Economic values for production traits of Morada Nova meat sheep in a pasture based production system in semi-arid Brazil

AbstractEconomic values were estimated for meat sheep raised in a pasture based production system in semi-arid Brazil using data on the Morada Nova hair sheep breed. The traits considered were lambing percentage (LP), litter size (LS), lamb mortality (LM), yearling mortality (YM), ewe and ram mortality (AM), female slaughter weight (FSW), male slaughter weight (MSW), ewe adult weight (EAW), ram adult weight (RW), carcass yield (CY), number of lambings per year (NLY), age at first lambing (AFL) and number of anthelminthic doses used per year (AC). The economic values were estimated using the profit equation (profit=revenue−costs) after a one unit and 1% increase of each trait, keeping all other traits at their mean value. With a 1% increase in the traits, the economic values (US$ per ewe per year) for LP, LM, MSW, CY and NLY were 0.781, −0.138, 0.416, 0.827 and 0.781, respectively. The production system with Morada Nova sheep grazing native “caatinga” pasture in Brazilian Northeast, exclusively for meat production, is profitable when taking into account all costs of production, including that of family labour. Carcass yield was shown to be an important selection objective. As it is expressed when the animal is slaughtered, further studies need to be carried out with this population to aid in the choice of appropriate selection criteria for the improvement of this trait

Efeito da incorporação da covariância entre os efeitos direto e materno sobre a análise para a característica dias para ganhar 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;¹;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.The aim of this work was to study the effect of the covariance between maternal and direct effects on estimatives of genetic parameters and on predictions of breeding values for days to gain 160 kg in the pre-weaning period (D160). The analysis were carried out using the MTDFREML software. The model 1 included the direct and maternal genetic effects and permanent environmental effect and the fixed effects of the contemporaneous group and the covariable age of dam at calving, assuming the covariance between maternal and direct effect (sigmaam;¹;0); the model 2 included the same effects of model 1, but the covariance between maternal and direct effects was considered zero (sigmaam=0). The rank correlations were obtained using Spearman correlation. The direct and maternal heritabilities for D160, were respectively, 0.12 ± 0.01 and 0.09 ± 0.02, for the model 1, and 0.12 ± 0.01 and 0.07 ± 0.02, for the model 2. The correlation between maternal and direct effects was -0.14 ± 0.12 (model 1). The inclusion of the covariance between maternal and direct effects in the analysis models had no influence on the genetic parameters and on the rank of the animals classified by breeding values, when all population was considered. However, as it reduced the proportion of selected animal was reduced there was a corresponding reduction on ranking animals through the two models

Embryo production in Morada Nova and Somalis Brasileira ewes

Superovulatory response and embryo yield in 19 Morada Nova and 20 Somalis Brasileira ewes was analyzed. All animals were synchronized with the insertion of an intravaginal device (CIDR(r)) on Day 0, replaced by a new device on Day 7, which remained in place until Day 14 and superovulated with 133mg of porcine FSH (pFSH) in decreasing doses at 12h intervals from Day 12 until Day 15 of the treatment, and a single dose of equine chorionic gonadotropin (eCG, 200UI) on Day 14 (i.e., administered in CIDR removal). Fifty hours after CIDR(r) removal, females were inseminated by laparoscopy. All embryos were recovered by laparotomy 5 days after insemination. Sheep which responded to the superovulation protocol (P>0.05) included 74% of the Morada Nova ewes and 50% of the Somalis Brasileira ewes. Morada Nova showed better results (P<0.05) than Somalis Brasileira in number of ovulations (15.38 ± 5.24 vs. 10.56 ± 2.83), total structures (11.00 ± 7.55 vs. 3.33 ± 1.94) and embryo yields (6.79 ± 5.35 vs. 2.90 ± 2.18). Despite the high fertilization rate, degenerate embryo rate was high for both breeds, with an overall rate of 39% (57/145). In conclusion, superovulatory response and embryo yields in Morada Nova ewes were considered sufficient to justify the use of this procedure in genetic resources conservation programs. However, improvements to embryo quality and control of precocious regression of corpus luteum are necessary to produce better results in the MOET program, with minimal variations and maximum embryo yield in Morada Nova and Somalis Brasileira ewes

Validação de um subconjunto de SNPs específicos para certificação racial de ovinos no Brasil

O objetivo deste trabalho foi avaliar a utilidade de um subconjunto de 18 polimorfismos de nucleotídeo único (SNPs) para a certificação das raças de ovinos Crioula Brasileira, Morada Nova (MN) e Santa Inês (SI). Dados de 588 animais foram analisados com o programa Structure. Em 82% dos casos, observou-se designação racial correta com confiança acima de 90%. A maioria dos casos de designação incorreta de raça foi observada em MN e SI. Portanto, apesar de o subconjunto de 18 SNPs ter confiabilidade elevada, ele não é suficiente para a inequívoca certificação das raças estudadas, principalmente das deslanadas. É necessário o desenvolvimento de um painel mais preciso para uso amplo em certificação racial.The objective of this work was to evaluate the usefulness of a subset of 18 single nucleotide polymorphisms (SNPs) for breed identification of Brazilian Crioula, Morada Nova (MN), and Santa Inês (SI) sheep. Data of 588 animals were analyzed with the Structure software. Assignments higher than 90% confidence were observed in 82% of the studied samples. Most of the low-value assignments were observed in MN and SI breeds. Therefore, although there is a high reliability in this subset of 18 SNPs, it is not enough for an unequivocal assignment of the studied breeds, mainly of hair breeds. A more precise panel still needs to be developed for the widespread use in breed assignment

Validation of a microsatellite panel for parentage testing of locally adapted and commercial goats in Brazil

Brazilian goats are generally kept in small herds and extensive rearing systems, mainly in the northeastern region of the country. Despite production improvement in recent years, the lack of pedigree control has affected genetic progress. This study aimed to validate a panel of 16 microsatellites for parentage testing in locally adapted and commercial goats breeds raised in Brazil, as well as to compare its efficiency with the panel recommended by the Brazilian Ministry of Agriculture, Livestock and Supplies (MAPA) in 2004. The number of alleles and expected heterozygosity (He) per marker ranged from four to 18, and from 0.051 to 0.831, respectively. Using all markers, 100% of parentage cases of the validation dataset were resolved with a strict confidence level of 95%. The 16 microsatellites panel showed adequate exclusion power (99.99%) and identity accuracy (99.99%). Suggestions for improvement of the marker panel endorsed by MAPA are provided

EFEITO DO LEVAMISOL E DO EXTRATO ETANÓLICO DE FOLHAS DE Momordica Charantia SOBRE A DERMATOFITOSE EXPERIMENTAL EM COELHOS

O objetivo deste trabalho foi avaliar o efeito do levamisol e do extrato etanólico das folhas de Momordica charantia na dermatofitose experimental. Para tanto, coe¬lhos jovens, Nova Zelândia, machos, divididos em grupos, receberam, por via oral, durante quinze dias consecutivos Tween 20 (1%, controle; n=5), levamisol (25 mg/Kg/PV; n=4) ou extrato etanólico de M. charantia (EE, 10 mg/Kg/PV, n=6) a partir do 15º dia inoculação por Microsporum canis. Foram realizadas as contagens total e diferencial de leucócitos do sangue periférico, cultivo do raspado de pele e avaliação histopatológica das lesões. O levamisol e o EE reduziram os escores de avaliação histológica das lesões provocadas pelo M. canis e não induziram modificação dos leucócitos circulantes. O tratamento com levamisol provocou alterações na pele infectada em relação ao controle (

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