Deoxynivalenol (DON) is the most common mycotoxin found in cereals produced in France and Europe. The study was initiated to assess the effect of different factors such as cultivation system, previous crops, varieties and fungicide application on the DON content of wheat. Between 1999 and 2002, samples were collected from 765 wheat fields and the agronomic and climatic factors pertaining to those fields recorded. The different factors involved in DON contamination were then evaluated by the segmentation method. The results showed that occurrence of DON and contamination levels were correlated with various risk factors. Conducive climate at flowering, previous cultivation of maize, no tillage and a susceptible cultivar combine to create conditions for very high DON content in a wheat crop. With a low risk previous crop, DON contamination depends on the sensitivity of cultivars against Fusarium. The hierarchy of the different agronomical and climatic factors has become better appreciated and could assist the wheat industry better manage potential DON contamination.

An experiment was conducted to evaluate the effect of heat drying temperature on the nutritive value of corn for roosters and pigs. Two batches of a French cultivar grown in two consecutive years were treated by a two-step drying process. The first temperature was used to remove approximately two-thirds of the moisture, and the second was applied in order to obtain a final grain moisture of approximately 15%. Six treatments each year were compared: for Corn 1, control, 80-80, 100-90, 120-100, 140-110 and 160-120-degrees-C; for Corn 2, control, 100-90, 120-100, 130-105, 140-110 and 160-120-degrees-C.True metabolizable energy and true digestibility of protein and amino acids of both corns, and digestibility of starch in Corn 2 only, were measured with six intact 1-year old (Isa Brown) roosters per treatment. Apparent ileal digestibility of protein and amino acids of Corn 2 was determined with four castrated male (Large White) pigs weighing between 60 and 80 kg and fitted with an end-to-end ileo-rectal anastomosis.The heat drying processing had no effect on the chemical composition of the corns. In digestibility experiments with roosters, the optimal heat drying temperature to obtain the best nutritive value (true metabolizable energy and digestibility of protein and lysine) was at 120-100-degrees-C. However, treatment temperature had no effect on the digestibility of starch. In digestibility experiments with pigs, the apparent ileal digestibility of protein decreased regularly with temperature from the first treatment (100-90-degrees-C). For roosters and pigs, artificial drying at high temperatures had detrimental effects on the nutrient value of grain, especially for lysine. In our experimental conditions, the inlet air temperature during drying should never exceed 130-degrees-C.

Utilization of white-flowered smooth-seeded spring peas (Pisum sativum hortense, CV Amino) in diets for sows was studied in an experiment with 536 litters from 137 individually-fed sows. Control sows were fed on diets based on cereal and soya-bean meal whereas for sows of the experimental group cereal and soya-bean meal were partly replaced by 16% pea meal in gestation diets and 24% pea meal in lactation diets. Diets with pea meal were well consumed. Changes of sow liveweight with successive parities were similar in control and experimental groups. On average, there was no difference in litter size between the two groups. Piglet birthweight, weaning weight and piglet mortality rate did not differ significantly between the control and experimental groups. Farrowing frequency was similar in the two groups and culling rate of sows was slightly less in the experimental group. It is concluded that white-flowered smooth-seeded spring peas can be widely used in diets for sows without any adverse effects.

increased by 60 p. 100 compared to the control value).The noticeable differences between the effects of WB and RB diets on Ca-P metabolism might be attributed to the 16-times higher dietary phytase activity of RB.However, other variables such as trial length or percentage of bran incorporation might explain these differences.Our results clearly demonstrate that high dietary phytase levels or rich phytase by-products lead to a better P utilization.A reduction of requirements for inorganic P might save money since this P is still one of the most expensive feed ingredient in pig feeding.Comparative efficiency of four iron dextran injectable solutions

Two types of diets were compared in a « sow trial carried out between 1980 and 1982. The compound diets used as control contained maize, wheat, barley, bran, soyabean meal, fish meal, minerals and vitamins. The simplified diets contained only wheat, soyabean meal, minerals and vitamins. The simplified diets contained only wheat, soyabean meal, minerals and vitamins. Dietary supplies were almost equivalent :

In a first trial involving 336 crossbred piglets we compared four experimental diets based on wheat and soyabean meal, containing 0, 3, 6 and 9 p. 100 lupin and offered as pellets. In a second trial concerning 400 crossbred piglets we tested the effect of incorporation of 10 p. 100 lupin in diets offered either as flour or as pellets. In these trials weaned piglets weighed 7.9 and 7.5 kg and had the mean age of 27.7 and 28.3 days, respectively. They were fed ad libitum for two weeks, the first age diet already used before weaning, then for 28 days the experimental diets (25.7 and 21.9 kg). The results of the first trial showed that the decrease in the feed intake was only significantly marked at the highest level of incorporation and during the first two weeks of experiment. The feed efficiency of diets containing lupin was reduced by 6 p. 100 as compared to the diet without lupin. The results of the second trial showed that the improvement of the feed efficiency obtained by pelleting was similar with and without lupin. This improvement corresponded to that observed in former studies. Conversely, the presence of lupin led to a decrease in the feed intake of nearly 10 p. 100 and of the growth rate of 6 to 7 p. 100. This confirms our results of 1982 and allows to conclude that the use of lupin in second age diets is not advisable. Four diets based on wheat and soyabean meal including 0 p. 100, 3 p. 100, 6 p. 100, 9 p. 100 of «

Three daily feed restriction levels during gestation were compared : 7.15, 7.95 and 8.75 Meat D.E., i.e. 2.3 kg feed per day (diet I), 2.5 kg feed per day (diet 11) and 2.7 kg feed per day (diet III), the daily crude protein supply being similar.During lactation, all the sows were fed the same 15 p. 100 protein diet.Results recorded until 7 reproductive

In a second trial we compared a control diet (maize-soyabean meal) with a diet contai- ning 36 p. 100 peas stored for one year and with two diets containing 36 p. 100 peas of the last crop supplemented or not with tryptophan.Storage of peas did not change its feeding value since the nutritional characteristics remained constant.Supplementation with tryptophan increased the animal performance.During the growing period the feed efficiency of the supplemented diet was improved by 7 p. 100 as compared to the non- supplemented diet, but remained 11 p. 100 lower than that of the control diet.During the finishing period it was 5 p. 100 higher than that of the non supplemented diet and was equal to that of the control diet.

In the second experiment, 4 protein sequences were compared in order to determine whether the protein level during fattening was related to the post-weaning level (interaction ?).The four sequences were chosen so as to represent the 4 currently encountered possibilities (high-high, i.e. 22-18 p. 100 crude protein, high-low, 22-15 p. 100, low-high, 18-18 p. 100, low-low, 18-15 p. 100).Post-weaning protein level had no significant subsequent effect during fattening, either on growth or body composition.No statistically significant interaction between post-weaning and fattening protein levels was evidenced with the 4 sequencies of the second experiment.Thus, the protein sequence to be chosen should be that supplying optimum growth performance during each period, i.e. 22-18 p. 100.However the farmer (rearer/feeder) manufacturing the feeds himself might prefer to make one only feed.He should then choose sequence 18-18 giving similar results as sequence 22-18.Influence of management system (separation or mixing of sexes)on the performance of castrated male pigs and females F. GROSJEAN

a normal commercial rapeseed oil-meal : dry matter : 90 ; total crude protein : 39

Two trials (A and B) were made with 98 and 96 fattening pigs, respectively, kept in individual pens to compare several types of barley with variable contents of crude fibre components under the same conditions of protein and energy supply.A total of 7 batches of barley were compared in both trials : a naked barley, a spring barley, a two-row winter barley and two six-row winter barleys with a crude fibre content ranging from 1.9 to 6.6 p. 100 DM.Six batches of barley were compared in trial A (I.N.R.A.) and three batches of regular barley in trial B (LT.C.F.).In each experiment the diets based on barley were compared to a control diet (maize-soybean meal).Several batches of raw materials were common to both trials.In order to use the same energy restriction plan for all the animals we took into account the respective digestible energy values of the different kinds of barley measured in five of them during a previous digestibility study or estimated on the basis of their Weende crude fibre content according to the equation Y = 4 072 -110 X established during the same study (P EREZ et al., 1980).A single diet was offered in each treatment to females and castrated males and over the whole fattening period.All the diets exhibited the same lysine/energy ratio (2.5 g/Mcal ED).The same trend were observed in both trials, but performances were slightly higher in trial B. For the same theoretical digestible energy supply were obtained very similar growth performance and carcass qualities with the different diets.The energy conversion ratios (Mcal ED/kg weight gain) were equivalent whatever the nature of the barley, showing that the energy value of the different barleys were properly adjusted.

A total of 396 purebred Large White piglets were weaned at 27 days. During 13 days they received only a 1st age diet and thereafter the experimental diets for 28 days. Farm experimental diets were tested : wheat-soybean oil-meal and triticale-soybean oil-meal including 18 and 22 p. 100 crude protein. They were offered ad libitum in the form of dry meal. A very marked effect of the protein level, there were only few differences between the two cereals : the intake of triticale slightly exceeded that of wheat (+ 4.7 p. 100) and therefore led to a light improvement of the growth rates (+ 4.3 p. 100). On an average, the feed conversion ratios were identical for the two cereals (wheat : 1.85 triticale : 1.83).