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Genetic parameters were estimated for scrotal circumference adjusted to 365 (SC365) and 450 (SC450) days of age, age at first calving (AFC), accumulated productivity (AP), stayability (STAY), loin eye area (LMA), thickness of subcutaneous fat over the 12th-13th ribs (BF), thickness of subcutaneous fat over the rump (RF), and shear force measured by Warner-Bratzler shear force (WBSF) of polled Nellore cattle. Bayesian analysis bi characteristics were performed by adopting linear animal model, whereas STAY analyzes used the linear threshold model. Heritability estimates were equal to 0.31 (SC365), 0.37 (SC450), 0.16 (AFC), 0.25 (AP), 0.16 (STAY), 0.30 (LMA), 0.13 (BF), 0.24 (RF), and 0.15 (WBSF), indicating moderate response to selection. Genetic and residual correlations between SC365 and SC450 were high and positive (0.91 and 0.74, respectively), as well as the genetic correlations of AP with SC365, SC450, AFC, and STAY (0.61, 0.62, -0.69, and 0.83, respectively). Genetic and residual correlations of WBSF with reproductive and carcass characteristics exhibited high standard deviations, however favorable.

The conformation is directly related to the quality of the movements, and can direct the selection by equine aptitude. This study aimed to identify which are the morphometric measurements that explain the total variance available in the marcha batida and picada gaits of young Mangalarga Marchador horses. Analyses were performed by evaluating 20 linear measurements of 420 champion horses. Measures were separated by gender (male-M and female-F), type of marcha, (batida-MB e picada-MP) and divided into eight age groups. Principal component analysis (PCA) was used to identify which measurements were most important in determining marcha variance by selecting principal component (PC) which sum of eigenvalues was able to explain the minimum percentage of 80% of the total variation. The PC number varied randomly according to age groups, being 2 to 3 in both genders in MP, 3 to 4 for M-MB, and up to 5 for F-MB, suggesting lower overall variability in MP, and higher in F-MB. There was no defined pattern concerning the amount of PC per age group, demonstrating that each category may have independent variations. Although, some repetitions of variables occurred similarly in different ages, sexes, and marcha types, the responsibility for the highest occurrence of variation was the posterior cannon and gaskin length. The significant variance in the length of these segments, regardless of gender, age, and marcha, and the fact they are not measured daily suggested there is not only a lack of standardization of these segments, but there is also size compensation among them since the group evaluated is composed of breed champions. RESUMO: A conformação pode estar diretamente relacionada a qualidade dos movimentos direcionando a seleção dos equinos por aptidão. Objetivou-se identificar quais medidas lineares explicam a variância total disponível nas marchas batida e picada em cavalos jovens da raça Mangalarga Marchador. As análises foram realizadas pela avaliação de 20 medidas lineares de 420 equinos campeões de exposições, separados por sexo (macho-M e fêmeas-F), tipo de marcha (batida-MB e picada-MP) e oito grupos etários. Utilizou-se análise de componentes principais (ACP) para identificar quais características eram mais importantes na determinação da variância das marchas, selecionando aquelas contidas em CP, cuja soma de autovalores foi capaz de explicar o percentual mínimo de 80% da variação total. O número de CP variou de acordo com as faixas etárias, sendo de 2 a 3 em M e F-MP, de 3 a 4 para M-MB e até 5 para F-MB, o que sugere menor variação em animais de MP, e maior em F-MB. Não houve padrão na quantidade de CP por classe etária demonstrando variações independentes entre categorias. A maior variância geral foi explicada pelo comprimento de canela posterior e perna. A grande variância no comprimento desses segmentos, independentemente de sexo, idade, tipo de marcha e o fato dos mesmos não serem mensurados cotidianamente, sugere que não ocorre somente a ausência de padronização, mas também há compensação de tamanho entre eles, visto que se avaliou apenas animais campeões da raça.

In tropical countries, it is common to import semen from dairy taurine cattle breeds based on the genetic evaluations carried out in the countries of origin. Therefore, the objective of this study is to verify if the selection of sires based on the DPR (daughter pregnancy rate) estimated in the US genetic evaluation implies on the reduction of the days open of their daughters in Brazil. Data were collected from 325 daughters of 42 Holstein bulls stratified by DPR (DPR < -2, DPR > -2 and < 0, DPR > 0 and < 2, Group DPR > 2). The DPR data was collected from the 2018 US genetic evaluation of Holstein cattle. Each sire had in the database at least 4 daughters of reproductive age, raised in Freestall system and submitted to fixed-time artificial insemination. All the daughters evaluated were from the same farm. To compare the number of days open of each DPR group, a Tukey test with a 0.05 level of significance was performed. The results are shown in Table 1. The results demonstrated the selection of sires based on DPRs estimated in the US genetic evaluation impacts positively Brazilian herds, reducing cows days open.

Locally adapted cattle herds such as Curraleiro Pé Duro (CDP) are rustic and adapted to the tropics and are able to survive in extreme environmental conditions such as the Brazilian Semi-Arid region. The study aimed to identify copy number variants (CNVs) possibly related to CPD adaptive traits. A total of 126 CPD animals were genotyped using the Illumina Bovine50K Genotyping BeadChip (Illumina Inc., San Diego, CA). To reduce false positives, the LRR of each SNP was adjusted for the GC content of 1 Mb window surrounding the SNP and PennCNV software was applied to 29 autosomes to detect CNVs. All samples with standard deviation of LRR > 0.30, standard deviation of BAF > 0.001, wave factor > 0.05, samples with > 150 CNVs and CNVs presenting length < 50kb were discarded for downstream analysis. BEDtools suite was used to map CNVs onto genes using the BioMart tool (Bos taurus UMD 3.1 assembly). Gene lists were mapped onto curated biological process and gene categories using the PANTHER classification system. 635 CNVs were identified after quality control of the autosomal chromosomes (51 deletions and 584 insertions). The CNVs length ranged from 50.6 kb (BTA20) up to 1,362 kb (BTA7) with a mean and median of 179.4 kb and 148.8 kb, respectively, corresponding to 0.03% of the bovine genome. The CNVs identified were overlapping with 339 genes, which we can highlight GRIK2 (BTA9:48476204), PCDH18 (BTA17:20336068), IGF2 (BTA4:32077891) previously reported in the literature as involved with flight time (temperament), rectal temperature and reproduction, respectively. The functional enrichment analysis demonstrated that the main enriched pathways (P < 0.05) were regulation of biogenesis (GO:0071840) and catalytic activities (GO 0005198). The CNVs identified as potentially related to adaptive traits may be used to select animals of higher adaptive value to a tropical environment.