The influence of initial length of uterus per embryo and gestation stage on prenatal survival, development and sex ratio in the pig

The effects of initial uterine length per embryo and stage of gestation on embryonic survival, development and sex ratio were determined by systematically restricting embryos to 5, 10, 15, 20, 25, 30, 35, 40, 45 or more than 50 cm of initial uterine length per potential embryo and examining the reproductive tracts at d 17, 23, 29, 35 or 41 of gestation. At d 3 the mean length of a uterine horn was 169 $\pm$ 35 cm with a range of 80 to 255 cm. The mean number of corpora lutea (CL) was 12.4 $\pm$ 2.34 from both ovaries. Ovulation rate was positively correlated with the length of uterine horns (r =.3769). Prenatal survival rate was highly correlated with initial allotted uterine space from 5 to 25 cm/CL (r =.95, p $$.1) and when embryos were restricted to 15 cm to above, sex ratio of male to female was 49:51. Stage of gestation had little effect on sex ratio. Male fetuses occupied more uterine space than females in both crowded and roomy sections (p $<$.05). At d 41 males were lighter than females in crowded sections (male 10.17 gm, female 11.56 gm) but heavier than females in sections with assigned space greater than 25 cm/CL (male 12.91 gm, female 12.05 gm) (p $<$.05).

Name thesis:degree_name

Ph.D.

Level thesis:degree_level

Dissertation

Discipline thesis:degree_discipline

Animal Sciences

Grantor

University of Illinois at Urbana-Champaign

Year dc:date

2011

Author dc:creator

• Chen, Zhaoying

Contributors dc:contributor

• Dziuk, Philip J.

• Biology, Animal Physiology

Statement dc:rights

• Copyright 1992 Chen, Zhaoying

Language dc:language

eng

Identifier

AAI9236422
(UMI)AAI9236422

OAI identifier oai:identifier

oai:www.ideals.illinois.edu:2142/20256