@article{quijandria_dezaldivar_robison_1983, title={SELECTION IN GUINEA-PIGS .1. ESTIMATION OF PHENOTYPIC AND GENETIC-PARAMETERS FOR LITTER SIZE AND BODY-WEIGHT}, volume={56}, ISSN={["0021-8812"]}, DOI={10.2527/jas1983.564814x}, abstractNote={Data on 202 sires, 718 dams and 3,192 progeny from a selection experiment were used to estimate phenotypic and genetic parameters for litter size and body weight in guinea pigs. Effects of sex and parity were estimated. Heritability estimates were obtained from offspring-parent regression and from intraclass correlation of paternal and maternal half-sibs. Genetic and phenotypic correlations also were estimated. Parity effects were significant only for weight traits. Sex effects were significant for weights at several ages. Significant negative linear effects of number born alive were found for birth, weaning and 13-wk weights. Heritability estimates from daughter-dam regression were .10 +/- .05, .06 +/- .02 and .08 +/- .02 for number born, number born alive and number weaned and .12 +/- .03, -.13 +/- .03 and .12 +/- .02 for birth, weaning and 13-wk weights, respectively. Paternal half-sib heritability estimates were .02 +/- .04, .10 +/- .04 and .17 +/- .05 for birth, weaning and 13-wk weights. Heritability values from components for maternal half-sibs were .30 +/- .30, .16 +/- .31 and .15 +/- .31 for number born, number born alive and number weaned, respectively. Genetic correlations among weights at different ages were .24 to 1.2 and among litter size traits were .51 to .77. Genetic correlations between litter size traits and birth and weaning weights ranged from -.61 to -.97; whereas correlations of litter size traits with 13-wk weight were .31 to .39. Genetic parameters estimated from similarity among relatives agreed very well with realized heritabilities and genetic correlations obtained from selection.}, number={4}, journal={JOURNAL OF ANIMAL SCIENCE}, author={QUIJANDRIA, B and DEZALDIVAR, LC and ROBISON, OW}, year={1983}, pages={814–819} }
 @article{quijandria_zaldivar_robison_1983, title={SELECTION IN GUINEA-PIGS .2. DIRECT RESPONSE FOR LITTER SIZE AND BODY-WEIGHT}, volume={56}, ISSN={["0021-8812"]}, DOI={10.2527/jas1983.564820x}, abstractNote={Four generations of selection for litter size, 13-wk weight and an index combining litter size and 13-wk body weight were conducted in a guinea pig population formed by intercrossing several local lines from different areas of Peru. A random selection control line was maintained also. Responses in the selected traits per generation were .069 +/- .069, 19.1 g +/- 16.2 and 2.5 +/- 20.3 for the litter size, 13-wk weight and index lines, respectively. Realized heritabilities were estimated by two methods. Estimates obtained from regression of response on cumulative selection differentials were .01 +/- .45 for litter size, .27 +2- .06 for 13-wk weight and -.09 +/- .13 for index values. Estimates from weighted multiple regression procedures were .07 +/- .01, .18 +/- .004 and .04 +/- .01 for litter size, 13-wk weight and index, respectively.}, number={4}, journal={JOURNAL OF ANIMAL SCIENCE}, author={QUIJANDRIA, B and ZALDIVAR, M and ROBISON, OW}, year={1983}, pages={820–828} }
 @article{quijandria_muscari_robison_1983, title={SELECTION IN GUINEA-PIGS .3. CORRELATED RESPONSES TO SELECTION FOR LITTER SIZE AND BODY-WEIGHT}, volume={56}, ISSN={["0021-8812"]}, DOI={10.2527/jas1983.564829x}, abstractNote={Correlated responses in number born, number born alive, number weaned, birth weight, weaning weight, 13-wk weight and index were evaluated in a guinea pig population after four generations of single trait and index selection for number born alive and 13-wk weight. Regressions of correlated response on generation number in the 13-wk weight line were all positive, but were significant only for birth weight (5.65 +/- .66 g) and index (25.58 +/- 9.90). In the litter size line, significant responses were found for 13-wk weight (21.17 +/- 5.34 g) and birth weight (.80 +/- .21 g). All other responses in this line, except number weaned (-.05 +/- .08), were positive but nonsignificant. There were no significant trends in the index line. Regression coefficients from weighted multiple regression analyses suggested significant improvement in number born (.07 +/- .002), number born alive (.006 +/- .002) and number weaned (.01 +/- .001) in the 13-wk weight line. Regression values in the litter size line were .03 +/- .001 and -.04 +/- .001 for number born and number weaned, respectively. The other regressions were positive but nonsignificant except for weaning weight, which was nonsignificantly negative. None of the correlated responses to index selection was significant. Realized genetic correlations between 13-wk weight and number born alive and index were .37 +/- 1.54 and .31 +/- .98, respectively. The correlation between index and number born alive was .19 +/- 5.18.}, number={4}, journal={JOURNAL OF ANIMAL SCIENCE}, author={QUIJANDRIA, B and MUSCARI, J and ROBISON, OW}, year={1983}, pages={829–832} }
 @article{quijandria_1982, title={Single trait and index selection for litter size and body weight in guinea pigs}, volume={43}, number={6}, journal={Dissertation Abstracts International. B, Sciences and Engineering}, author={Quijandria, B., Jr.}, year={1982}, pages={1673} }