ABSTRACT The aim of present study was to investigate the effect of phytase supplementation on growth performance, mineral digestibility, and tibia calcium and phosphorous in broilers fed low phosphorus diets. Three hundred broiler chicks were allotted to six different treatments with five replicates each (10 chicks/replicate). T1: Control, 0.5% available phosphorus (Av.P); T2: 0.35P, 0.35% Av.P; T3: 0.20P, 0.20% Av.P; T4: 0.35P-1Phy, diet 0.35P + 1000FTU/kg phytase; T5: 0.20P-2Phy, diet 0.20P + 2000 ftu/kg phytase; T6: 0.20P-3Phy, diet 0.20P + 3000 ftu/kg phytase. Feed intake and weight gain were higher (p=0.001) in broilers fed phytase supplemented diets. Feed conversion ratio was better (p<0.01) in the 0.35P-1Phy than in the others. Calcium and P digestibility was higher (p<0.05) in the 0.35P-1Phy than the 0.35P, 0.20P and 0.20P-2Phy, groups. The highest (p<0.05) tibia ash was observed in the 0.35P and 0.35P-1Phy groups rather than the 0.20P at 21st day, while at 33rd day it was higher (p<0.05) in the control than in 0.20P. At 21st day, tibia Ca content was higher (p<0.05) in the 0.35P-1Phy group as compared to 0.20P and 0.35P, while at 33rd day, tibia Ca content in the control and 0.20P-2Phy groups was higher (p<0.05) than that of 0.20P and 0.35P. Furthermore, tibia P content was higher (p<0.05) in all phytase supplemented groups. It could be concluded that dietary available phosphorus at 0.35% with phytase addition at 1000 FTU/kg reduces the cost per unit weight gain by 9.17%, with positive effects on growth performance.

ABSTRACT This experiment was planned to evaluate the effects of phytase supplementation with or without organic acid (OA) on performance, protein, calcium (Ca), phosphorus (P) and sodium (Na) digestibility and carcass parameters in broiler chickens fed low Ca and low P diets in comparison to a high Ca and high P diet with standard specifications. For this purpose, two iso-nitrogenous and iso-caloric diets were prepared in such a way that one diet had high Ca (9.80) and high P (4.50) and second diet had low Ca (8.50) and low P (2.40), respectively. Low Ca and low P diet was further supplemented with enzyme phytase @ 500 FTU/kg, and phytase @ 500 FTU/kg + organic acid (1 kg/ton). Rations were offered to seven replicates of ten birds each, from day 1 to 21. Results revealed that the experimental treatments had no effect on feed intake and growth performance of birds (p>0.05). Carcass parameter results showed highest thigh meat yield % and liver weight % in the birds fed diet with low Ca & P and supplemented with enzymes phytase (p<0.05). Fecal P and Na digestiblities were high (p<0.05) in experimental broilers fed low Ca low P with enzyme phytase supplementation as compared to the diet without phytase supplementation. It is concluded that phytase and OA supplementation in the starter diet with low Ca and low P level did not influence intake, growth and feed conversion of the broilers. However, thigh meat yield percent and mineral digestiblities (P and Na) increased in the broilers that received the diet with low Ca and low P level and supplemented with enzyme phytase.

ABSTRACT The aim of this study was to investigate the effect of bile acids and lipase supplementation in low energy (LE) diets on growth, fat digestibility, serum lipid profile and meat quality of broilers. Seven hundred one-day-old broiler chicks were divided into 5 dietary treatments with five replicates of 28 birds each. The five treatments were: i) high energy diet (HE; metabolizable energy (ME) = 3,000 and 3,170 kcal/kg for starter and finisher diet), ii) low energy diet (LE; ME = 2,900 and 3,070 kcal/kg for starter and finisher diet), iii) LE diet supplemented with 300 g/ton bile acids (LEB), iv) LE diet supplemented with 180 g/ton lipase (LEL), v) LE diet supplemented both with bile acids (300 g/ton) and lipase (180 g/ton). The experiment lasted 35 days having starter phase from days 1-21 and finisher phase from days 22-35. Dietary inclusion of both bile acids and lipase in LE diet had no effect (p>0.05) on body weight (BW) gain and feed intake. High energy diet reduced feed intake and BW gain during starter and overall period; however, during finisher phase BW gain was similar in all dietary treatments. Dietary energy level had no effect on feed conversion ratio. Fat digestibility (p>0.05) both in the starter and finisher phase was not affected by the dietary treatments. Concentration of total cholesterol, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol and triglycerides were not affected by the dietary treatments (p>0.05). Meat quality of breast and thigh muscle was unaffected due to the dietary treatments (p>0.05). It is concluded that the supplementation of bile acids alone or in combination with lipase in low-energy diets did not improve broiler performance, fat digestibility, serum lipid profile and meat quality.