The greatest feed intake (FI) was observed in Peshawari variety followed by Mianwali and Lakha Table (2). With respect to dietary treatments, reduced (P<0.05) FI was observed with high dense diets. In interaction of varieties and different dense diets, minimum FI (569.8±4.4) was observed in Lakha variety fed high dense diet, whereas higher FI (640.7±3.6, 640.0±3.4 and 639.0±3.9) was found in low Lys diets fed birds of all varieties. Greater FI in Peshawari variety may be attributed to the genetic variation among varieties. It has already been reported Peshawari variety has higher FI as compare to Lakha and Mianwali
(Jatoi et al., 2014). High dense diets in birds reduced FI because dense diet full fill the nutritional requirement of the birds and satiated them
(Corzo et al., 2005). In current study, decrease in FI might be attributed to satiated effect of dense diet on intake of birds. Similar finding of lower FI due to high dense diets has also been reported in broilers
(Corzo et al., 2005; Sklan and Plavnik, 2002). Other possible reason to decrease the feed intake might be due branched chain AA which results in a decrease of FI (
Trottier and Easter, 1995).
Body weight gain (230.4±7.1, 230.1±4.6 and 240.6±7.3) was similar (P>0.05) in all varieties. Dietary treatments resulted in a higher (P<0.05) BWG in birds fed high and medium dense diets (244.3±4.2 and 241.8±8.2) is higher in comparison to low Lys diets (214.9±3.6). Interaction between varieties and AA densities displayed improved (P<0.05) BWG in Mianwali with high dense (252.0±17.4), followed by Mianwali with medium dense (251.4±7.15), Lakha with medium (244.7±8.03) and high dense (239.2±15.5) diets. Higher BWG (240.6±7.3) in MW Aseel reared under dense diets could be due to increased protein synthesis which involves the role of dietary amino acids
(Dozier et al., 2008). Dense diet improve the nutritional status of the feed and recent study has reported improved body weight gain and FCR in males Aseel in nutritionally improved diets
(Zia et al., 2017). Interactions of amino acids, play a vital role in the protein synthesis like Lys, methionine and arginine interaction involves in the synthesis of creatine that improves the muscle growth
(Chamruspollert et al., 2002). Similar with our findings
Ngambi et al., 2017 also reported that diet dense with threonine improve performance of slow-growing Venda chickens
(Ngambi et al., 2017).
Varieties showed similar (P>0.05) FCR. The dietary treatment improved (P<0.05) FCR, where linearly improved (P<0.05) FCR was observed by increasing diet densities from lower to higher dense diets. Dietary treatments demonstrated improved (P<0.05) FCR in all varieties fed high and medium dense diet and Mianwali variety (2.35±0.06 and 2.37±0.17) in particular compared to diet containing control level of AA. Improved FCR of Mianwali Aseel might be attributed to the lower FI and higher weight gain, since birds perform better with increasing AA densities
(Zhai et al., 2013, 2014). Similar findings have also been reported in broiler fed AA supplemented diets (
Quentin et al., 2003). Furthermore,
Li et al., 2013 reported increasing Lys level enhance FCR in local Chinese chicken. Phase wise WG and FCR also showed significant differences (P<0.05). Where for 0-14 WG for all dietary treatments were 87.5±3.5, 87.5±2.3, 64.9±4.2 and FCR were 2.04±0.04, 2.14±0.03, 2.84±0.06 for L1, L2 and L3 respectively. For 15-28 WG were 154.3±6.4, 156.8±4.9, 150±4.8 and FCR 2.67±0.09, 2.64±0.04, 3.08±0.07 for L1, L2 and L3 Lys regimens (Fig 1).
Protein efficiency ratio (PER) shows similar results like FCR, whereas varieties showed similar (P<0.05) PER. The dietary treatment improved (P<0.05) PER, where linearly improved (P>0.05) PER was observed by increasing diet densities from low to high dense diets. Dietary treatments demonstrated improved (P<0.05) PER in all variety fed on high and medium dense diets. Better (P>0.05) LER reflected in birds fed high dense diets.
Dietary treatments had no significant effect (P>0.05) on immune status. Overall immune responses were much protective against ND, IB and IBD diseases (Table 3). Higher growth rate in MW chicken did not compromised immune response which might be attributed to the result of amino acids relation with immune system in terms of lymphocyte proliferation and activation
(Tsiagbe et al., 1987), improve cellular redox status, cytotoxic cell-mediated immunity, serum blocking activity, and haemagglutinin titre
(Konashi et al., 2000). Better immune response against different diseasesdue to Lys and methionine supplementation especially against ND has already been highlighted (
Bouyeh 2012). Recently a study with Aseel concluded that nutritional manipulation can increase glutathione peroxidase and ultimate superior performance with improve blood biochemical profile
(Zia et al., 2016).
Dietary treatments had a significant effect (P<0.05) on all body conformation traits except keel length and shank circumference. Overall medium dense diets showed better body conformation traits (5%) followed by high dense (2.5%) then control diets (Table 4). Length of feathers decreased in response to decreased dietary protein intake (
Wylie and Hocking, 1999). Effect on body confirmation traits might be the effect of differential nutrient partitioning due to increase nutrient densities, which resulted in better body frame development
(Sikur et al., 2004).