Developments of reproductive management and biotechnology in the pig

Abstract

This review aims to describe changes in production environment, management tools and technology to alleviate problems seen with the present hyperprolific sow model. Successful parturition in the pig includes the possibility to express adequate maternal behaviour, rapid expulsion of piglets, complete expulsion of placenta, elimination of uterine contamination and debris, neonatal activity and colostrum intake. We focus on management of large litters, including maternal behaviour, ease of parturition, colostrum production, piglet quality parameters and intermittent suckling. There are also some interesting developments in technology to assess colostrum and immune state of the piglet. These developments may be utilized to improve the success rate of reproductive management around farrowing, lactation and after weaning. We also discuss new insights in how to examine the health of the mammary gland, uterus and ovaries of hyperprolific sows. Finally, we assess the latest developments on breeding and technology of hyperprolific sows, including artificial insemination (AI), real-time ultrasound of the genital tract and embryo transfer (ET). We conclude that 1) for the sow to produce sufficient colostrum, both the behavioural and physiological needs of the sow need to be met before and after parturition. Furthermore, 2) new ultrasound and biopsy technology can be effectively applied for accurate diagnosis of inflammatory processes of the udder and uterus and timing of AI regarding ovulation to improve insemination efficiency. Finally, 3) developments in cryopreservation of germ cells and embryos appear promising but lack of valid oocyte collection techniques and nonsurgical ET techniques are a bottleneck to commercial ET. These latest developments in management of parturition and reproductive technology are necessary to cope with the increasing challenges associated with very large litter sizes.

Coping with large litters: management effects on welfare and nursing capacity of the sow

“…On the other hand, in a warmer climate, pigs should be robust and more resilient under heat and should be less susceptible to being becoming stressed under such conditions. However, hyperprolific sows may actually be quite sensitive to heat when compared with less productive breeds [ 61 ].…”

Tools and Protocols for Managing Hyperprolific Sows at Parturition: Optimizing Piglet Survival and Sows’ Reproductive Health

“…Furthermore, severe edema of the mammary gland before parturition will have a negative impact on teat accessibility, reduce colostrum quality, and increase the risk of PDS [48,49]. The degree of mammary gland edema can be graded visually or via ultrasound [48,49,55]. At visual inspection, sows with severe udder edema have dimpled skin with persistent marks of the floor (Figure 1A).…”

“…Further, teats are swollen and mammary glands are indistinct ( Figure 1A) [48,49]. Ultrasound of the mammary glands shows thickened dermal and subdermal tissues, hyperechoic lobuloalveolar tissue with enlarged blood vessels, and severe shadowing ( Figure 1B) [48,49,55]. Also at the end of lactation, the assessment of the mammary gland, as described above, is crucial and should be used for the decision of removing the sow from the herd.…”

Troubled Process of Parturition of the Domestic Pig

“…On the other hand, hotter climate will need pigs to be robust and more resilient under heat with less susceptible to becoming stressed under those conditions. Hyper-prolific sows, however, may actually be quite sensitive to heat in comparison to less productive breeds [81].…”