Thomas W. Geary

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Traits used for identification of replacement beef heifers and feeding levels provided during postweaning development may have major financial implications due to effects on maintenance requirements and level of lifetime production. The current study evaluated the effects of 2 levels of feeding during the postweaning period on growth, G:F, and ultrasound(More)
Previous research indicated that the size of the ovulatory follicle at the time of insemination significantly influenced pregnancy rates and embryonic/fetal mortality after fixed-timed AI in postpartum cows, but no effect on pregnancy rates was detected when cows ovulated spontaneously. Our objective was to evaluate relationships of fertility and(More)
A microsatellite-based genome scan of a Wagyu x Limousin F(2) cross population previously demonstrated QTL affecting LM area and fatty acid composition were present in regions near the centromere of BTA2. In this study, we used 70 SNP markers to examine the centromeric 24 megabases (Mb) of BTA2, including the Limousin-specific F94L myostatin allele(More)
Induced ovulation of small dominant follicles (SF, < 12 mm; CO-Synch protocol) in postpartum beef cows resulted in formation of corpora lutea (CL) that exhibited a delayed rise in progesterone (P4) compared with CL from large dominant follicles (LF, > 12 mm). Experiment 1 characterized P4 concentrations from ovulation to subsequent estrus among GnRH-induced(More)
Pregnancy failure in livestock can result from failure to fertilize the oocyte or embryonic loss during gestation. The focus of this review is on cattle and factors affecting and mechanisms related to uterine insufficiency for pregnancy. A variety of factors contribute to embryonic loss and it may be exacerbated in certain animals, such as high-producing(More)
Primiparous beef cows produced in 3 calving systems were used in a 2-yr study with a completely random design to measure milk yield throughout a 190-d lactation (2002, n = 20; 2003, n = 24 per calving system). Calving occurred in late winter (average calving date = February 4 +/- 2 d), early spring (average calving date = March 30 +/- 2 d), and late spring(More)
Infertility and subfertility are important and pervasive reproductive problems in both domestic animals and humans. The majority of embryonic loss occurs during the first three weeks of pregnancy in cattle and women due, in part, to inadequate endometrial receptivity for support of embryo implantation. To identify heifers of contrasting fertility, serial(More)
The objectives of this study were to evaluate the effects of immunization against recombinant GnRH fusion proteins and growth promotants on onset of puberty, feedlot performance, and carcass characteristics of beef heifers. Heifers were immunized against an ovalbumin fusion protein containing 7 GnRH peptides (oGnRH, n = 12), a thioredoxin fusion protein(More)
Synchronization of dominant follicle development and control of ovulation/oocyte retrieval are commonly used assisted reproductive technologies in both cattle and humans. The final maturation of the dominant follicle is intimately tied to the final maturation of the oocyte, preovulatory secretion of estradiol, preparation of follicular cells for(More)
Energetic efficiency was evaluated in composite bred heifers born from dams receiving 1·8 or 1·2 kg/d winter supplementation for approximately 80 d before parturition. Heifers were then developed post-weaning and randomly assigned to heifer development treatments of either control (100 %; ad libitum; n 8/year) or restricted (80 %; fed 80 % of(More)