Preliminary research results on application of a local medicinal herb (Achyranthes aspera) as dietary supplement to sows to prevent diarrhea in piglets 

Pham Hong Son, Pham Quang Trung, Tran Quang Vui  and  Dinh Thi Bich Lan

Hue University of Agriculture and Forestry
phson.nl@hueuni.edu.vn

 Abstract

Diarrhea in piglets can be a good model for studying the effects of medicinal herbs on animals. With the aim to test the possible positive and negative effects of the herb “co xuoc”, which is recommended to treat diarrhea in suckling children, levels of 0, 20 and 40 g (fresh material) were given  per os to groups each of 3 sows from day 100 of gestation through lactation to weaning at 45 days post-parturition. Measurements were made of incidence of diarrhea, litter size and weight gain performance of the piglets, as well as on their immune response and gut microflora.

The analysis of the data indicated that  “co xuoc” supplementation to sows decreased diarrhea prevalence in piglets, increased their growth rate but decreased the litter size. There was no apparent effect on the immune response of piglets and on their gut microbial flora.

Key words:  “co xuoc”, medicinal herbs, sows, pregnancy, lactation, diarrhea, weaning weight, litter size, gut microflora, immune response

Introduction  

Diarrhea in piglets is an important disease as it commonly appears in piglets from the 1st to 20th day of age, causing high mortality, and subsequent economic loss (Dao Trong Dat et al 2001). Treatment of diseased neonatal animals with antibiotics often leads to their growth retardation. Adding antibiotics to feeds as preventative agents can lead to selection of drug-resistant bacterial strains. Application of probiotics and prebiotics instead of antibiotics as feed supplements is a new choice; use of medicinal herbs comes into this category.  In Vietnam, some medicinal herbs are traditionally used for treating diarrhea in suckling children by giving them per os to the mothers. For this research, the  herb “co xuoc” (Achyranthes aspera) was chosen, because it is easy to cultivate, and is not rejected by the pigs when blended with other feeds.  "Co Xuoc" is also traditionally used in humans against rheumatism, nephritis oedema and prolonged fever, as well as  diarrhea and dysentery), with a recommendation that it should not be used during pregnancy (Le Quy Nguu and Tran Thi Nhu Duc 1999). However, these traditional  recommendations and claims are not experimentally tested.  As the effects of  "Co Xuoc" are still not experimentally tested, it is proposed to use diarrhea in piglets as a model for studying the effects of the herb on animals.

The aims of the experiment were to test if the herb  "Co Xuoc":

• might cause troubles to pregnant pigs

• given to sows would prevent diarrhea in the piglets

• would increase body weight of weaning pigs

• would cause an immune response and changes in the gut microbial flora 

 

Methods

Nine sows in their second gestation were used. Starting on the 100th day of gestation (about 15 days before farrowing), and during lactation, three of them were given per os  20 g daily (dose recommended for humans), another three were given 40 g (double-size dose) and the third group of three sows was used as negative control. The health condition of the animals was observed daily. After farrowing,  live weight of the piglets was  measured at birth, 15, 30 and 45 days later. Samples of faeces were collected on the 5th, 10th, 15th, 20th, 25th, 30th, 35th, 40th and 45 th days for determining total aerobic microbial flora as well as of Escherichia coli, and Salmonella plus Shigella. Observations were made of diarrhea prevalence in the piglets.  On the 20th day of age each piglet was injected with a dose (as used for 5 chickens) of Newcastle disease virus (NDV) vaccine as a marker antigen for measuring humoral immune responses of the animals, which was determined 10 and 20 days later (at 30 and 40 days of piglet age).

The  following parameters were recorded:

• Body weight measured individually, with an exception of the weights at birth which were determined for the  litter as a whole;

• Diarrhea prevalence (if visible over a period of 5 days is counted as one case), cases/total number of piglets;

• Total aerobic bacteria: numbers of 24-hour-incubated colonies on nutrient agar medium contaminated with 0.2 ml of serially diluted (to 10⁷) faeces samples (Cottral 1978) ;

• E. coli and Salmonella+Shigella: the numbers of genus-specific 24 h colonies on differential (EMB and Istrati) agars (Cottral 1978);

• Immune response: antibody titers to NDV with haemagglutination inhibition reaction (HI) (Cottral 1978).

For data analysis, mean values, standard deviation and ANOVA were used (Snedecor and Cochran 1980). Eliminatory analysis with range correlation (Spearman method of analysis;  reviewed in Snedecor and Cochran [1980]) was applied to non-experimental parameters, such as effects of litter size on piglet diarrhea prevalence, and on weaning body weights (45 day age).

 

Results

Diarrhea prevalence in piglets

Per os application of the herb (Achyranthes aspera) to the sows decreased diarrhea in the piglets (Table 1; Figure 1). However, attention should be paid on the number of piglets in experimental and negative control groups, which wouldl be tested father by analyzing the effect of non-experimental factors.

 Figure 1: Prevalence of diarrhea in the piglets according to amounts of the herb fed to the sows

Effect of the herb application on the content of total aerobic microbes E. coli and Salmonella+Shigella in faeces of piglets

There was no relationship between the herb application and the counts of total aerobic microbes,  E. coli and Salmonella+Shigella in piglet faeces. The numbers of the microbes (data not shown) were also not different in animals showing diarrhea or not showing diarrhea, indicating that the numbers of microbes may not be related to diarrhea in piglets.  However, if the data of the bacterial numbers  five days after birth are analyzed they appear to show a positive effect  of "coxuoc" on microbial flora changes (Table 1).

Table 1. Mean numbers (with SD) of aerobic microbes, Escherichia coli, and Salmonella+Shigella (as 106/g) in faeces of piglets from the different experimental groups
Trials	Microbs	Age days of piglets
		5	10	15	20	25	30	35	40	45
0g	Total aerobs	4059 ±1167	2050 ±38.7	431 ±124	790 ±224	483 ±154	944 ±131	826 ±201	523 ±60	371 ±61
	E. coli	175.98 ±58.21	84.92 ±19.46	59.92 ±19.46	250.75 ±87.66	121.53 ±43.36	408.63 ±70.69	335.34 ±130.46	82.81 ±22.20	96.59 ±24.35
	Sal.+ Shi	357.41 ±133.29	19.98 ±12.65	20.27 ±12.65	75.34 ±41.93	51.44 ±27.96	82.35 ±12.68	57.32 ±20.33	32.33 ±8.55	19.12 ±7.30
20g	Total Aerobs	463.06 ±121.16	1816.02 ±327.86	3368.02 ±408.95	747.49 ±71.89	865.95 ±127.28	425.76 ±128.83	588.94 ±88.44	518.00 ±77.37	485.22 ±148.5
	E. coli	111.68 ±45.53	220.96 ±42.39	276.14 ±72.83	179.54 2±2.29	272.43 ±79.89	73.78 ±15.98	247.15 ±58.15	202.92 ±37.45	170.13 ±56.43
	Sal.+ Shi	112.04 ±42.21	58.59 ±19.17	196.32 ±45.86	48.32 ±7.78	49.23 ±11.65	31.25 ±5.41	92.93 ±30.43	28.44 ±6.45	14.5 ±5.56
40g	Total Aerobs	184.51 ±33.82	215.12 ±46.39	360.14 ±100.62	102 ±26.4	375.28 ±41.78	652.16 ±96.3	114.77 ±41.27	114.43 ±19.37	389.76 ±69.13
	E. coli	22.37 ±4.88	59.47 ±17.63	139.92 ±65.26	32.7 ±2.0	90.82 ±18.09	245.79 ±54.65	52.99 ±28.94	74.16 ±30.26	203.42 ±50.28
	Sal.+ Shi.	5.2 ±1.05	14.99 ±3.80	13.27 ±4.06	4.1 ±0.7	15.40 ±3.67	74.91 ±21.07	14.65 ±9.00	8.59 ±2.99	28.21 ±6.76

 

Immune response of piglets

There was no difference in the immune response due to administering the herb (Figure 2).

Figure 2: Immune response of piglets to NDV antigen

 Growth rate of piglets

The growth rate of the piglets increased according to the level of the herb administered to the sows (Figure 3).

 

Figure 3: Changes in live weight of the piglets in response to administration of the herb to the sows

Effect of "Co xuoc"  on litter size

The effect of the herb on litter size is an  important parameter as this medicinal species is not recommended to be used by  pregnant women. The data in figure 4 appear to corroborate this recommendation as there is a suggestion that the litter size was reduced when increasing amounts of the herb were given to the sows in the later stages of pregnancy. At this stage (>100 days) of gestation, the foetuses have developed large enough to be aborted instead of being absorbed by the placenta. Further experiments are required to investigate the effects of the herb given during lactation.

 

Figure 4: Relationship between level of "Co Xuoc"  administered to the sows and the litter size at birth

 

Conclusions

Application of  herbal medicines to prevent diseases in neonatal animals is a new but promising development. The results of our research are preliminary and require further testing.  The tentative conclusions are:

Supplementation of “co xuoc” per os daily to sows in late pregnancy and during lactation:

• Decreases diarrhea prevalence in the piglets and increases the growth rate to weaning

• Appears to decrease litter size, although visible reproduction abnormalities (such as abortion and still-births) were not seen

• Is not related to the gut bacterial flora and not related to humoral immune response.

 

Acknowledgements

This research was partially financed by the bilateral SAREC project 2000-2002.
 

References

Cottral C A 1978  Manual of standardized methods for veterinary microbiology. Cornell University Press, London, pp. 69-74.

Dao Trong Dat, Phan Thanh Phuong, Le Ngoc My and Huynh Van Khang 2001 Benh o lon nai va lon con [Diseases in sows and piglets, in Vietnamese], Nong nghiep Publishing House, Vietnam

Le Quy Nguu and Tran Thi Nhu Duc 1999  Duoc tai Dong y [Eastern medicinal materials, in Vietnamese]. Thuan Hoa Publishing House, Vietnam

Snedecor  G W and Cochran W G (eds.) 1980 Statistical methods, 7th ed., the Iowa State University Press Ames, Iowa, USA.

 

Received 27 March 2003; Accepted 20 June 2003

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