Breed and heterosis effects on reproduction and production traits of Girolando cows

The objective of this study was to evaluate the breed and heterosis effects on reproductive traits, test-day milk yield, and 305-day milk yield in different lactations of crossbred Girolando cows. Data consisted of test-day milk yield records of first (118,831 records), second (63,227), and third lactation (44,512) and their relative productive (test-day milk yield, 305-day milk yield, and lactation length) and reproductive (age at first calving, calving interval, days open, and dry period) records of 35,582 Girolando cows from Brazil, collected from 1998 to 2014. The heterosis effect of the evaluated traits in Girolando cattle was estimated by MIXED procedure in SAS. Girolando cows showed a negative (favorable) and significant heterosis effect for reproductive traits. The dry periods between the first and second calving and between the second and third calving showed the greatest gains in heterosis (21.93 and 10.41%, respectively). All the evaluated productive traits showed a significant and similar heterosis effect between the three lactations. The use of crossbreeding strategies between the Holstein and Gyr breeds, instead of using the pure breed, is indeed a good alternative to increase the economic efficiency of the dairy activity in the different production systems in tropical environments.(AU)

Differentially abundant proteins associated with heterosis in the primary roots of popcorn.

Although heterosis has significantly contributed to increases in worldwide crop production, the molecular mechanisms regulating this phenomenon are still unknown. In the present study, we used a comparative proteomic approach to explore hybrid vigor via the proteome of both the popcorn L54 ♀ and P8 ♂ genotypes and the resultant UENF/UEM01 hybrid cross. To analyze the differentially abundant proteins involved in heterosis, we used the primary roots of these genotypes to analyze growth parameters and extract proteins. The results of the growth parameter analysis showed that the mid- and best-parent heterosis were positive for root length and root dry matter but negative for root fresh matter, seedling fresh matter, and protein content. The comparative proteomic analysis identified 1343 proteins in the primary roots of hybrid UENF/UEM01 and its parental lines; 220 proteins were differentially regulated in terms of protein abundance. The mass spectrometry proteomic data are available via ProteomeXchange with identifier "PXD009436". A total of 62 regulated proteins were classified as nonadditive, of which 53.2% were classified as high parent abundance (+), 17.8% as above-high parent abundance (+ +), 16.1% as below-low parent abundance (- -), and 12.9% as low parent abundance (-). A total of 22 biological processes were associated with nonadditive proteins; processes involving translation, ribosome biogenesis, and energy-related metabolism represented 45.2% of the nonadditive proteins. Our results suggest that heterosis in the popcorn hybrid UENF/UEM01 at an early stage of plant development is associated with an up-regulation of proteins related to synthesis and energy metabolism.

F1 Holstein x Zebu Cows in late pregnancy show physiological adaptation when raised in semiarid environment / Vacas F1 Holandês x Zebu no terço final de gestação apresentam adaptação fisiológica quando criadas no ambiente semiárido

This study aimed to verify the adaptability of F1 Holstein x Zebu cows during the late pregnancy third, raised in the semiarid region of Minas Gerais, by means of physiological responses. A total of ten cows were used, all in fourth pregnancy. To characterize the climatic environment, daily collections of air temperature, air relative humidity and wind speed were carried out to enable the calculation of the Globe Temperature and Humidity Index (GTHI) and Radiant Thermal Load (RTL). The physiological parameters analyzed were: respiratory frequency, rectal temperature and surface body temperature, at 10 am and 3 pm. The adaptability tests used were Heat Tolerance Index (HTI) and Heat Tolerance Coefficient (HTC). The climatic environment was out of thermal comfort in the afternoon. There were significant differences (p < 0.05) for the values of the physiological parameters. However, these responses were within the comfort range recommended for crossbred animals. The adaptability tests confirmed that the animals show adaptation to the semiarid environment of Minas Gerais, showing differences (p < 0.05) on HTC between 10 am (2.52) and 3 pm (2.64), and the HTI showed an average of 9.64, a value that is very close to the index 10. It is concluded that the F1 Holstein x Zebu cows in the late pregnancy third are adapted to the climate in the semiarid region of Minas Gerais, by not [...]

O trabalho teve como objetivo verificar a adaptabilidade de vacas F1 Holandês x Zebu no terço final de gestação, criadas no semiárido mineiro, por meio das respostas fisiológicas. Foram utilizadas 10 vacas, todas de quarta gestação. Para caracterizar o ambiente climático foram realizadas coletas diárias de temperatura do ar, umidade relativa do ar e velocidade do vento, para possibilitar o cálculo do Índice de Temperatura de Globo e Umidade (ITGU) e da Carga Térmica Radiante (CTR). Os parâmetros fisiológicos analisados foram: frequência respiratória, temperatura retal e temperatura da superfície corporal, às 10:00 e 15:00 horas. Os testes de adaptabilidade utilizados foram: Índice de tolerância ao calor (ITC) e coeficiente de tolerância ao calor (CTC). O ambiente climático esteve fora das condições de conforto térmico no período da tarde. Houve diferença significativa (p < 0,05) para os valores de parâmetros fisiológicos, contudo, essas respostas estiveram dentro da faixa de conforto recomendados para animais mestiços. Os testes de adaptabilidade confirmaram que os animais apresentam adaptação ao ambiente do semiárido mineiro, apresentando diferenças (p < 0,05), de CTC entre o horário das 10:00 h (2,52) e 15:00 h (2,64), e o ITC apresentou uma média de 9,64, valor aproximado do índice 10. Conclui-se que, as vacas F1 Holandês x Zebu no terço final de gestação são adaptadas ao [...]

F1 Holstein x Zebu Cows in late pregnancy show physiological adaptation when raised in semiarid environment / Vacas F1 Holandês x Zebu no terço final de gestação apresentam adaptação fisiológica quando criadas no ambiente semiárido

This study aimed to verify the adaptability of F1 Holstein x Zebu cows during the late pregnancy third, raised in the semiarid region of Minas Gerais, by means of physiological responses. A total of ten cows were used, all in fourth pregnancy. To characterize the climatic environment, daily collections of air temperature, air relative humidity and wind speed were carried out to enable the calculation of the Globe Temperature and Humidity Index (GTHI) and Radiant Thermal Load (RTL). The physiological parameters analyzed were: respiratory frequency, rectal temperature and surface body temperature, at 10 am and 3 pm. The adaptability tests used were Heat Tolerance Index (HTI) and Heat Tolerance Coefficient (HTC). The climatic environment was out of thermal comfort in the afternoon. There were significant differences (p < 0.05) for the values of the physiological parameters. However, these responses were within the comfort range recommended for crossbred animals. The adaptability tests confirmed that the animals show adaptation to the semiarid environment of Minas Gerais, showing differences (p < 0.05) on HTC between 10 am (2.52) and 3 pm (2.64), and the HTI showed an average of 9.64, a value that is very close to the index 10. It is concluded that the F1 Holstein x Zebu cows in the late pregnancy third are adapted to the climate in the semiarid region of Minas Gerais, by not [...](AU)

O trabalho teve como objetivo verificar a adaptabilidade de vacas F1 Holandês x Zebu no terço final de gestação, criadas no semiárido mineiro, por meio das respostas fisiológicas. Foram utilizadas 10 vacas, todas de quarta gestação. Para caracterizar o ambiente climático foram realizadas coletas diárias de temperatura do ar, umidade relativa do ar e velocidade do vento, para possibilitar o cálculo do Índice de Temperatura de Globo e Umidade (ITGU) e da Carga Térmica Radiante (CTR). Os parâmetros fisiológicos analisados foram: frequência respiratória, temperatura retal e temperatura da superfície corporal, às 10:00 e 15:00 horas. Os testes de adaptabilidade utilizados foram: Índice de tolerância ao calor (ITC) e coeficiente de tolerância ao calor (CTC). O ambiente climático esteve fora das condições de conforto térmico no período da tarde. Houve diferença significativa (p < 0,05) para os valores de parâmetros fisiológicos, contudo, essas respostas estiveram dentro da faixa de conforto recomendados para animais mestiços. Os testes de adaptabilidade confirmaram que os animais apresentam adaptação ao ambiente do semiárido mineiro, apresentando diferenças (p < 0,05), de CTC entre o horário das 10:00 h (2,52) e 15:00 h (2,64), e o ITC apresentou uma média de 9,64, valor aproximado do índice 10. Conclui-se que, as vacas F1 Holandês x Zebu no terço final de gestação são adaptadas ao [...](AU)

Genetic analysis of water-deficit response traits in maize.

A set of sixty inbred lines of maize (Zea mays L.) were screened in the greenhouse at the seedling stage under both normal and water-deficit conditions. Six water deficit-tolerant inbred lines were selected based on root to shoot ratios. These selected lines were crossed in a diallel pattern. The parental, F1, and reciprocal cross plants were planted in a field under both normal and water-deficit conditions. Normal irrigation was applied to the control set, while the water-deficit set received 50% of normal irrigation levels. Analyses of variance of various morpho-physiological parameters identified significant differences among the selected lines under both conditions, indicating the presence of significant genetic variability. Variance components for general combining ability (GCA), specific combining ability (SCA), and reciprocal effects for all the parameters were estimated to determine the relative importance of additive and non-additive or dominance type of gene action. Variance components for GCA were larger than for SCA indicating the preponderance of additive types of gene action for all the traits under study. Hybrids developed from inbred lines W-10 and W-64SP proved to have the best grain yield under normal and water-deficit conditions. Under water-deficit conditions, the best performing cross was B-34 x W-10. Hence, these inbred lines and the hybrids might be of value in future breeding programs.

Sympatry between Alouatta caraya and Alouatta clamitans and the rediscovery of free-ranging potential hybrids in Southern Brazil.

Records of sympatry between Alouatta caraya and A. clamitans are rare despite their extensive range overlap. An example of their current sympatry and the rediscovery of free-ranging potential hybrids of A. caraya and A. clamitans in the forests of the Upper Paraná River, Southern Brazil, are reported in this paper. Eight groups were observed in the study area: five monospecific groups of A. caraya, two of A. clamitans, and a group containing two adult males and two adult females of A. caraya and a sub-adult male and two adult females identified as Alouatta sp. The color of the last three individuals was a mosaic between the two species; this is consistent with previously described variations in museum specimens collected in the Paraná River in the 1940s that had been identified as potential hybrids. The results from this study emphasize the need for scientific studies in the region of the Ilha Grande National Park, one of the few regions in the Paraná River that currently harbors both howler species.

Hybridization and invasiveness in the freshwater snail Melanoides tuberculata: hybrid vigour is more important than increase in genetic variance.

Many invasive taxa are hybrids, but how hybridization boosts the invasive process remains poorly known. We address this question in the clonal freshwater snail Melanoides tuberculata from Martinique, using three parental and two hybrid lines. We combine an extensive field survey (1990-2003) and a quantitative genetic experiment to show that hybrid lines have outcompeted their parents in natural habitats, and that this increased invasiveness co-occurred with pronounced shifts in life-history traits, such as growth, fecundity and juvenile size. Given the little time between hybrid creation and sampling, and the moderate standing genetic variance for life-history traits in hybrids, we show that some of the observed trait changes between parents and hybrids were unlikely to arise only by continuous selection. We therefore suggest that a large part of hybrid advantage stems from immediate heterosis upon hybridization.

Estimation of direct and maternal breed effects for prediction of expected progeny differences for birth and weaning weights in three multibreed populations.

Direct and maternal breed effects on birth and 200-d weights were estimated for nine parental breeds (Hereford [H], Angus [A], Braunvieh [B], Limousin [L], Charolais [C], Simmental [S], Gelbvieh [G], Red Poll [R], and Pinzgauer [P]) that contributed to three composite populations (MARC I = 1/4B, 1/4C, 1/4L, 1/8H, 1/8A; MARC II = 1/4G, 1/4S, 1/4H, 1/4A; and MARC III = 1/4R, 1/4P, 1/4H, 1/4A). Records from each population, the composite plus pure breeds and crosses used to create each composite, were analyzed separately. The animal model included fixed effects of contemporary group (birth year-sex-dam age), proportions of individual and maternal heterosis and breed inheritance as covariates, and random effects of additive direct genetic (a) and additive maternal genetic (m) with covariance (a,m), permanent environment, and residual. Sampling correlations among estimates of genetic fixed effects were large, especially between direct and maternal heterosis and between direct and maternal breed genetic effects for the same breed, which were close to -1. This resulted in some large estimates with opposite sign and large standard errors for direct and maternal breed genetic effects. Data from a diallel experiment with H, A, B, and R breeds, from grading up and from a top cross experiment were required to separate breed effects satisfactorily into direct and maternal genetic effects. Results indicate that estimation of direct and maternal breed effects needed to predict hybrid EPD for multibreed populations from field data may not be possible. Information from designed crossbreeding experiments will need to be incorporated in some way.