Effect of supplementing sows with Solanum glaucophyllum, a natural source of calcitriol, on farrowing performance, piglet survival and litter performance

The number of piglets weaned per sow per year is a main determinant of the performance of breeding sows. Consequently, the genetic progress in pigs is connected with the success in breeding larger litter sizes. With increasing average litter size in the sow population, the economic weight of litter size diminishes and that of piglet survival at farrowing and during nursing increases (Quinton et al., 2006). At the same time, farrowing duration and expulsion interval between piglets may increase, which has been related to a greater occurrence of stillborn piglets (Udomchanya et al., 2019). However, means to shorten the duration of parturition do not always support piglet survival. For instance, the injection of oxytocin may, indeed, shorten the farrowing duration but this does not guarantee a concomitant reduction in the occurrence of stillborn piglets (Udomchanya et al., 2019). In order to increase survival rates of piglets before and after birth, empirical managerial improvements like the use of farrowing crates, optimal sow fitness at farrowing and the use of rescue desks are useful. These measures could be supported by supplementing the diet of the sows with ingredients that facilitate the farrowing process and support piglet vitality and growth. ABSTRACT. Survival of piglets until weaning is a major contributor to the rentability of pig production systems. Large litters are often associated with complications and prolongation of the farrowing duration causing piglet mortality. The vitamin D status of the pregnant female is known to play a role in parturition problems. The present experiment investigated the effect of Solanum glaucophyllum in the diet of sows on farrowing duration and progeny survival and growth. Solanum glaucophyllum was distributed in a feed supplement to gestating sows from one week before farrowing until weaning of the piglets. Control sows received the same feed supplement but without S. glaucophyllum. Sows at an earlier gestation stage and piglets did not receive S. glaucophyllum. From 108 farrowing events and litters, on average 14.3 total born and 12.7 liveborn piglets were observed. Solanum glaucophyllum had no positive effect on the farrowing duration (222 vs. 219 min for experimental vs. control sows, respectively), average piglet expulsion interval (17.2 vs. 17.3 min), piglet vitality at birth, piglets death during nursing (2.03 vs. 1.74 piglets/litter) and piglets average daily gains (both 274 g). The proportion of stillborn piglets was even higher in sows receiving S. glaucophyllum than in control ones. Nevertheless, further studies on hyperprolific sows having no access to direct sunlight and with diets clearly deficient in either vitamin D or calcium are needed to show whether S. glaucophyllum is effective in parturient sows or not. Received: 16 November 2021 Revised: 27 January 2022 Accepted: 10 February 2022