@article{neely_robison_1983, title={ESTIMATES OF HETEROSIS FOR SEXUAL-ACTIVITY IN BOARS}, volume={56}, ISSN={["0021-8812"]}, DOI={10.2527/jas1983.5651033x}, abstractNote={Data on 118 Duroc, Yorkshire and reciprocal cross boars were utilized to evaluate the effect of crossbreeding on mating behavior. Boars were penned with an estrous gilt on 2 consecutive days. Number of mounts (proper and improper), sexual interest score and whether a successful mating occurred were recorded. Times at which each of these events occurred were recorded also, allowing calculation of times to first mount, to final mount and to completion of mating. Most importantly, more crossbred boars completed a mating than purebred boars (69 vs 27%). Crossbreds had greater sexual interest (P less than .05), more mounts and a higher proportion of properly oriented mounts (P less than .05). Crossbreds also began mounting activity (first mount, first proper mount and final mount; P less than .05) earlier and required less time to complete a mating (P less than .05) than purebred boars. Heterosis values for number of proper and improper mounts, proportion of proper mounts and sexual interest were 2, 53, 32 and 52%, respectively. Time to first mount, to final mount and to completing mating had heterosis values of -34, -29 and -20%, respectively. Scrotal measures taken at 140 and 168 d and at post-trial castration, as well as excised testes measures and sperm numbers, showed heterosis; however, no consistent associations between these traits and behavior traits were found. These data suggest that crossbred boars were more sexually active than purebred boars, perhaps due to an advanced physiological or behavioral stage.}, number={5}, journal={JOURNAL OF ANIMAL SCIENCE}, author={NEELY, JD and ROBISON, OW}, year={1983}, pages={1033–1038} } @article{neely_johnson_dillard_robison_1982, title={GENETIC-PARAMETERS FOR TESTES SIZE AND SPERM NUMBER IN HEREFORD BULLS}, volume={55}, ISSN={["0021-8812"]}, DOI={10.2527/jas1982.5551033x}, abstractNote={Paternal half-sib heritability and genetic correlation estimates were obtained utilizing data from 578 Hereford bulls from 66 sires. Bulls were maintained in three lines (weaning weight, postweaning gain and control) of an ongoing selection project. Growth performance traits studied were adjusted 205-d weaning weight, 365-d weight, individual feed efficiency, sonoray fat thickness and postweaning gain. Heritability estimates for these traits were .15 +/- .17, .33 +/- .19, .46 +/- .21, .28 +/- .18 and .52 +/- .21, respectively. Scrotal measurements taken were circumference of both testes and length and diameter of right testis at 205 and 365 d of age. Heritability estimates were .08 +/- .20, .07 +/- .20 and .28 +/- .24 at 205 d, and .44 +/- .24, .16 +/- .21 and .40 +/- .24 at 365 d, respectively. Excised testes traits, circumference, right testis length, diameter and weight, total sperm in the testes and sperm/gram of testes had heritability estimates of .21 +/- .26, .19 +/- .26, .02 +/- .24, .63 +/- .27, .14 +/- .21 and -.13 +/- .18, respectively. Genetic correlations of scrotal measurements at 205 d with scrotal measurements at 365 d and excised testes traits were negative. Scrotal measurements at 365 d had high positive genetic correlations with excised testes size, weight and total sperm. These relationships suggest that selection for increase of scrotal size at 365 d should increase testes size and weight and sperm numbers. Genetic correlations of weights and gain with scrotal measurements at 365 d and excised testes characteristics were moderate to high, in a favorable direction. Genetic correlations of testes traits with feed efficiency were essentially zero, while those with fat thickness were moderately positive. These results suggest that increasing testes size should not adversely affect growth performance traits except through the reduction in selection intensity.}, number={5}, journal={JOURNAL OF ANIMAL SCIENCE}, author={NEELY, JD and JOHNSON, BH and DILLARD, EU and ROBISON, OW}, year={1982}, pages={1033–1040} } @article{neely_1982, title={Sexual behavior and testicular development in purebred and crossbred boars}, volume={43}, number={6}, journal={Dissertation Abstracts International. B, Sciences and Engineering}, author={Neely, J. D.}, year={1982}, pages={1673} } @article{neely_johnson_robison_1980, title={HETEROSIS ESTIMATES FOR MEASURES OF REPRODUCTIVE TRAITS IN CROSSBRED BOARS}, volume={51}, ISSN={["1525-3163"]}, DOI={10.2527/jas1980.5151070x}, abstractNote={Data on 354 Duroc, Yorkshire and reciprocal cross boars were utilized for the estimation of heterosis for measures of reproductive traits in boars. Testis length and width of intact boars were measured at 56, 84, 112, 140 and 168 days of age. At 168 days, testes were excised and evaluated for paired testes width, right testis length and weight, sperm per gram of testis, total sperm in testes and weight and sperm counts of epididymides. Crossbred boars had heavier body weights (P<.05) and tended to have longer, wider testes at all ages. Excised testes of crossbred boars were larger (P<.01) and had higher (P<.05) numbers of sperm. Crossbred boars also had more sperm per gram of testis (P<.05), which may be considered a measure of efficiency of sperm production. Heterosis values for length, weight, total sperm, sperm per gram of right testis and combined width of testes were 8.5, 25.4, 33.7, 23.3 and 10.4%, respectively. Adjustment for body weight tended to decrease heterosis estimates, to 2.5, 8.1, 14.4, 15.1 and 4.5%, respectively. These results suggest that the larger testes and higher testes sperm counts of crossbred boars were due in part to an increase in activity of spermatogenic elements that are not associated with an increase in body weight. Heterosis values for epididymal sperm in the caput region were large, whereas heterosis values for sperm in the cauda region were small. This may suggest that crossbred boars were eliminating more sperm either through increased frequency of masturbation or increased sperm output per masturbation.}, number={5}, journal={JOURNAL OF ANIMAL SCIENCE}, author={NEELY, JD and JOHNSON, BH and ROBISON, OW}, year={1980}, pages={1070–1077} }