HT-2 and T-2 toxins are two of the most potent trichothecenes; they have a combined (HT-2+T-2) temporary Tolerable Daily Intake (TDI) of 0.06 µg/kg body weight/day. The distribution of HT-2 and T-2 appears to be largely restricted to Europe. Of the cereal species, HT-2 and T-2 usually have higher incidences and concentrations on oats followed by barley and then wheat, however, this can vary between countries. Survey data from Nordic countries have indicated that these mycotoxins have increased in recent years, reaching concentrations of >1000 µg/kg HT-2+T-2 in some samples. HT-2 and T-2 have also been detected in malting barley in France, and in particular in spring sown varieties. A newly identified species, Fusarium langsethiae, has been implicated as a producer of HT-2 and T-2 in European cereals. There is limited data available regarding this species' pathogenicity and mycotoxin production. The impact of agronomy on the concentration of HT-2 and T-2 in cereals has not been clearly identified, but it is evident that it is different to the impact of agronomy on deoxynivalenol. Processing of cereals can have a major impact on the HT-2 and T-2 content of cereals. Oats are de-hulled during processing for human consumption; de-hulling reduces the mycotoxin content of oats by more than 90%. During the malting and brewing of barley the concentration of HT-2 and T-2 increases and decreases within various stages of the processes and the final mycotoxin load of beers will depend on the individual processes used by each maltster and brewer. Whether these mycotoxins are an issue for human health cannot be determined until a full TDI is calculated based on more long-term exposure studies, and human exposure levels are calculated from surveys of retail products using new, highly sensitive assays.

The nutritional value of different categories of peas was measured in mash or pelleted diets using adult cockerels. Twenty-five round and white-flowered peas (feed peas), 12 round and coloured-flowered peas and five wrinkled and white-flowered peas were used in mash diets. From the same batches, 11 feed peas, five coloured peas and four wrinkled peas were tested in pelleted diets.Mean apparent metabolizable energy (AME) values were 12·02, 11·35 and 10·50 MJ/kg dry matter (DM) for feed peas, coloured peas and wrinkled peas respectively in mash diets and 13·18, 12·72 and 11·63 MJ/kg DM for the same categories in pelleted diets.Mean starch digestibility was 0·905, 0·887 and 0·802 for feed peas, coloured peas and wrinkled peas respectively in mash diets and 0·985, 0·984 and 0·840 for these categories in pelleted diets.Mean protein digestibility was 0·788, 0·643 and 0·798 for feed peas, coloured peas and wrinkled peas respectively in mash diets and corresponding values for peas in pelleted diets were 0·855, 0·743 and 0·853.Pelleting thus had a positive effect on the nutritional value of peas and this improvement was all the more important because the AME and protein digestibility of the pea in mash diets was low.The nutritional value of feed peas for cockerels was not strongly correlated with chemical composition or to digestibility data obtained in the pig.

Sequential feeding programs (Seq) of 2 feeds, 1 protein rich-energy poor and 1 energy rich-protein poor, during the same day or every other day were compared with a control complete diet for male broiler growth and body composition from 15 d to market weight. In experiment 1, BW gain and breast meat yield were significantly lower than those of controls for 24-h-cycle Seq with extreme protein content difference between the 2 feeds. BW gain and breast meat yield were higher than those of controls when feeds with moderate differences [feed moderately rich in protein (PM) = 26% CP; feed moderately rich in energy (EM) = 16% CP] were fed. Feeding periods that were half as long but changed twice as frequently gave less favorable results. In experiment 2, effects of allowing access to feed for different lengths of time were measured. The treatments in a 24-h cycle were a constant control diet, 50% PM-50% EM, 40% PM-60% EM, or 80% PM-20% EM decreasing to 40% PM-60% EM. Chickens fed 40% PM-60% EM had a 6% lower BW gain and a 3% higher feed/gain ratio and were fatter than those from other treatments. In experiment 3, male chickens fed a 48-h-cycle Seq of EM and PM every other day had the same BW gain, feed intake, and feed/gain ratio as controls. In experiment 4, five 48-h-cycle Seq with varying differences of energy and protein contents between EM and PM gave similar or slight reduction of performances compared with controls. A field trial with 8 flocks of broilers confirmed that feeding high and low protein feeds on alternate days resulted in performance similar to that from feeding a complete feed despite large day-to-day variations in lysine intake. Converse to shorter phases, Seq for 48-h cycles offers new opportunities for practical application and also for studies of short-term regulation of protein and lipid metabolism in chickens.

Phytasic activity and phytic P content, which are important factors in determining the availability of P, were measured in 56 wheat samples. The different agronomic and genetic factors which could have an influence on these two variables were studied, specifically N and/or P fertilisation, date of harvest, preharvest sprouting and variety of French wheat. Phytasic activity ranged from 206 to 775mUg−1, with an average of 508mUg−1 and a standard deviation of 109mUg−1. Only the variety of wheat appeared as a significant factor explaining the endogenous phytasic activity (P=0·006). The phytic P content varied between 0·92 and 2·80gkg−1 DM, with an average of 2·18gkg−1 and a standard deviation of 0·35gkg−1 DM. None of the factors studied significantly affected the phytic P content of the wheat. This content was correlated with the total P content (r=0·56;P<0·05). The activity of the endogenous phytase was independent of the quantity of its substrate, the phytic phosphorus of the kernels of wheat.

The European Commission has considered the appropriateness of setting a maximum level for T-2 and HT-2 toxins in cereals and cereal products in future. Occurrence studies show that oats, and to a lesser extent barley, seem to accumulate higher levels of these toxins than other cereals. Consequently, ARVALIS – Institut du végétal has conducted a field survey in collaboration with different French partners (cooperatives and merchants, agro industries and research institutes). The agronomic factors identified to reduce the risk of T-2 and HT-2 toxins on barley are different from those identified for deoxynivalenol (DON). They are, in decreasing order of importance: sowing date, rotation (number of small grain cereals in the last 2 years), tillage (with a smaller impact than for DON), and possibly varietal susceptibility and fungicide protection. Finally, this field survey shows that DON, and T-2 and HT-2 toxins seem to be opposed, which probably means a different risk management for these different mycotoxins.