Direct-fed microbials in sow diets can improve piglet health

Thursday, December 5, 2013

Research suggests that sow diets supplemented with Bacillus can have a direct impact on the neonatal piglet's continuously maturing GI microbial population and subsequent growth performance

by JANICE MURPHY

When added to the sow diet, direct-fed microbials (DFM) can provide health benefits to the sow herself as well as her piglets. This is possible by improving health status and immunity, reducing pathogens within the sow and the surrounding environment, as well as enhancing performance.

The gastrointestinal (GI) tract of a neonatal piglet is sterile at birth. It becomes colonized by bacteria from the sow during birth and in its environment. Clostridium perfringens and Clostridium difficile are common sources of diarrhea in piglets, especially during the first week of life when individual immunity is developing. Clostridial scours compromise litter performance, increase preweaning mortality and present an economic challenge for many commercial swine operations.

Previous studies in pigs have focused on using DFM for postweaning diarrhea and as growth promoters in grower-finisher diets. Research examining the addition of DFMs to sow diets, with the objective of improving piglet performance or resistance to disease, is rare. However, some studies have reported lower preweaning mortality and greater weaning weights in piglet litters from sows supplemented with Bacillus and Enterococcus faecium.

Researchers in Indiana recently used a Bacillus-based DFM to assess how well it could prevent clostridial scours in neonatal piglets, selecting strains that were particularly effective at inhibiting the growth of C. perfringens and C. difficile. The objective of this study was to evaluate changes in the performance and microbial population of the GI tract of neonatal piglets who nursed sows supplemented with a Bacillus-based DFM.

In all, 208 mixed-parity sows, including some gilts, were fed one of two dietary treatments during the gestation and lactation periods – a standard corn-soybean meal control diet or the control diet containing a DFM with two strains of Bacillus subtilis spores (3.75 × 105 total cfu/g feed for six weeks before and throughout the lactation period). The diets were formulated to meet or exceed National Research Council's recommended nutrient requirements for sows. There were no antibiotics in the experimental diets, and the piglets were not creep-fed during suckling.

The health status of the herd remained high, and there was no visual evidence of clostridial scours in the piglets, throughout the experiment. Twenty-one piglets from each treatment were euthanized on day 3 of lactation, and 15 piglets per treatment on day 10 of lactation, to assess the microbial population present in the GI tract.

There were no significant differences in daily feed intake, pre-farrow or estimated post-farrow body weight, weaning weight and wean-to-estrus interval between control and DFM-supplemented sows. However, DFM-treated sows did tend to gain less body weight during lactation compared to control sows (Table 1). Sows fed the DFM-supplemented diet farrowed significantly more total pigs and pigs born alive than control sows (Table 2), though the number of stillborn and mummies did not differ significantly.

Litters nursing DFM-supplemented sows had significantly higher weaning weights compared with the litters nursing control sows (Table 3). Although initial litter weight was also significantly greater for litters nursing DFM-supplemented sows, the improvement in litter weaning weight was at least partially due to the tendency towards an improvement in litter ADG compared with the control litters. These improvements in litter performance may be partially attributed to a decrease in the microbial challenge from the environment, allowing the piglets to focus their energy on growth rather than battling disease.

Individual piglet performance was also assessed by weighing pigs individually from a subset of 50 litters from DFM-supplemented sows and 48 litters from control sows (Table 3). There were no significant differences in piglet performance between treatments in this subset of the litters.

Clostridium counts in the intestinal tract of the piglets at three and 10 days of age were not significantly different between DFM and control piglets. Terminal Restriction Fragment Length Polymorphism (RFLP) analysis was used to characterize GI microbial populations in the ileum and colon of the piglets. The results indicated that there was a greater incidence and quantity of Lactobacillus gasseri/johnsonii in the ileum and colon of pigs nursing sows supplemented with DFM on day 3.

The presence of E. coli was significantly greater in the colon of pigs nursing control sows on day 3. On day 10, both the presence and quantity of Lactobacillus species were significantly greater in the colon of pigs with the DFM treatment.

Research suggests that the presence of certain Lactobacillus species shortly after birth, particularly L. gasseri, may promote a healthier GI microbial population by displacing pathogenic species such as E. coli and C. perfringens.

The results of this experiment indicate that supplementing sow diets with Bacillus supplementation can have a direct impact on the neonatal piglet's continuously maturing GI microbial population and subsequent growth performance. If this benefit can be realized through DFM inclusion in sow diets, there is no need to administer supplements to individual piglets. This would result in significant labour and cost savings for pork producers. BP

Janice Murphy is a former Ontario agriculture ministry swine nutritionist who now lives and works in Prince Edward Island.

Source: A. A. Baker, E. Davis, J. D. Spencer, R. Moser and T. Rehberger. 2013. "The effect of a Bacillus-based direct-fed microbial supplemented to sows on the gastrointestinal microbiota of their neonatal piglets," J ANIM SCI 2013, 91:3390-3399. http://www.journalofanimalscience.org/content/91/7/3390