An experiment was executed to test the hypothesis that supplementation of dietary threonine ( d-Thr ), above NRC recommendation to diets containing poorly digestible protein source ( PS ) may compensate its detrimental effects on overall performance of broilers. In total, nine hundred 1-day-old mixed sex broilers (Ross-308) were randomly distributed over 6 (2 × 3) experimental diets comprising 5 replicates of 30 broilers each for 35 d. The experimental diets contain either soybean meal ( SBM ) or canola meal ( CM ) with 3 levels (100, 110, and 120% of NRC recommendation) of d-Thr. During the course of the trial (0 to 35 D), interactions ( P < 0.05) between PS and d-Thr were observed for feed intake ( FI ), body weight gain ( BWG ), feed conversion ratio ( FCR ), carcass, and gut health parameters. The broilers fed recommended level (100%) of d-Thr had 7 and 5% poorer FCR compared with those fed diets with 110 and 120% d-Thr, respectively. For villus height ( VH ), an interaction ( P = 0.007) was found between PS and d-Thr level. Broilers consuming SBM diets had 22% longer villi, 10% deeper crypts, and 30% greater VH to crypt depth ratio ( VCR ) compared to those fed CM. The broilers fed 110% d-Thr diets had 9% lower crypt depth ( CD ) and 15% greater VCR compared with those fed diets containing NRC recommended levels. CM resulted in 9% lower protein digestibility with lower ( P < 0.05) of some AA, whereas it was improved by 7% in broilers fed 120% d-Thr supplemented diets. The bursa and spleen weights were positively affected ( P < 0.001) by PS. Threonine supplementation (10%) resulted in 25% greater thymus, 18% heavier bursa, and 30% greater infectious bursal disease titer. In conclusion, supplementation of d-Thr, above NRC recommendation, resulted in a better growth performance and carcass traits, improved ileal digestibility of protein and amino acids, better gut health, and immunity in broilers.

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The gene sequence encoding the mannose-binding homodimeric protein Allium sativum leaf agglutinin (ASAL) was introduced into maize inbred lines to achieve resistance against sap-sucking corn leaf aphids in transgenic lines. Maize transformants were generated after the co-cultivation of immature maize embryos with the Agrobacterium strain LB4404 harbouring a recombinant Ti-binary ASAL construct driven by the polyubiquitin promoter. The preliminary screening of maize transformants was performed via GUS histochemical analysis, and PCR and Southern blotting confirmed the insertion of the transgene and its stable integration in five transgenic maize lines. Transcript abundance was quantified by a quantitative real-time PCR assay, which revealed variable expression of the ASAL transgene among five transgenic maize lines. The highest mRNA expression of the ASAL gene was found in the A23 transgenic maize line, while the lowest expression was found in the AU1 transgenic maize line. In planta bioassays in the T 1 progeny of the transgenic maize lines revealed high resistance against corn leaf aphids compared to the control non-transgenic line. The mortality of the infesting aphids (Rhopalosiphum maidi) was found to vary from 40 to 71% compared to that of the non-transgenic control maize line. Keywords Corn leaf aphid . Mannose binding lectin . Transgenic maize . In planta bioassay Abbreviations ASAL Allium sativum leaf agglutinin GUS β-glucuronidase PCR Polymerase chain reaction TMVΩ TMVΩ translational enhancer T 1 first generation progeny plants Bt Bacillus thuringenesis NOS nopaline synthase gene * Bushra Tabassum

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