Genome Wide Association Study for Heifer Pregnancy in Nellore Cattle

Considering the economic importance of sexual precocity in Brazilian beef cattle production systems, we were interested in a genome wide association study (GWAS) to find genomic regions that might explain the genetic variability of precocity assessed from heifer pregnancy rates. Given each suggestive region of large effect, we were interested in contrasting the two paternally-inherited haplotype alleles to identify sires that were heterozygous for the effect caused by that region. The database consists of reproductive information on 1,337 Bos indicus Nellore heifers, from three different herds in Brazil. GWAS results identified genomic regions on chromosomes 5, 14 and 18 that explained more than 1% of the total genetic variance. Haplotype analysis for the chromosome 5 region showed heterozygote sires with significant differences in reproduction between their half-sib progenies

Estimation of Genetic Parameters of Heat Tolerance for Production Traits in Canadian Holsteins Cattle.

Understanding how cows respond to heat stress has helped to provide effective herd management practices to tackle this environmental challenge. The possibility of selecting animals that are genetically more heat tolerant may provide additional means to maintain or even improve the productivity of the Canadian dairy industry, which is facing a shifting environment due to climate changes. The objective of this study was to estimate the genetic parameters for heat tolerance of milk, fat, and protein yields in Canadian Holstein cows. A total of 1.3 million test-day records from 195,448 first-parity cows were available. A repeatability test-day model fitting a reaction norm on the temperature-humidity index (THI) was used to estimate the genetic parameters. The estimated genetic correlations between additive genetic effect for production and for heat tolerance ranged from -0.13 to -0.21, indicating an antagonistic relationship between the level of production and heat tolerance. Heritability increased marginally as THI increased above its threshold for milk yield (0.20 to 0.23) and protein yield (0.14 to 0.16) and remained constant for fat yield (0.17). A Spearman rank correlation between the estimated breeding values under thermal comfort and under heat stress showed a potential genotype by environmental interaction. The existence of a genetic variability for heat tolerance allows for the selection of more heat tolerant cows

Ericaceae of the Serra Negra, Minas Gerais, Brazil

Serra Negra is a fragment of the Mantiqueira Range located among Lima Duarte, Santa Bárbara do Monte Verde, Rio Preto and Olaria, with altitudes between 800 and 1700 m. The vegetation is represented by a mosaic of forests and field environments, of which the "campo rupestre" must be highlighted, due to its occurrence in the whole altitudinal range in the area. A wide floristic study was conducted between the years 2003 and 2014 and the collected specimens were deposited in the Herbarium Leopoldo Krieger (CESJ), of the Universidade Federal de Juiz de Fora. The aim of the present study was to conduct a floristic and taxonomic inventory to the family Ericaceae of the Serra Negra. It were recorded eight species belonging to three genera, of which Gaylussacia and Agarista were the richest, with four and three species, respectively, and Gaultheria represented by just one species. Identification keys, descriptions, illustrations of diagnostic characters, and comments of geographic distribution, ecological and taxonomic are provided.A Serra Negra é um fragmento do Complexo da Mantiqueira, localizado entre os municípios de Lima Duarte, Santa Bárbara do Monte Verde, Rio Preto e Olaria, com altitudes variando entre 800 e 1700m. A vegetação apresenta um mosaico composto por florestas e ambientes campestres, destacando-se o campo rupestre por toda a amplitude altimétrica. Um amplo estudo florístico foi realizado entre os anos de 2003 e 2014, e os espécimes coletados foram depositados no Herbário Leopoldo Krieger (CESJ), da Universidade Federal de Juiz de Fora. O objetivo do presente estudo foi realizar um inventário florístico e taxonômico para a família Ericaceae da Serra Negra. Foram registradas oito espécies pertencentes a três gêneros, sendo Agarista e Gaylussacia os mais ricos, com quatro e três espécies respectivamente, e Gaultheria representado por apenas uma espécie. São apresentadas chaves de identificação, descrições das espécies, ilustrações de caracteres diagnósticos e comentários de distribuição geográfica, ecológicos e taxonômicos

Reproductive tract size and position score: Estimation of genetic parameters for a novel fertility trait in dairy cows.

The dairy industry is moving toward selecting animals with better fertility to decrease the economic losses linked to reproductive issues. The reproductive tract size and position score (SPS) was recently developed in physiological studies as an indicator of pregnancy rate and the number of services to conception. Cows are scored as SPS 1, 2, or 3 based on the size of their reproductive tract and its position in the pelvis, as determined by transrectal palpation. The objective of this study was to estimate genetic parameters for SPS to assess its potential as a novel fertility trait. Phenotypes were collected at the University of British Columbia's research herd from 2017 to 2020, consisting of 3,247 within- and across-lactation SPS records from 490 Holstein cows. A univariate animal model was used to estimate the variance components for SPS. Both threshold and linear models were fit under a Bayesian approach and the results were compared using the Spearman rank correlation (r) between the estimated breeding values. The 2 models ranked the animals very similarly (r = 0.99), and the linear model was selected for further analysis. Genetic correlations with other currently evaluated traits were estimated using a bivariate animal model. The posterior means (± posterior standard deviation) for heritability and repeatability within- and across-lactation were 0.113 (± 0.013), 0.242 (± 0.012), and 0.134 (± 0.014), respectively. The SPS showed null correlations with production traits and favorable correlations with traditional fertility traits, varying from -0.730 (nonreturn rate) to 0.931 (number of services). Although preliminary, these results are encouraging because SPS seems to be more heritable than and strongly genetically correlated with number of services, nonreturn rate, and first service to conception, indicating potential for effective indirect selection response on these traits from SPS genetic selection. Therefore, further studies with larger data sets to validate these findings are warranted

Suitability of the predatory mites Iphiseiodes zuluagai and Euseius concordis in controlling Polyphagotarsonemus latus and Tetranychus bastosi on Jatropha curcas plants in Brazil

One of the most promising plant species for biofuel production in Brazil is the physic nut Jatropha curcas. Major phytosanitary problems include the attack of two pest mite species, the broad mite Polyphagotarsonemus latus and the spider mite Tetranychus bastosi. Owing to pesticide-related problems, there is an increasing demand for sustainable environmental-friendly control methods such as biological control. In this study we evaluated the suitability of the predatory mite species Iphiseiodes zuluagai and Euseius concordis in controlling P. latus and T. bastosi on J. curcas. The number of T. bastosi killed by I. zuluagai was lower than the number of P. latus consumed.Euseius concordis preyed upon both T. bastosi and P. latus but the number of prey killed was always lower in comparison with I. zuluagai. However, P. latus and T. bastosi are suitable for the development of I. zuluagai and E. concordis as oviposition of both predators did not differ in relation to prey species. The preference of I. zuluagai for leaves of plants infested by either P. latus or T. bastosi, combined with the higher values for predation obtained by this predatory mite when fed on P. latus, compared to those values obtained by E. concordis, suggests that I. zuluagai can be more efficient than E. concordis in reducing populations of P. latus and T. bastosi under field conditions. Furthermore, we report here on the first record of predatory mites associated with P. latus and T. bastosi on native J. curcas plants in Brazil. In conclusion, we emphasize the crucial importance of predatory mites as agents of natural biological control of mite pests on J. curcas in small farms