Off-campus UNL users: To download campus access dissertations, please use the following link to log into our proxy server with your NU ID and password. When you are done browsing please remember to return to this page and log out.
Non-UNL users: Please talk to your librarian about requesting this dissertation through interlibrary loan.
Effects of the reproductive cycle and age on calcium and phosphorus metabolism and bone integrity of sows
Abstract
The purpose was to determine the effects of the reproductive cycle and age on Ca and P metabolism and bone integrity of sows. Five-day balance studies were conducted and sows were slaughtered during the last trimester of gestation, lactation, or the last trimester of the subsequent gestation. Young sows were examined during their first gestation (n = 11), first lactation (n = 10), or second gestation (n = 10). Mature sows were examined during their fifth gestation (n = 10), fifth lactation (n = 9), or gestation (n = 9). All sows were fed 1.9 kg/d of a common diet (.76% Ca and.63% P) during gestation and were allowed ad libitum access to the same diet during lactation. Metatarsals, femurs, calcanei, coccygeal vertebrae, thoracic vertebrae and ribs were tested. Sows consumed and absorbed more Ca and P during gestation than during lactation. Digestibility of Ca and P increased during lactation in comparison to gestation. During lactation, mature sows consumed and retained more Ca and P than young sows, but young sows retained more Ca and P than mature sows during gestation. Young sows retained more Ca and P during gestation than during lactation whereas mature sows retained more Ca and P during lactation than during gestation. Bone mass and strength of both young and mature sows decreased during lactation but they were restored by the end of the subsequent gestation. This decrease was more severe in young sows than in mature sows. In general, bones of mature sows were heavier, larger, more mineralized, withstood more total force, and had similar or greater bone tissue strength. Cortical bone was affected little by reproduction in comparison to trabecular bone. The thoracic vertebrae and rib were most sensitive to the effects of reproduction and age on bone properties. Ultrasonic transmission velocity of the calcaneus was positively correlated with bone strength, but accounted for only a small proportion of variation. Bone mass and bone density described more of the variation in total force required to break the bone and bone tissue strength, respectively than did percent ash. Mature sows had larger and stronger bones than did young sows, and their bones were affected less by lactation. In the adult animal, bone mass and density are more important response criteria than percent ash.
Subject Area
Livestock|Anatomy & physiology|Animals|Biomedical research
Recommended Citation
Giesemann, Mark Allen, "Effects of the reproductive cycle and age on calcium and phosphorus metabolism and bone integrity of sows" (1992). ETD collection for University of Nebraska-Lincoln. AAI9308175.
https://digitalcommons.unl.edu/dissertations/AAI9308175