A note on naked oats as a substitute for wheat and barley for young pigs

In a 28-day experiment on 18 gilts and 18 barrows of Polish Landrace x Duroc (18-42 kg body weight) the nutritional value of naked oats cv. Akt was determined. Three diets (BW, BO, and O) containing 0, 35 and 73.8% of oats, which formed 0, 50 and 100% of the dietary cereals, were used. The BW control diet contained barley and wheat; the BO diet, only wheat; in the O diet, both wheat and barley were replaced by oats. The BW, BO and O diets were supplemented with 2.5,1.6, and 0% of soyabean oil, respectively. The daily feed intake (DFI), average daily gains (ADG), and feed conversion ratio (FC) tended to be greater in the BO group fed the diet containing 35% oats than in groups BW and O, respectively (907 vs 822 and 803 g and 1.85 vs 2.00 and 2.01 kg/kg; P>0.05). The results suggest that naked oats in an amount of 35% (50% of the diet cereals) can provide a good source of nutrients for young pigs.


INTRODUCTION
The naked oats grown in Poland contain 14.4-15.7%crude protein of high biological value, 1.8-2.3%crude fibre and 7.6-8.0%ether extract in dry matter (Kosieradzka and Fabijahska, 1995;Maciejewicz-Rys and Sokol, 1999).Earlier research showed that naked oat could be a successful alternative to maize in diets for pigs (Friend et al, 1988;Brand and van der Merwe, 1996).
Akt is the first Polish cultivar of naked oats (registered in 1997), and the area of its cultivation is constantly expanding.The aim of our experiment was to assess the nutritional value of this cultivar of naked oats as a replacement for wheat and barley in the feeding of young pigs.

MATERIAL AND METHODS
The experiment was performed on 36 young pigs, 18 gilts and 18 barrows about 18.0 kg body weight, aged 8 weeks, crosses of Polish Landrace gilts and Duroc boars.The pigs, 12 in each group, were kept in pairs (one gilt and one barrow) in flat-deck cages fitted with self-feeders and automatic water nipples.
The pigs were fed on diets with naked oat cv.Akt, supplying 0, 50 and 100% of the cereal in diets BW, BO and O, respectively (Table 1).The soyabean control diet BW was composed of wheat and barley; oat (35%) replaced wheat in diet BO; in diet O wheat and barley were substituted with oat (73.81%).The cereal was ground to medium particles on a roller mill.The diets were balanced according to the Nutrient Requirements of Pigs (1993) and contained 1.09% lysine and 0.32% methionine.The experiment lasted for 28 days, daily feed intake, average daily gains, and feed conversion ratio were determined.
One-way analysis of variance and the Duncan multiple range test were used to analyze the results of the experiment.

RESULTS
Naked oat contained 11.4% protein, 2.8% crude fibre, and 7.2% ether extract.There were no significant differences in the daily feed intake between the diets, although the pigs tended to eat less of the diet with the maximum amount of oat (1649, 1676 and 1609 g of the BW, BO and O diets, respectively) (Table 2).The average daily gains of pigs were high.The use of 35% naked oat as a substitute for wheat in the diet caused a non-significant increase in the growth rate of pigs (from 822 to 907 g daily).Oat used in an amount of 73.8% as the only cereal in diet O was as effective in terms of daily gains as a combination of barley and wheat supplemented with plant oil in the BW control diet.The pigs that received the barley-oat (BO) diet were slightly better at feed efficiency compared with the pigs fed on the barley and wheat or oat diets (1.85 vs 2.00 and 2.01 kg/kg; P>0.05).

DISCUSSION
The results show that naked oat in an amount of 35% (50% of the dietary cereal) was willingly consumed and provided a good source of nutrients for young pigs, with its nutritional value being superior when applied in a combination with barley to that of a barley and wheat diet.Growth performance of pigs did not improve when the contribution of oat was increased to 73.8% of the diet.However, the daily feed intake slightly decreased.In the experiments on younger pigs, the intake of diets containing 71.5 or 73.8% of naked oat decreased significantly (Brand and van der Merwe, 1996;Falkowski et al, 2000).It was found that in diets for pigs growing from 8.7 to 21 kg of body weight, the amount of naked oat should not exceed 47.9% (Brand and van der Merwe, 1996).
In our experiment, the use of naked oat saved high-protein feed, such as soyabean meal, and fat in the nutrition of young pigs.

CONCLUSIONS
Naked oat is a valuable cereal dietary component for young pigs and can replace up to 74% of wheat and/or barley and save feed protein and fat.

TABLE Diets
supplying per kg of diet: vit.A 13500 IU, vit..