تأثير احلال بذور الكتان الكاملة في النظام الغذائي منخفض الطاقة على أداء الدجاج اللاحم والتعبير الجيني المعرض للإجهاد الحراري

Effect of Replace Whole Flaxseed in Reduced Energy Diet on Broiler Chicken Performance and Gene Expression under Heat Stress

Summery
Adapting to rising global temperatures while maintaining production efficiency is an important emerging challenge for the poultry industry. Under hot temperatures especially in Iraq, birds reduce their feed intake, and this is the main factor explaining the degradation of bird performance. This experiment, was conducted to determine the effects of whole flaxseed in a reduced energy diet on broiler performance parameters, like body weight (BW), weight gain (WG), feed intake (FI), feed conversion ratio (FCR), lipids profile, meat quality, liver function, immunity, IGF_1 gene expression in liver tissue was quantitated using real-time quantitative PCR, intestinal morphology of broiler chickens and carcass characteristics, under heat stress conditions.
A total of 250 straight- run one-day old (Ross 308) broiler chicks were divided randomly to five groups each group (50/birds) with 2 replicates. Each replicate was subdivided to 25 birds/pen. The control negative treatment (T1) fed corn-soybean diet. The second treatment control positive (T2) fed corn-soybean diet under heat stress. The third treatment (T3) fed flaxseed-corn- soybean diet by using of flaxseed 7.5% g / kg in starter and grower 10% g/ kg under heat stress. The fourth treatment (T4) fed flaxseed _ reduced energy (200 KCL) diet by using of flaxseed 7.5% g / kg in starter and grower 10% g/ kg under heat stress. The fifth treatment (T5) fed reduced energy diet (200 KCL) under heat stress. The experiment period was five weeks. This study was carried out in a private brooding house, from 27 December 2023 to 31 January 2024. Blood samples were collected on end of experiment in day 35 of the experiment. A significant (P≤0.05) were observed among treatments in weekly BW, WG, FI and F.C.R. The highest significant increase (P≤0.05) in productive traits (BW, WG) in the (T3) and (T4) groups that feed with flaxseed. However, FI and FCR were decrease significantly (P≤0.05). Meat quality enhanced in the T3 and T4 groups by increase the omega-3 meat content [α-linolenic acid, eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA)] were increase significantly (P≤0.05) by using GC mass technique in the (T3) and (T4) compared with the control fed with corn-soybean diet. The lipid profile enhanced significantly (P≤0.05) in the (T3) and (T4) groups compared with the control. The cholesterol, triglyceride, LDL, vLDL were decrease significantly (P≤0.05) in the (T3) and (T4) compared with the control. However, HDL was increase significantly (P≤0.05). The aspartate aminotransferase (AST) and alanine aminotransferase (ALT) activity was decrease significantly (P≤0.05) in the (T3) and (T4) compared with the control. The immune status against ND and IBD virus enhanced significant (P≤0.05) in the (T3) and (T4) groups compared with the control. The groups (T3) and (T4) increased the IGF1 gene expression in the liver compared with the control treatment (P≤0.05). Significant increases (P≤0.05) were obtained in villus height, crypt depth, villus width and villus area in (T3) and (T4) compared to the control group. In conclusion, adding whole flaxseeds and flaxseed _ reduced energy diet at rate 7.5 percentage of whole flaxseed in starter and grower 10 in broiler chicken diet lead to improve growth performance, healthy meat enriched with omega-3 (ALA, EPA, DHA) by using GC mass technique. Additionally, reducing using oil and corn in diet.
In summary, using whole flaxseed the source of omega-3 FAs may enhance the performance of broiler chickens and elevate the omega-3 level in their meat. The intake of whole flaxseed enhanced the expression of the liver IGF-1 gene, which is crucial for the differentiation and metabolism of myogenic cell lines across different species. Insulin-like growth factors (IGFs) regulate somatic and muscular development in broiler chickens. The inclusion of whole flaxseed in a reduced-calorie diet led to elevated expression of the IFG-1 gene, improved performance, and enhanced intestinal structure and mucin activity. Implementing a reduced calorie diet will lower feed expenses and is ideal under heat stress conditions. Our results correspond with the guidelines provided by Aviagen (Nutrition Specification, 2022).