Mahdie Nikbakhetzadeh; Heydar Zarghi; َAbolghasem Golian
Volume 22, Issue 1 , March 2020, , Pages 105-116
Abstract
The aim of this study was to investigate the effect of finisher diet nutrient density and slaughter age on energy and protein retention efficiency of broiler chickens. Three hundred 23-day-old Cobb-500 male broiler chickens were assigned in a 5×2 factorial arrangement of completely randomize ...
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The aim of this study was to investigate the effect of finisher diet nutrient density and slaughter age on energy and protein retention efficiency of broiler chickens. Three hundred 23-day-old Cobb-500 male broiler chickens were assigned in a 5×2 factorial arrangement of completely randomize design with 10 treatments, 6 replicates and 5 birds each. The experimental treatments included five nutrient levels of finisher diets (102.5, 100, 97.5, 95, and 92.5% levels of nutrient composition recommendations stated by the Cobb-500 Commercial Management Guide) and two slaughtered ages (38 and 46 days of age). As increased dietary nutrient density significantly and l inearlyincreased weight gain, feed efficiency, energy and protein retention efficiency and decreased maintenance energy requirements per unit of weight gain (P<0.05). By increasing slaughter age from d38 to d46, above indices significantly deteriorated (P<0.05). The highest residual feed intake belonged to birds fed the finisher diet with 97.5% of strain recommendation nutrients level. Dietary nutrient density level for optimal weight gain, feed efficiency, and energy and protein retention efficiency by linear broken line models were estimated 101.7, 98.7, 97.7 and 99.5% of strain recommendation, respectively. Whereas, these values were 2.3-5.5 percent less than those estimated by the quadratic broken-line model. As a conclusion, residual feed intake methodology can be a viable alternative to measure dietary energy efficiency. Formulation broiler finisher diet with nutrients concentration lowers than 97.5% of strain recommendation is not suitable.
Heydar Zarghi; َAbolghasem Golian; Ahmad Hassanabadi; Farhad Khaligh
Volume 20, Issue 4 , February 2019, , Pages 577-587
Abstract
The present study was conducted to determine the zinc (Zn) requirement in broiler chickens fed wheat-soy based diet. Two hundred fifty day-old broiler chicks (Ross 308), were randomly assigned to a completely randomised design (CRD) experiment with 5 treatments, and 5 replicates of 10b each. The experimental ...
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The present study was conducted to determine the zinc (Zn) requirement in broiler chickens fed wheat-soy based diet. Two hundred fifty day-old broiler chicks (Ross 308), were randomly assigned to a completely randomised design (CRD) experiment with 5 treatments, and 5 replicates of 10b each. The experimental treatments included five dietary Zn levels (30, 70, 110, 150, and 190 mg/kg) provided by the addition of reagent grade “ZnSO4.7H2O”. The experiment lasted from 1-42d of age. Increasing dietary Zn level to 70mg/kg significantly increased 10, 24 and 42d live body weight (LBW), feed intake (FI) and weight gain (WG) during 1-10, 25-42 and 1-42d of age and feed efficiency (FE) during 1-10d of age. The linear broken-line (LBL), quadratic-broken line (QBL) and the quadratic polynomial (QP) regression models were used to estimate the Zn requirement. The Zn requirement for optimal final LBW and FI, WG, and FE during 1-42d of ages by LBL model were 68.77, 83.12, 66.99 and 62.75 mg/kg of diet, and by QBL model 70.00, 79.93, 69.63 and 58.01 mg/kg of diet, respectively. In conclusion, Zn requirement varied between 58-83 mg/kg, which is higher than NRC and is lower than strain recommendation in the broiler chickens fed wheat-based diet.
Seyd Ahmad Sahaf; Heydar Zarghi; َAbolghasem Golian
Volume 20, Issue 1 , May 2018, , Pages 131-143
Abstract
This experiment was conducted to evaluate the effect of raw and/or autoclaved grass pea (Lathyrus sativus L.) seed in diet on performance and egg quality of laying hens. Three hundred and thirty-six Leghorn laying hens strain W-36 at 87 week of age were assigned in a completely randomize designed (CRD) ...
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This experiment was conducted to evaluate the effect of raw and/or autoclaved grass pea (Lathyrus sativus L.) seed in diet on performance and egg quality of laying hens. Three hundred and thirty-six Leghorn laying hens strain W-36 at 87 week of age were assigned in a completely randomize designed (CRD) experiment with 7 treatments, 6 replicates and 8 birds each. The experimental treatments included; corn-soybean meal (control) diet, and 8, 16 and 24% dietary levels of either raw or autoclaved grass pea grain. The experiment lasted for 12 weeks. Feed consumption, egg production percentage and egg mass of hens fed diets containing different levels of raw and autoclaved grass pea grain were significantly lower and their feed conversion ratio was significantly higher than those fed control diet. The autoclaving of grass pea grain resulted in significant increase in performance and eggshell quality indices in birds fed diets containing 16 and 24% grass pea grain. Although autoclaving of grass pea grain reduced the negative effect of its replacement in the diet on performance and egg characteristics, however, it could not compensate the reduction in performance. According to the results of this experiment, the utilization of raw grass pea grain is not recommended in laying hen diets. Also, autoclaving process alone can’t destroy the anti-nutritional factors present in grass pea grain.
Fereshteh Jamile; Abolghasem Golian; Hasan Kermanshahi; Ahmad Hasanabadi; Heydar Zarghi
Volume 18, Issue 2 , June 2016, , Pages 287-297
Abstract
The purpose of this study was to determine the effect of two levels of four commercial multi-enzymes on the apparent metabolizable energy corrected for nitrogen (AMEn) and digestibility of crude fat, crude protein, dry matter, and organic matter in broiler chickens through total excreta collection method. ...
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The purpose of this study was to determine the effect of two levels of four commercial multi-enzymes on the apparent metabolizable energy corrected for nitrogen (AMEn) and digestibility of crude fat, crude protein, dry matter, and organic matter in broiler chickens through total excreta collection method. One hundred thirty male broiler chicks were assigned to 45 metabolic cages involving 9 treatments, and 5 replicates of 3 chicks each. A control diet was made so that wheat was the sole source of energy supply. Eight experimental diets were prepared with the addition of one or two recommended levels of each commercial multi-enzymes to the control diet. The chickens had free access to feed and water ad-libitum from 17 to 23 days of age. Gross energy, crude protein, crude fat, organic matter, and dry matter were measured in feed and excreta samples. Addition of one or two recommended levels of different commercial enzymes to diet significantly increased (P< 0.05) AMEn and apparent digestibility of fat, protein, dry matter, and organic matter in wheat. However, there was not a significant difference between the levels and the four types of added commercial enzymes on AMEn and nutrient digestibility values. The results revealed that metabolisable energy value of Falat wheat improved by 70 to 120 kcal per kg, regardless of the type and activity of the four commercial enzymes used in this study.