RESUMO Objetivou-se com este estudo avaliar a viabilidade econômica da inclusão de ureia na ração fornecida para cordeiros terminados em confinamento. Foram utilizados 24 cordeiros machos não castrados, mestiços Dorper, com 2 a 5 meses de idade e 25,0 ± 4,3 kg de peso corporal (PC). O delineamento experimental foi inteiramente casualizado com quatro tratamentos e seis repetições, onde os tratamentos foram os teores de 0,0; 0,5; 1,0 e 1,5% de ureia na ração, com base na matéria seca (MS). Os cordeiros foram alimentados ad libitum por 56 dias e abatidos com 37,9 ± 5,1 kg de PC. Os índices econômicos analisados foram custo das rações, custo do fator marginal (CFM), receita do fator marginal (RFM), receita líquida (RL) e relação benefício:custo (RBC). A ração sem ureia apresentou o maior custo (0,30 US$/kg MS) e a ração com 1,0% MS de ureia teve o menor custo (0,23 US$/kg MS). O CFM apresentou resposta quadrática aos níveis de ureia, alcançando o menor valor (0,28 US$/dia) com a inclusão de 0,9 a 1,0% MS de ureia na ração. O menor e o maior valor de RL foram obtidos a partir das rações sem e com 1,5% MS de ureia, respectivamente (0,26 e 0,34 US$/dia). A ração sem ureia apresentou a pior RBC (1,74), enquanto a ração com 1,0% MS de ureia resultou na melhor RBC (2,09). O melhor retorno econômico na terminação de cordeiros em confinamento é obtido com rações contendo 1,0 a 1,5% MS de ureia.

SUMMARY The aim of this study was to evaluate the economic viability of the inclusion of urea in the ration provided to feedlot lambs. Twenty-four non-castrated male lambs, crossbred Dorper, with 2-5 months of age and a body weight (BW) of 25.0 ± 4.3 kg were used. A completely randomized design with four treatments and six replicates was adopted, in which the treatments were urea levels of 0.0, 0.5, 1.0 and 1.5% in the ration, on a dry matter (DM) basis. Lambs were fed ad libitum for 56 days and slaughtered at a BW of37.9 ± 5.1 kg. The analyzed economic indexes were the cost of the rations, cost of marginal factor (CMF), revenue of marginal factor (RMF), net revenue (NR) and benefit: cost ratio (BCR). The ration without urea presented the highest cost (0.30 US$/kg DM) and the ration with 1.0% DM of urea had the lowest cost (0.23 US$/kg DM). The CMF had a quadratic response to the urea level, reaching the lowest value (0.28 US$/day) with the addition of 0.9 to 1.0% DM of urea. The lowest and the highest NR values were obtained from the rations without and with 1.5% DM of urea, respectively (0.26 and 0.34 US$/day). The ration without urea had a worse BCR (1.74), whereas the ration with 1.0% DM of urea resulted in a better BCR (2.09). A better economic return for lambs finishing in feedlots is obtained with rations containing 1.0 to 1.5% DM of urea.

Resumo O objetivo deste estudo foi caracterizar a dinâmica de alguns parâmetros hematológicos em cordeiros recém-nascidos sadios, antes e após a ingestão de colostro. Foram coletadas amostras sanguíneas de 28 cordeiros recém-nascidos, determinando-se o eritroleucograma, as concentrações de proteína plasmática total (PPT) e de fibrinogênio nos momentos pré e pós-colostro. Os dados foram analisados comparando-se a variabilidade dos parâmetros entre os dois momentos. O hematócrito (P<0,001), a concentração de hemoglobina (P<0,05) e o volume globular médio (VGM) (P<0,05) diminuíram após a ingestão de colostro, enquanto a concentração de hemoglobina globular média (CHGM) aumentou (P<0,01) no momento pós-colostro. Houve aumento no número de leucócitos totais (P<0,001) e nas contagens absolutas de neutrófilos segmentados (P<0,05) e de linfócitos (P<0,01) após a ingestão de colostro. As concentrações de PPT e de fibrinogênio também aumentaram no momento pós-colostro (P<0,001 e P<0,01, respectivamente). O eritroleucograma, as concentrações de PPT e de fibrinogênio variam consideravelmente antes e após a ingestão de colostro, sendo modificados em função da própria ingestão do colostro e/ou da adaptação dos processos fisiológicos do animal à vida extrauterina. Portanto, recomenda-se que a interpretação de hemogramas realizados em cordeiros recém-nascidos seja feita com base em intervalos de referência específicos para o período neonatal.

Abstract The aim of this study was to characterize the dynamics of some hematological parameters in healthy newborn lambs before and after colostrum intake. Blood samples of 28 newborn lambs were collected, determining the erythro-leukogram, the total plasma protein (TPP) and fibrinogen concentrations in pre and post-colostrum moments. The data were analyzed comparing the variability of the parameters between the two moments. The packed cell volume (P<0.001), the hemoglobin concentration (P<0.05) and the mean corpuscular volume (MCV) (P<0.05) decreased after colostrum intake, while the mean corpuscular hemoglobin concentration (MCHC) increased (P<0.01) at the post-colostrum moment. There was an increase in the total white blood cell count (P<0.001) and in the absolute counts of segmented neutrophils (P<0.05) and lymphocytes (P<0.01) after colostrum intake. The TPP and fibrinogen concentrations also increased at the post-colostrum moment (P<0.001 and P<0.01, respectively). The erythro-leukogram, the TPP and fibrinogen concentrations vary considerably before and after colostrum intake, being modified according to the own colostrum intake and/or the adaptation of the physiological processes of the animal to the extrauterine life. Therefore, it is recommended that the interpretation of complete blood cell counts performed in newborn lambs be made based on the specific reference intervals for the neonatal period.

This study intended to evaluate three identification devices for adult goats reared in semi-intensive system. They were (1) the ruminal bolus, electronic identification device composed of non-toxic ceramic and weighing 74.4 g; (2) small ear tag on left ear, visual identification device with dimensions of 50 × 15mm; and (3) big ear tag on right ear, also a visual identification device with dimensions of 42 × 48 mm. Twenty-two crossbred Boer female goats with mean age of 4 years and mean body weight (BW) of 52.6 kg were used. The identification devices were applied on all animals. Time spent for administration/application, readability and retention rate of devices were assessed. Problems during and after the application of devices, as well as device losses were recorded. Evaluations were performed one day and one week after application, then, monthly, for six months. The time spent for administration/application of the devices showed mean of 21 s and was similar between the evaluated devices. One big ear tag was lost, which decreased the retention rate of this device to 95.5%. The other devices showed retention rate of 100%. The readability was 100% for all studied devices. Small ear tags and ruminal boluses used in this study are recommended for adult goats. Production systems, environment, and ear tags with large dimensions may affect the retention rates of these visual identification devices.