Guilherme J. M. Rosa

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Recently a protocol was developed that precisely synchronizes the time of ovulation in lactating dairy cows (Ovsynch; GnRH-7d-PGF2 alpha-2d-GnRH). We evaluated whether initiation of Ovsynch on different days of the estrous cycle altered the effectiveness of this protocol. The percentage of cows (n = 156) ovulating to the first GnRH was 64% and varied (P <(More)
Reproducing kernel Hilbert spaces (RKHS) methods are widely used for statistical learning in many areas of endeavor. Recently, these methods have been suggested as a way of incorporating dense markers into genetic models. This note argues that RKHS regression provides a general framework for genetic evaluation that can be used either for pedigree- or(More)
Ovarian function was compared between nulliparous heifers (n = 29; 10 to 16 mo old) and lactating Holstein cows (n = 31; 55.9 +/- 3.5 d postpartum). Follicular dynamics, corpus luteum growth, and regression, and serum steroid concentrations were evaluated through ultrasonography and daily blood sampling. Most heifers (27 of 29) but only 14 of 31 cows had(More)
The identification of genes and deduced pathways from the mature human oocyte can help us better understand oogenesis, folliculogenesis, fertilization, and embryonic development. Human metaphase II oocytes were used within minutes after removal from the ovary, and its transcriptome was compared with a reference sample consisting of a mixture of total RNA(More)
The objective of this study was to investigate the association of the signal transducer and activator of transcription 5A (STAT5A) gene with fertilization rate, embryonic survival, and milk production and composition in cattle. The STAT proteins are transcription factors that are specifically activated to regulate gene transcription when cells encounter(More)
The objective of the present study was to assess the predictive ability of subsets of single nucleotide polymorphism (SNP) markers for development of low-cost, low-density genotyping assays in dairy cattle. Dense SNP genotypes of 4,703 Holstein bulls were provided by the USDA Agricultural Research Service. A subset of 3,305 bulls born from 1952 to 1998 was(More)
Pigs from the F(2) generation of a Duroc x Pietrain resource population were evaluated to discover QTL affecting growth and composition traits. Body weight and ultrasound estimates of 10th-rib backfat, last-rib backfat, and LM area were serially measured throughout development. Estimates of fat-free total lean, total body fat, empty body protein, empty body(More)
Genome-wide association studies using single nucleotide polymorphisms (SNPs) can identify genetic variants related to complex traits. Typically thousands of SNPs are genotyped, whereas the number of phenotypes for which there is genomic information may be smaller. When predicting phenotypes, options for statistical model building range from incorporating(More)
Quantitative reverse transcription polymerase chain reaction (qRT-PCR) is currently viewed as the most precise technique to quantify levels of messenger RNA. Relative quantification compares the expression of a target gene under two or more experimental conditions normalized to the measured expression of a control gene. The statistical methods and software(More)
Two experiments compared follicular and luteal development and circulating steroid concentrations from induced luteolysis to ovulation in lactating Holstein cows (n = 27; 40.0 +/- 1.5 kg milk/day) vs. nulliparous heifers (n = 28; 11 to 17 mo-old) during summer (Experiment 1), and in lactating (n = 27; 45.9 +/- 1.4 kg milk/d) vs. dry cows (n = 26) during(More)