Teat necrosis of newborn piglets influenced by farrowing induction and boar effect

Teat necrosis of newborn piglets might result in shorter teats, ‘pin teats’, teat sphincter insufficiency, or non-functional, ‘blind’ teats in affected female piglets. It can cause substantial economic loss in the production of high-quality breeding gilts. Protective methods (adhesive bandages) are rarely used in the practice or, even if applied, sometimes their use is belated or not effective enough. Thus, the knowledge of prevalence-influencing factors is crucial in order to minimize losses. Therefore, the aim of our investigation was to determine the effect of farrowing induction and boar on the prevalence of teat necrosis.

The investigation was carried out in a farrow-to-finish farm working with 900 sows. The pregnant gilts and sows that did not farrow by the 115th day of pregnancy were administered 2 ml PGF Veyx injection (Veyx-Pharma, Germany) i.m. No teat protection was used on the piglets during the trial. The teats of piglets were observed at the age of 3–4 days. Statistical analyses were carried out with SAS (SAS Institute Inc., Cary, NC, USA) statistical software using the GLM procedure. Litter size at birth was used as a covariate factor in the analyses of treatment effects. In case of significant treatment effects, the statistical difference between means was determined by Tukey’s test.

The litter size of sows with induced (n=87) or natural farrowing (n=112) was similar (11.3 vs. 11.5; P> 0.05). However, in litters of sows with induced farrowing, the average number of piglets having teat necrosis strongly tended to be higher (6.1 vs. 5.4, P=0.056). It is generally accepted that sows producing elevated levels of oestrogen during farrowing deliver piglets born with swollen teats. If the floor surface is not smooth enough, it can traumatise the teats, resulting in necrosis. Recent research indicates that the application of PGF2α analogues can further increase the sow’s oestrogen level. This supports our findings and the generally accepted theory regarding the processes underlying teat necrosis. In our study, certain boars had significantly (P of boar effect < 0.001) more affected piglets than other boars of the same genotype. This phenomenon is quite interesting as it suggests that some boars transmit to their progeny an unknown factor that increases the sensitivity of piglets to elevated oestrogen in sows.

The endogenous oestrogen effect has been associated with elevated oestrogen levels of sows at farrowing, which is even more pronounced if induced farrowing is practised.

Selection of boars for a low prevalence of teat necrosis among their progeny may be a natural way to reduce predisposition to teat necrosis.

Disclosure of Interest: None Declared.