Comparative Effects of Four Imported Premix Sources on Growth Performance, Carcass Traits, Blood Biochemistry, Immune Response, and Cecal Microbiota Counts of Ross 308 Broiler Chickens
Mohammed Kadhim Mahdi Al-Husseini *
Department of Animal Production, College of Agriculture, University of Karbala, Karbala, Iraq.
Abbas Salem Al-Mijawi
Department of Animal Production, College of Agriculture, University of Karbala, Karbala, Iraq.
*Author to whom correspondence should be addressed.
Abstract
Imported premixes differ widely in their declared vitamin, mineral, amino acid and additive contents, and this variability may translate into measurable differences in broiler performance and physiology. A 35-day feeding trial was conducted to compare four commercially imported premix sources—an Iranian product (Premix 1, T1, used as the comparison treatment), a Dutch product (Premix 2, T2), a Jordanian product (Premix 3, T3) and a Canadian product (Premix 4, T4)—each included at 2.5% in corn–soybean meal starter and grower diets fed to Ross 308 broilers. A total of 120 one-day-old chicks of uniform weight (40.00 ± 2.00 g) were allocated to four treatments in a completely randomised design, with three replicate cages of ten birds each. Live body weight, weight gain, feed intake, feed conversion ratio (FCR) and production index were recorded weekly; carcass traits, serum lipid and protein profiles, haematological indices, antibody titres against Newcastle disease virus (NDV) and infectious bursal disease virus (IBDV), and caecal Lactobacillus and Escherichia coli populations were assessed at 35 days of age. Premix source significantly (P ≤ 0.05) affected nearly all production traits. Birds fed the Dutch premix (T2) recorded the highest final body weight, cumulative weight gain and feed intake, together with the most favourable cumulative FCR, whereas birds fed the Canadian premix (T4) achieved the highest production index. The Jordanian premix (T3) was associated with the highest serum total protein, globulin, red blood cell count, haemoglobin and packed cell volume, whereas T4 produced the strongest antibody response against NDV. High-density lipoprotein cholesterol was significantly higher in T3 and T4 than in T1, while total cholesterol, triglycerides, low-density lipoprotein and very-low-density lipoprotein were unaffected by treatment. Caecal Lactobacillus and E. coli counts did not differ significantly among treatments. These findings indicate that, despite broadly similar declared nutrient specifications, the four imported premixes differed in their biological effects on growth, carcass composition and physiological status in broilers, with the Dutch and Canadian products showing advantages for different response variables relative to the Iranian comparison premix.
Keywords: Ross 308, imported premix, growth performance, carcass traits, blood biochemistry