It has always been true that weaning is one of the most stressful moments in pigs’ life due to the sudden shift from high-protein, high-fat and high-lactose milk to low-protein, low-fat, low-lactose and high-carbohydrate solid feed. Shortly after weaning, the gastrointestinal tract appears to be susceptible to this feed shift. Diet shift is just another factor which can be added to other sources for stress like immunological and environmental stresses.

Weaning induces many unwanted changes that can be summarised as follows:

• A decrease in the immune response of the small intestine due to the damage that occurs in the epithelial lining that contains the mucin-secreting cells.
  
  
• A substantial increase in E. coli and Clostridium perfringens populations concomitant with a sharp decrease in Lactobacillus species.
  
  
• Villus atrophy due to the shifting to the solid diet (just after weaning, the digestive tract of the pigs is almost empty for three to six hours which is considered as a golden opportunity for microbes to attack the epithelial lining of the small intestine and cause the previously mentioned morphological damage). Also it is very common to observe a significant decrease in villous height followed by an increase in the crypt depth.

These changes count for the vast majority of health and performance problems that occur at this critical time. As consequences to these changes, digestive disorders appear to cause improper growth performance through poor nutrients digestibility which is followed by an increase in the feed conversion ratio.

The improper nutrients digestibility and the enteritis caused by pathogens are the most important factors leading to diarrhoea incidence and mortality in newly weaned pigs. Just after weaning, there are some facts that most producers believe in like the growth performance of pigs is normally decreased, health also is adversely affected by weaning and mortality is a common incidence during that time.

On the other hand, there is another fact in the mind of all producers: the performance of pigs during the nursery phase is the key limiting factor in the pigs’ future productivity until the marketing step.

In the light of all mentioned above, it seems that we can achieve a successful post-weaning performance mainly though supporting and stabilising the gastrointestinal tract. Regardless of the different weaning programmes, pigs still need powerful, safe and sometimes uncommon solutions to overcome the weaning-related problems and hence change these old facts regarding animals’ health and growth performances after weaning.

Different natural feed additives and growth promoters were studied for their possible effects on improving pig performance. Phytogenics are a potent group within the family of natural growth promoters which have been shown to exert many positive effects within the gastrointestinal tract.

A 28-day experiment on 23-day-old pigs was conducted to investigate the potential of a phytogenic product (Biomin® P.E.P.) in comparison to an antibiotic growth promoter on the productive performance of newly weaned pigs under the conditions in Korea. A total of 360 weaned pigs equally distributed into three groups with four replicates as follows:

• Group 1: Negative control (commercial diet)
• Group 2: Positive control(commercial diet + 100ppm apramycin per ton)
• Group 3: Treatment (commercial diet + 125ppm P.E.P. per ton).

Phytogenics versus Antibiotics: Effects on Bodyweight

For a very long time, antibiotics have been used in animal feed as medical treatments and as growth promoters but since 2006, Europe has banned the use of antibiotics as growth promoters in animal rations. This decision created major problems for producers since they observed a pronounced decrease in live body weight, high mortality rate and a significant increase in the incidences of diarrhoea in their herds. This response was expected because of the weak nature of young pigs during the early stages of their lives. Furthermore, in our current case (Korea) the producers are not be free to use antibiotics as feed additives. The Korean food and drug administration banned the use of the antibiotics in animal rations from July 2011.

In the present study, the phytogenic product was shown to exert a positive effect on the live body weight at 50 days of age (Figure 1a) where pigs fed on P.E.P. had significantly higher body weights than those fed on the antibiotic growth promoter (1,530-g difference) and numerically higher weights than the negative control group (230-g difference).

Phytogenics and FCR

Feed conversion ratio (FCR) is affected by different parameters including mainly gastrointestinal health and feed quality. For producers, feed conversion ratio represents an important parameter in the production process. Figure 1b shows that the phytogenic improved feed conversion ratio by about six per cent than the negative control group and to a greater extent (11.5 per cent) than the antibiotic fed group. This finding confirms the efficiency of phytogenics on improving nutrient utilisation and stabilising the gastrointestinal tract.

Figure 1a and 1b. Live weight (left) and feed conversion ratio (right) of commercial pigs at 50 days of age. a,b - significant differences with experiment (p<0.05)

No Mortality with Phytogenics

Piglets are born weak and for a considerable amount of time, they are observed to be susceptible to different diseases and stressors. It is known that mortality appears especially at the early life stage. This is why mortality always peaked at birth and at weaning. Furthermore, considering the complexity of reasons that lead to death at the end, it seems that mortality control at the weaning phase is a distant dream. Data regarding bodyweight and feed conversion ratio revealed that the negative control group has a performance quite similar to the phytogenics group. However, as shown in Figure 2, the difference became clear where the negative control group had a mortality rate of 2.5 per cent and the phytogenic group showed zero per cent. Also, the phytogenic group performed better than the antibiotic group which had a 1.7 per cent mortality rate.

Figure 2. Mortality rate of commercial pigs at 50 days of age

Profits behind Phytogenics

The cost-benefit analysis (Table 1) shows the differences between different treatments regarding to total feed cost in a quite short period (23 to 50 days of age). Diet supplementation with Biomin P.E.P. resulted in reducing total feed cost by four per cent and 15 per cent compared to the negative and positive control groups, respectively.

Conclusion

It is a fact that there is no escape from having improper performance shortly after weaning and it is accompanied with increasing mortality rate. After reviewing the presented data, we can in fact control this very sensitive period through having better live body weight, lower feed conversion ratio, reduced mortality and reduction in the feed cost.

Other data not shown indicate that Biomin P.E.P. is modulating the gastrointestinal tract by controlling total microbial count, increasing nutrient digestibility and influencing immune response. In order to achieve a successful transition from milk to solid feed, it is a must to increase feed quality and one of the possible ways is the enrichment through using phytogenics as feed additives to support growth performance in newly weaned pigs.

It is also worth mentioning that phytogenics could be a powerful solution for producers on an early weaning programme.

Finally, all facts that we know about post-weaning difficulties can be controlled if we support our herds by increasing the quality of their rations by adding phytogenics.

April 2012