Effect of dietary fatty acid pattern on growth, body fat composition and antioxidant parameters in broilers

The effects of dietary fat supplementation on performance, fatty acid (FA) composition of tissues and antioxidant defence system of broilers were studied. Male broilers were placed in 20 floor pens (60 broilers per pen). The broilers were fed by diets with added different energy sources: lard (L); sunflower oil (SFO); soybean oil (SBO); and linseed oil (LSO). The treatments did not modify significantly growth performance and feed intake of the broilers. There was no effect of dietary FA pattern on reduced glutathione level and glutathione peroxidase activity of plasma, erythrocyte and liver samples. However, higher PUFA content of the diet resulted in a significant increase in malondialdehyde level of erythrocytes and liver. The broilers fed LSO diet more effectively maintained their antioxidant status with enhanced plasma radical scavenger capacity. FA composition in tissues reflected the FA pattern of the diets, although proportion of FAs with four or more double bonds was metabolic specific. LSO diet increased the level of C18:3, C20:5 and C22:6 in tissue lipids in relation to L, SFO and SBO diets. Significantly increased plasma radical scavenging capacity in concert with the enhanced C20:5 and C22:6 proportion in liver and muscle during LSO feeding indicate metabolic changes to counteract the oxidative injury. This may be related to the compounds produced after different biochemical pathways of n-6 and n-3 FAs.

Comparison of fullfat soybean, sunflower seed and protected fat as fat supplements for their effect on the performance of growing-finishing bulls and carcass fatty acid composition

One hundred and twelve Holstein bulls (179-203 kg) were allotted to four dietary treatment groups (I: control; II: fullfat soybean diet; III: sunflower seed diet, and IV: protected fat diet) and used in a 120-day comparative feedlot trial to evaluate the effect of toasted fullfat soybean, whole sunflower seed and protected fat (calcium soap) on their weight gain, feed conversion and carcass fatty acid composition. The diets consisted of 45-46% concentrate and 55-54% corn silage. Digestibility, nutritive value as well as degradability were also determined. The apparent digestibility of dry matter, organic matter, N-free extract and crude protein as well as nutritive value were almost similar for the four diets. However, crude fibre, acid detergent fibre (ADF) and neutral detergent fibre (NDF) digestibilities decreased with increasing fat level but the differences were not significant. The inclusion of fullfat soybean or whole sunflower seed significantly (P < 0.05) increased the digestion of fat. Ruminal degradability of protein and dry matter were significantly (P < 0.01) lower for toasted fullfat soybean mixture compared to whole sunflower mixture. The inclusion of toasted fullfat soybean, whole sunflower seed and calcium soap in the diets was not effective in improving the bulls' weight gain or feed conversion in this trial. As both toasted fullfat soybean and whole sunflower seed increased the proportions of C18:1, C18:2 and C18:3 in adipose fat tissue and decreased the proportion of C16:0, they consequently significantly (P < 0.01) increased the ratio of unsaturated fatty acids. Whole sunflower seed was more effective than fullfat soybean. However, inclusion of the calcium soap had no effect on the fatty acid profiles in the present study.

Protein degradability, amino acid composition, trypsin inhibitor and urease activity of raw and heat-treated fullfat soybean

The effects of different heat treatments were studied on chemical composition, protein degradability, amino acid composition, trypsin inhibition and urease activity. Three lactating Holstein cows fitted with rumen cannulae were used. Fullfat soybean was prepared employing different forms of heat treatment: dry-extrusion at 150 degrees C for 25 s (treatment I); wet-extrusion at 95 degrees C for 30 min (treatment II); toasted soybean at 105 degrees C for 30 min (treatment III) extracted soybean meal (treatment IV); and untreated soybean (treatment V). The incubation times were 0, 2, 4, 8, 16, 24 and 48 h. Samples of raw and heat-treated soybean before incubation and the undegraded fraction after 4 and 16 h of incubation were analyzed for amino acids. The results showed that heat treatments did not modify chemical composition, but significantly reduced the content of trypsin inhibition and urease activity, as well as decreased protein degradability. The dry extrusion technique was comparatively the most effective. Amino acid content was not significantly influenced by different techniques, but the quantity of amino acids escaping degradation in the rumen increased.

[Joint research on the precise determination of the energy and protein requirements of fattening pigs. 6. The effect of various energy and protein levels on the performance and feed expenditure of fattening pigs]

Scientific feeding experiments with hybrid pigs of the type Hungahib in the fattening period between 30 and 100 kg were carried out with one repetition as part of a joint international experiment. Feed, nutrient and energy expenditure were tested on 3 levels of energy supply (100 : 85 : 70%) and 3 levels of protein supply (18 : 16 : 14%) in the fattening period between 30 and 60 kg and 16 : 14 : 12% in the fattening period between 60 and 100 kg). In addition to this, parallel metabolism experiments were carried out to determine the digestibility and the N-balance of the feed mixtures used. The cost of feeding was also taken into consideration. The best results with regard to the fattening performance and the minimising of feed cost were achieved with the following ration type: (Table: see text). The fattening performance with this ration type was 712 g average daily live weight gain in the range between 30 and 60 kg live weight in the 1st fattening experiment and 601 g in the 2nd fattening experiment. A classification of the expenditure values has been attempted in the 10th contribution to this series of publications dealing with the total results of the joint international experiment.

[Joint research on the precise determination of the energy and protein requirements of fattening pigs. 10. Comparative evaluation of the research for the precise determination of the energy and protein requirements of fattening pigs]

Institutes from 5 CMEA countries took part in complementary joint investigations in order to ascertain the variance in energy and protein requirement and parameters of nutrient and energy metabolism with such fattening pigs as test animals as characterise the prospective breeding development in each of the countries and in order to establish the bases for the critical revision of the norms of energy and protein requirement for fattening pigs and, if necessary, their more precise determination. The most important conclusion drawn from the comparative assessment of the results presented in 9 articles is that due to wide variations in the energy and protein requirement values between the individual investigators as well as within the institutions themselves, norms of energy and protein requirement for fattening can only be adopted between countries when adequate investigations under the specific conditions of the individual countries justify this.