Genetic diversity in the Portuguese Mertolenga Cattle Breed assessed by pedigree analysis

Research Areas: Agriculture ; Veterinary Sciences ; ZoologyThe Mertolenga beef cattle, currently with 27,000 breeding females in Portugal, is the largest Portuguese native breed, despite some variation in the breeding stock over the last years. The purpose of this study was to estimate parameters related to the population structure and genetic diversity and to investigate the major factors affecting genetic erosion in the breed, based on the pedigree herdbook information collected since the 1950s, including records on 221,567 animals from 425 herds. The mean generation intervals were 6.4 years for sires and 7.1 years for dams, respectively. The rate of inbreeding per year was 0.183% ± 0.020% and the correspondent effective population size was 38.83. In the reference population (35,017 calves born between 2015 and 2019), the average inbreeding and relatedness were 8.82% ± 10% and 2.05% ± 1.26%, respectively. The mean relationship among animals from the same and from different herds was 29.25% ± 9.36% and 1.87% ± 1.53%, respectively. The estimates for the effective number of founders, ancestors, founding herds and herds supplying sires were 87.9, 59.4, 21.4 and 73.5, respectively. Although the situation of the Mertolenga breed is not alarming, these results indicate the need to adopt measures to maintain the genetic variability of the population.info:eu-repo/semantics/publishedVersio

Inbreeding depression on beef cattle traits: Estimates, linearity of effects and heterogeneity among sire-families

Records from up to 19054 registered cows and 10297 calves in 155 herds of the Alentejana cattle breed were used to study the effects of individual (Fi) and maternal (Fm) inbreeding on reproductive, growth and carcass traits, as well as assessing the importance of non-linear associations between inbreeding and performance, and evaluating the differences among sire-families in the effect of Fi and Fm on calf weight at 7 months of age (W7M). Overall, regression coefficients of performance traits on inbreeding were small, indicating a minor but still detrimental effect of both Fi and Fm on most traits. The traits with the highest percentage impact of Fi were total number of calvings through life and calf weight at 3 months of age (W3M), followed by longevity and number of calves produced up to 7 years, while the highest effect of Fm was on W3M. Inbreeding depression on feed efficiency and carcass traits was extremely small and not significant. No evidence was found of a non-linear association between inbreeding and performance for the traits analyzed. Large differences were detected among sire-families in inbreeding depression on W7M, for both Fi and Fm, encouraging the possibility of incorporating sire effects on inbreeding depression into selection decisions

Avaliação biométrica do terço posterior de bovinos de raça alentejana: resultados preliminares

The biometric evaluation is an evaluation method that aims to know the size of the animals from the measurement of several biometric elements. This type of evaluation should be associated with linear evaluation to understand which animals have desirable characteristics related to growth and muscular development. The aim of this study was to perform a biometric evaluation of the backpart of Alentejana cattle portuguese breed; the specific objectives were to perform measurements of various elements of the animal, like thoracic perimeter, body length, width and length of the rump. This work has been carried out so far in several farms affiliated with the breeders association (Associação dos Criadores de Bovinos da Raça Alentejana), based in Herdade da Coutada Real in Assumar, Monforte, between April and June 2017. 134 animals were measured during this period but a wider database was used, with information from 1342 animals from the breeder´s association, with measurements and presenting global reference values: the height at the withers (1,34±0,60m in females and 1,50±0,02m in males), the body length (1,617±0,900m in females and 1,77±0,02m in males), the thoracic perimeter (2,057±0,900m in females and 2,373±0,046m in males), the rump length (0,558±0,430m in females and 0,626±0,009m in males), the outside rump width (0,557±0,004m in females and 0,734±0,059m in males) and the hip-femural width (0,492±0,060m in females and 0,548±0,014m in males). From the results obtained we concluded that there was a positive evolution over the years, related to the animal’s size and conformation and we noticed a great homogeneity between animals, which is justified by values of standard deviation (between 0.030 and 0.207) and coefficient of variation low (between 5.8% and 14%). This type of evaluation is still rarely used by breeder’s associations, but there is expected that their use will help them in the selection and breeding of animals, when associated with other selection methods, like linear evaluation.info:eu-repo/semantics/publishedVersio

Influência da dupla ninhada nos parâmetros produtivos e comportamentais em genética Danbred

Publicação resultante do painel apresentado no XX Congresso Nacional de Zootecnia.The pressure that the swine sector has been suffering searching for methods and techniques that are more efficient, capable of increasing the number of piglets per sow, led to the hiperprolific sows, which go against the conventional concepts of swine facilities concerning farrowing crates. Also, the animal welfare when it comes to farrowing crates starts to become a very discussed subject, as much for the piglets as for the sows. After several studies developed in various locations, which evidenced the benefits of farrowing crates with mixed litters, it was decided to study that kind of litter. Thereby it was tested if the productive values of hiperprolific sows would increase, and also if it would increase the welfare of the piglets. The study was conducted between 11th of April and 19th of July in Santo Cristo’s farm, which is exploited by Euroeste, SA. company, located in Cartaxo, Portugal. The aim of this study was to evaluate if mixed litters help to wean more piglets, if they gain more weight by having more food options, and if their welfare is improved, helping the animal to be better prepared for the future, after weaning. Initially, through analysis with SAS software, which included the fixed effects of type of method used (if mixed litter or control), the location in the farm where they were, the month of birth, the age at weaning and the cycle of the sow, we evaluated the number of piglets weaned per sow, the average weight per weaned piglet, the daily weight gain calculated with the total values of the weights, the daily weight gained calculated with the average values of the piglets, and the percentage of weaned animals in comparison to the initial number of litters. Secondly, through the SAS program, were analysed the individual weights registered at weaning of 857 piglets, with an average weight of 5,91±1,41kg, with the aim of evaluating the environmental factors such as the method, location in the farm, month of weaning, age at weaning, cycle of the sow and age of the piglets at the beginning of the study. In conclusion for the production parameters this method does not show significant improvements however, it also has no disadvantage in productive terms, which demonstrates that it is a viable alternative to the intensive systems of isolated farrowing systems implemented today in most of the intensive farms. Secondly, it can also be concluded that, in behavioural terms, this method showed some improvement in pre-weaning behaviour, by improving the interactions between litters, and the natural contact between the animals and the increase of consumption of pre-starter.info:eu-repo/semantics/publishedVersio

Avaliação genética no cavalo Puro-sangue Lusitano

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Consanguinidade no cavalo Puro-sangue Lusitano

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Linear profiling in Lusitano horses: genetic parameters and plans for further development

info:eu-repo/semantics/draf

Reproductive performance of Saanen and Alpine goats in three different breeding seasons

O valor económico de produtos da exploração caprina como o leite e a carne de cabrito podem sofrer importantes flutuações em função da época do ano, em consequência da procura e da sua oferta no mercado, condicionada pelo período de anestro sazonal dos caprinos. Avaliou-se o desempenho reprodutivo de caprinos das raças Saanen e Alpina, em diferentes épocas de beneficiação (maio, agosto e novembro), com base na informação de 5701 registos reprodutivos, obtidos numa exploração comercial. Analisaram-se os resultados de doze épocas de cobrição consecutivas, recolhendo-se dados relativos a parâmetros reprodutivos (diagnóstico de gestação positivo - DG+ , parição, aborto, hidrometra e prolificidade) de cada uma das raças utilizadas, bem como de fatores ambientais que os pudessem influenciar (mês de beneficiação, número de lactação e produção de leite). Recorreu-se ao “efeito macho” para indução e sincronização do estro. Na época de cobrição de maio, os animais foram ainda sujeitos a tratamento hormonal (implante de melatonina “Melovine®”, colocado 45 dias antes do início das cobrições). A beneficiação foi realizada por monta natural (relação macho/fêmea de 1/15-20) durante um período de 42 dias. O DG foi efetuado por ecografia, 45 dias após a retirada dos bodes. As probabilidades independentes do animal ter DG+ , parir ou abortar foram analisadas por regressão logística, através do PROC LOGISTIC, e a prolificidade com o PROC GLM, ambos do programa SAS (SAS Institute, 2004). Estimaram-se as médias dos quadrados mínimos da prolificidade segundo os fatores estudados e realizaram-se os respetivos testes de diferenças entre médias. As taxas de DG+ , parição, aborto e hidrometra foram de 74,4%, 70,4%, 4,0% e 1,9%, respetivamente. Nos meses de maio, agosto e novembro registaram-se taxas de DG+ , 65,6%, 78,7% e 80,0%, respetivamente. Apenas a taxa de DG+ foi influenciada significativamente pelo mês de beneficiação e pelo número de partos. As estimativas de “odds ratio” do DG+ para os efeitos mês de beneficiação e número de partos foram de 2,1 e 2,7 (mês 8 vs 5 e mês 11 vs 5, respetivamente), e de 2,1, 2,7, 3,2, 2,9 e 3,0 (parto 1, 2, 3, 4, 5 vs parto 0, respetivamente). Observou-se uma ligeira superioridade da prolificidade da raça Saanen (1,83), relativamente à raça Alpina (1,69), e do mês de beneficiação agosto, relativamente aos meses maio e novembro. A prolificidade aumentou ainda com o número de parto, atingindo um valor máximo ao 3º parto.Reproductive performance of Saanen and Alpine goats in three different breeding seasons (May, August and November) was analyzed using 5701 reproductive records from twelve consecutive breeding seasons in a commercial dairy goat farm. Reproductive data (positive pregnancy diagnosis (PD+), parturition, abortion, hydrometra and prolificacy) have been analyzed for the effects of breed, month of breeding, lactation number and milk yield. The male effect was used for estrus induction and synchronization. In the May breeding season, a hormonal treatment was added (Melovine® melatonin implant placed 45 days before the start of the breeding season). Breeding was by natural mating (male/female ratio 1/15-20) for 42 days. PD was performed by ultrasonography 45 days after the withdrawal of the males. The independent probabilities of PD+, parturition and abortion were analyzed by logistic regression with SAS PROC LOGISTIC, and prolificacy was analyzed with SAS PROC GLM (SAS Institute, 2004). Least squares means have been estimated for prolificacy as a function of the factors under study and respective differences among means. PD+, parturition, abortion and hydrometra rates were 74.4, 70.4, 4.0 and 1.9 percent, respectively. PD+ rates in May, August and November were 65.6, 78.7 and 80.0 percent, respectively. Only the PD+ was significantly influenced by the month of breeding and the number of parturitions. “Odds ratio” estimates for month of breeding and number of parturitions, respectively, were 2.1 and 2.7 (August vs. May and November vs. May, respectively) and 2.1, 2.7, 3.2, 2.9 and 3.0 (parturitions 1, 2, 3, 4 and 5, respectively, vs. parturition 0). Prolificacy was slightly higher in the Saanen breed (1.83) than in the Alpine (1,69), and in the August matings than in those of May and November. Prolificacy increased with the number of parturition, reaching its maximum value in parturition 3.info:eu-repo/semantics/publishedVersio

Reproductive performance of danbred sows on a commercial pig farm

Avaliou-se o desempenho produtivo de uma linha genética de suínos hiperprolífica, numa exploração industrial intensiva de produção de porcos para abate. Utilizou-se um total de 238 fêmeas da linha genética DanBred, beneficiadas com sémen de varrascos de raça Duroc ou Pietrain. Analisaram-se diversos parâmetros produtivos, considerando como variáveis de resposta o número de leitões nascidos por parto: totais, vivos, mortos e mumificados. Nos primeiros dias pós-parto, procedeu-se à uniformização das ninhadas e, posteriormente, avaliou-se o número leitões desmamados. Determinaram-se algumas estatísticas descritivas dos parâmetros produtivos em estudo com recurso ao Proc Means do SAS. Procedeu-se a uma análise de variância com o Proc GLM do SAS e através de um modelo linear que incluiu os efeitos da linha genética do varrasco e o efeito linear e quadrático do número de parto, com o objetivo de avaliar como estes efeitos ambientais influenciaram as variáveis de resposta. O número médio de leitões por parto totais, vivos, mortos e mumificados foi 19,04 ± 4,87, 16,69 ± 3,87, 1,57 ± 1,82 e 0,79 ± 1,83, respetivamente. O número médio de leitões nascidos vivos foi superior aos valores médios obtidos em Portugal e em explorações dinamarquesas, incluindo explorações que se encontram no top 10% mais produtivas, situando-se próximo do limite inferior do Top 3 dinamarquês. O número médio de leitões desmamados (13,34 ± 2,00) sugere que devam ser melhoradas as condições pós-parto e/ou aleitamento.The reproductive performance of a hyperprolific line of pigs on an intensive farrow-to-finish farm was analyzed. A total of 238 DanBred sows, inseminated with Duroc or Pietrain semen, were used. On the first days post-partum, litters were equalized; at weaning, litter size was recorded. Several productive parameters were analyzed, considering as response variables the total number of piglets born, and the numbers of born alive, stillborn and mummified piglets, per farrowing. Some descriptive statistics of the productive parameters under study have been determined with SAS Proc Means. Analysis of variance was performed with SAS Proc Mixed and a linear model including sire genetic line and linear and quadratic parity effects. The average number of piglets born alive per farrowing (16.69 ± 3.87) was higher than average numbers attained in Portugal and on Danish farms, including part of the top 10 percent, being close to the lower limit of the Danish Top 3. The average number of piglets weaned (13.34 ± 2.00) suggests that post-partum and/or suckling conditions should be improved.info:eu-repo/semantics/publishedVersio