin led to improved productivity over the coast-cross hay available in the Federal District -Brazil.

The once bred ewe slaughter method proposes the use of female lamb to produce a lamb and then both are slaughtered, increasing income and high quality meat production. Thus, this study evaluated the growth and reproduction performance of ewe lamb from Santa Inês (SI), a naturalized genetic resource, and their crosses (Dorper x Santa Inês (DOR), Texel x Santa Inês (TEX), Ile de France x Santa Inês (ILE)), as well as the survivability and development of their offspring. The animals were weighed monthly from birth to 12-months age. Samples of milk were collected on approximately 30 days of lactation. The physical-chemical analysis of milk was performed. SI females (2.94 kg) had significantly lower birth weight than DOR (3.80 kg) and TEX (3.87 kg). ILE females had higher weaning weight and weight at 12 months than SI females, which reflected in higher daily weight gain (ADG) (108.46 g/day) than TEX and SI. The pregnancy rates at 12 months were ILE (57.14%), TEX (25%), DOR (50%), and SI (28.57%), with TEX and SI differing of ILE and DOR (p = 0.03). Therefore, in semi-confinement and in a once-bred ewe production system using crossbreeding and allying meat production and reproduction, we recommend the use of Dorper and Ile de France breeds for crossbreeding with Santa Inês females. These results demonstrated the useful of a local genetic resource in productive system aiming a low cost meat production.

Two experiments were carried out to evaluate the influence of genetic group, pregnancy and animal age on the carcass traits and commercial cut patterns of sheep carcasses. In the first experiment, the effect of pregnancy and genetic group were evaluated on 61 eleven month old Santa Inês ewes and their crosses with Texel, Dorper and Ile de France. Experiment 2 was carried out with 132 Santa Inês nulliparous or lambed ewes slaughtered with ages ranging from 6 to 48 months to evaluate the influence of age on carcass traits. For both experiments, hot carcass weight, cold carcass weight, carcass yield, cold carcass yield and carcass length were measured, as well as the yields and percentages of shoulder, neck, loin, belly, ribs, leg and leg length and perimeter. In experiment 1, the Santa Inês breed presented similar carcass and cut traits compared to the others genetic groups evaluated, except for fasting body weight. Lambed animals had lower body condition score than nulliparous females. In experiment 2, fasting body weight, loin, rib and leg weights, as well as the leg perimeter, presented a quadratic effect with increasing age. Ideal slaughter age is before 16 months to obtain more expensive cuts.