ABSTRACT We aimed to verify whether age influences the biochemical profile of healthy lambs during the first four months of life by characterizing the dynamics of its parameters and verifying whether there are differences between the profiles of growing animals and the reference values established for adults. Blood samples of 34 ½ White Dorper × ½ Suffolk female lambs were collected at 30, 60, 90, and 120 days of age, and the serum concentrations of total proteins, total globulins, albumin, urea, creatinine, bilirubins (total, conjugated, and unconjugated), total cholesterol, triglycerides, glucose, gamma-glutamyltransferase, aspartate aminotransferase, and creatine kinase were determined. Descriptive statistics of these parameters were performed to compare them with the reference intervals used for adult sheep. Age influenced the dynamics of all the biochemical parameters between 30 and 120 days of age. Moreover, except for the total, conjugated and unconjugated bilirubins, total cholesterol, and aspartate aminotransferase means, the values of the lambs differed from the reference intervals established for adults. In conclusion, there is an influence of age on biochemical parameters in healthy female lambs in the first four months of life, and often the biochemical parameters of young animals differ from those of adults. Therefore, the interpretation of tests performed on growing animals should be made based on specific reference intervals for this age group.

The widespread use of moxidectin (MOX), a parasiticide used in the sheep breeding, has induced the parasite resistance in Brazilian farms. As a consequence, the farmers often increase the dose and frequency of drug utilization, and disregards safety of meat or milk. In order to establish adequate therapeutic treatment it is necessary to know the pharmacokinetics of the drug in the animal's body. Thus, high performance liquid chromatography-electrospray ionization-tandem mass spectrometry (HPLC-ESI-MS/MS) method was developed for the determination of MOX in serum lamb. Serum samples were treated with acetonitrile to precipitate proteins. A clean up by dispersive extraction in solid phase (SPE-d), using primary/secondary amine (PSA) and C18 sorbents, followed by freezing was performed. Method validation presented precision (coefficient of variation) and accuracy (recovery%) between 1.7-6.7 and 80.0-107.3%, respectively. The limit of quantification (LOQ) of the method was 2.0 ng mL-1 and a linear response was obtained over a range of 2.0 to 100 ng mL-1. This method was successfully applied to the determination of MOX in serum from suffolk lamb to evaluate the pharmacokinetic profile.

Resumo: O controle das endoparasitoses gastrintestinais em pequenos ruminantes tem sido tradicionalmente realizado por meio do uso indiscriminado dos anti-helmínticos, porém essa prática tem resultado em grande pressão de seleção de parasitas resistentes. Métodos seletivos (ex: FAMACHA/FMC e contagem de ovos nas fezes/OPG) e que apresentem boa sensibilidade para identificar os animais que necessitam receber o tratamento químico são importantes alternativas aos métodos tradicionais. O objetivo desse trabalho foi determinar a sensibilidade e a especificidade do método FMC, usado para detectar anemia causada por Haemonchus contortus em ovinos da raça Suffolk, em duas categorias de alta suscetibilidade; cordeiros lactentes e ovelhas durante a fase de lactação. A conjuntiva ocular de 42 cordeiros lactentes e 35 ovelhas em lactação foi avaliada usando o método FMC, em intervalos de 14 dias, durante cinco meses. O hematócrito (Ht) foi utilizado como padrão-ouro para avaliação clínica de anemia dos animais. Para o cálculo de sensibilidade e especificidade, diferentes critérios foram utilizados: animais classificados como 4 e 5 ou 3, 4 e 5 e anêmicos pelo Ht (teste positivo); animais classificados como 1, 2 e 3 ou 1 e 2 e não anêmicos pelo Ht (teste negativo). Três valores de corte para Ht (≤22%, ≤19% ou ≤15%) foram utilizados para confirmar a anemia. Entre os gêneros observados nas coproculturas, H. contortus (61,5%) e Ostertagiasp (21,3%) foram os mais prevalentes. Em ambas as categorias, a inclusão do FMC 3 como teste positivo, elevou a sensibilidade mas reduziu a especificidade do método. Quando o FMC 3 foi considerado anêmico, o percentual de falsos negativos foi próximo a zero, no entanto, houve aumento no número de tratamentos aplicados em animais não anêmicos (falso positivo). Durante as avaliações, a maior parte dos cordeiros (73%) e das ovelhas (53%) permaneceu nas categorias de FMC 1 e 2. Apenas 5% dos cordeiros e 8% das ovelhas foram classificados com os dois maiores graus de anemia (FMC 4 e 5). Os resultados indicam que o FMC pode ser utilizado para identificar os cordeiros lactentes e ovelhas em fase de lactação com sinais clínicos de anemia decorrentes da infecção por H. contortus. Para ambas as categorias, foi necessário incluir o FMC 3 como positivo para aumentar a sensibilidade do método; reduzindo o risco de morte de animais anêmicos não diagnosticados (falsos negativos).

Abstract: The control of gastrointestinal parasites in small ruminants has traditionally involved the indiscriminate use of anthelmintic drugs that resulted in a high parasite selection pressure for anthelmintic resistance. Selective methods (ex.: FAMACHA/FMC and faecal egg count/EPG), which have good sensitivity to identify animals that need drug treatment, are important alternative methods for parasite control. The objective of this study was to determine the sensitivity and specificity of the FMC method to detect clinical anemia caused by Haemonchus contortus in two highly susceptible categories of Suffolk sheep; suckling lambs and lactating ewes. The ocular conjunctivae of 42 suckling lambs and 35 lactating ewes were evaluated using the FMC method at 14 days interval for five months. Hematocrit (Ht) served as the gold standard for anemia evaluation. To calculate the sensitivity and specificity of the FMC method, different criteria were adopted: animals classified as 4 and 5, or 3, 4 and 5, were considered to be anemic (positive test), and animals classified as 1, 2 and 3, or 1 and 2 were considered to be non-anemic (negative test). Three standard values of Ht (≤22%, ≤19% or ≤15%) were used to confirm anemia. Among the prevalent genera of helminths H. contortus (61.5%) and Ostertagia sp. (21.3%) were the most predominant species in the coproculture. For both categories, the inclusion of FMC 3 as a positive test increased the sensitivity but decreased the specificity of the method. When FMC 3 was included as anemic, the percentage of false negative was close to zero, but a greater number of treatments were applied to non-anemic animals (false positive). Most of the lambs (73%) and ewes (57%) remained in categories 1 or 2 throughout the trial. Only 5% of the lambs and 8% of the ewes were classified as the two major stages of anemia (4 and 5). The results indicate that the FMC is a safe method to be used in lambs and lactating ewes with clinical anemia from H. contortusinfection. For both categories, it was necessary to include FMC 3 as a positive condition to increase the sensitivity of the method and to reduce the risk of death of undiagnosed anemic animals (false negatives).

The influence of early weaning and concentrate supplementation strategies on sward characteristics, forage chemical composition and lamb productivity were evaluated in four production systems on Tifton-85 pasture: suckling lambs not supplemented until slaughter; suckling lambs supplemented with concentrate in creep feeding until slaughter; early-weaned lambs not supplemented until slaughter; and early-weaned lambs supplemented with concentrate until slaughter. Structural, morphological and productive characteristics of pasture were measured. The forage was chemically analyzed to estimate its composition. Lambs average daily gain and productivity were calculated. Sward height, forage and morphological components mass were lower in systems without weaning. Forage production was higher in systems with supplementation. Higher levels of neutral and acid detergent fiber were observed in forage ingested by lambs in creep feeding and by weaned and unsupplemented lambs. Average daily gain was higher for lambs in creep feeding (275 g/d) and lower for the weaned and unsupplemented animals (57 g/d). Productivity was higher for weaned and supplemented lambs (21 kg lamb body weight, BW gain/ha/d). Lower productivity was observed in systems without supplementation (5 kg lamb BW gain/ha/d on average). Ewes modify the sward conditions improving the pasture characteristics and the quality of forage produced. Changes in sward conditions affect the chemical composition of forage ingested by lambs. Early weaning may be an alternative to maximize pasture utilization in small areas. Concentrate supplementation may increase lamb performance and productivity in grazing systems. If the objective is to improve lamb individual performance, creep feeding should be used.

The objectives of this study were to estimate the phenotypic correlations of residual feed intake (RFI) and gross feed efficiency (GFE) with hematological and metabolic blood profiles of lambs and to determine the differences for these traits in animals of different RFI classes. Twenty Ile de France male lambs, 115±8 days of age and 31.3±4.1 kg of body weight (means ± SD), were individually housed and their dry matter intake was measured over 65 days. They were weighed every 13 days to determine the average daily weight gain and two blood samples were collected at the last two weighings (at 07h30) for analysis of blood variables. The animals were divided into two classes: negative RFI (most efficient: <0.5 SD below the mean; n = 6) and positive RFI (least efficient: >0.5 SD above the mean; n=8). There were associations among RFI and the serum metabolic variables for albumin (rRFI = 0.74) and creatinine (rRFI = -0.45) and between GFE and serum albumin (rGFE = -0.70). Less efficient animals as measured by RFI had higher serum albumin and lower creatinine levels and showed a tendency to have a greater concentration of total plasma protein. Other serum biochemical parameters were not correlated with GFE and RFI, and no differences between RFI classes were found. There was a correlation between the percentage of eosinophils and RFI (rRFI = -0.65), and such more efficient animals had a higher proportion of these cells and a trend to have a lower percentage of monocytes. This study provided evidence indicating associations between RFI and protein metabolism, as reflected by the serum albumin and creatinine. The hematological findings suggest that RFI is related to susceptibility of lambs to stressand should provide a basis for further research in this regard.

Dois experimentos foram realizados com o objetivo de avaliar o efeito da substituição do milho por polpa cítrica peletizada e resíduo úmido de cervejaria sobre a digestibilidade aparente dos nutrientes da dieta, os parâmetros ruminais e o desempenho de ovinos. As dietas foram definidas pela substituição do milho (controle) pela polpa cítrica peletizada ou pela mistura de resíduo úmido de cervejaria e polpa cítrica. No experimento 1, para avaliação do consumo, da digestibilidade aparente dos nutrientes e dos parâmetros ruminais, foram utilizados 12 machos da raça Santa Inês canulados no rúmen, distribuídos em delineamento experimental de blocos completos casualisados, com três dietas e quatro repetições. No experimento 2, para avaliação do desempenho, foram confinadas 48 fêmeas, que foram alimentadas com as mesmas dietas do experimento 1. A substituição do milho pela polpa cítrica peletizada não influenciou o consumo nem a digestibilidade dos nutrientes da dieta, diferente da inclusão de resíduo úmido de cervejaria, que reduziu o consumo e a digestibilidade aparente dos nutrientes, com exceção apenas da FDN, cuja digestibilidade aparente foi similar entre as dietas. A inclusão de resíduo úmido de cervejaria na dieta reduziu as concentrações ruminais de acetato e propionato e aumentou a relação acetato/propionato e o pH ruminal. Em geral, não há diferença entre a dieta contendo milho e aquela contendo polpa cítrica em substituição total ao milho. A utilização de resíduo úmido de cervejaria, no entanto, reduz o ganho médio diário, o peso corporal final e a eficiência alimentar.

Two experiments were carried out with the objective to determine the effect of replacing corn by dried citrus pulp and wet brewer grain on apparent digestibility of nutrients of the diet, ruminal parameters and performance of sheep. The diets were defined by the replacement of corn (control) by dried citrus pulp or by a mixture of wet brewer grain and citrus pulp. In experiment 1, for evaluation of intake, apparent digestibility of nutrients and ruminal parameters, 12 Santa Ines ram lambs fitted with canulas in the rumen were assigned to a randomized complete block design with three diets and four replicates. In experiment two, for performance evaluation, 48 ewe lambs were confined and fed the same diets of experiment 1. Replacement of corn by dried citrus pulp did not affect intake or digestibility of nutrients in the diet. However, the inclusion of wet brewer grain reduced intake and apparent digestibility of nutrients, with exception of NDF. Apparent digestibility of NDF was similar among diets. Inclusion of wet brewer grain in the diet decreased ruminal concentration of acetate and propionate and increased acetate/propionate ratio and ruminal pH. In general, there is no difference between the diet containing corn and that containing citrus pulp in total replacement to corn. The use of wet brewer grain, however, reduces average daily gain, final body weight and feed efficiency.