Review: In vivo measures of mammary development in gestating gilts
In a recent study published in the December 2017 issue of the Journal of Animal Science, researchers found using a tape or ultrasound imaging an effective measurement of udder morphology in late-pregnant gilts. These techniques were used to estimate mammary gland development and composition.
With increases in liter sizes, sows must produce very large quantities of milk to sustain the growth of their piglets; because of this, understanding and predicting mammary development has become an important piece of the management of gilts and sows. Currently, such research involves the slaughter of animals to collect mammary tissue. While there have been recent studies exploring measurements from live animals, this current study is the first to investigate the potential relationship between in vivo measurements and actual dissection and chemical measures of mammary development in gestating gilts, leading to more cost-effective form of collecting data related to milk yield.
There were 33 Yorkshire x Landrace gilts used in this study, and they were bred from a pool of Duroc boars and housed in individual stalls throughout gestation. It was discovered that the AREA (parenchymal area measured by ultrasound) and EXT (the distance between the base of the teat and the exterior junction of the udder with the abdomen) were correlated with the weight of the parenchymal tissue. The EXT measure also provided as reliable an estimate of the parenchymal weight as the measure of parenchymal area using ultrasound.
The results of this study indicate that there are other, more cost- and time-effective means of collecting data relating to mammary development. The positive correlation between AREA and EXT and the parenchymal tissue weight could be helpful in estimating mammary development in future studies where animals cannot be slaughtered, and the fact that that the EXT measurement provided as reliable an estimate as an ultrasound measurement means this should be considered as a potential selection criteria to improve sow milk yield. Researchers have concluded that even though chemical measurements are the best method to determine mammary composition, current results indicate that some easily obtainable in vivo measurements can give an indication of mammary development in late-pregnant sows.
To view the full article, “In vivo measures of mammary development in gestating gilts,” visit www.journalofanimalscience.org.