Morada Nova lambs' meat production potential description through morphometric evaluation / Descrição do potencial de produção de carne de cordeiros Morada Nova por meio da avaliação morfométrica

Morada Nova breed has a low effective herd, and its white variety is in risk of extinction. The selection of individuals based on breed standard without correlation with productive aptitude is predominant today. We believe that the best way to rescue this valuable genetic resource is to describe its productive potential for commercial use. Thus, this study described the meat production potential of Morada Nova lambs through morphological and zoometric data, performance and carcass characteristics. Twenty-four non-castrated male lambs from two genetic groups were used: Morada Nova red (MNR) and crossbreed Morada Nova (red x Morada Nova white-MNF1) distributed in a completely randomized design. Univariate and multivariate analysis were used. The yields of commercial cuts and the physicochemical characteristics and qualitative measurements of the carcass were similar between the genetic groups. Seven of the 28 characteristics of the carcass were greater in MNF1 lambs. The chest height, rump height and anamorphosis index showed to be important variables in the choice of MN lambs with meat production potential. Based on factor and hierarchical cluster analysis, the Morada Nova beef morphometric index (MNBMI) was created. Both of groups have high thoracic development, ability to produce meat, weight gain, feeding efficiency and breathing capacity, infusing greater rusticity and adaptability; however, the application and validation of the developed index showed superiority for meat production in the crossed lambs. Thus, the MNF1 lambs are a sustainable option for sheep production in drylands.

A raça Morada Nova possui um baixo rebanho efetivo, e sua variedade branca está em risco de extinção. A seleção de indivíduos com base no padrão racial sem correlação com a aptidão produtiva é predominante até hoje. Acreditamos que a melhor forma de resgatar esse valioso recurso genético é descrever seu potencial produtivo para uso comercial. Assim, este estudo teve como objetivo descrever o potencial de produção de carne de cordeiros Morada Nova por meio de dados morfológicos e zoométricos, desempenho e características de carcaça. Foram utilizados 24 cordeiros machos não castrados de dois grupos genéticos: Morada Nova Vermelho (MNV) e mestiços Morada Nova (vermelho x Morada Nova branco-MNF1) distribuídos em delineamento inteiramente casualizado. Análises univariadas e multivariadas foram utilizadas. Os rendimentos dos cortes comerciais e as características físico-químicas e medidas qualitativas da carcaça foram semelhantes entre os grupos genéticos. Sete, das 28 características da carcaça, foram maiores nos cordeiros MNF1. A altura do peito, altura da garupa e índice de anamorfose mostraram-se variáveis ​​importantes na escolha de cordeiros MN com potencial de produção de carne. Com base na análise fatorial e hierárquica de agrupamento, foi elaborado o índice morfométrico da carne da raça Morada Nova (IMCMN). Ambos os grupos apresentam alto desenvolvimento torácico, capacidade de produção de carne, ganho de peso, eficiência alimentar e capacidade respiratória, infundindo maior rusticidade e adaptabilidade, porém, a aplicação e validação do índice desenvolvido mostrou superioridade para produção de carne nos cordeiros cruzados. Assim, os cordeiros MNF1 são uma opção sustentável para a produção ovina em terras áridas.

Vacuolização neuronal e degeneração espinocerebelar em filhote de Rottweiler / Neuronal vacuolation and spinocerebellar degeneration in a Rottweiller puppy

Background: Spinocerebellar degenerations and neuronal vacuolations are alterations characterized by the formation of vacuoles in the nervous tissue, commonly called status spongiosus. This condition occurs in young Rottweiler dogs causing a disease called Neuronal Vacuolation and Spinocerebellar Degeneration. Clinically, it presents with ataxia of the pelvic limbs, which evolves to generalized ataxia, tetraparesis, and laryngeal paralysis. Histologically, spongiform and vacuolar alterations of the neuropil and neurons are highlighted. This reports a case of neuronal vacuolation and spinocerebellar degeneration in a Rottweiler puppy. Case: Necropsy was performed on the cadaver of a 5-month-old Rottweiler bitch that had been presenting with ataxia for approximately 1 month, in addition to dyspnea, pulmonary crepitations, and microphthalmia. Macroscopic evaluation revealed pale ocular and oral mucosae; marked gastric dilatation and abdominal distension; pulmonary hemorrhage and edema; hepatosplenomegaly; fatty degeneration of the liver; and congestion of meningeal blood vessels. Microscopically, histological evaluation of the spinal cord showed an increase in gray matter cellularity with marked presence of oligodendrocytes and microglia cells; moderate to severe multifocal intracytoplasmic micro- and macrovacuoles with displacement of the neurons' nuclei to the periphery of the cell; central chromatolysis of the neurons adjacent to neurons affected by vacuolation; and mild multifocal necrosis associated with mild multifocal neuronophagia. The white matter exhibited discrete digestion chambers, in addition to marked diffuse congestion of the leptomeninges. In the cerebellum, neurons in the nerve nuclei (emboliform, globose, and fastigial) showed moderate multifocal vacuoles in the cytoplasm, whereas adjacent neurons showed central chromatolysis, necrosis, and mild neuronophagia. Additional histological findings included lymphoid hyperplasia, fatty degeneration of the liver, pulmonary edema, and pulmonary hemorrhage. Discussion: Spongiform and degenerative encephalopathies are diseases recognized worldwide, mainly in cattle and sheep. However, the identification of these changes in new species has led to the need for further investigations. In dogs, the first reports occurred in 1995 and 1997 in Rottweiler animals. This disease affects young dogs, and although its pathogenesis is not completely known, it is believed to be associated with a genetic mutation in the RAB3GAP1 gene. Clinically, it is associated with clinical neurological manifestations, including progressive ataxia of the pelvic limbs, changes in spinal reflex, disordered proprioceptive reactions, laryngeal paralysis, as well as behavioral and gait alterations. In the clinical evaluation, leukoencephalomyelopathy and neuroaxonal dystrophy should be diseases considered as possible differential diagnoses, as they present with similar alterations. However, in histological evaluation, the exclusion of both is basically due to the absence of neuronal vacuolization. Unfortunately, the definitive diagnosis is only made post mortem, through a histopathological evaluation of the nervous tissue. Because it is a disease whose pathogenesis is little known and which shows signs of having a genetic character, histopathological examination for diagnostic purposes in young animals with neurological signs is of great importance.

Polysaccharide storage myopathy in two Percheron horses / Miopatia por acúmulo de polissacarídeo em dois equinos da raça Percheron

Polysaccharide storage myopathy (PSSM) is a genetic disorder or by undetermined cause characterized by the abnormal accumulation of glycogen and polysaccharides in skeletal muscle fibers. The present report describes two Percheron horses, from different properties in the municipality of Pouso Redondo -SC, with locomotor clinical signs that started after work. The clinical signs observed were rigid gait, mainly of the pelvic limbs, muscle weakness, and recumbency. In the first case, the animal was diagnosed with severe multifocal rhabdomyonecrosis, moderate multifocal myoglobin nephrosisand severe diffuse transmural fibrinonecrotic gastritis. PSSM was confirmed by the presence of polysaccharide inclusions in myofiber sarcolemma visualized by periodic acid-Schiff (PAS) staining. In the second case, the horse presented two episodes ofmuscle disorder after work. The therapeutic protocol was based on penicillin, flunixin meglumine and fluid therapy with ringer lactate. An increase in creatine kinase (669.0 UI/L) and aspartate aminotransferase (669.0 UI/L) was observed in the serum biochemical evaluation. Research for mutation in the GYS1 gene was performed, with a positive heterozygote result. After rest and gradual recovery, the horse was only submitted to light work, with no return of the clinical condition since then. Thus, this report describes two cases of PSSM with distinct clinical evolution and diagnostic methods.(AU)

A miopatia por acúmulo de polissacarídeos (PSSM) é uma desordem genética ou de causa indeterminada caracterizada pelo acúmulo anormal de glicogênio e polissacarídeos nas fibras musculares esqueléticas. O presente relato descreve dois cavalos Percheron, oriundos de diferentes propriedades do município de Pouso Redondo ­SC, com sinais clínicos locomotores que iniciaram após o trabalho. Os sinais clínicos observados foram marcha rígida, principalmente dos membros pélvicos, fraqueza muscular, e decúbito. No primeiro caso, o animal foi diagnosticado com rabdomionecrose multifocal acentuada, nefrose mioglobínica multifocal moderada e gastrite fibrinonecrótica transmural difusa acentuada. A PSSM foi confirmada pela presença de inclusões polissacarídicas no sarcolema de miofibras visualizadas pela coloração com ácido periódico de Schiff (PAS). No segundo caso, o equino apresentou dois episódios de disfunção muscular após o trabalho. O protocolo terapêutico foi baseado em penicilina, flunixin megluminee fluidoterapia com ringer lactato. Um aumento de creatina quinase (669,0 UI/L) e aspartato aminotransferase (669,0 UI/L) foi observado na avaliação bioquímica sérica. Foi realizada pesquisa de mutação nogene GYS1, com resultado heterozigoto positivo. Após repouso e recuperação gradual, o cavalo foi submetido apenas a trabalhos leves, sem retorno do quadro clínico desde então. Assim, este relato descreve dois casos com PSSM com evolução clínica e métodos diagnósticos distintos.(AU)

Idiopathic subfertility in stallions. Clinical approaches to a complex problem

At least 30-40% of stallions in commercial breeding programs are moderately fertile and 8-12% are subfertile (0.5-3% with severe subfertility). From the total reported cases of the subfertility, in 2-20% of the stallions the cause is unknown or was not established. The objective of this work is to present the concept of subfertile stallion based on the current state of knowledge and advanced molecular diagnostic technologies. Low pregnancy rates have been reported in stallions with normal semen quality after conventional evaluation. Acrosome reaction (AR) is necessary for natural fertilization and impaired acrosome reaction (IAR) leads to subfertility or infertility in horses, however, AR test is not included in routine semen analysis. Genome-wide association study identified FKBP6 as a strong candidate gene responsible for this failure. The gene encodes for FK506 binding protein 6 (FKBP6) which is involved in sperm development and functions. We could conclude that the evaluation of the acrosomal status is essential in cases of stallions with good motility, concentration, morphology and viability but unexplained (idiopathic) subfertility or infertility. It is important to highlight the recent increase in reports of fertility problems in stallions related to disorders of genetic origin.(AU)

Carcinoma de células escamosas (cce) em cão na região prepucial: relato de caso / Squamous cell carcinoma (scc) in dog in the preputial region: case report / Carcinoma de células escamosas (cce) en perro de la región prepucial: reporte de un caso

A expectativa de vida dos animais de companhia vem aumentando devido as mudanças comportamentais e de cuidados dos tutores. Em analogia, com as idades cada vez mais avançadas, é comum o desenvolvimento de doenças associadas, sendo o tumor o mais comum entre elas. Todavia, as neoplasias mais comuns na clínica de pequenos animais estão associadas ao sistema tegumentar. O carcinoma de células escamosas (CCE), ou carcinoma espinocelular, é uma neoplasia de epitélio, maligno, de crescimento lento e de baixo potencial metastático. Sua etiologia ainda não é precisamente conhecida e a causa exógena mais comum e descrita pela literatura é a exposição à luz ultravioleta, gerando consequentes lesões nas estruturas genéticas e imunogênicas na pele. Além disso, essas lesões apresentam-se de forma mais comum em animais de pelagem clara, com grande exposição solar e em área anatômicas hipopigmentadas. O prognóstico varia de acordo com a localização e o estágio clínico, sendo favorável o diagnóstico realizado precocemente, e o tratamento consiste na avaliação clínica seguida do protocolo adequado O presente relato de caso tem como objetivo principal reunir e discutir informações associadas sobre o carcinoma de células escamosas em caninos e felinos, abordando aspectos clínicos e patológicos, a fim de facilitar o raciocínio sobre o CCE, desde sua abordagem inicial, até seu diagnóstico final e estadiamento.(AU)

The life expectancy of companion animals has been increasing due to behavioral and care changes of the guardians. In analogy, with the increasingly advanced ages, the development of associated diseases is common, the tumor being the most common among them. However, the most common neoplasms in the small animal clinic are associated with the integumentary system. Squamous cell carcinoma (SCC), or squamous cell carcinoma, is a malignant, slow-growing, low-potential metastatic epithelial neoplasm. Its etiology is not yet precisely known and the most common exogenous cause described by the literature is exposure to ultraviolet light, generating consequent lesions on the genetic and immunogenic structures in the skin. In addition, these lesions are more common in light-haired animals, with high exposure to the sun, and in hypopigmented anatomical areas. The prognosis varies according to the location and clinical stage, being favorable to the early diagnosis, and the treatment consists in the clinical evaluation followed by the appropriate protocol. The present case report has as its main objective to gather and discuss associated information about squamous cell carcinoma in canines and cats, addressing clinical and pathological aspects, in order to facilitate the reasoning about the CCE, from its initial approach, to its final diagnosis and staging.(AU)

La esperanza de vida de los animales de compañía ha ido en aumento debido a los cambios de comportamiento y cuidado de los guardianes. Por analogía, con las edades cada vez más avanzadas, el desarrollo de enfermedades asociadas es común, siendo el tumor el más común entre ellos. Sin embargo, las neoplasias más comunes en la clínica de animales pequeños se asocian con el sistema tegumentario. El carcinoma epidermoide (CCE), o carcinoma epidermoide, es una neoplasia epitelial metastásica maligna de crecimiento lento y bajo potencial. Su etiología aún no se conoce con precisión y la causa exógena más común descrita por la literatura es la exposición a la luz ultravioleta, generando lesiones consecuentes en las estructuras genéticas e inmunogénicas de la piel. Además, estas lesiones son más comunes en animales de pelo claro, con alta exposición al sol, y en áreas anatómicas hipopigmentadas. El pronóstico varía según la localización y el estadio clínico, siendo favorable al diagnóstico precoz, y el tratamiento consiste en la evaluación clínica seguida del protocolo adecuado. El presente reporte de caso tiene como objetivo principal reunir y discutir información asociada sobre el carcinoma epidermoide en caninos y gatos, abordando aspectos clínicos y patológicos, con el fin de facilitar el razonamiento sobre el CCE, desde su abordaje inicial, hasta su diagnóstico final y estadificación.(AU)

The impact of heterogeneity of variances on the genetic evaluation of performance traits in Nellore cattle

The objective was to evaluate the existence of heterogeneity of variances and its impact on the genetic evaluation of ponderal performance in sires of the Nellore breed. We used records of adjusted body weights at 210 (W210), 365 (W365), and 450 (W450) days of age. Both W365 and W450 were combined by principal component analyses using the first component (PC). Average daily gain (ADG) was obtained by difference between W450 and W210. The classes of standard deviations (SD) for W210, PC, and ADG were obtained by the standardization of means of herd-year means subclasses, with positive values composing the high SD and values equal and less than zero composing the SD. The model included the fixed effects of contemporary group and age at calving as a covariate, random genetic additive, and maternal genetic (except for PC) effects, and the permanent maternal environment. Variance components were obtained by Gibbs sampling. Posterior means of heritability in analyses without considering heterogeneity of variances ranged from 0.15±0.01 to 0.31±0.01. Posterior means of genetic correlations between the two classes of SD for W210, PC, and ADG were equal to 0.85±0.04, 0.83±0.03, and 0.71±0.08, respectively. Spearman correlation to breeding values of sires for ADG as the selection intensity increased in them, and the correlations between breeding values in general analyses were more correlated with those predicted in the high DP. Therefore, when there is a higher selection intensity on the sires only for the ADG criterion, there is a significant presence of the heterogeneity of variances and impact on the genetic evaluation of the sires. Thus, for ADG, the predictions of breeding values obtained by the genetic evaluation model in which the heterogeneity of variances are not considered are more weighted by the class of greater heterogeneity.(AU)

Multilayer perceptron applied to genotypes classification in diallel studies

In the last decades, a new trend to use more refined analytical procedures, such as artificial neural networks (ANN), has emerged to be most accurate, efficient, and extensively applied for mining and data prediction in different contexts, including plant breeding. Thus, this study was developed to establish a new classification proposal for targeting genotypes in breeding programs to approach classical models, such as a complete diallel and modern prediction techniques. The study was based on the standard deviation values of an interpopulation diallel and it also verified the possibility of training a neural network with the standardized genetic parameters for a discrete scale. We used 12 intercrossed maize populations in a complete diallel scheme (66 hybrids), evaluated during the 2005/2006 crop season in three different environments in southern Brazil. The implemented MLP architecture and other associated parameters allowed the development of a generalist model of genotype classification. The MLP neural network model was efficient in predicting parental and interpopulation hybrid classifications from average genetic components from a complete diallel, regardless of the evaluation environment.(AU)

Evaluation of Bayesian methods of genomic association via chromosomic regions using simulated data

The development of efficient methods for genome-wide association studies (GWAS) between quantitative trait loci (QTL) and genetic values is extremely important to animal and plant breeding programs. Bayesian approaches that aim to select regions of single nucleotide polymorphisms (SNPs) proved to be efficient, indicating genes with important effects. Among the selection criteria for SNPs or regions, selection criterion by percentage of variance can be explained by genomic regions (%var), selection of tag SNPs, and selection based on the window posterior probability of association (WPPA). To also detect potentially associated regions, we proposed measuring posterior probability of the interval PPint), which aims to select regions based on the markers of greatest effects. Therefore, the objective of this work was to evaluate these approaches, in terms of efficiency in selecting and identifying markers or regions located within or close to genes associated with traits. This study also aimed to compare these methodologies with single-marker analyses. To accomplish this, simulated data were used in six scenarios, with SNPs allocated in non-overlapping genomic regions. Considering traits with oligogenic inheritance, WPPA criterion followed by %var and PPint criteria were shown to be superior, presenting higher values of detection power, capturing higher percentages of genetic variance and larger areas. For traits with polygenic inheritance, PPint and WPPA criteria were considered superior. Single-marker analyses identified SNPs associated only in oligogenic inheritance scenarios and was lower than the other criteria.(AU)

Evaluation of a new additive-dominance genomic model and implications for quantitative genetics and genomic selection

The Fisher's infinitesimal model is traditionally used in quantitative genetics and genomic selection, and it attributes most genetic variance to additive variance. Recently, the dominance maximization model was proposed and it prioritizes the dominance variance based on alternative parameterizations. In this model, the additive effects at the locus level are introduced into the model after the dominance variance is maximized. In this study, the new parameterizations of additive and dominance effects on quantitative genetics and genomic selection were evaluated and compared with the parameterizations traditionally applied using the genomic best linear unbiased prediction method. As the parametric relative magnitude of the additive and dominance effects vary with allelic frequencies of populations, we considered different minor allele frequencies to compare the relative magnitudes. We also proposed and evaluated two indices that combine the additive and dominance variances estimated by both models. The dominance maximization model, along with the two indices, offers alternatives to improve the estimates of additive and dominance variances and their respective proportions and can be successfully used in genetic evaluation.

Genetic evaluation and selection of cocoa tree clones / Avaliação genética e seleção de clones de cacaueiro

The cultivation of cocoa is of great socio-economic importance worldwide. Cocoa beans are the essential raw material for chocolate production. The variability of cacao studied presents only a small fraction of the existing genetic diversity, mainly in the Amazon region. Furthermore, just a small part of this variability has been exploited in cocoa breeding. Thus, the present study processed the genetic evaluation and selection of cocoa clones, based on morpho-agronomical traits. For this, we evaluated 145 clones, during 37 harvests from, four consecutive years. The following traits were evaluated: total number of fruits collected (TNFC), total number of healthy fruits (TNHF), weight of wet seeds from healthy fruits (WWSHF), average weight of wet seeds per healthy fruit (AWWSHF), weight of dry seeds from healthy fruit (WDSHF), average weight of dry seeds per healthy fruit (AWDSHF), percentage of fruits with witches' broom disease (PFWB), percentage of fruits with borer (PFBR), percentage of fruits with germinated seeds (PFGS), number of branches with witches' broom disease (NBWB), and number of inflorescence with witches' broom disease (NIWB). Significant differences (P < 0.05) among the clones were observed for all traits, which reveal an expressive variability and possibility of gains with selection. The highest significant correlations (P < 0.05) occurred between traits TNFC and TNHF (0.94), TNHF and AWWSHF (0.86), and TNHF and AWDSHF (0.86). Based on the selection index, the clones POUND 12 and CAB 12, 228, 253, 257, 258, and 422 were the most suitable for selection.

O cultivo do cacau tem grande importância socioeconômica mundial. Os amêndoas de cacau são a matéria-prima essencial para a produção de chocolate. A variabilidade do cacaueiro avaliada representa apenas uma pequena fração da diversidade genética existente, principalmente na região amazônica. Além disso, apenas uma pequena parte dessa variabilidade foi explorada no melhoramento de cacau. Dessa forma, o presente estudo teve como objetivo realizar a avaliação genética e seleção de clones de cacau, com base em características morfo-agronômicas. Para isso, foram avaliados 145 clones, durante 37 colheitas, em quatro anos consecutivos. As seguintes características de frutos e sementes foram avaliadas: número total de frutos colhidos (NTFC), número total de frutos sadios (NTFS), peso de sementes úmidas dos frutos sadios (PSUFS), peso médio de sementes úmidas dos frutos sadios (PMSUFS), peso de sementes secas dos frutos sadios (PSSFS), peso médio de sementes secas dos frutos sadios (PMSSFS), porcentagem de frutos com vassoura-de-bruxa (PFVB), porcentagem de frutos com broca (PFBR), porcentagem de frutos com sementes germinadas (PFSG), número de ramos com vassoura-de-bruxa (NRVB) e número de almofadas florais com vassoura-de-bruxa (NAFVB). Diferenças significativas (P < 0,05) entre os clones foram observadas para todas as características, o que revela uma expressiva variabilidade e possibilidade de ganhos com a seleção. As maiores correlações significativas (P < 0,05) ocorreram entre os caracteres NTFC e NTFS (0,94), NTFS e PMSUFS (0,86) e, NTFS e PMSSFS (0,86). Com base no índice de seleção, os clones POUND 12 e CAB 12, 228, 253, 257, 258 e 422 foram considerados os mais adequados para a seleção.

Reciprocal recurrent selection for obtaining water-deficit tolerant maize progeny / Seleção recorrente recíproca para obtenção de progênies de milho tolerantes ao déficit hídrico

In view of the need to increase genetic variability to obtain materials with a significant capacity to drought tolerance, this study conducted a cycle of a reciprocal recurrent selection of full-sib families of maize. To this end, 64 full-sib families of maize were evaluated in two environments according to their morpho-agronomic data in a randomized block design with two replicates. It were analyzed of Male flowering (MF); Female flowering (FF); Flowering interval (IF); days for flowering (DF); Plant height (PH); Ear height (EH); number of plants at the Stand (NPS); Number of broken plant (NBrP); Number of bedded plants (NBeP); Strawing (St); Ear length (EL); Ear diameter (ED); Ear number (EN); Prolificacy (Pr); Number of diseased ears (NDE); Number of ears attacked by pests (NEP); Ear weight (EW); Yield (YIE) and Total Chlorophyll Index (TCI). The analysis of variance was performed by the F test at 5% significance level, and also the evaluation of genetic parameters. Regarding morpho-agronomic data, the analysis of variance and the analysis of genetic parameters showed that there was no interaction genotype x environment with regard to the genetic variability among the families under study. Lastly, the final selection of the superior genotypes was made on the basis of the ranking of the 40 most productive families, from which, combined with the molecular data, the 30 most productive, most drought-tolerant, and most genetically diverse ones were selected to compose the next cycle of recurrent maize selection aiming water-stress tolerance.

Tendo em vista a necessidade de aumentar a variabilidade genética para obter materiais com significativa capacidade de tolerância à seca, este estudo conduziu um ciclo de seleção recorrente recíproca de famílias de irmãos completos de milho. Para tanto, 64 famílias de irmãos completos de milho foram avaliadas em dois ambientes de acordo com seus dados morfoagronômicos em um delineamento de blocos casualizados com duas repetições. Foram analisados o florescimento masculino (MF); florescimento feminino (FF); Intervalo de florescimento (IF); dias para florescimento (DF); Altura da planta (PH); Altura da espiga (EH); número de plantas na parcela (NPS); Número de planta quebrada (NBrP); Número de plantas com acamadas (NBeP); empalhamento (St); Comprimento da espiga (EL); Diâmetro da espiga (DE); Número de espigas (EN); Prolificidade (Pr); Número de espigas doentes (EQM); Número de espigas atacadas por pragas (NEP); Peso de espiga (EW); Rendimento de grãos (YIE) e Índice de clorofila total (TCI). A análise de variância foi realizada pelo teste F com nível de significância de 5% e também pela avaliação dos parâmetros genéticos. Em relação aos dados morfoagronômicos, a análise de variância e a análise dos parâmetros genéticos mostraram que não houve interação genótipo x ambiente no que diz respeito à variabilidade genética entre as famílias em estudo. Por fim, a seleção final dos genótipos superiores foi feita com base no ranking das 40 famílias mais produtivas, das quais, combinadas com os dados moleculares, foram selecionadas as 30 mais produtivas, mais tolerantes à seca e mais geneticamente diversificadas. para compor o próximo ciclo de seleção recorrente de milho visando tolerância ao estresse hídrico.

Depicting latent variables considering different pig genetics and nutritional plans in crossbred pigs

We aimed to reduce the dimensionality of quantitative traits in pigs applying factor analysis. Quantitative variables were collected, and the factor analysis extracted five factors with biological meaning related to performance, carcass quality, carcass yield, meat quality, and initial pH. These factors were posteriorly used as dependent variable to evaluate the effects of genetic groups (Piau, Duroc, and Pietrain crossbreds), nutritional plans (low, medium and high lysine levels) and sex. An interaction effect between genetic group and sex was observed in performance, in which Duroc crossbred showed the greatest scores. The Pietrain genetic group showed greater values of carcass quality compared with Duroc and Piau, while Piau crossbred pigs had greater values for meat quality compared with Pietrain and Duroc. A greater carcass yield was observed in Pietrain crossbred compared with Duroc pigs. Pigs fed under low lysine level had the lowest performance values. Carcass yield was affected by nutritional plans, in which the medium lysine level showed the greatest values. Meat quality was improved by the nutritional plan with high lysine level compared with the low lysine level. Initial pH showed increased means when using nutritional plans with low and medium lysine levels in diet composition. With regard to sex effects, a greater carcass quality was found for gilts compared with barrows. The reduction of the data dimensionality allowed the joint evaluation of genetic group, nutritional plan, and sex based on new latent variables that represented the original dataset under easier framework based on factors' biological interpretation.(AU)

Mega-environment analysis of maize breeding data from Brazil

ABSTRACT: The development and recommendation of single cross maize hybrids (SH) to be used in extensive land areas (mega-environments), and in different crop seasons requires many experiments under numerous environmental conditions. The question we asked is if the data from these multi-environment experiments are sufficient to identify the best hybrid combinations. The aim of this study was to critically analyze the phenotype data of experiments of yield, established by a large seed producing company, under a high level of imbalance. Data from evaluation of 2770 SH were used from experiments conducted over four years, involving the first and second crop seasons, in 50 locations of different years and regions of Brazil. Different types of analysis were carried out and genetic and non-genetic components were estimated, with emphasis on the different interactions of the SH with the environments. Results showed that the coincidence of common hybrids in these experiments is normally small. The estimates of the correlations between of the hybrids coinciding in the environments two by two is of low magnitude. The hybrid × crop season interaction was always expressive; however, the interactions of hybrids and other environmental variables were also important. Under these conditions, alternatives were discussed for making with the information obtained from the experiments, can be more efficient on the process to obtain new hybrids by companies.

Effect of rearing, season of birth, and father on labyrinth behaviour of dairy heifers

Objective of this study was to test the hypotheses that heifer's behaviour after 12 months (M) are impacted by rearing (feeding/housing) before weaning, seasons of birth, and father lineage. Fifty-one Holstein heifers (born in year seasons SB1, SB2, SB3, and SB4, originating from 4 fathers) were assigned to one of three rearing treatments: restricted suckling (RS), calf in pen with mother to 21st day, suck three times daily, then group pen (6 kg milk) to weaning; unrestricted suckling (US), calf in pen with foster cows (6 kg milk) to weaning; conventional rearing (CR), calf in the hutch to 56th day, then group pen to weaning (milk replacer 6 kg). After weaning at the 84th day, heifers were kept in groups with the same ration. The labyrinth behaviour was tested in the 12th and 19th M of the age. In the evaluation factors rearing and season of birth, groups US and SB3 solved the passage of the labyrinth the fastest (868.0 s, 857.4 s), the slowest were CR and SB1 (1148.2 s, 1257.5 s). The results show that the manner (housing/feeding) used to rear heifers and season of birth may impact their later labyrinth behaviour.

Genetic evaluation of oocyte and embryo production in dairy Gir cattle using repeatability and random regression models

The objective of this work is to estimate genetic parameters and breeding values to improve embryo and oocyte production, using repeatability and random regression models (RRM) for Gir dairy cattle. We used 11,398 records of ovum pick-up from 1,747 dairy Gir donors and evaluated sixteen different models: the traditional repeatability model and fifteen RRM, each of which considered a different combination of Legendre polynomial regressors to describe the additive genetic and permanent environment effects. The 4G1P model (four regressors for the genetic effect and one regressor for the permanent environment effect) is the most suitable model to analyze the number of viable and total oocytes, while the 3G1P is the best model to analyze the number of cleaved and viable embryos, according to the values of the Akaike information criterion (AIC) and the Bayesian information criterion (BIC). The heritability estimated with the RRM was higher than that estimated with the repeatability model. The high repeatability reported for oocyte and embryo count traits indicates that donors, which had high oocyte and embryo counts in the first ovum pick-up, should maintain this result in the next ovum pick-up. Genetic correlations between adjacent ages were high and positive, while genetic correlations between extreme ages were weak. We observed a reranking of the top sires and females (heifers and cows) over the period evaluated. The reliability of the estimated breeding values by RRM showed changes across age, and the expected genetic gains by RRM are larger. This shows that RRM is most suitable alternative for the evaluation and selection of oocyte and embryo count traits.(AU)

Análises computadorizadas da motilidade espermática (CASA): conceitos e possibilidades de padrões / Computerized analysis of sperm motility (CASA): concepts and possibilities of standards

O melhoramento genético possibilitou a evolução da eficiência e taxas de desfrute da pecuária nacional. A biotécnica da IATF (Inseminação Artificial por Tempo Fixo) consolidou-se como a principal ferramenta de disseminação de genética melhorada em rebanhos de leite e de corte. A avaliação espermática laboratorial tem o objetivo de analisar o potencial de reprodutores/partidas de sêmen e buscar a desafiadora tarefa de determinar e estabelecer características confiáveis que possam ser utilizadas como indicadores de fertilidade. Nesse contexto emerge o sistema CASA (Computer-Assisted Sperm Analysis) como ferramenta promissora para obtenção de parâmetros indicativos de fertilidade seminal.(AU)

Genetic improvement enabled the evolution and efficiencies of national livestock activity. The IATF (Fixed Time Artificial Insemination) biotechnology, has established itself as the main tool for the dissemination of improved genetics in dairy and beef herds. Laboratory sperm evaluation aims to analyze the potential of a sires/semen batches and seek the challenging task of determining and establishing reliable characteristics that can be used as fertility indicators. In this context, the computerized system of sperm motility (CASA) emerges as a promising tool for obtaining parameters indicative of seminal fertility.(AU)

Molecular characterization and association of lactoferrin gene to subclinical mastitis in goats (Capra hircus)

The study characterized the lactoferrin (Lf) mRNA gene in different goat breeds in the Philippines and determined its association with subclinical mastitis (SCM). The study involved collection of milk at second week of lactation (n=75) and blood samples (n=5) to obtain extracted RNA and using cDNA to amplify Lf gene through polymerase chain reaction. The nucleotide and amino acid sequences were determined and used as reference in the evaluation of phylogenetic relationship. Amplified products were utilized for RFLP analysis before determining the association of the gene with SCM. Results of the study demonstrated that Lf gene in goats registered a molecular weight of 2135. Nucleotide and amino acid sequence of Lf gene revealed high similarity (99%) in Saanen, Anglo-Nubian and Philippine native goats with that of Capra hircus (U53857) Lf gene submitted to GenBank. Phylogenetic studies showed that Lf gene of Anglo-Nubian, Saanen and Native goats clade together with Lf gene of C. hircus (U53857). Three genotypes in goats were documented using the restriction enzymes AluI and HaeIII. Based on the Statistical analysis, association (comp 5.65, p = 0.0308) has been established between the Lf genes of goats with genotype BB to SCM using HaeIII restriction enzyme.(AU)

Comparação de métodos de sexagem em filhotes de serpentes da espécie Python brongersmai / Comparing methods of sex identification in Python brongersmai snakelets

Com a ascensão de animais exóticos no mercado pet, observou-se a necessidade de maiores estudos nesta área. Este estudo teve como objetivo comparar diferentes métodos de sexagem em filhotes de serpentes da espécie Python brongersmai (Bloody Python), sendo utilizados 14 filhotes com aproximadamente 1 ano e 9 meses de vida, oriundos do Criadouro Comercial de Fauna Silvestre e Exótica ­ CCF, autorização de manejo N° 414064, localizado no município de Cornélio Procópio ­ PR. Foi utilizado a introdução da probe metálica de sexagem para contagem de escamas, mensurações do Comprimento Rostro-Cloacal (CRC), Comprimento Pós-Cloacal (CPC), Comprimento Total (CT); avaliação ultrassonográfica dos órgãos reprodutivos e perfil genético (DNA), indicando a fidedignidade de cada um. Observou-se uma eficácia de 100% na determinação do sexo através das amostras de DNA, enquanto a sexagem a partir da contagem de escamas via probe metálica e o dimorfismo sexual por mensurações corporais permitiram apenas uma classificação sexual prévia, sofrendo variações quando comparadas, mostrando-se como métodos inconclusivos. Já a ultrassonografia não foi eficaz para o processo de sexagem em serpentes filhotes de até aproximadamente 1 ano e 9 meses de idade da espécie Python brongersmai.(AU)

With the increment of exotic animal's trade in the pet business, the necessity of more studies in this area was observed. This study aimed at comparing different methods of sex identification in Python brongersmai snakelets (Bloody Python), using 14 baby snakes aged 1 year and 9 months approximately, from commercial breeding of wild and exotic fauna, situated in Cornélio Procópio ­ PR. Methods used were the probing technique introduction, measurement of snout-vent length, post-vent length, total length; ultrasound evaluation of reproductive organs and genetic profile exam (DNA samples), denoting the veracity of each one. A 100% efficacy was observed in the study of sexual determination through DNA samples, while the other methods were shown to be inconclusive, whilst the sexing scale count via the probing technique introduction and sexual dimorphism by bodily measurements permitted only a previous sexual classification, suffering variations when compared, showing to be inconclusive methods. The ultrasound evaluation was not efficient for the sexing process in snakelets aged approximately 1 year and 9 months in Python brongersmai.(AU)

In vitro and in vivo parameters for identification of landrace pigs with low reproductive performance / Parâmetros in vitro e in vivo para detecção de machos suínos Landrace com baixo desempenho reprodutivo

In pig farming, measurements of production parameters play a fundamental role in the success of the activity. Minimal differences in fertility between breeders can lead to less reproductive efficiency and, less productivity. However, assessing the fertility of each male and the early identification of subfertile males is a difficult task to be performed. Thus, the aim of this study was to evaluate the use of in vitro and in vivo parameters in the identification of subfertile males of the Landrace breed, aiming to collaborate with genetic improvement programs, routine optimization in the Genetic Diffusion Units (GDUs) and the results of performance. In experiment 1, an approach to identify males with subfertility was evaluated based on retrospective data. For this, the results (averages of birth rates, number of total births and average percentages of female and male piglets per litter) were evaluated for a total of 996 matings and 847 parturitions. The inseminations came from ejaculates of 32 males, who had at least 19 females inseminated with homospermic doses in the concentration of 2.5 x 109 total sperm from the same male. As for the birth rate (BR), an average of 85.47% ± 6.05 was observed with a group of median males, seven males that stood out and one individual (M32) with a performance of 58.06% ± 9.0. For the total number of piglets born (PB) the average was 13.41 ± 0.56, with three males with better performance and one (M32) with very poor performance (8.62 ± 0.59). In experiment 2, it was verified whether evaluations of inseminating doses (ID) of semen in vitro (motility and sperm morphology) after 96 hours of storage had correlations with fertility in vivo, which can be used to identify subfertile males. The evaluations were performed on 30 ejaculates regarding the means of BR and PB, considering only those who had at least 7 females inseminated. There were no correlations between the motility assessments and semen morphological changes and the reproductive parameters evaluated. The results obtained in vivo, referring to BR and PB, demonstrated that it was possible to identify differences between males, the individual (M32) had the worst results for the percentages of BR and PB. It is concluded that there are males of high and low fertility and that only the in vitro analyzes carried out in this study are not enough to categorize them, however, the evaluation of retrospective data was efficient for this purpose.(AU)

Na suinocultura moderna, as mensurações de parâmetros de produção têm papel fundamental para o sucesso da atividade. No entanto, a avaliação da fertilidade de cada macho e a identificação precoce de machos subférteis é uma tarefa difícil de ser realizada. O objetivo deste estudo foi avaliar a utilização de parâmetros in vivo e in vitro na identificação de machos subférteis da raça Landrace, visando colaborar com os programas de melhoramento genético, otimização da rotina nas Unidade de Difusão Genética (UDGs) e dos resultados a campo. No experimento 1, foi proposta uma abordagem de identificação dos machos subférteis tendo como base dados retrospectivos. Para isso, foram avaliados os resultados (médias das taxas de parto, número de nascidos totais e média das porcentagens de leitões fêmeas e machos por leitegada) de um total de 996 coberturas e 847 partos. As inseminações foram oriundas de ejaculados de 32 machos, que tiveram ao menos 19 fêmeas cobertas com doses homospérmicas na concentração de 2,5 x 109 de espermatozoides totais e obrigatoriamente do mesmo macho. Quanto a taxa de parto (TP) obtivemos uma média de 85,47% ± 6,05 e observou-se um grupo de machos medianos, sete machos que se destacaram positivamente e um indivíduo (M32) com um desempenho 58,06 ± 9,0. Para número de leitões nascidos totais (NT) obtivemos uma média de 13,41 ± 0,56 e notou-se três machos com melhor desempenho e um (M32) com péssimo desempenho (8,62 ± 0,59). No experimento 2, foi verificado se as avaliações das doses inseminantes (DI) de sêmen in vitro (motilidade e morfologia espermática) após 96 horas de armazenamento apresentaram correlação com a fertilidade in vivo. As avaliações foram realizadas em 30 ejaculados quanto às médias de TP e NT, considerando apenas ejaculados que tiveram ao menos 7 fêmeas inseminadas. Não foram verificadas correlações entre as avaliações de motilidade e alterações morfológicas do sêmen com os parâmetros produtivos avaliados. Os resultados obtidos in vivo, referentes a TP e NT, mostrou que foi possível identificar diferença entre os machos, onde o indivíduo (M32) apresentou os piores resultados para as porcentagens de TP e NT. Desta forma, pode-se concluir que existem machos de alta e baixa fertilidade e que somente as análises in vitro realizadas neste estudo não são suficientes para categorizá-los, no entanto, a avaliação de dados retrospectivos foi eficiente para esta finalidade.(AU)

Mega-environment analysis of maize breeding data from Brazil

The development and recommendation of single cross maize hybrids (SH) to be used in extensive land areas (mega-environments), and in different crop seasons requires many experiments under numerous environmental conditions. The question we asked is if the data from these multi-environment experiments are sufficient to identify the best hybrid combinations. The aim of this study was to critically analyze the phenotype data of experiments of yield, established by a large seed producing company, under a high level of imbalance. Data from evaluation of 2770 SH were used from experiments conducted over four years, involving the first and second crop seasons, in 50 locations of different years and regions of Brazil. Different types of analysis were carried out and genetic and non-genetic components were estimated, with emphasis on the different interactions of the SH with the environments. Results showed that the coincidence of common hybrids in these experiments is normally small. The estimates of the correlations between of the hybrids coinciding in the environments two by two is of low magnitude. The hybrid × crop season interaction was always expressive; however, the interactions of hybrids and other environmental variables were also important. Under these conditions, alternatives were discussed for making with the information obtained from the experiments, can be more efficient on the process to obtain new hybrids by companies.