@article{toelle_robison_1985, title={ESTIMATES OF GENETIC CORRELATIONS BETWEEN TESTICULAR MEASUREMENTS AND FEMALE REPRODUCTIVE TRAITS IN CATTLE}, volume={60}, ISSN={["1525-3163"]}, DOI={10.2527/jas1985.60189x}, abstractNote={Data from 528 male and 645 female progeny of 63 sires were used to estimate genetic correlations between female and male reproductive traits. Data were from two Hereford herds involved in a long-term selection program of the North Carolina Agricultural Experiment Service. Testicular measurements of circumference, diameter, length and volume were obtained on bulls at 205 and 365 d. Testicular growth measures were defined as differences between 205-and 365-d measurements. Heifers were placed in the breeding herd as yearlings and given two breeding seasons to produce a calf. Traits utilized from females were three age-at-first-breeding traits, two age-at-first-calving traits, two pregnancy rate traits, rebreeding interval and calving interval. Genetic correlations were estimated from half-sib and from sire-daughter analyses. Seventy-five percent or more of the correlations of testicular measurements with pregnancy rats, age at first breeding and age at first calving were in the favorable direction. Average correlations were .62, -.55 and -.66, respectively. For each of the remaining female traits, approximately 50% of the correlations were favorable and the average correlations were small. Correlations were summarized by testicular measurement with favorable correlations given a negative sign. Testicular diameter had more favorable correlations (80%) than length, volume or circumference (70%). However, average correlations were similar (-.31, -.30, -.34 and -.26, respectively). Testicular measurements taken at either 205 or 365 d had the same percentage of favorable correlations (72%), while testicular growth measurements had a slightly higher percentage of favorable correlations (78%). Average correlations of 365-d measures were higher (-.38) than either 205-d or growth measures (-.25 and -.28, respectively). Heritabilities for testicular measurements tended to be moderate to high, while those for female reproduction tended to be low to moderate. These results suggest that selection for increased testicular size would lead to improvement in female reproduction, particularly an increase in calving rate and a decrease in age at first breeding.}, number={1}, journal={JOURNAL OF ANIMAL SCIENCE}, author={TOELLE, VD and ROBISON, OW}, year={1985}, pages={89–100} }
 @article{toelle_robison_1985, title={Estimates of genetic relationship between testes measurements and female reproductive traits in swine}, volume={102}, DOI={10.1111/j.1439-0388.1985.tb00680.x}, abstractNote={SummaryData from two Duroc populations and one Yorkshire population were utilized to evaluate the relationships between testes measurements on males and reproduction of their female relatives. Approximately 350 Duroc litters from 100 sires and 100 Yorkshire litters from 50 sires were represented in the data. Testes measurements of length, combined width and volume were taken at 140 d and 168 d. Female traits measured were age at first breeding, conception rate, age at first farrowing, number born alive and number born dead. Daughter‐sire regressions estimated from the Duroc data suggest that number born alive is favorably associated with testes measurements. However, number born dead, conception rate and age at first farrowing tended to be unfavorably associated with testes measurements. Age at first breeding was unfavorably associated with 168 d measurements while it was favorably associated with 140 d measurements. In the sib analysis, age at first breeding was favorably correlated with testes measures. Unfavorable correlations existed between testes measurements and number born dead. Further, age at first farrowing and number born alive were favorably correlated with 140 d testes measures but unfavorably correlated with 168 d measures. In Yorkshires, age at first breeding, age at first farrowing and conception rate of daughters were favorably associated with all testes measurements of sires. Also, some favorable regressions of number born alive and number born dead on testes measurements were obtained. In the sib analyses, all testes measures were favorably correlated with all female reproductive traits except conception rate. These results suggest that improvement of female reproductive traits by indirect selection on testes measurements may be very useful in Yorkshires but would be less useful in Durocs.}, number={2}, journal={Journal of Animal Breeding and Genetics}, author={Toelle, V. D. and Robison, O. W.}, year={1985}, pages={125} }
 @article{toelle_1985, title={Genetic relationship between testes measurements and female reproductive traits in cattle and swine}, volume={45}, number={10}, journal={Dissertation Abstracts International. B, Sciences and Engineering}, author={Toelle, V. D.}, year={1985} }
 @article{toelle_johnson_robison_1984, title={GENETIC-PARAMETERS FOR TESTES TRAITS IN SWINE}, volume={59}, ISSN={["0021-8812"]}, DOI={10.2527/jas1984.594967x}, abstractNote={Data were collected from 1,245 Duroc boars and 527 Yorkshire boars. This represents 128 Duroc and 57 Yorkshire sires. Body weights, testis length and combined testes width at 140 and 168 d were obtained. Of these boars, 432 were castrated at a later age to evaluate relationships between in situ measures and excised testis traits. Heritabilities for testis length, width and volume at 140 d ranged from .16 to .25 in both Duroc and Yorkshire data. Heritabilities for testis measurements at 168 d ranged from .16 to .36 in both data sets. Favorable negative genetic relationships were found between in situ testis measures and age to 104 kg and backfat adjusted to 104 kg. Correlations among in situ measurements were high and positive. All excised testicular traits were highly heritable except for right epididymis weight and excised testis width. Correlation estimates among excised testis traits were generally positive. Phenotypic and genetic correlation estimates between live (in situ testis and growth performance traits) measurements and excised testis traits were generally favorable. This study suggests that in situ testis measurements should be good predictors of sperm production. It also suggests that selection for testis size should not be antagonistic to selection for growth performance traits.}, number={4}, journal={JOURNAL OF ANIMAL SCIENCE}, author={TOELLE, VD and JOHNSON, BH and ROBISON, OW}, year={1984}, pages={967–973} }
 @article{toelle_robison_1983, title={BREED PRENATAL, BREED POSTNATAL AND HETEROSIS EFFECTS FOR POST-WEANING TRAITS IN SWINE}, volume={57}, ISSN={["0021-8812"]}, DOI={10.2527/jas1983.572313x}, abstractNote={Crossfostering techniques were used to evaluate breed prenatal, breed postnatal and heterosis effects in Duroc and Yorkshire swine. Traits analyzed for these effects were: age adjusted to 104 kg (DAYS), backfat adjusted to 104 kg (AJBF), average daily gain (ADG), weight/day of age (WDA), unadjusted backfat (BF) and weight at 154 d (WT154). Breed prenatal (genetics and prenatal maternal) effects were important for BF and WT154 (P less than .10). Pigs gestated by Duroc dams tended to be fatter and weigh more at 154 d than pigs from Yorkshire dams. Breed postnatal effects were important only for AJBF (P less than .05). Pigs reared by Duroc nurses were fatter than pigs reared by Yorkshire nurses. Prenatal dam x postnatal nurse interaction effects were important for BF (P less than .10) and AJBF (P less than .05). Heterosis values were -10.2, 8.0, 13.7, 13.6, 14.1 and 7.7% for DAYS, AJBF, ADG, WDA, WT154 and BF, respectively. Differences between purebred and crossbred pigs were larger when purebred and crossbred pigs were reared in the same litter than when reared separately. These data suggest that intra-litter competition between purebred and crossbred pigs may have a detrimental effect on postweaning growth for purebred pigs.}, number={2}, journal={JOURNAL OF ANIMAL SCIENCE}, author={TOELLE, VD and ROBISON, OW}, year={1983}, pages={313–319} }
 @article{toelle_robison_1982, title={BREED PRENATAL, BREED POSTNATAL AND HETEROSIS EFFECTS FOR PREWEANING TRAITS IN SWINE}, volume={55}, ISSN={["0021-8812"]}, DOI={10.2527/jas1982.552263x}, abstractNote={Crossfostering techniques were used to evaluate breed prenatal, breed postnatal and heterosis effects in Duroc and Yorkshire swine. Survival rate, individual weights at 0, 21 and 42 d, and weight gains from 0 to 21, 0 to 42, and 21 to 42 d were analyzed. When crossbred pigs were produced, prenatal effects were larger for Durocs for survival (P<.01) and all weight traits (P<.10). When purebred pigs were produced, Durocs had significantly larger breed prenatal effects for birth weight (P<.05). Yorkshires, rearing crossbred pigs, had larger (P<.10) breed postnatal effects than Durocs for all preweaning traits except survival and birth weight. When rearing purebred pigs, breed postnatal effects for Yorkshires were larger (P>.10) for all traits except birth weight. This suggests that crossbred pigs may provide a suckling stimulus or a demand to which a Yorkshire nurse is more responsive than a Duroc nurse. Heterosis values ranged from 5.6% for birth weight to 16.9% for 21-to 42-d wt gain. Yorkshires had larger breed postnatal effects than Durocs for 0 to 21-d litter gain (P<.10), 42-d litter wt (P<.05) and 0 to 42-d litter gain (P<.05). However, breed postnatal effects were not significantly different for 21-d litter weight. This suggests that 21-d litter wt may not be the best estimate of postnatal maternal performance.}, number={2}, journal={JOURNAL OF ANIMAL SCIENCE}, author={TOELLE, VD and ROBISON, OW}, year={1982}, pages={263–273} }