Feed intake during lactation is crucial for optimal sow and piglet performance. Higher intake can increase litter weight gain whilst reducing backfat and body weight losses and improve sow lifetime performance. High temperature and humidity can severely affect sow intake and a recent study shows a lactation flavour could potentially reduce this negative effect.
Kansas State University ran two trials of a feed flavour. The first was during the summer in their old 1970s lactation facility and the second during the winter in newly renovated buildings. The ration used was very high specification at 1.07 % SID-Lysine and 10.5 MJ/kg net energy. All sows were fed dry feed through Gestal feeders and piglets had no access to creep feed.
In the summer months the average temperature was 27.9 deg. C and relative humidity (RH) was 62.2 %. The farrowing house was environmentally regulated with fans, drip coolers and cooling tubes that directed ambient air onto the sow. The sows fed the flavour treatment tended to have an extra 0.4 kg/d intake from farrow to day 10 and farrow to wean kg/d intake overall (both P = 0.052). Piglets from the flavour fed sows were 0.3 kg/pig heavier at weaning (P = 0.039).
The trial was repeated in the winter and in new farrowing accommodation where the average temperature was 23.3 deg. C and RH was 41.4 %. Sow intake in the second part of the trial was higher and there was no overall difference in feed intake when feeding the flavour and, in fact, the intake from d 2 – 10 showed a tendency to be 0.3 kg/d lower (P = 0.052) which is not explained or discussed by the authors.
Previous trials in Brazil (Silva et al., 2021) showed improvements in performance in both hot and cool conditions though the cool conditions average 23.1 deg. C and 56.5 % RH and the climate x treatment results weren’t reported as were non-significant (P > 0.10).
The KSU trial also followed the piglets into the nursery where half were fed a starter feed flavour. Piglets from sows that were fed the lactation flavour and were heavier at weaning maintained that benefit through the nursery stage but there were no benefits of feeding the starter feed flavour.
The trials discussed here are good quality and of interest but, as common with sow trials, with little consistency in results. The evidence suggests that in the UK’s temperate climate a feed flavour is not necessary or would have limited benefit. Where intake is low or in extended periods of higher temperatures, then a flavour may be worth considering if intake and litter gain is heavily affected and environmental and other management interventions have been exhausted.
Silva et al., 2021: https://doi.org/10.1016/j.livsci.2021.104559
Spinler et al., 2023: https://doi.org/10.1093/tas/txad056