Constipation. Constipation in pregnant sows can lead to poor mammary gland development, low breast expansion, no milk after delivery, small birth weight of piglets, and many weak piglets. When transferred to the farrowing house, if constipation is found on the pig B-ultrasound, on the one hand, feces remain in the large intestine, squeezing the birth canal, causing dystocia, which will prolong the sow's delivery time, and the piglets will suffocate due to lack of oxygen, thereby increasing the number of stillbirths; constipation can cause vulvar edema, rectal prolapse, vaginal congestion, and vaginal stenosis, causing dystocia. On the other hand, sows have poor defecation and long intestinal residue time, which is conducive to the large-scale reproduction of bacteria in feces, increasing the possibility of urinary tract infection in sows. Constipation often leads to loss of appetite and no milk after delivery in sows, and pig B-ultrasound is often used for examination.

Urinary tract infection. It is common for sows to have grayish white and yellow viscous secretions flowing out of the vagina when lying on the ground during pregnancy. There is no obvious change in appetite, and scabs of secretions can be seen around the vulva. Some of them are manifested by prolonged delivery time, reduced litter size, decreased body condition of sows, decreased lactation performance and maternal instinct after delivery. There are abnormal conditions in the pig B-ultrasound examination. After delivery or abortion, the sick pigs have a fever, eat less or no food, are unwilling to stand up, and have urination movements, but the amount of urine is small each time, and they strain from time to time. With the straining, a foul-smelling reddish-brown sticky or purulent secretion flows out of the vagina, and some contain fragments of the placenta. In addition, the sick pigs also show emaciation, abnormal or delayed estrus, and increased return to estrus, which greatly reduces the production capacity of the sows.

Piglets cannot eat enough breast milk, have weak constitution, reduced survival rate, slow growth, and 43% of the causes of death of newborn piglets are sows' lack of milk. Therefore, it is necessary to use pig B-ultrasound to examine the sow's breasts.

link: https://www.bxlimage.com/nw/315.html