Ocorrência da infecção por Cryptosporidium spp. em cabritos (Capra hircus) / Occurrence of infection by Cryptosporidium spp. in goat kids (Capra hircus)

O presente estudo teve como objetivo determinar a ocorrência da infecção por Cryptosporidium spp. em cabritos de Quixadá, Ceará, Brasil. Participaram do estudo 400 cabritos, com idade entre três e 360 dias, de ambos os sexos, com e sem padrão racial definido, procedentes de 25 estabelecimentos rurais distribuídos em três circuitos. As fezes foram cadastradas de acordo com o aspecto e cor, distribuídas em tubos tipo "eppendorf®" e congeladas in natura a -20°C, até o momento das extrações de DNA genômico do parasito com auxílio de kit comercial. Para amplificação de fragmentos da subunidade 18S do RNA ribossômico (rRNA) foi utilizada a "Nested"-PCR. A ocorrência de Cryptosporidium spp em cabritos de Quixadá foi de 7,50% (30/400). A frequência no período seco e no chuvoso foi de 9,55% (19/199) e 5,47% (11/201), respectivamente (χ²=2,39 e P>0,05). Amostras positivas foram identificadas em 64,00% (16/25) das propriedades estudadas e dessas amostras 50,00% (15/30) e 70,00% (21/30) tinham as fezes com aspecto e cor normais, respectivamente, sugerindo que cabritos assintomáticos estão eliminando oocistos. Não foi observada positividade para Cryptosporidium spp. em animais com 301 a 360 dias, demonstrando que animais mais velhos apresentam menos possibilidade de se infectarem com o parasito...

The present study aimed to determine the occurrence of infection by Cryptosporidium spp. in goat kids from Quixadá, Ceará, Brazil. The study included 400 goat kids of both sexes, 3 to 360 days old, with or without defined breed, originating from 25 farms distributed in three circuits. Feces were registered in accordance with the appearance and color, distributed into tubes Eppendorf tubes and frozen in natura at-20°C until the moment of extraction of genomic DNA from the parasite with the aid of a commercial kit. For amplification of fragments of the 18S subunit of ribosomal RNA (rRNA) was used to Nested PCR. The occurrence of Cryptosporidium spp. in goats kids of the Quixadá was 7.50% (30/400). The frequency in the dry period and rainy was 9.55% (19/199) and 5.47% (11/201) respectively (χ²=2.39 and P>0.05). Positive samples were identified in 64.00% (16/25) of the studied farms, and from these samples 50.00% (15/30) and 70.00% (21/30) had feces with normal appearance and color respectively, suggesting that the asymptomatic goats were eliminating oocysts. No positivity for Cryptosporidium spp. was observed in 301 to 360-day-old goats, demonstrating that older animals have less chance to become infected with the parasite...

Estimativas de parâmetros genéticos para características de crescimento em ovinos da raça Somalis Brasileira / Genetic parameters estimates for growth traits in Somalis Brasileira hair sheep breed

Objetivou-se estimar parâmetros genéticos para características de crescimento em ovinos da raça Somalis Brasileira. Os dados utilizados neste estudo foram provenientes do rebanho da Embrapa Caprinos e Ovinos, localizado na cidade de Sobral - CE. Os dados continham registros de 1.120 animais no arquivo de pedigree. As características analisadas foram: peso ao nascer (PN), peso ao desmame (PD), ganho de peso do nascimento ao desmame (GND) e peso adulto (PA). As estimativas dos componentes de (co)variâncias e os parâmetros genéticos foram obtidos pelo método da Máxima Verossimilhança Restrita não Derivativa (DFREML), utilizando o programa MTDFREML. Nas análises unicaracterística, as herdabilidades foram de magnitude baixa a moderada. As magnitudes das herdabilidades maternas foram todas superiores às herdabilidades diretas. As herdabilidades das análises multicaracterísticas entre PN, PD e GND superaram as análises unicaracterísticas. As correlações genéticas apresentaram grande variação quanto aos seus valores.

The aim of this study was to estimate genetic parameters for growth traits in Somalis Brasileira hair sheep breed. The data used in this study were from the flock of Embrapa Caprinos and Ovinos, located in the city of Sobral - CE, Brazil. Data contained records of 1,120 animals in the pedigree file. The analyzed traits were birth weight (PN), weaning weight (PD), weight gain from birth to weaning (GND) and adult weight (PA). Estimates of (co)variances and genetic parameters were obtained by Derivative Free Restricted Maximum Likelihood Method (DFREML) using the MTDFREML software. The heritabilities were low to moderate in univariate analysis. The maternal heritabilities were higher than direct heritabilities. The heritabilities in multivariate analysis exceeded those in univariate analysis. The values of genetic correlations varied widely.

Aromatase gene and its effects on growth, reproductive and maternal ability traits in a multibreed sheep population from Brazil

We determined the polymorphism C242T of the aromatase gene (Cyp19) and its allelic frequency, as well as the effect of the variants on productive and reproductive traits in 71 purebred Santa Inês sheep, 13 purebred Brazilian Somali sheep, nine purebred Poll Dorset sheep, and 18 crossbred 1/2 Dorper sheep. The animals were genotyped using the PCR-RFLP technique. The influence of the animal's genotype on its performance or on the performance of its lambs was analyzed by the least square method. Another factor assessed was the importance of the animal's genotype in analysis models for quantitative breeding value estimates, and whether there were differences among the averages of breeding values of animals with different genotypes for this gene. In the sample studied, no AA individuals were observed; the AB and BB frequencies were 0.64 and 0.36, respectively. All Brazilian Somali sheep were of genotype BB. All 1/2 Dorper BB animals presented a lower age at first lambing, and the Santa Inês BB ewes presented a lower lambing interval. In these same genetic groups, AB ewes presented higher litter weight at weaning. This is evidence that BB ewes have a better reproductive performance phenotype, whereas AB ewes present a better maternal ability phenotype. However, in general, animals with genotype AB presented better average breeding values than those with genotype BB.

Genetic parameters for growth, reproductive and maternal traits in a multibreed meat sheep population

The genetic parameters for growth, reproductive and maternal traits in a multibreed meat sheep population were estimated by applying the Average Information Restricted Maximum Likelihood method to an animal model. Data from a flock supported by the Programa de Melhoramento Genético de Caprinos e Ovinos de Corte (GENECOC) were used. The traits studied included birth weight (BW), weaning weight (WW), slaughter weight (SW), yearling weight (YW), weight gain from birth to weaning (GBW), weight gain from weaning to slaughter (GWS), weight gain from weaning to yearling (GWY), age at first lambing (AFL), lambing interval (LI), gestation length (GL), lambing date (LD - number of days between the start of breeding season and lambing), litter weight at birth (LWB) and litter weight at weaning (LWW). The direct heritabilities were 0.35, 0.81, 0.65, 0.49, 0.20, 0.15 and 0.39 for BW, WW, SW, YW, GBW, GWS and GWY, respectively, and 0.04, 0.06, 0.10, 0.05, 0.15 and 0.11 for AFL, LI, GL, LD, LWB and LWW, respectively. Positive genetic correlations were observed among body weights. In contrast, there was a negative genetic correlation between GBW and GWS (-0.49) and GBW and GWY (-0.56). Positive genetic correlations were observed between AFL and LI, LI and GL, and LWB and LWW. These results indicate a strong maternal influence in this herd and the presence of sufficient genetic variation to allow mass selection for growth traits. Additive effects were of little importance for reproductive traits, and other strategies are necessary to improve the performance of these animals.

Efeito da incorporação da covariância entre os efeitos direto e materno sobre a análise para a característica dias para ganhar 160 Kg / Effect of the covariance between maternal and direct effects on the analyses for the traits days to gain 160 kg

O objetivo deste trabalho foi estudar o efeito da covariância entre os efeitos direto e materno sobre as estimativas dos parâmetros genéticos e nas predições dos valores genéticos, direto e materno, para a característica dias para ganhar 160 kg (D160) na fase pré-desmama. Os parâmetros e as predições dos valores genéticos foram estimados utilizando o aplicativo MTDFREML. O modelo 1 incluiu os efeitos genéticos direto e materno e de ambiente permanente, além do efeito fixo de grupo contemporâneo e da covariável idade da vaca ao parto, assumindo a covariância entre o efeito direto e materno (sigmaam 0); o modelo 2, considerou os mesmos efeitos do modelo 1, mas a covariância entre os efeitos direto e materno foi considerada nula (sigmaam=0). As estimativas de correlação de classificação dos animais pelos valores genético foram realizadas utilizando a correlação de Spearman. As estimativas de herdabilidade direta e materna para D160 foram respectivamente, 0,12 ± 0,01 e 0,09 ± 0,02, sob o modelo 1, e 0,12 ± 0,01 e 0,07 ± 0,02, sob o modelo 2. A correlação genética entre os efeitos direto e materno foi de -0,14 ± 0,12 (modelo 1). A inclusão da covariância entre os efeitos direto e materno nos modelos de análises não alterou a estimativa dos parâmetros genéticos e a classificação dos animais pela ordem dos valores genéticos estimados, quando se considerou toda a população. Entretanto, verificou-se que à medida que diminui a proporção de animais selecionados diminui a correspondência entre a classificação dos animais obtida pelos dois modelos.

Effect of 0.9 percent saline solution and phosphate buffer saline at different temperatures and incubation times on the morphology of goat preantral follicles

The present work investigated the efficiency of 0.9 percent saline solution and Phosphate Buffered Saline (PBS) in the preservation of goat preantral follicles in situ at different temperatures and incubation times. The ovarian pair of each animal was divided into 19 fragments. One ovarian fragment was taken randomly and fixed (control). The other 18 fragments were randomly distributed in tubes containing 0.9 percent saline solution or PBS at 4, 20 or 39 ºC for 4, 12 or 24 h. A total of 5,921 preantral follicles were examined. The quality of preantral follicles was evaluated by classical histology. The storage of ovarian fragments in 0.9 percent saline solution or PBS at 4 ºC did not reduce significantly the percentage of morphologically normal follicles when compared with the control, except after preservation in 0.9 percent saline solution for 24 h. The storage of ovarian fragments at 20 or 39°C reduced the percentage of normal preantral follicles when compared to the control, except after preservation in PBS at 20°C for 4 h. In conclusion, this study showed for the first time that goat preantral follicles can be stored in situ successfully at 4 ºC in 0.9 percent saline solution for 12 h and in PBS for 24 h, and at 20 ºC in PBS for 4 h