Effect of dietary anise flavour on performance of sows and their litter at different weaning ages

Insufficient feed intake by sows during lactation is problematic because sows require large amounts of energy and nutrients for high milk production. A low feed intake during lactation may lead to greater bodyweight (BW) loss, lower milk production, and reproductive problems that may result in early culling of sows (Eissen et al. 2000). Feed intake is greatly influenced by the chemical senses of olfaction and taste, and feed flavouring agents can be added to enhance the smell and taste of feed in order to stimulate intake. In addition, Wang et al. (2014) reported that flavour increased the average daily feed intake (ADFI) of lactating sows, as well as improving the ADFI and average daily gain (ADG) of weanling pigs. According to Maes et al. (2004), the back fat measurements constitute a valuable tool to monitor and improve the productivity and efficiency of high producing pig herds. The objective of the present study was to evaluate the effect of dietary anise flavour (AF) on performance of lactating sows and their litters.

A total of 120 sows (Landrace × Yorkshire, average parity 2.7) with a bodyweight (BW) of 237 ± 1.9 kg (mean ± SE; BW measured at 7 days before farrowing) was allotted into one of four treatments using a 2 × 2 factorial arrangement of treatments with two AF levels (0 or 0.05%) and two weaning ages (21 or 28 days of age). Sows were fed a commercial diet with AF (n = 60) or without AF (n = 60) from d 100 of gestation and throughout lactation. All diets were formulated to meet or exceed the NRC (2012) requirements. The gestation diet had 13.19 MJ metabolisable energy (ME)/kg, 131 g/kg crude protein (CP) and 6.5 g/kg available lysine (AvLys), and the lactation diet had 13.44 MJ ME/kg, 171 g/kg CP and 10 g/kg AvLys. The AF (DadHank Biotechnology Corporation, Chengdu, China) was a non-hygroscopic powder and contained 33.47% eugenol, 11.09% coconut aldehyde, 10.22% linalool, and 9.52% anethole. On the day before farrowing and at weaning, the backfat of sows was measured 6 cm off the midline at the tenth rib using a real-time ultrasound instrument (Piglot 105, SFK Technology, Herlev, Denmark). Data were analysed by using the MIXED procedure (SAS^®; USA). Variability of all the data was expressed as standard error (SE) and a probability level of P < 0.05 was considered as statistically significant.

Sows fed with AF diets had higher (P < 0.05) ADFI and lower (P < 0.05) back fat loss than those fed with non-AF diets (Table 1). Sows weaned at d 28 had lower (P < 0.05) back fat loss compared with those weaned on d 21, whereas no difference (P > 0.05) was observed on weaning BW between piglets in the AF group and non-AF group. In conclusion, the results showed that dietary AF supplementation could increase ADFI and decrease back fat loss of lactating sows. Moreover, early weaning is helpful for reducing back fat loss of lactating sows.

Table 1.  Effects of anise flavour (AF) on performance of sows