Cellulase supplementation benefits performance and apparent faecal digestibility of dietary components in lactating sows and their piglets

During lactation, the demands of milk production and limited nutrient intake can cause catabolic conditions (Kim and Easter 2003). The fibre component of sows’ diet is recognised to add an important source of energy to pregnant sows because it is processed through microbial fermentation in the gastrointestinal tract (Schoknecht 1997). However, monogastric animals do not have the enzymes to hydrolyse the dietary fibre contents. Thus, supplementation of exogenous enzyme is necessary to optimise nutrient utilisation. It was hypothesised that a corn-soybean meal based diet, containing high fiber byproducts when supplemented with cellulase, could improve feed intake, nutrient digestibility and reduce backfat loss in lactating pigs and improve performance in their litters.

A total of 15 first parity sows (Landrace × Yorkshire) with their initial body weight (BW) (205 ± 1.6 kg; mean ± SD) and backfat thickness (P2) of 21.6 mm were randomly allocated into one of three treatments with five replicates per treatment. Dietary treatments were as follows: CON (corn-soybean meal-based control); EZ1 (CON + 0.05% cellulase); and EZ2 (CON + 0.10% cellulase). The guaranteed activity of cellulase was 12 000 U/g (AT Life Science Inc., Cheongwon, South Korea). The treatment diets were fed 40 days before farrowing until weaning (25 days after parturition). Sows were fed on a commercial gestation and lactation feed divided into two daily meals in mash form. The calculated metabolisable energy, crude fibre and available lysine content of the gestation diet was 13.38 MJ/kg, 32.1 g/kg and 15.8 g/kg, respectively, and those of the lactation diet were 14.5 MJ/kg, 28.7 g/kg and 14.9 g/kg, respectively. The BW and P2 of sows were measured 4 days before farrowing, and also on d 2 and 25 after birth. Cross-fostering was performed within gestation treatment groups to adjust to 10 piglets per sow. Piglets were not offered creep feed. The average daily gain (ADG) of piglets was measured from d 1 to 25 (weaning). Fresh faecal samples were collected by rectal massage on d 21 to 25 of lactation from all five sows per treatment to determine the coefficient of total tract apparent digestibility (CTTAD) of dry matter (DM), nitrogen (N) and gross energy (GE). Chromium oxide (0.2%) was added to the sow diets as an indigestible marker for a period of 7 days before faecal collection. All data were analysed in accordance with a completely randomised design using the GLM procedure (SAS^®; USA). The individual sow or litter of piglets was used as the experimental unit. Differences among the treatment means were determined by using the Tukey’s test with P < 0.05 indicating statistical significance.

The supplementation of cellulase had no significant effect on BW and feed intake of lactating sows. At weaning, P2 loss decreased significantly (P < 0.05) in EZ2 (2.8 mm) compared with CON (4.0 mm). During d 14 to 21, there was an increase in the ADG of piglets from sows fed EZ1 (276 g) than CON (251 g) and during d 21 to d 25, the ADG of piglets increased (P < 0.05) in EZ1 (288 g) and EZ2 (275 g) compared to CON (260 g). The CTTAD of DM in EZ2 (0.739) increased (P < 0.05) relative to CON (0.726), and that of N also increased (P < 0.05) in EZ2 (0.763) compared with CON (0.742), but no improvement in CTTAD of energy was observed (data not shown). In conclusion, it is suggested that 0.01% cellulase supplementation to corn-soybean meal-based diet exerts beneficial effects to sows in improving their backfat thickness at weaning and also helped to improve CTTAD of DM and N but not energy. Dietary lipids may be directly deposited in milk fat. However, if the dietary intake of lipids is greater than the needs for these functions, excess lipids will be stored in the body as body lipids, mainly in adipose tissue. Thus, there is a reduction in P2 backfat loss. Also, piglets born from sows fed enzyme-supplemented diets showed positive effects in improving their ADG. Due to the difficulty in having gestating sows of the same age and body weight at the same time only 15 sows were used in this study. Given this major limitation, further studies with additional sows animals are suggested.