نوع مقاله : مقاله پژوهشی
نویسندگان
1 استاد گروه علوم دامی دانشکده کشاورزی دانشگاه تبریز
2 استاد تغذیه دام دانشکده کشاورزی دانشگاه تبریز
3 استاد بازنشته گروه علوم دامی دانشکده کشاورزی دانشگاه تبریز
4 استادیار گروه علوم دامی دانشکده کشاورزی دانشگاه تبریز
چکیده
کلیدواژه‌ها
عنوان مقاله [English]
نویسندگان [English]
Introduction: In order to accurate feed formulation and improve production performance, it is necessary to determine the nutritive value of common feedstuffs used in animal nutrition. The main reason for use of data that reported by NRC (1994, 2001) is formulation of balanced ration. But data reported by NRC can over or underestimate the nutritive value of feedstuffs due to diversity in growth stage, type and variety, climate and weather condition, physical and chemical properties of soil and presences of anti-nutritional factors. So determining chemical compositions, mineral contents and gross energy content of common feedstuffs is useful to farmers to improve growth performance of animals. The aim of this study was to determine chemical compositions, mineral contents and gross energy content of common animal feed sources from East Azerbaijan province including barley grain (n=26), wheat grain (n=27) and wheat bran (n=15) with standard analytical methods. Material and methods: Barley grain, wheat grain and wheat bran are most common feedstuffs that used in animal and poultry nutrition. The feedstuff samples were collected with random stratified sampling method. Thus all studied cities of east Azerbaijan province classified in 30 zones and then the villages randomly selected. In order to proximate analyses of samples, feedstuffs were homogenized in the view of size and moisture by laboratory grinding. Dry matter, crude ash, ether extract and crude fiber content of samples were determined by AOAC method (1995) and crude protein was determined by micro kjeldahl. Cell wall or Neutral detergent fiber (NDF) and acid detergent fiber (ADF) contents of samples were determined by fibretec. Descriptive statistics parameters were calculated by Mean procedure of SAS software and means comparison were done by SAS software (2000). The paired and non-paired t test were used to compare means of recent research and the data of Guilan, Kordestan and Kermansh provinces and NRC data. Results and discussion: The results showed that mean dry matter (DM) content of barley grain, wheat grain and wheat bran were 925.5± 2.88, 909.32± 6.56 and 915.0 ± 9.31 g/kg, and mean crude protein (CP) concentrations were 137.3± 14.52, 129.6± 10.67 and 178.9 ± 11.86 g/kg of dry matter, respectively, that differed significantly with the NRC (1994) data (P<0.01). The range of crude protein of wheat grain was 114.9 to 158.5 g/kg and the range of crude ash 14.2 to 29.8. The nitrogen free extract (NFE) and non-fibrous carbohydrate (NFC) content of wheat grain were determined 806.1 and 667.4 g/kg. The differences of NFE and NFC was 138.7 g/kg that relate to Structural carbohydrate in NFE section. Ether extract (EE) content of wheat bran was 43.7 ± 3.48 g/kg that showed no significant difference with NRC (1994) data, but EE content of barley and wheat grain were 20.3± 1.08 and 21.1 ± 0.48 g/kg, respectively and showed a significant difference with NRC (1994) data (P<0.01). Crude protein and crude ash content of east Azerbaijan barley grain was 34 g/kg higher than Kermanshah barley grain and 7.8 g/kg lower than Kermanshah barley grain, respectively. The mean value of dry matter, crude protein, ether extract, ADF and NDF of east Azerbaijan barley grain had significant difference with NRC data (P<0.01). Because of the higher kernel to hull ratio in east Azerbaijan barley grain, crude protein content of barley grain was 13.3 g/kg higher than NRC data. Calcium content of barley grain, wheat grain and wheat bran were 1.4 ± 0.3, 3.3± 0.67 and 1.46 ± 0.35 g/kg of dry matter and differences were significant except in wheat bran (P<0.01). Differences in mineral contents of feedstuffs used in this research can be due to differences in genotype, chemical and physical properties of soil, climate and weather condition and stage of growth. The hemicellulose content of barley grain in comparison of wheat grain is 58.3 g/kg higher, but the ratio of hemicellulose to ADF in barley grain is lower than wheat grain that the main reason is higher level of cellulose and lignin in barley grain in comparison of wheat grain (Azizzi 1996, Fazaeli 1992 and McDowell 1992). Conclusion: Due to significant differences in chemical compositions and mineral contents of feedstuffs in East Azerbaijan province with the NRC (1994) data, it is suggested that for balanced diet formulation, local data of nutrient composition of feed sources were used.
کلیدواژه‌ها [English]
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