CH-1725 Posieux www.alp.admin.ch
andreas.gutzwiller@alp.admin.ch
FUSARIUM CONTAMINATED BEDDING STRAW AND PIG FERTILITY
Andreas Gutzwiller and Jean-Louis Gafner, Federal Research Station Agroscope Liebefeld-Posieux, Switzerland
THE PROBLEM
Straw is good for the welfare of sows, but:
Straw is generally more heavily contaminated with theFusarium mycotoxins deoxynivalenol (DON) and zearalenone than the corresponding grains.
Swiss pig breeders and veterinary practitioners suspect mycotoxin contaminated straw to be an important cause of sow infertility.
The effects of Fusariumcontaminated straw on sow fertility were therefore examined under experimental conditions.
ANIMALS, MATERIALS AND METHODS
1. Preliminary study: During 2 reproductive cycles (=2 pregnancies
+ 2 lactations), 8 sows were kept on mycotoxin contaminated straw, 8 control sows were kept on uncontaminated straw.
2. Second study: 40 sows on mycotoxin contaminated straw, 40 sows on uncontaminated straw during one reproductive cycle.
3. Lab test
6 samples of contaminated straw were soaked in an „artificial saliva“
(electrolyte solution) for 3 minutes to imitate straw chewing by sows.
DON and zearalenone analysis (ELISA) of samples obtained before and after soaking.
MYCOTOXINS IN CONTAMINATED STRAW (1 LOAD OF 5 TONS)
The large variation of mycotoxin levels in the 12 analysed samples of one batch of straw (5 tons) shows thatFusariumtoxins are less evenly distributed in straw than in grains.
FERTILITY OF THE SOWS
1. Preliminary study (16 sows):Contaminated straw had no effect on fertility (data not shown).
2. Second study (80 sows):
STRAW MYCOTOXIN LEVELS AFTER SOAKING IN ELECTROLYTE SOLUTION
DON and zearalenone concentration in 6 straw samples soaked in an artificial saliva (median values)
DON and to a lesser degree zearalenone were partially washed out from straw.
Analysed values median minimum maximum
DON, mg/kg 1.4 0.4 5.6
Zearalenone, mg/kg 0.9 <0.15 8.1
unsoaked soaked P1
DON, mg/kg 1.2 0.3 <0.05
Zearalenone, mg/kg 0.58 0.51 0.10
mycotoxin control P1
Sows bred, n 40 40
pregnant after one or two oestrus cycles, n
36 36
Piglets born alive per sow, n 8.3±4.42 8.8±2.8 0.57 Piglets weaned per sow, n 8.2±4.4 8.3±3.2 0.88
Birth weight, kg 1.5±0.3 1.6±0.3 0.09
Weight gain of nursing piglets, g/day
236 ± 48 243±43 0.18
TAKE HOME MESSAGES
By merely chewing contaminated straw, pigs will probably absorb DON.
AlthoughFusariumcontaminated bedding straw is claimed by practitioners to affect sow fertility, it was impossible to reproduce these negative effects under experimental conditions.
1 kg of bedding straw per sow and day
Computer controlled feeding of pregnant sows kept in groups
One hour per day on pasture
Exposure to Fusariumcontaminated straw had no effect on pregnancy, number of piglets born alive and weight gain of the piglets, although it tended to decrease birth weight (P= 0.09).
1 Probability of error; 2means and standard deviations
1P= probability of error for unsoaked vs. soaked
