The relationship of gestation length, age and weight at breeding, and gestation gain to sow productivity at farrowing
Omtvedt, I.T.; Stanislaw, C.M.; Whatley, J.A.
J Anim Sci 24(2): 531-535
1965
Accession: 025914623
The breeding and farrowing records for 301 sows and 390 gilts were analyzed to study the association of gestation length, age and weight at breeding, gestation gains, and sex ratio of litter size and weight and individual pig birth weight. Gestation length was significantly correlated (P > .01) with number of pigs farrowed per litter (-.16), litter birth weight (-.12), and pig birth weight (0.12). An increase in age of gilts at breeding resulted in significant (P > .01) increases in litter size (r = 0.12), average pig weight (r = 0.16) and litter weight (r = 0.19). The association of age at breeding with litter size and weight was primarily a result of older gilts being heavier at breeding. However, the partial correlation between age at breeding and individual pig weight holding breeding weight constant was 0.16 (P > .01). An increase in weight at breeding resulted in a significant (P >.01) increase in litter size (r = 0.19) and litter weight (r = 0.24), while gestation gain was negatively correlated with litter size (-.14). Average pig weight was positively correlated with gestation gains (0.16), but this relation was reduced when litter size was held constant. Litter size was closely associated with litter weight (r = 0.83) and individual pig weight decreased as litter size increased (r = -.55). Deviations from linearity were detected for the relationship between litter size and average pig weight.