The Experts below are selected from a list of 945 Experts worldwide ranked by ideXlab platform
Fred M. Hopkins - One of the best experts on this subject based on the ideXlab platform.
-
Breeding soundness evaluations of 3648 yearling beef bulls using the 1993 Society for Theriogenology guidelines
Theriogenology, 2002Co-Authors: S.p Kennedy, J.c. Spitzer, Fred M. Hopkins, H.l. Higdon, William C. BridgesAbstract:Abstract Our objective was to perform a retrospective analysis of breeding soundness evaluations (BSEs) as classified by the 1993 Society for Theriogenology (SFT) guidelines [Chenoweth et al., Guidelines for using the bull breeding soundness evaluation form, in: Theriogenology Handbook, 1993, pp. B-10]. Data included BSE information obtained from five performance-testing stations in South Carolina (SC1, SC2, SC3) and Tennessee (TN1, TN2) from 1986 through 1999 on 3648 Angus, Brangus, Charolais, Chianina, Gelbvieh, Limousin, Polled Hereford, Santa Gertrudis, Simbrah, and Simmental bulls. Analyses were simplified by classifying all bulls as either satisfactory or unsatisfactory potential breeders. Of the 3648 bulls evaluated, 76.2% were classified as satisfactory potential breeders. Of all bulls evaluated, 4.0% were unsatisfactory due to inadequate spermatozoal motility, 7.0% due to inadequate spermatozoal morphology and 2.6% due to a combination of inadequate motility and morphology. Unsatisfactory classifications due to non-spermatozoal parameters out of all bulls were 10.2%, with 7.1% for inadequate scrotal circumference and 3.1% for physical abnormalities. For satisfactory and unsatisfactory bulls, respectively, means and standard deviations were 35.8±2.7 and 33.0±4.1 cm (P
-
outcomes of breeding soundness evaluation of 2898 yearling bulls subjected to different classification systems
Theriogenology, 2000Co-Authors: H.l. Higdon, J.c. Spitzer, Fred M. Hopkins, William C. BridgesAbstract:Abstract This study is a retrospective analysis comparing data on yearling bull breeding soundness evaluation (BSE) subjected to 3 different classification systems: the Society for Theriogenology (SFT) 1983 and 1993 systems, and the Western Canadian Association of Bovine Practitioners (WC) 1993 system. Data were collected at 5 performance bull-test stations located in South Carolina and Tennessee from 1986 through 1996. Yearling bulls (n = 2898) that were 10 to 20 mo of age were used in the analysis. To simplify analysis, bulls were determined to be either satisfactory or unsatisfactory potential breeders (including those classified as questionable, deferred or unsatisfactory). Data were analyzed 1) within location where a location was treated as an individual experiment, 2) with breeds and locations collapsed, and 3) within age-group where each age-group was treated as an individual experiment. An ANOVA was performed using GLM procedures of SAS, and this model was used to generate least square means for the proportion of bulls classified as satisfactory and the 5 possible unsatisfactory outcomes due to inadequacies in scrotal circumference, spermatozoal morphology, spermatozoal motility, a combination of inadequate spermatozoal morphology and motility, or physical abnormalities. Inadequate scrotal circumference or physical abnormality did not affect differences for BSE outcomes among systems. Using the SFT93 system, bulls failed at a higher rate due to inadequate spermatozoal morphology (P
-
the new society for Theriogenology breeding soundness evaluation system
Veterinary Clinics of North America-food Animal Practice, 1997Co-Authors: Fred M. Hopkins, J.c. SpitzerAbstract:In 1993, The Society for Theriogenology published revised standards for breeding soundness evaluation of bulls. These revised standards replaced the old semen score format with minimum acceptable scores for scrotal circumference (varies with age), motility (30% or fair), and morphology (70%).
-
Breeding Soundness Evaluation of Yearling Bulls
Veterinary Clinics of North America: Food Animal Practice, 1997Co-Authors: J.c. Spitzer, Fred M. HopkinsAbstract:Breeding Soundness Evaluations (BSEs) are a useful tool to improve reproductive performance and profitability in beef herds. Veterinarians providing this service must be thorough in their evaluation, especially in yearling bulls. The 1993 Society for Theriogenology guidelines for BSE provide appropriate standards for classifying yearling bulls; veterinarians are advised to adhere to these standards as minimums for classification of the satisfactory potential breeder.
-
new guidelines for the evaluation of bulls for breeding soundness
American Association of Bovine Practitioners Proceedings of the Annual Conference, 1993Co-Authors: P J Chenoweth, J.c. Spitzer, Fred M. Hopkins, Rolf E LarsonAbstract:New guidelines for bull breeding soundness examinations (BSE) were recently adopted by the American Society for Theriogenology. Major new features included the abandonment of numerical scores in favor of threshold values which must be achieved for scrotal circumference (minimum threshold of 30 cm at 15 months of age), spermatozoal motility (minimum threshold of 30% individual motility) and spermatozoal morphology (minimum threshold of 70% normal sperm). The latter requirement is seen to reduce the emphasis on classification systems (e.g. "primary'' and "secondary'' abnormalities) for sperm morphology assessment. Bulls are classified as being either "satisfactory'' or "unsatisfactory" or they are placed in a "classification deferred" category. Forms and explanatory notes are available to members of the society for Theriogenology from the Society office.
J.c. Spitzer - One of the best experts on this subject based on the ideXlab platform.
-
Breeding soundness evaluations of 3648 yearling beef bulls using the 1993 Society for Theriogenology guidelines
Theriogenology, 2002Co-Authors: S.p Kennedy, J.c. Spitzer, Fred M. Hopkins, H.l. Higdon, William C. BridgesAbstract:Abstract Our objective was to perform a retrospective analysis of breeding soundness evaluations (BSEs) as classified by the 1993 Society for Theriogenology (SFT) guidelines [Chenoweth et al., Guidelines for using the bull breeding soundness evaluation form, in: Theriogenology Handbook, 1993, pp. B-10]. Data included BSE information obtained from five performance-testing stations in South Carolina (SC1, SC2, SC3) and Tennessee (TN1, TN2) from 1986 through 1999 on 3648 Angus, Brangus, Charolais, Chianina, Gelbvieh, Limousin, Polled Hereford, Santa Gertrudis, Simbrah, and Simmental bulls. Analyses were simplified by classifying all bulls as either satisfactory or unsatisfactory potential breeders. Of the 3648 bulls evaluated, 76.2% were classified as satisfactory potential breeders. Of all bulls evaluated, 4.0% were unsatisfactory due to inadequate spermatozoal motility, 7.0% due to inadequate spermatozoal morphology and 2.6% due to a combination of inadequate motility and morphology. Unsatisfactory classifications due to non-spermatozoal parameters out of all bulls were 10.2%, with 7.1% for inadequate scrotal circumference and 3.1% for physical abnormalities. For satisfactory and unsatisfactory bulls, respectively, means and standard deviations were 35.8±2.7 and 33.0±4.1 cm (P
-
outcomes of breeding soundness evaluation of 2898 yearling bulls subjected to different classification systems
Theriogenology, 2000Co-Authors: H.l. Higdon, J.c. Spitzer, Fred M. Hopkins, William C. BridgesAbstract:Abstract This study is a retrospective analysis comparing data on yearling bull breeding soundness evaluation (BSE) subjected to 3 different classification systems: the Society for Theriogenology (SFT) 1983 and 1993 systems, and the Western Canadian Association of Bovine Practitioners (WC) 1993 system. Data were collected at 5 performance bull-test stations located in South Carolina and Tennessee from 1986 through 1996. Yearling bulls (n = 2898) that were 10 to 20 mo of age were used in the analysis. To simplify analysis, bulls were determined to be either satisfactory or unsatisfactory potential breeders (including those classified as questionable, deferred or unsatisfactory). Data were analyzed 1) within location where a location was treated as an individual experiment, 2) with breeds and locations collapsed, and 3) within age-group where each age-group was treated as an individual experiment. An ANOVA was performed using GLM procedures of SAS, and this model was used to generate least square means for the proportion of bulls classified as satisfactory and the 5 possible unsatisfactory outcomes due to inadequacies in scrotal circumference, spermatozoal morphology, spermatozoal motility, a combination of inadequate spermatozoal morphology and motility, or physical abnormalities. Inadequate scrotal circumference or physical abnormality did not affect differences for BSE outcomes among systems. Using the SFT93 system, bulls failed at a higher rate due to inadequate spermatozoal morphology (P
-
the new society for Theriogenology breeding soundness evaluation system
Veterinary Clinics of North America-food Animal Practice, 1997Co-Authors: Fred M. Hopkins, J.c. SpitzerAbstract:In 1993, The Society for Theriogenology published revised standards for breeding soundness evaluation of bulls. These revised standards replaced the old semen score format with minimum acceptable scores for scrotal circumference (varies with age), motility (30% or fair), and morphology (70%).
-
Breeding Soundness Evaluation of Yearling Bulls
Veterinary Clinics of North America: Food Animal Practice, 1997Co-Authors: J.c. Spitzer, Fred M. HopkinsAbstract:Breeding Soundness Evaluations (BSEs) are a useful tool to improve reproductive performance and profitability in beef herds. Veterinarians providing this service must be thorough in their evaluation, especially in yearling bulls. The 1993 Society for Theriogenology guidelines for BSE provide appropriate standards for classifying yearling bulls; veterinarians are advised to adhere to these standards as minimums for classification of the satisfactory potential breeder.
-
new guidelines for the evaluation of bulls for breeding soundness
American Association of Bovine Practitioners Proceedings of the Annual Conference, 1993Co-Authors: P J Chenoweth, J.c. Spitzer, Fred M. Hopkins, Rolf E LarsonAbstract:New guidelines for bull breeding soundness examinations (BSE) were recently adopted by the American Society for Theriogenology. Major new features included the abandonment of numerical scores in favor of threshold values which must be achieved for scrotal circumference (minimum threshold of 30 cm at 15 months of age), spermatozoal motility (minimum threshold of 30% individual motility) and spermatozoal morphology (minimum threshold of 70% normal sperm). The latter requirement is seen to reduce the emphasis on classification systems (e.g. "primary'' and "secondary'' abnormalities) for sperm morphology assessment. Bulls are classified as being either "satisfactory'' or "unsatisfactory" or they are placed in a "classification deferred" category. Forms and explanatory notes are available to members of the society for Theriogenology from the Society office.
P Mermillod - One of the best experts on this subject based on the ideXlab platform.
-
161 successful interspecific pregnancy after transfer of in vitro produced sika deer cervus nippon nippon embryo in red deer cervus elaphus hippelaphus surrogate hind
Reproduction Fertility and Development, 2008Co-Authors: Yann Locatelli, J C Vallet, G Baril, Jeanluc Touze, A Hendricks, X Legendre, M Verdier, P MermillodAbstract:The aim of the present study was to assess the in vivo competence of in vitro-produced sika deer (Cervus nippon nippon) embryos after freezing–thawing and transfer into red deer (Cervus elaphus hippelaphus) recipients. During the breeding season, 11 adult sika deer hinds were synchronized as oocyte donors with an intravaginal sponge (45 mg of fluorogestone acetate, FGA) inserted for 12 days and removed immediately after laparoscopic ovum pick-up (LOPU), and renewed after 3 days. Ovarian stimulation was induced with an i.m. injection of 75 µg of cloprostenol (Estrumate) given on Day 8, followed by 3 i.m. injections of 0.1, 0.1, and 0.05 IU of ovine FSH (Ovagen) on Days 10 and 11 at 12-h intervals. On Day 12, hinds were anesthetized and oocytes were collected by LOPU from follicles >2 mm using an 18 G needle under moderate vacuum. COC were recovered and morphologically evaluated for quality (graded from 1 to 5). COC were then submitted to in vitro maturation, fertilization, and culture (IVM, IVF, and IVC) as described previously (Locatelli Y et al. 2005 Theriogenology 64, 1729–1739). For IVC, embryos were co-cultured with a monolayer of ovine oviduct epithelial cells in synthetic oviduct fluid medium supplemented with 10% FCS. On Day 8 post-insemination, all sika deer embryos at the blastocyst stage were cryopreserved via a standard bovine slow-freezing protocol. Of 44 LOPU sessions performed during the 1-month study, an average of 7.5 ± 0.38 follicles were aspirated (mean ± SEM), allowing the recovery of 3.65 ± 0.38 COC per hind and per session, of which 80.0% were suitable for IVM (grades 1 and 2). Of 142 oocytes recovered, 57 cleaved after IVF (40.1%), and 14 embryos (24.6% of cleaved) reached the blastocyst stage after 8 days. At the end of the breeding season, 7 adult red deer hinds were synchronized as embryo recipients by inserting 2 intravaginal sponges per female (90 mg of FGA), for 13 days. Injections (i.m.) of 400 IU of eCG and 125 µg of cloprostenol (Estrumate) were administered 72 h before sponge removal. At Day 8 after sponge removal, straws containing frozen embryos were thawed and cryoprotectant was removed as described previously (see Locatelli Y et al. 2005 Theriogenology 64, 1729–1739). Two sika deer embryos were surgically transferred into uterine horn (unilaterally) of each red deer recipient. One of 7 red deer recipients was diagnosed pregnant by ultrasonography on Day 56. A healthy male sika deer fawn was born unassisted after 224 days of gestation. No complications were observed in initial recognition of the sika deer fawn by the red deer surrogate mother, nor in subsequent interactions. To our knowledge, this is the first report of an interspecific pregnancy obtained after in vitro embryo production and embryo transfer in deer species. In conclusion, interspecific embryo transfer after IVP may represent a useful tool for the preservation and amplification of captive residual populations of endangered deer species. Further studies are required to increase the rate of cleavage after LOPU-IVF as well as viability of frozen–thawed IVP embryos.
Butler Stephen - One of the best experts on this subject based on the ideXlab platform.
-
The effect of strain of Holstein-Friesian cow on size of ovarian structures, periovulatory circulating steroid concentrations, and embryo quality following superovulation
Elsevier Science Inc., 2012Co-Authors: De Feu, Patton Joe, Evans A.c.o., Lonergan P., Butler StephenAbstract:This is the author’s version of a work that was accepted for publication in Theriogenology. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. A definitive version was subsequently published in Theriogenology, 70(7), Oct. 2008, DOI: 10.1016/j.Theriogenology.2008.06.030When managed under grass-based systems of production, the NZ strain of Holstein-Friesian cow has superior reproductive performance compared to the NA strain despite having similar SCM yields. This study compared the ontogeny of early pregnancy events in NZ and NA cows. Ten NZ and 10 NA cows were submitted to a superovulation protocol on three occasions. Blood samples were collected daily from every cow from day -3 to +7 relative to a synchronised oestrus during each superovulation protocol. Pre-ovulatory oestradiol concentrations, follicle diameter, post-ovulatory progesterone concentrations, CL diameter, and circulating insulin-like growth factor-I concentrations did not differ between the two strains. Uteri were non-surgically flushed 7 d post AI, embryos were isolated and graded. The proportion of transferable embryos recovered was higher (P
-
Effect of grass dry matter intake and fat supplementation on progesterone metabolism in lactating dairy cows
Elsevier Science B.V., 2012Co-Authors: Hutchinson, Ian A., Evans A.c.o., Lonergan P., Dewhurst, Richard J., Butler StephenAbstract:This is the author’s version of a work that was accepted for publication in Theriogenology. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. A definitive version was subsequently published in Theriogenology, volume 78 (4), September 2012: pages 878-886. DOI:10.1016/j.Theriogenology.2012.04.001Progesterone (P4) metabolism in dairy cattle can be manipulated by alterations in dry matter intake and diet composition. Our objectives were to determine the effects of grazing allowance and fat supplementation on P4 metabolism in lactating dairy cows. Forty mid- to late-lactation Holstein-Friesian dairy cows were used in a completely randomized block design, with a 2 × 2 factorial arrangement of treatments. Cows were assigned to receive 1 of 2 pasture allowances (ad libitum allowance [AL], 9.5 kg dry matter per day, or restricted allowance [R] 7 kg dry matter per day) and 1 of 2 fat supplementation treatments (750 g per day saturated fat [F] or no fat supplement [NF]). All cows received an additional 4 kg per day of concentrate. Grass dry matter intake (GDMI) was measured 5 wk after the initiation of dietary treatment. Cows were treated with prostaglandin F2α (PGF2α) to eliminate the endogenous source of P4, and two intravaginal progesterone-releasing devices (CIDR) were inserted into each cow for a period of 8 days. Regular blood samples were taken before and after the removal of the intravaginal progesterone-releasing devices, and analyzed for P4 concentrations. The half-life (t½) and metabolic clearance rate (MCR) of P4 was calculated for each cow. There was no effect of GDMI or fat supplementation on the t½ or MCR of P4. There was a tendency for an interaction between GDMI and fat supplementation on the t½ of P4; cows on the restricted-F diet tended to have a longer P4 t½ than cows on the ad libitum-F diet. It was concluded that greater alterations in GDMI than achieved in the current study are required to change P4 metabolism. A combination of fat supplementation and restricted feeding slows P4 clearance, which may have beneficial implications for fertility
-
Effect of grass dry matter intake and fat supplementation on progesterone metabolism in lactating dairy cows
'Elsevier BV', 2012Co-Authors: Hutchinson, Ian A., Evans A.c.o., Lonergan P., Dewhurst, Richard J., Butler StephenAbstract:Peer-reviewedThis is the author’s version of a work that was accepted for publication in Theriogenology. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. A definitive version was subsequently published in Theriogenology, volume 78 (4), September 2012: pages 878-886. DOI:10.1016/j.Theriogenology.2012.04.001Progesterone (P4) metabolism in dairy cattle can be manipulated by alterations in dry matter intake and diet composition. Our objectives were to determine the effects of grazing allowance and fat supplementation on P4 metabolism in lactating dairy cows. Forty mid- to late-lactation Holstein-Friesian dairy cows were used in a completely randomized block design, with a 2 × 2 factorial arrangement of treatments. Cows were assigned to receive 1 of 2 pasture allowances (ad libitum allowance [AL], 9.5 kg dry matter per day, or restricted allowance [R] 7 kg dry matter per day) and 1 of 2 fat supplementation treatments (750 g per day saturated fat [F] or no fat supplement [NF]). All cows received an additional 4 kg per day of concentrate. Grass dry matter intake (GDMI) was measured 5 wk after the initiation of dietary treatment. Cows were treated with prostaglandin F2α (PGF2α) to eliminate the endogenous source of P4, and two intravaginal progesterone-releasing devices (CIDR) were inserted into each cow for a period of 8 days. Regular blood samples were taken before and after the removal of the intravaginal progesterone-releasing devices, and analyzed for P4 concentrations. The half-life (t½) and metabolic clearance rate (MCR) of P4 was calculated for each cow. There was no effect of GDMI or fat supplementation on the t½ or MCR of P4. There was a tendency for an interaction between GDMI and fat supplementation on the t½ of P4; cows on the restricted-F diet tended to have a longer P4 t½ than cows on the ad libitum-F diet. It was concluded that greater alterations in GDMI than achieved in the current study are required to change P4 metabolism. A combination of fat supplementation and restricted feeding slows P4 clearance, which may have beneficial implications for fertility
Maurizio Monaci - One of the best experts on this subject based on the ideXlab platform.
-
breeding soundness examination of chianina marchigiana and romagnola yearling bulls in performance tests over a 10 year period
Theriogenology, 2007Co-Authors: Lakamy Sylla, S Borgami, G. Stradaioli, Maurizio MonaciAbstract:Abstract The objectives of the present study were (i) to establish the mean value of scrotal circumference (SC), sperm motility, concentration and morphology at 13±1 months of age for Chianina, Marchigiana, and Romagnola breeds and (ii) to assign Italian beef bulls at the end of a growth performance test to a potential breeder category by applying the guidelines of the Society for Theriogenology in 1993 (SFT93). Of 1,315 bulls, 869 were not given the breeding soundness examination for the following reasons: not passing the growth performance test ( n =445), no training for semen collection ( n =404), and presence of genital abnormalities ( n =20). Testicular length and diameter and SC exhibited a logarithmic trend over time, with an R 2 value of 0.963, 0.979, and 0.978 ( P P P 6 cells/mL) was higher than those in Chianina (751.63±444.45×10 6 cells/mL, P 6 cells/mL). Progressive sperm motility was 61.30±11.24%, 62.18±11.17%, and 58.48±14.40% in Romagnola, Marchigiana, and Chianina, respectively. Total spermatozoal abnormalities were higher in Chianina (23.35±15.41%). Sperm concentration was positively related to testicular length ( P P P
-
breeding soundness examination of chianina marchigiana and romagnola yearling bulls in performance tests over a 10 year period
Theriogenology, 2007Co-Authors: Lakamy Sylla, S Borgami, G. Stradaioli, Maurizio MonaciAbstract:The objectives of the present study were (i) to establish the mean value of scrotal circumference (SC), sperm motility, concentration and morphology at 13+/-1 months of age for Chianina, Marchigiana, and Romagnola breeds and (ii) to assign Italian beef bulls at the end of a growth performance test to a potential breeder category by applying the guidelines of the Society for Theriogenology in 1993 (SFT93). Of 1,315 bulls, 869 were not given the breeding soundness examination for the following reasons: not passing the growth performance test (n=445), no training for semen collection (n=404), and presence of genital abnormalities (n=20). Testicular length and diameter and SC exhibited a logarithmic trend over time, with an R(2) value of 0.963, 0.979, and 0.978 (P<0.001), respectively. The SC of Romagnola (33.82+/-2.47 cm) was higher than those of Chianina (33.28+/-2.65 cm, P<0.001) and Marchigiana (33.05+/-2.20 cm, P<0.001). Sperm concentration in Romagnola (875.89+/-416.13x10(6)cells/mL) was higher than those in Chianina (751.63+/-444.45 x 10(6)cells/mL, P<0.05) and Marchigiana (862.57+/-421.87 x 10(6) cells/mL). Progressive sperm motility was 61.30+/-11.24%, 62.18+/-11.17%, and 58.48+/-14.40% in Romagnola, Marchigiana, and Chianina, respectively. Total spermatozoal abnormalities were higher in Chianina (23.35+/-15.41%). Sperm concentration was positively related to testicular length (P<0.01), diameter (P<0.001), and SC (P<0.001). Satisfactory breeders presented high sperm motility compared with deferred and unsatisfactory ones, whereas unsatisfactory breeders had a higher number of abnormal spermatozoa. By applying the SFT93 guidelines, we showed that 74.72%, 78.01%, and 80.16% of Chianina, Marchigiana, and Romagnola bulls, respectively, have been classified as satisfactory potential breeders.
