Estimativas de parâmetros genéticos e análise de agrupamento para resistência e resiliência à verminose em ovinos de corte Santa Inês

The objective of this work was to estimate genetic parameters for traits related to resistance to endoparasites in Santa Inês sheep, for a possible inclusion in sheep breeding programs, as well as to evaluate the additive genetic pattern of the animals using cluster analyzes, in order to assess whether there are groups within the population that can be used as candidates for selection for resistance to endoparasites. The studied traits were: Famacha score, fecal egg counts (FEC), packed cell volume (PCV), total plasma protein (TPP), body condition score (BCS), and body weight (BW). Heritability estimates ranged from 0.17 (0.05) for TPP to 0.31 (0.07) for BCS. The cluster analyzes based on the breeding values identified four clusters. Famacha and BCS can be recommended as selection criteria for resistance to hematophagous endoparasites because they can respond to selection and are easy to be measured. Animals from cluster 1 have great potential as candidates for selection because of their additive genetic pattern, taking into account body weight and endoparasite resistance due to higher breeding values for BW, BCS, PCV, and TPP and lower breeding values for Famacha and FEC.O objetivo deste trabalho foi estimar parâmetros genéticos para características relacionadas à resistência a endoparasitas em ovinos Santa Inês, para uma possível inclusão em programas de melhoramento genético de ovinos, bem como avaliar o padrão genético aditivo dos animais por meio de análises de agrupamento dos valores genéticos, para verificar se há subgrupos dentro da população que possam ser utilizados como candidatos à seleção para resistência a endoparasitas. As características estudadas foram: score Famacha, contagem de ovos fecais (FEC), volume globular (PCV), proteína plasmática total (TPP), escore de condição corporal (BCS) e peso corporal (BW). As estimativas de herdabilidade variaram de 0,17 (0,05) para TPP a 0,31 (0,07) para BCS. As análises de agrupamento com base nos valores genéticos identificaram quatro grupos. Famacha e BCS podem ser recomendados como critérios de seleção de resistência a endoparasitas hematófagos, uma vez que podem responder à seleção e são facilmente medidos. Os animais do grupo 1 apresentam grande potencial como candidatos para seleção em razão do seu padrão genético aditivo, ao se levar em consideração peso corporal e resistência ao endoparasita devido aos maiores valores genéticos para BW, BCS, PCV e TPP e aos menores valores genéticos para Famacha e FEC

Reaction norm models for study genotype × environment interaction in Nellore cattle

O objetivo deste estudo será avaliar a importância da interação genótipo x ambiente (IGA) e o efeito de diferentes práticas de seleção sobre a sensibilidade ambiental de características de crescimento e reprodutivas em machos e fêmeas de bovinos da raça Nelore provenientes de três linhas de seleção (NeC=Nelore Controle, NeS= Nelore Seleção, e NeT=Nelore Tradicional), bem como estimar tendências genéticas para cada linha, tanto para o MA, quanto para a capacidade geral de produção (intercepto da norma de reação) e para a capacidade específica de responder às variações ambientais (inclinação da norma de reação). Um total de 9.065 informações de peso a desmama padronizado (P210), 8.757 informações do peso à seleção (PS), 7.799 informações sobre a altura da garupa (ALT) de machos e fêmeas, 3.331 informações sobre a perímetro escrotal (PE) coletadas aos 378 dias de idade em machos e 2.311 dias para o primeiro parto (DPP) em fêmeas da raça Nelore, nascidos entre 1981 e 2017 no Centro Bovinos de Corte, do Instituto de Zootecnia de Sertãozinho, SP. Os componentes da (co) variância e os parâmetros genéticos para as todas as características nas três linhas foram estimados usando um modelo animal padrão (MA) e um modelo de norma de reação (MNR) utilizando amostrador de Gibbs. O descritor ambiental adotado foram as soluções dos grupos de contemporâneos. O MNR homocedástico apresentou, em geral, o melhor ajuste para todas as características estudadas. Os coeficientes de herdabilidade para todas as características foram maiores quando estimadas pelo MNR. As médias de herdabilidade das características estudadas variaram de 0,08 a 0,36 para P210 direto e 0,18 a 0,40 para P210 materno, 0,39 a 0,75 para PS de machos e fêmeas; 0,52 a 0,79 para ALT de machos e fêmeas; 0,46 a 0,68 para PE, e 0,06 a 0,57 para DPP, para as três linhas de seleção, ao longo do descritor ambiental. As correlações genéticas entre intercepto e inclinação variaram de -0,62 a 0,32 para P210 direta, -0,29 a 0,10 para P210 materna; 0,03 a 0,81 para PS, -0,19 a 0,63 para ALT; -0,14 a 0,39 para PE; e -0,87 a -0,42 para DPP, para as três linhas de seleção. As tendências genéticas estimadas tanto pelo MA quanto para o intercepto (do MNR) demostraram incremento para as linhas selecionadas para maior diferencial de peso pós-desmama e uma tendência nula para a linha NeC, exceto para DPP. As tendências genéticas para inclinação das normas de reação e a porcentagem de animais plásticos evidenciam que os animais das linhas NeC e NeT tenderam responder de forma mais modesta as mudanças ambientais, enquanto a linha NeS foi mais responsiva às mudanças ambientais. Foi possível observar que houve reclassificação dos touros para todas características devido à baixa correlação entre ambientes desfavoráveis e favoráveis, principalmente para as linhas NeC e NeT. Para a linha NeS somente houve reclassificação de touros para as características ALT e DPP. Os resultados indicaram que os efeitos da IGA são importantes e devem ser considerados nas avaliações genéticas de bovinos Nelore e que as diferentes práticas de seleção podem interferir na sensibilidade ambiental dos animais.The aim of this study was to evaluate the importance of genotype-environment interaction (G×E) and the effects of different selection practices on the environmental sensitivity of reproductive and growth traits in males and females of three Nellore cattle lines [control (NeC), selection (NeS), and traditional (NeT) lines] with different selection goals. Moreover, genetic trends for the intercept and slope were estimated for each line, and the possible reclassification of sires was examined. A total of 9,065 records of weaning weight adjusted over 210 days (W210); 8,208 records of selection weight (SW); 7,799 records of hip height (HH); 3,331 records of scrotal circumference (SC), and 2,311 records of days to first calving (DFC) from Nellore cattle born between 1981 and 2017 at the Advanced Beef Cattle Research Center of the Animal Science Institute /APTA/SAA, Sertãozinho, SP, Brazil, were utilized in the study. (Co)variance components and genetic parameters for all traits were estimated using a standard animal model (AM) and a reaction norm model (RNM) using a reaction norm model using Gibbs sampler. The environmental descriptor adopted were the solutions of contemporary groups (CG). The RNM showed, in general, the best fit for all traits studied. Mean heritability of the studied traits ranged from 0.08 to 0.36 for direct W210 and 0.18 to 0.40 for maternal W210, 0.39 to 0.75 for males and females SW; 0.52 to 0.79 for HH of males and females; 0.46 to 0.68 for SC, and 0.06 to 0.57 for DFC, along the environmental descriptor. The genetic correlations coefficients between intercept and slope ranged from -0.62 to 0.32 for direct W210, -0.29 to 0.10 for maternal W210; 0.03 to 0.81 for SW, -0.19 to 0.63 for HH; -0.14 to 0.39 for SC; and -0.87 to -0.42 for DFC, in all cattle lines. Genetic trends estimated by both AM and intercept of the reaction norm showed gains for the direct effects for the for selected lines for greater postweaning weight differential and a null trend for the NeC line, except for DFC. Genetic trends for the slope and proportion of plastic genotypes indicated that the NeS line was more responsive to environmental changes, whereas the NeC and NeT lines tended to respond more modestly to environmental changes and to be more robust. Reclassification of sires was observed for all traits, specifically in the NeC and NeT lines, because of the weak correlation between the opposite extreme environments. In the NeS line, reclassification of sires was observed for HH and DFC traits. Our results indicate that the effects of genotype by environment interaction are important and should be considered in genetic evaluations of Nellore cattle. Moreover, different selection practices affected the environmental sensitivity of Nellore selection lines tested in this study

Influence of calf sex on milk production in dairy Gyr cows

Many factors can influence milk yield. Among them are included the environmental, genetics factors and gene-environment interaction. Studies aiming to identify the magnitude of these factors are needed. The effect of calf sex on milk yield is controversial. Therefore, the objective of this work was to investigate the influence of calf gender on milk production along the lactation (P305) of Gyr cows. Data of 18,898 lactation records between the years of 1987 to 2013 were acquired in the official milk control of Brazilian Association of Zebu Breeders (ABCZ) database and analyzed by the least squares method. The linear model for P305 included the fixed effects of calf sex, contemporary group and age of cow at calving within the calf sex as co-variable linear and quadratic. Significant difference was found for the sex of the calf (P<0.01) and the adjusted means of P305 of cows that gave birth to male and female calves were, respectively, 3,565.6 and 3,492.3 kg. Also, there was significant effect of the age of the cow at calving nested within sex of the calf (P<0.01). For female calves the linear and quadratic regression coefficients for the cow age at calving were 17.32 and -0.077 kg, respectively. When the calves were male these coefficients were 21.23 and -0.098 kg, describing a quadratic relation which the production peak was observed at 104 months of age. Hence, Gyr cows produce significantly more milk for sons than for daughters across lactation. This fact could be explained by the fact of male calves normally born heavier than female ones and by the fact of Gyr cows require mostly the presence of the calf to produce milk along the lactation. Thus, might have a physiological adaptation by the Gyr cows to provide more feed for the heaviest calves, generally, male calves

Comparison of scrotal biometry, ultrasonographic attributes of testicles and seminal characteristics of nellore and caracu bulls - preliminary data

Breeding soundness examination allows evaluating characteristics indicative of male fertility. However, these characteristics can differ between breeds. The aim of the present study was to compare the scrotal biometry, ultrasonographic attributes of testicles and seminal characteristics of Nellore and Caracu bulls. The measurements were performed at the Institute of Zootechnics, located in the city of Sertãozinho, SP, from October 2016 to January 2017. Seventy-one mature bulls were grouped according to breed: (1) Nellore animals (n=46, 32.06 ± 9.53 months old, 633.24 ± 132.80 Kg); (2) Caracu animals (n=25, 25.80 ± 4.24 months old, 579.92 ± 107.66 Kg). The B-mode ultrasonographic evaluation of the testicles was performed using a portable scanner (Mindray Z5®, Shenzhen, China) connected to a 7.5-MHz linear transrectal transducer. The ultrasound images were analyzed by Image Pro Plus 7.0â„¢ software (Media Cybernetics Inc., San Diego, CA, USA), to determine mean numerical pixel values (NPVs) and pixel heterogeneity (standard deviation of NPVs) of the testicular parenchyma. The scrotal circumference (SC) was obtained using a tape measure and the testicular volume (TVol) was obtained by the formula: 2 {(R2) x Ï€ x TL}, where R= radius (diameter/2), TL = testicular length and Ï€ = 3.14. The computer assisted sperm analysis (CASA) evaluated: total motility (%TM); progressive motility (%PM) and rapid cells (RAP). The vigor (VIG) was evaluated by optical microscopy, and the sperm concentration (CONC) was obtained by an SDM-1 photometer (Minitub®, Germany). Sperm morphology was analyzed using a phase-contrast microscopy to determine the major, minor and total defects. The ultrasonographic attribute data were analyzed using the GLM procedure, while the scrotal biometry and seminal characteristics were analyzed using the GENMOD procedure (P<0.05). There were differences between Nellore and Caracu bulls in the NPVs (78.46 ± 1.61 vs. 72.03 ± 2.19), pixel heterogeneity (13.45 ± 0.19 vs. 12.57 ± 0.26), TVol (230.99 ± 0.00 cm3 vs. 267.52 ± 0.00 cm3), SC (34.91 ± 0.00 cm vs 37.30 ± 0.00 cm), VIG (2.82 ± 0.01 vs. 2.32 ± 0.02), major defects (6.60 ± 0.01% vs. 14.06 ± 0.01%) and total defects (12.19 ± 0.00% vs. 20.43 ± 0.00%), respectively. In conclusion, the testicular parenchyma of Nelore bulls presented higher echogenicity and was more heterogeneous in relation to the Caracu bulls. In addition, the testicular volume, scrotal circumference and percentage of spermatic defects were higher in Caracu bulls

Effects of the prolonged supplementation with polyunsaturated fatty acids on quality of frozen sperm of Nelore bulls

Lipids in the sperm plasma membrane can influence the success of cryopreservation. The aim of this study was to evaluate the frozen semen quality of Nelore bulls supplemented with polyunsaturated fatty acids (PUFAs). Semen samples of 12 Nellore bulls (521.4 kg ± 11.4 kg) with 24 months average age were used. Bulls were kept in pasture of Brachiaria brizantha cv Marandu, with protein mineral salt and water ad libitum, and were supplemented from 14 to 24 months of age according to the groups: group 1 (G1, n=6) supplemented with PUFAs (Megalac-E®) and group 2 (G2, n=6) had no PUFAs supplementation. At 24 months of age, semen collection was performed by eletroejaculation. The semen was diluted in BotuBov® (7% glycerol) and loaded at room temperature into 0.5 mL straws (concentration 50 x 106 spermatozoa/mL). For cooling and freezing curves (0.25 °C/min to 5 °C, equilibration time at 5 °C for 4 hours, and -20 °C/min), a programmable semen cryopreservation system (Tetakon, TK 4000) was used, and after freezing the straws were stored in liquid nitrogen (-196 °C). The straws were thawed in a water bath at 37 ºC for 30 seconds and the post-thaw evaluations were performed by computer-assisted sperm analysis (CASA) . The evaluated parameters were: total motility (MT; %), progressive motility (MP; %), rapid cells (RAP; %), average path velocity (VAP; μm s), straight-line velocity (VSL; μm s), curvilinear velocity (VCL; μm s), amplitude of lateral head displacement (ALH; μm), beat cross frequency (BCF; Hz), straightness (STR; %) and linearity (LIN; %). For statistical analysis the UNIVARIATE procedure of SAS ® was performed. No differences were observed for frozen sperm quality parameters between G1 and G2: MT (74.66 ± 3.04 vs. 76 ± 3.04, P = 0.76), MP(59.00 ± .,57 vs. 60.16 ± 2.57, P = 0.75), RAP (75.75 ± 3.18 vs. 72.66 ± 3.18, P = 0.84), VAP (91.00 ± 3.92 vs. 90.20 ± 3.92, P = 0.88), VSL(75.25 ± 2.73 vs. 74.77 ± 2.73, P = 0.90), VCL (148.76 ± 7.40 vs. 147.64 ± 7.40, P = 0.91), ALH (5.90 ± 0.26 vs. 5.92 ± 0.26, P = 0.96), BCF (27.44 ± 0.84 vs. 29.58 ± 0.84, P = 0.08), STR (83.91 ± 0.92 vs. 84.16 ± 0.92, P = 0.85) and LIN (54.08 ± 1.10 vs. 54.08 ± 1.10, P = 1). The supplementation of bulls with PUFAs does not improve the quality of frozen semen evaluated by sperm kinetics parameters using CASA

Análise da curva de crescimento em fêmeas da raça Santa Inês

O artigo não apresenta resumo em português

Analysis of growth curve in Santa Ines females sheep

In a sheep production system, the growth-related characteristics have direct relationship to both, quantity and quality of meat. The objective of this study was to evaluate the application of non-linear models to report the growth curve of Santa Inês sheep. Weights of 140 females, born from2010 to 2012, from a single herd at Cravinhos- SP were used. The weights were measured from birth to about one year of age and the ages were grouped together in biweekly classes. The average weight observed at birth was of 3.77±0.92 kg. The non-linear models utilized in the data adjustment were the Brody, Gompertz, Logistic and Von Bertalanffy models, adjusted by the Gauss-Newton method by means of NLIN procedure, available in SAS software. The parameters which compose the functions, Wt (kg) is the weight in time t (days); A (kg) is the asymptotic weight when age tends to infinity; b is an integration constant, related to the initial weights of the animals and not well defined biological interpretation, and k is the maturity rate. The average estimates for A and k, are the most important from an zootechnical parameters point of view, mainly because heavier females tend to create faster growing sheep. All the models evaluated reached convergence. The quality of the models adjustment was done by error mean square (EMS) means. From the EMS results , the Gompertz model showed the best adjustment, which indicates increased association between the observed and estimated weights, in spite of the EMS values being quite close in all models, pointing out that all were adequate to report the growth curve from birth to one year of age in females of Santa Inês breed

Análise da curva de crescimento em fêmeas da raça Santa Inês

O artigo não apresenta resumo em português

Influência do sexo do bezerro no desempenho produtivo de vacas leiteiras

Investigating factors that could affect milk production of cows is an important way to improve the efficiency of production systems. This purpose of this study was to verify and quantify the influence of calf sex on milk production and lactation length in herds of Holstein, Gir, and Guzera cows. Data from 10,780 lactations of 4,807 Holstein cows that calved between 2001 and 2013; 18,898 lactations of 13,172 Gir cows that calved between 1985 and 2013; and 5,277 lactations of 3,972 Guzera cows that calved between 1987 and 2013 were used. Both the accumulated 305-day milk yield (P305) and the length of the lactation period up to 305 days (DL305) were evaluated. Analysis of variance was performed by the least squares method using the GLM procedure in the SAS statistical program. The P305 was not influenced by the sex of the calf in the Holstein breed. However in the zebu breeds (Gir and Guzera), both P305 and DL305 were significantly affected (P < 0.01) by the sex of the calf, with higher production and average length of lactation in cows that calved males. In addition, a significant difference was also nested within sex of calf and age at first calving (P < 0.05) in the Gir breed. The results indicate that for the zebu breeds, calf sex influences production characteristics.A investigação de fatores que interferem na produção de vacas leiteiras é de grande importância para eficiência dos sistemas de produção. O objetivo do trabalho foi verificar e quantificar a influência do sexo do bezerro sobre produção de leite e sobre a duração da lactação em rebanhos das raças Holandesa, Gir Leiteiro e Guzerá. Foram avaliadas 10.780 lactações de 4.807 vacas Holandesas, paridas entre 2001 e 2013; 18.898 lactações de 13.172 vacas Gir Leiteiro paridas de 1985 a 2013 e 5.277 lactações ocorridas entre 1987 e 2013, de 3.972 vacas Guzerá. As características estudadas foram produção de leite acumulada em 305 dias e duração da lactação (até 305 dias). A análise de variância foi realizada pelo método de quadrados mínimos, através do procedimento GLM do programa estatístico SAS. A produção de leite acumulada aos 305 dias (P305) na raça Holandesa não foi influenciada pelo sexo do bezerro. Entretanto, para os animais de origem zebuína (Gir leiteiro e Guzerá), ambas as características foram significativamente influenciadas (P < 0,01) pelo sexo do bezerro, sendo observadas maiores produções de leite e duração de lactação para vacas que pariram machos. Também foi observada diferença significativa do sexo do bezerro aninhado dentro de idade da vaca ao parto (P < 0,05) para a raça Gir leiteiro. Estes resultados indicam que para as raças zebuínas, o sexo do bezerro influenciou as características de produção

Brazilian Flora 2020: Leveraging the power of a collaborative scientific network

International audienceThe shortage of reliable primary taxonomic data limits the description of biological taxa and the understanding of biodiversity patterns and processes, complicating biogeographical, ecological, and evolutionary studies. This deficit creates a significant taxonomic impediment to biodiversity research and conservation planning. The taxonomic impediment and the biodiversity crisis are widely recognized, highlighting the urgent need for reliable taxonomic data. Over the past decade, numerous countries worldwide have devoted considerable effort to Target 1 of the Global Strategy for Plant Conservation (GSPC), which called for the preparation of a working list of all known plant species by 2010 and an online world Flora by 2020. Brazil is a megadiverse country, home to more of the world's known plant species than any other country. Despite that, Flora Brasiliensis, concluded in 1906, was the last comprehensive treatment of the Brazilian flora. The lack of accurate estimates of the number of species of algae, fungi, and plants occurring in Brazil contributes to the prevailing taxonomic impediment and delays progress towards the GSPC targets. Over the past 12 years, a legion of taxonomists motivated to meet Target 1 of the GSPC, worked together to gather and integrate knowledge on the algal, plant, and fungal diversity of Brazil. Overall, a team of about 980 taxonomists joined efforts in a highly collaborative project that used cybertaxonomy to prepare an updated Flora of Brazil, showing the power of scientific collaboration to reach ambitious goals. This paper presents an overview of the Brazilian Flora 2020 and provides taxonomic and spatial updates on the algae, fungi, and plants found in one of the world's most biodiverse countries. We further identify collection gaps and summarize future goals that extend beyond 2020. Our results show that Brazil is home to 46,975 native species of algae, fungi, and plants, of which 19,669 are endemic to the country. The data compiled to date suggests that the Atlantic Rainforest might be the most diverse Brazilian domain for all plant groups except gymnosperms, which are most diverse in the Amazon. However, scientific knowledge of Brazilian diversity is still unequally distributed, with the Atlantic Rainforest and the Cerrado being the most intensively sampled and studied biomes in the country. In times of “scientific reductionism”, with botanical and mycological sciences suffering pervasive depreciation in recent decades, the first online Flora of Brazil 2020 significantly enhanced the quality and quantity of taxonomic data available for algae, fungi, and plants from Brazil. This project also made all the information freely available online, providing a firm foundation for future research and for the management, conservation, and sustainable use of the Brazilian funga and flora