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Made available in DSpace on 2020-12-10T09:08:50Z (GMT). No. of bitstreams: 1 final9461.pdf: 114265 bytes, checksum: b19f1ac5d7ca29942b7ed1237d7d0556 (MD5) Previous issue date: 2020

It is estimated that as many as 40 to 50% of reproducing females are culled each year in modern pig production; astonishgly, almost half of these culls are associated with sows before their third and fourth parity (ENGLEBON et al., 2016). Decreased sow longevity is not only an economic problem for the pig industry but also results in poor animal welfare. To maximize profitability, sows should be retained in the breeding herd up to parity six, since higher parity dams wean numerically more and heavier piglets per year when compared to first and second parity sows (GRUHOT et al., 2017); nevertheless, in commercial pig operations 30% of sows are culled by parity three, being reproductive failure one of the major reasons for involuntary culling of low parity sows (TANI et al., 2018). On this path, disappointing litter size, anestrus and return to estrus following insemination are regarded as major causes for removal of reproducing females (KOKETSU et al., 2017). However, aside of been caused by intrinsic unbalances, these failures can also suffer the influence of external factors, e.g. deficient estrous detection, incorrect moment of insemination, poor semen quality and reproductive diseases, therefore some sows might be culled for wrong reasons. The present study aimed to evaluate the culling decision accuracy of sows with reproductive failure from commercial breeding herds through examination of reproductive and urinary tracts post mortem. Made available in DSpace on 2020-09-17T04:39:37Z (GMT). No. of bitstreams: 1 final9062.pdf: 167554 bytes, checksum: 227d01a6d65e093a70e8445176532788 (MD5) Previous issue date: 2019

Made available in DSpace on 2018-12-11T17:03:43Z (GMT). No. of bitstreams: 0 Previous issue date: 2016-05-01 Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) Boar spermatozoa arising from the sperm-rich ejaculate fraction are reported to have a more stable plasma membrane and are more resistant to cold shock and premature acrosome reaction than spermatozoa from the whole ejaculate. Furthermore, seminal plasma (SP) can increase the cryotolerance of boar spermatozoa, and in other domestic species, it has the ability to reverse cryopreservation damage. This study aimed to evaluate the effects of boar SP arising from the whole sperm-rich ejaculate fraction (SP-SRF) on the integrity, stability, and peroxidation of sperm membranes after thawing. Each ejaculate (n = 24) was divided among 4 treatments: control (CT), centrifuged and suspended in autologous SP-SRF (CS), centrifuged with withdrawn SP-SRF (CW), and post-thawed SP arising from the whole sperm-rich fraction addition to CW (CWSP). After thawing, all treatments were incubated for 5, 60, and 120 min and were analyzed for membrane integrity, fluidity, and peroxidation by flow cytometer. The absence of SPSRF increased the lipid disorder (P < 0.05) but had no effect on lipid peroxidation (P > 0.05) or membrane integrity (P > 0.05). However, the increase in lipid disorder by withdrawal of SP-SRF was reversed by SP-SRF addition (P < 0.05) to the post-thawing medium, whereas plasma and acrosomal membrane integrity (P > 0.05) and lipid peroxidation (P > 0.05) were unchanged. In conclusion, despite the centrifugation effects, the addition of SP arising from the whole sperm-rich fraction to post-thawed boar semen decreased sperm lipid disorder without an influence of the sperm membrane integrity and peroxidation. Laboratory of Andrology and Technology of Swine Embryos Department of Animal Reproduction School of Veterinary Medicine and Animal Science University of São Paulo Laboratory of Swine Research Department of Animal Nutrition and Production School of Veterinary Medicine and Animal Science University of São Paulo Department of Veterinary Medicine School of Animal Sciences and Food Engineering University of São Paulo Department of Animal Reproduction and Veterinary Radiology School of Veterinary Medicine and Animal Science São Paulo State University (UNESP) Department of Animal Reproduction and Veterinary Radiology School of Veterinary Medicine and Animal Science São Paulo State University (UNESP) FAPESP: 2011/23484-8 FAPESP: 2013/08070-8