Phenotypic characterisation and production system of the Nordestino horse from a multivariate perspective.

Zootechnical data is a big challenge in the extensive rearing system of Brazilian locally adapted breeds once smallholdings with limited resources and funds rear them. So, information on Brazil's breeding system of locally adapted breeds is still scarce; this situation is more challenging for equine breeds. The present study aimed to describe the local rearing systems and the phenotypic profile of the Nordestino horse breed in Paraíba state and contribute to breed conservation. Data from males (entire and castrated) and females from 50 municipalities in Paraíba state were used. Two hundred sixty-nine animals (111 females, 121 castrated males, and 37 entire males) from 129 breeders were analyzed. A questionnaire consisting of direct and objective questions was applied to understand the breeding system adopted. There was a predominance of the extensive breeding system (85%), which reflects the adaptation of the Nordestino Horse to the region's natural conditions. The lower frequency of use of cultivated pastures may be related to issues of economic viability since the maintenance of cultivated pastures may require additional investments compared to the use of natural pastures. Entire males had a minimum withers height (WH) of 135 cm. Of the 11 morphometric measurements, only five were considered discriminating by the stepwise analysis. The remaining Nordestino horses have morphological characteristics within the breed standard.

Does crossbreeding improve the performance and carcass traits of Berganês sheep?

This study aimed to evaluate the performance and carcass of lambs of different genotypes through univariate and multivariate analysis. Intact male lambs of the Berganês (BG), Berganês x Santa Inês (BSI), and Berganês x Dorper (BD) genotypes and the control group Dorper x Santa Inês (DSI) were used. Eight lambs of each genotype were used, aged between 4 and 5 months, with an average initial weight of 27.52 ± 3.79 kg, distributed in a completely randomized design. Data were tested by analyzing variance, followed by Tukey's test and principal component analysis (PCA) and discriminant analysis (DA). Slaughter body and average daily gain were higher for BD and BG than BSI (P < 0.05). On the other hand, BSI, BD, and DSI showed higher cold carcass yield than BG (P < 0.05). Lower cooling losses (CL) and more excellent conformation were observed in DSI (P < 0.05). BD showed a higher carcass compactness index (CCI), and DSI showed a higher leg compactness index (LCI) (P < 0.05). PCA produced seven components explaining 83.59% of total data variability. Based on the discriminant analysis, LCI, CL, CCI, and conformation showed greater power to distinguish the genotypes, with a high index of the lambs' classification to their respective genotypes. The crossbreeding improved carcass yield and reduced cooling weight loss. The Berganês ecotype and its crossbreeds have performance and carcass traits compatible with the DSI genotype. According to the DA, heterogeneity was found between the Berganês ecotype and its crossbreeds, with CL, LCI CCI, and conformation showing greater discrimination power.

Diversity Analysis and Genetic Relationships among Local Brazilian Goat Breeds Using SSR Markers.

The genetic diversity of six Brazilian native goats was reported using molecular markers. Hair samples of 332 animals were collected from different goat breeds (Moxotó, Canindé, Serrana Azul, Marota, Repartida, and Graúna) from five states of Northeast Brazil (Paraíba, Pernambuco, Rio Grande do Norte, Bahia, and Piauí). A panel of 27 microsatellites or single sequence repeats (SSRs) were selected and amplified using a polymerase chain reaction (PCR) technique. All populations showed an average allele number of over six. The mean observed heterozygosity for Brazilian breeds was superior to 0.50. These results demonstrated the high genetic diversity in the studied populations with values ranging from 0.53 (Serrana Azul) to 0.62 (Repartida). The expected average heterozygosity followed the same trend ranging from 0.58 (Serrana Azul) to 0.65 (Repartida), and the values obtained are very similar for all six breeds. The fixation index (Fis) had values under 10% except for the Moxotó breed (13%). The mean expected heterozygosity of all Brazilian populations was over 0.50. Results indicated a within-breed genetic variability in the Brazilian breeds based on the average number of alleles and the average observed heterozygosity. The interbreed genetic diversity values showed proper genetic differentiation among local Brazilian goat breeds.

Multivariate techniques in the analysis of carcass traits of Morada Nova breed sheep / Aplicação de técnicas multivariadas em características de carcaça de ovinos da raça Morada Nova

ABSTRACT: This study aimed to use multivariate techniques of principal component analysis and canonical discriminant analysis in a data set from Morada Nova sheep carcass to reduce the dimensions of the original data set, identify variables with the best discriminatory power among the treatments, and quantify the association between biometric and performance traits. The principal components obtained were efficient in reducing the total variation accumulated in 19 original variables correlated to five linear combinations, which explained 80% of the total variation present in the original variables. The first two principal components together accounted for 56.12% of the total variation of the evaluated variables. Eight variables were selected using the stepwise method. The first three canonical variables were significant, explaining 92.25% of the total variation. The first canonical variable showed a canonical correlation coefficient of 0.94, indicating a strong association between biometric traits and animal performance. Slaughter weight and hind width were selected because these variables presented the highest discriminatory power among all treatments, based on standard canonical coefficients.

RESUMO: Este estudo teve o objetivo de aplicar as técnicas multivariadas de componentes principais e discriminante canônica em um conjunto de dados de carcaça de ovinos da raça Morada Nova, a fim de reduzir a dimensionalidade do conjunto de variáveis originais, identificar quais as variáveis com o melhor poder discriminatório entre os tratamentos, além de quantificar a associação entre características biométricas e de desempenho. Os componentes principais gerados foram eficientes em reduzir a variação total acumulada em 19 variáveis originais, correlacionadas para cinco combinações lineares, os quais explicaram 80% da variação total contida nas variáveis originais. Os dois primeiros componentes principais juntos explicam 56,12% da variação total das variáveis avaliadas. Oito variáveis foram selecionadas pelo método stepwise. As três primeiras variáveis canônicas foram significativas, explicando 92,25% da variação total. A primeira variável canônica apresentou o coeficiente de correlação canônica de 0,94, o que indica uma alta associação entre as características de medidas biométricas e de desempenho animal. O peso corporal ao abate e a largura de garupa foram as variáveis selecionadas por apresentar o mais alto poder discriminatório dos tratamentos, com base nos coeficientes canônicos padronizados.

Do traditional sheep breeders perform conscious selection? An example from a participatory breeding program of Morada Nova sheep.

The implementation of sustainable breeding programs requires genetic breeding strategies that are appropriate for the reality production systems. It is also essential that the choice of animal selection criteria be based on breeders' knowledge and objectives. This work is an ethno-zootechnical study of the Morada Nova sheep breed and its crossbreeds. The goals of this study were to register and analyze indigenous breeders' knowledge and practices regarding animal selection criteria and to generate technical information to support a participatory breeding program of the breed. This study was conducted in the Morada Nova municipality in the state of Ceará, Brazil. Semi-structured interviews were evaluated using two groups of individuals, purebred Morada Nova sheep breeders (RMN, n = 13) and breeders of Morada Nova crossbreeds (MMN, n = 48). Interview questions were used to identify local selection criteria adopted by each group in the choice of animals for breeding. Data from the interviews were submitted to frequency distribution analysis and the Shapiro-Wilk test to verify their distribution. Later, the Kruskal-Wallis test was used to compare the two groups of farmers based on that information, in addition to multivariate statistical analysis and evaluation of Smith salience index. Breeders in the RMN group used selection criteria related to breed standards, such as pelage color. In contrast, breeders of the MMN group used criteria related to productivity, such as body conformation and milk production. Breeders should be engaged in the development of breeding programs, and it is important to consider their preferences and objectives when evaluating breeding animals.

Effect of the replacement of Tifton 85 with maniçoba hay on the performance of Morada Nova hair sheep.

The use of native and adapted forages is an alternative for sustainable production systems in northeast Brazil. The goal of this study was to evaluate the substitution of Tifton 85 by maniçoba hay on the performance and carcass traits of Morada Nova hair sheep. The 16 lambs that were used in this study initially weighed 19.36 ± 1.48 kg, were housed in individual pens, and were slaughtered at 58 days of confinement. The dry matter intake (839.84 g/day and 3.81% WB) was higher (P < 0.05) in sheep fed maniçoba hay. The feed conversion was 7.39 for sheep fed maniçoba hay. The empty body weight (21.61 kg) and cold carcass weight (11.40 kg) did not differ (P > 0.05) between sheep fed different hay types. The replacement of Tifton 85 by maniçoba hay did not influence the loin eye area (cm(2)) or carcass compactness index (kg/cm). The replacement of Tifton 85 by maniçoba hay in Morada Nova sheep diet did not affect the weight gain or carcass characteristics. The maniçoba hay can be considered a forage resource for feeding sheep in Brazilian semiarid tropics.

Estimation models of variance components for farrowing interval in swine

The main objective of this study was to evaluate the importance of including maternal genetic, common litter environmental and permanent environmental effects in estimation models of variance components for the farrowing interval trait in swine. Data consisting of 1,013 farrowing intervals of Dalland (C-40) sows recorded in two herds were analyzed. Variance components were obtained by the derivative-free restricted maximum likelihood method. Eight models were tested which contained the fixed effects(contemporary group and covariables) and the direct genetic additive and residual effects, and varied regarding the inclusion of the maternal genetic, common litter environmental, and/or permanent environmental random effects. The likelihood-ratio test indicated that the inclusion of these effects in the model was unnecessary, but the inclusion of the permanent environmental effect caused changes in the estimates of heritability, which varied from 0.00 to 0.03. In conclusion, the heritability values obtained indicated that this trait appears to present no genetic gain as response to selection. The common litter environmental and the maternal genetic effects did not present any influence on this trait. The permanent environmental effect, however, should be considered in the genetic models for this trait in swine, because its presence caused changes in the additive genetic variance estimates.

Este trabalho teve como objetivo principal avaliar a importância da inclusão dos efeitos genético materno, comum de leitegada e de ambiente permanente no modelo de estimação de componentes de variância para a característica intervalo de parto em fêmeas suínas. Foram utilizados dados que consistiam de 1.013 observações de fêmeas Dalland (C-40), registradas em dois rebanhos. As estimativas dos componentes de variância foram realizadas pelo método da máxima verossimilhança restrita livre de derivadas. Foram testados oito modelos, que continham os efeitos fixos (grupos de contemporâneo e covariáveis) e os efeitos genético aditivo direto e residual, mas variavam quanto à inclusão dos efeitos aleatórios genético materno, ambiental comum de leitegada e ambiental permanente. O teste da razão de verossimilhança (LR) indicou a não necessidade da inclusão desses efeitos no modelo. No entanto observou-se que o efeito ambiental permanente causou mudança nas estimativas de herdabilidade, que variaram de 0,00 a 0,03. Conclui-se que os valores de herdabilidade obtidos indicam que esta característica não apresentaria ganho genético como resposta à seleção. O efeito ambiental comum de leitegada e o genético materno não apresentaram influência sobre esta característica. Já o ambiental permanente, mesmo sem ter sido significativo o seu efeito pelo LR, deve ser considerado nos modelos genéticos para essa característica, pois sua presença causou mudança nas estimativas da variância genética aditiva.