Uso de LH ou eCG no último dia do protocolo superovulatório em bovinos

In the last decades several hormonal treatments to induce multiple ovulation and embryo transfer (MOET) have been developed. Tight control of the time of ovulation allowed the use of fixed-time artificial insemination (FTAI) in bovine embryos donors, facilitating animal management. Although, protocols that allow FTAI have evolved and yield as much embryo as conventional protocols that requires estrus detection, substantial increase in viable embryo production has not been observed in superestimulated bovine cattle. The present review put emphasis on superestimulatory protocols in wich the last two doses of pFSH are replaced by eCG or LH. Recent results indicate that an extra LH stimulus (using eCG or LH), on the last day of P-36 superestimulatory treatment, seems to improve transferable embryo yield in both Bos taurus and Bos indicus cattle.

Ovarian superstimulation using FSH combined with equine chorionic gonadotropin (eCG) upregulates mRNA encoding proteins involved with LH receptor intracellular signaling in granulosa cells from Nelore cows

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Parâmetros genéticos para o perfil de ácidos graxos do longissimus thoracis de bovinos da raça Nelore terminados em confinamento

Pós-graduação em Genética e Melhoramento Animal - FCAV

Análise ampla do genoma para detecção de erros de montagem no genoma de referência bovino e para detecção de locos relacionados a características de produção e reprodução da raça GIR

Pós-graduação em Genética e Melhoramento Animal - FCAV

Uso de extratos vegetais, vitaminas e sua associação sobre o desempenho, temperamento e qualidade de carne de bovinos nelore confinados com dieta de alto grão

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Prediction of genomic-enabled breeding values and genome-wide association study for feedlot average daily weight gain in Nelore cattle

Pós-graduação em Genética e Melhoramento Animal - FCAV

Global liver gene expression differences in Nelore steers with divergent residual feed intake phenotypes

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Non-synonymous mutations mapped to chromosome X associated with andrological and growth traits in beef cattle

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Effects of polyethylene film wrap on cooler shrink and the microbial status of beef carcasses

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Genomic data as the hitchhiker's guide to cattle adaptation: tracking the milestones of past selection in the bovine genome

The bovine species have witnessed and played a major role in the drastic socio-economical changes that shaped our culture over the last 10,000 years. During this journey, cattle hitchhiked on human development and colonized the world, facing strong selective pressures such as dramatic environmental changes and disease challenge. Consequently, hundreds of specialized cattle breeds emerged and spread around the globe, making up a rich spectrum of genomic resources. Their DNA still carry the scars left from adapting to this wide range of conditions, and we are now empowered with data and analytical tools to track the milestones of past selection in their genomes. In this review paper, we provide a summary of the reconstructed demographic events that shaped cattle diversity, offer a critical synthesis of popular methodologies applied to the search for signatures of selection (SS) in genomic data, and give examples of recent SS studies in cattle. Then, we outline the potential and challenges of the application of SS analysis in cattle, and discuss the future directions in this field.

Association of ADIPOQ, OLR1 and PPARGC1A gene polymorphisms with growth and carcass traits in Nelore cattle

In beef cattle farming, growth and carcass traits are important for genetic breeding programs. Molecular markers can be used to assist selection and increase genetic gain. The ADIPOQ, OLR1 and PPARGC1A genes are involved in lipid synthesis and fat accumulation in adipose tissue. The objective of this study was to identify polymorphisms in these genes and to assess the association with growth and carcass traits in Nelore cattle. A total of 639 animals were genotyped by PCR-RFLP for rs208549452, rs109019599 and rs109163366 in ADIPOQ, OLR1 and PPARGC1A gene, respectively. We analyzed the association of SNPs identified with birth weight, weaning weight, female yearling weight, female hip height, male yearling weight, male hip height, loin eye area, rump fat thickness, and backfat thickness. The OLR1 marker was associated with rump fat thickness and weaning weight (P < 0.05) and the PPARGC1 marker was associated with female yearling weight.

Low frequency of Y anomaly detected in Australian Brahman cow-herds

Indicine cattle have lower reproductive performance in comparison to taurine. A chromosomal anomaly characterized by the presence Y markers in females was reported and associated with infertility in cattle. The aim of this study was to investigate the occurrence of the anomaly in Brahman cows. Brahman cows (n = 929) were genotyped for a Y chromosome specific region using real time-PCR. Only six out of 929 cows had the anomaly (0.6%). The anomaly frequency was much lower in Brahman cows than in the crossbred population, in which it was first detected. It also seems that the anomaly doesn't affect pregnancy in the population. Due to the low frequency, association analyses couldn't be executed. Further, SNP signal of the pseudoautosomal boundary region of the Y chromosome was investigated using HD SNP chip. Pooled DNA of non-pregnant and pregnant cows were compared and no difference in SNP allele frequency was observed. Results suggest that the anomaly had a very low frequency in this Australian Brahman population and had no effect on reproduction. Further studies comparing pregnant cows and cows that failed to conceive should be executed after better assembly and annotation of the Y chromosome in cattle.

A genomewide association mapping study using ultrasound-scanned information identifies potential genomic regions and candidate genes affecting carcass traits in Nellore cattle

The aim of this study was to identify candidate genes and genomic regions associated with ultrasound-derived measurements of the rib-eye area (REA), backfat thickness (BFT) and rumpfat thickness (RFT) in Nellore cattle. Data from 640 Nellore steers and young bulls with genotypes for 290 863 single nucleotide polymorphisms (SNPs) were used for genomewide association mapping. Significant SNP associations were explored to find possible candidate genes related to physiological processes. Several of the significant markers detected were mapped onto functional candidate genes including ARFGAP3, CLSTN2 and DPYD for REA; OSBPL3 and SUDS3 for BFT; and RARRES1 and VEPH1 for RFT. The physiological pathway related to lipid metabolism (CLSTN2, OSBPL3, RARRES1 and VEPH1) was identified. The significant markers within previously reported QTLs reinforce the importance of the genomic regions, and the other loci offer candidate genes that have not been related to carcass traits in previous investigations.

First genetic identification of Cryptosporidium parvum subtype IIaA14G2R1in beef cattle in Brazil

The presence of Cryptosporidium spp. in a cattle herd registered with an outbreak of diarrhea was investigated and the the molecular subtyping of Cryptosporidium parvum was characterized. Fecal samples from 85 Nellore beef cattle (Bos indicus) were collected and examined with Ziehl-Neelsen modified staining method. Fifty-four cattle (63.52%) had Cryptosporidium spp. oocysts in their feces. Fragments of genes encoding the 18S ribosomal RNA subunit and a 60-kDa glycoprotein (gp60) were amplified by nested PCR accomplished in the 11 most heavily parasitized samples, and the amplicons were sequenced. Eight of the 11 analyzed samples were positive for 18S rRNA sequences and identified monospecific infections with C. parvum. Seven samples were positive for gp60 and identified subtypes IIaA15G2R1 (6/11) and IIaA14G2R1 (1/11). This report is the first for C. parvum subtype IIaA14G2R1 in beef cattle in Brazil.

Histologia e histomorfometria do retículo de bovino no período pré-natal

The development of the stomach of ruminants requires further studies because it is a complex process. Therefore, was analyzed the histology and histomorphometry of reticulum at each gestation period. Samples of Nelore fetuses (Bos taurus indicus) was divided in 5 groups: 1 - fetuses at 9 to 15 weeks (8 to 21cm) of gestation, 2 - fetuses at 16 to 22 weeks (23 to 37cm) 3 - fetuses at 23 to 29 weeks (40 to 58cm), 4 - fetuses at 30 to 36 weeks (61 to 77cm) and 5 - fetuses at 37-43 weeks (79 to 88cm). The histological sections were stained with hematoxylin and eosin and Mallory's trichrome and examined by light microscopy. In group 1, the fetuses with 11 cm, showed mucosal projections that eventually become primary crests, lamina propria and submucosa are fused and external and internal muscular and similar. At 16.5 inches, the primary crests had lamina propria and at 18.5 cm, appeared connections between the ridges. In group 2, at 31 cm started epithelial involvement around the crests. In group 3, the fetuses of 42 cm revealed the first secondary papillae and muscular mucosa in the upper portion of the primary crests. Thereafter, it was increased epithelial due to its positioning around the crests, thickening of the lamina propriasubmucosa, muscular layer, especially the internal muscular and serosa. It was concluded that the most visible changes occur in fetuses belonging to the first 3 groups, measurements for the epithelium, muscle layer and total wall were increasing and the other analyzed layers showed variations during fetal development.