Search

Modern industrial egg production is accompanied by a number of clinical problems related to the welfare of laying hens. Sternum injuries are some of the most common pathologies in this animal species. The sternum in hens is 9-12 cm long and is located in the ventral sagittal plane (1). This is the largest bone in the body of the hen and serves as the basis of the entire skeleton. Bone growth and ossification is a process that begins in the cranial part and gradually ends in the caudal part. In the early stages of the egglaying period (between 28 and 40 weeks of age), it is not yet fully ossified, and the caudal tip often remains cartilaginous (1). This makes the sternum more vulnerable to damage than other long bones that complete their ossification in time (2). A large percentage of birds housed in aviary breeding systems are affected by sternal fractures. Due to the way chickens are raised, the sternum is affected by morphological changes that are important for animal welfare. The main concern stems from the pain experienced by laying hens with fractures and deformities of the sternum. [ABSTRACT FROM AUTHOR]

The damages of the locomotor system and the skeletal system, in particular, are one of the major problems in the industrial poultry farming. The topic for the pathological changes in the keel bone in oviparous birds has become especially popular among scientists and researchers in recent years. The high incidence of keel bone damage (KBD) of laying hens in industrial complexes is one of the biggest welfare problems facing the industry. They lead to disturbance of the animal welfare, causing pain, limiting the ability to move and to perform the characteristic behaviour of the species. This in turn causes a decrease in productivity and unacceptably large losses not only for the individual producer but also for the whole sector. The problem with the KBD is widespread in Switzerland, Great Britain, the Nederland, Belgium, Germany, and Canada. Different genetic lines of laying hens are affected, as well as all types of breeding systems. In general, the etiological factors are reduced to three main groups - genetic predisposition, unbalanced diet and imperfections in housing systems. The causes and influencing factors of KBD remain unknown to the research community - a circumstance that seriously complicates the development of effective strategies to reduce their occurrence and severity. [ABSTRACT FROM AUTHOR]

Multiple gestations are high risk pregnancies which may be complicated by prematurity, low birthweight, preeclampsia, anaemia, postpartum haemorrhage, intrauterine growth restriction, neonatal morbidity and high neonatal and infant mortality. Preterm labor and birth represent the greatest risk to a multiple pregnancy. Sixty percent of multiples are born prematurely (<37 weeks) compared to about 10% of singleton pregnancies. Placental function is more likely to be abnormal in a multiple pregnancy. Another placental problem is twintwin transfusion, a life-threatening condition in identical twins. Preeclampsia, also known as toxemia, occurs 2 to 5 times more often in multiple pregnancies. Fifteen percent to 20% of women with twin pregnancies will experience preeclampsia, and an even higher percentage is preeclamptic in triplet or high-order pregnancies. Preterm labor and birth pose the greatest risk to a multiple pregnancy. Sixty percent of multiples are born prematurely (<37 weeks) compared to about 10% of singleton pregnancies. Fetal and Newborn complications such as preterm delivery, respiratory distress syndrome, brain damage are responsible for almost 10% of premature newborn deaths. Birth defects and stillbirths account for about 30% of the deaths in twins and multiple pregnancies. Low birth weight of less than 5.5 pounds (lb.) [2,500 grams] occurs in over half of twins. [ABSTRACT FROM AUTHOR]

Multiple gestations are high risk pregnancies which may be complicated by prematurity, low birthweight, pre-eclampsia, anaemia, postpartum haemorrhage, intrauterine growth restriction, neonatal morbidity and high neonatal and infant mortality. There are more multiple births today in part because more women are receiving infertility treatment, which carries a risk of multiple pregnancy. They are many risk factors for multiple pregnancy such as: race, heredity, maternal age and pregnancy history as well as fertility drugs and assisted reproductive technology(ART). The frequency of twins increases with maternal age and number of pregnancies. Multiple pregnancy is more common in women who utilize fertility medications to undergo ovulation induction or superovulation. Assisted reproductive technology (ART) procedures such as in vitro fertilization (IVF) also contribute to the increase in the multiple birth rate. The risk of multiple pregnancy increases as the number of embryos transferred increases. [ABSTRACT FROM AUTHOR]