Performance and diarrhoea in piglets following weaning at seven weeks of age: Challenge with E. coli O 149 and effect of dietary factors

Four dietary factors (ad libitum versus feed restriction, control versus protein restriction at ad libitum feeding, control versus inclusion of lupine as a protein source at ad libitum feeding, and control versus extra vitamin E at ad libitum feeding) were tested in four separate experiments for the effect on diarrhoea. To introduce a diarrhoea-like condition, half of the piglets were challenged with an inoculation of an E. coli O 149 dose of 1 x 108 colony forming units on day two and three after weaning (day of weaning = day one). All piglets were susceptible since the dams were tested mono-zygotic susceptible to the attachment site of E. coli O 149 in the intestines. Each of the four experiments included 32 piglets from 4 sows. The design was 2 x 2 factorial with dietary factor and E. coli O 149 challenge as the two factors, each at two levels. The piglets were housed individually during the experiment which lasted for 10 days from weaning at 7 weeks of age. The daily recordings included feed intake, weight and faeces score (from 1 = firm and solid to 6 = yellow and watery). Faeces from days 2 to 5 were tested for E. coli strains. In addition, blood was sampled and serum was analysed for E. coli antibodies, IgG and IgM. Generally the E. coli challenge had no effect on growth and feed intake whereas faeces score and number of faeces haemolytic bacteria increased and faeces dry matter decreased. Feed restriction decreased the weight gain while faeces characteristics were unaffected. An analysis including all four experiments revealed that a feed intake of less than 200 g day one after weaning seems to be associated with a relatively high incidence of a post-weaning diarrhoea-like condition. Protein restriction decreased faeces score and increased faeces dry matter while weight gain tended to decrease. Inclusion of lupine affected neither weight gain nor faeces characteristics. Extra vitamin E did not affect weight gain while faeces dry matter decreased, and faeces score and number of faecal haemolytic bacteria increased. The dietary treatments had no effect on the immunological responses. In conclusion, the studied dietary factors could not alleviate a diarrhoea-like condition and at the same time maintain the growth rate. Furthermore, the results indicate that performance can be improved if piglets achieve a daily feed intake of at least 200 g from day one after weaning

E-vitamin til økologiske smågrise efter fravænning

Virkningen af ekstra E vitamin på fravænningsdiarré blev undersøgt i tre økologiske svinebesætninger. Ved fravænning blev grisene i disse besætninger delt i to hold hvoraf det ene hold fik ekstra naturligt E vitamin i foderet (100 mg/kg), mens kontrolholdet fik samme foderblanding uden ekstra E vitamin. Foderblandingerne i de tre besætninger havde i forvejen et ret højt E vitamin indhold (55-150 mg alfa-tocoferol pr. kg). Gødningskarakter og vægt blev registeret på fravænningsdagen samt 5 dage og ca. 5 uger efter fravænning. Der var stor forskel i graden af diarré i de tre besætninger, men hverken i to problemfrie besætninger eller i en besætning med udbredt fravænningsdiarré havde den ekstra E vitamin nogen virkning på tilvækst og diarré. Foderblandingerne i de tre besætninger levede op til den nye norm for E vitamin (130 mg/FE, hvis E vitaminet tildeles som syntetisk E vitamin), og det er sandsynligt, at ekstra E vitamin udover denne norm er uden virkning. Fravænningsdiarré er i øvrigt et multifaktorielt problem hvor man udover ernæringsmæssige faktorer som E vitamin også skal være opmærksom på det generelle sygdomspres, hygiejne og stress m.m

Inoculation of weaned pigs with E. coli reduces depots of vitamin E

This study was designed to investigate the effect of vitamin E supplementation on vitamin E depots and immune responses in weaned pigs after an E. coli inoculation. The design was a 2×2 factorial with vitamin E supplementation (150 mg/kg RRR-α-tocopheryl acetate versus a control diet containing 60 mg all-rac-α-tocopheryl acetate) and E. coli 0 149 inoculation (inoculation of 1×108 CFU on day 2 and 3 after weaning versus inoculation of vehicle). The pigs were housed individually during the experiment which lasted for 10 days from weaning at 7 weeks of age. Blood was sampled on day 1 (day of weaning) and 9 of the experiment, and serum was analyzed for α-tocopherol concentration. On day 10 of the experiment, pigs were killed and samples of liver, heart, muscle, adipose tissue and intestinal epithelium were obtained, and immune cells (alveolar macrophages) were harvested, and analyzed for α-tocopherol concentration. Immune cells were furthermore analyzed for PGE2 synthesis after in vitro stimulation. The concentration of IgA and IgM was analyzed in samples obtained from the bile, and in mucosal and intestinal content from three sites of the intestine. The results showed that E. coli inoculation reduced the concentration of liver α-tocopherol with 30–37%, increased the concentration of IgA in bile, and reduced the concentration of IgM in intestinal content of pigs. The vitamin E supplementation increased the concentration of α-tocopherol in serum, organs and tissue samples except the adipose tissue. The stereoisomer composition of α-tocopherol in serum, liver and immune cells was highly influenced by the dietary provision of natural vitamin E. In conclusion, dietary natural vitamin E supplementation increased the α-tocopherol depots of the pigs, and notably the RRR-form of α-tocopherol, but had no influence on the measured immune responses. Irrespective of dietary supplementation with vitamin E, short-term inoculation of pigs with E. coli led to a decreased liver α-tocopherol status