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Physiological studies on turkeys
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Abstract: The responses of growing turkey to different dietary levels of betaine were investigated during the period from 12 to 20 weeks of age. Therefore, a basal diet was formulated to contain 21.37% CP and 3057 Kcal ME/kg. This diet was supplemented with betaine at levels of 0, 0.75, 1.5 and 2.25 g/kg diet. Thus, there were four treatment groups; each was fed to 50 birds (males and females) divided equally into two sub-groups of 25 males and 25 females in each.
Live body weight, body weight gain, feed intake and feed conversion ratio were recorded in each group. Also, mortality rate was recorded at 12, 14, 16, 18 and 20 wks of age. Keel length, shank length, tibia length, thigh length and breast width for all experimental birds were measured at 12, 14, 16, 18 and 20 wks of age.
Blood samples were collected at the end of the growing period for the determination of some blood parameters. Histological sections from breast and thigh muscles were examined. Also, liver histology was illustrated.
The obtained results could be summarized as the following:
1. Growth performance parameters:
1. Birds in T3 (1.5 g betaine/kg diet) showed the highest (P<0.05) final LBW and total weight gain (TWG) as compared to control birds or those in other treatment groups.
2. There was nearly similarity in total feed intake/bird among the
experimental groups, reflecting the best feed conversion ratio of birds in T3 (1.5g betaine) as compared to birds in other groups.
3.Males showed higher (P<0.05) final weight, feed intake and total gain,
and the better feed conversion ratio than females.
4.The interaction effect between betaine treatment and sex on all growth performance parameters was not significant.
2.Body measurements:
1.The superiority in final LBW of birds in T3 was associated with
improvement (P<0.05) in body measurements including breast width and length of keel, back, shank, tibia and thigh as compared to other groups.
2.Birds in other treatment groups (T2 and T4) did not differ significantly in growth performance parameters from that of the control birds.
3.Males showed higher (P<0.05) body measurements than females.
4.The interaction effect between betaine treatment x sex on all body measurements was not significant.
3.Blood parameters:
3.1.Protein metabolites:
1.Concentration of total proteins (TP) and albumin (AL) in blood plasma of turkey birds in T3 and T4 increased (P<0.05) as compared to the control ones. Globulin (GL) concentration increased (P<0.05) in T4. Concentration of creatinine and uric acid in blood plasma of birds was not affected by betaine treatment.
2.Males showed significantly (P<0.05) higher concentrations of total
protein and albumin, albumin: globulin ratio and creatinine than females.
Concentration of globulin and uric acid was not affected by sex of birds.
3. The interaction effect between treatment x sex on all protein metabolites was not significant.
3.2. Lipid metabolites:
1. Concentration of total lipids, triglycerides, LDL and HDL in blood plasma of birds was not affected significantly by feeding birds on diet
containing different levels of betaine as compared to the control diet. However, only concentration of total cholesterol in blood plasma of birds showed marked reduction by feeding betaine diets, but the differences were significant (P<0.05)with betaine supplementation at a level of 0.75 g/kg.
2. Females showed significantly (P<0.05) higher concentration of total
lipids, triglycerides and HDL than males. Concentration of total cholesterol and LDL was not affected by sex of birds.
3.The effect of interaction between betaine treatment and sex on concentration of lipid metabolites in this study was not significant.
3.3.Enzyme activity:
1.Feeding birds on diet containing 2.25 g/kg (T4) significantly (P<0.05) increased ALP activity as compared to the control, while did not differ significantly from birds in other betaine treatment groups. Activity of ALT, AST and ALT/AST ratio was not affected by betaine treatment, although activity of AST and ALT/AST ratio tended to increase and ALT activity tended to decrease in all betaine treatment groups as compared to the control group.
2.Males showed significantly (P<0.05) higher activity of AL T and lower ALP activity than females. Activity of AST and AST/ALT ratio was not affected by sex of birds.
3.The effect of interaction between treatment and sex on all enzymatic activity in this study was not significant.
4.Carcass quality:
1.Birds in T3 showed the highest (P<0.05) weights of carcass, giblets, gizzard, liver and heart as well as the highest percentage of giblets to preslaughter weight.
2.Birds in T2 showed the highest (P<0.05) weights of liver or heart relative to pre-slaughter weight. Weight of carcass and gizzard percentages as well as dressing percentage were not affected by dietary betaine treatment.
3.Birds fed diet contained 1.5 g betaine/kg (T3) showed significantly
(PSO.05) the longest major, heaviest and longest minor muscles as well as the longest thigh, while, feeding betaine at a level of 2.25 g/kg significantly (P<0.05) decreased thigh weight as compared to other treatments and controls. However, weight of major muscles and weight and percentage of breast meat were not affected significantly by betaine treatment.
4.Males showed higher (P<0.05) weights of carcass, giblets, gizzard, liver and heart. Females showed the higher (P<0.05) weights of giblets, gizzard and liver percentages.
5. Males showed significantly (P<0.05) higher weights and percentages of major, minor, thigh and breast than females.
6.The interaction effect between betaine treatment x sex on all carcass
traits was not significant.
5.Economic efficiency:
Viability rate was 100% in betaine treated groups and even in the control one. Although birds in T3 showed similar feed intake and higher feeding cost, they had the highest total gain and consequently the highest price of total gain. Therefore, from the economic point of view, birds in T3 showed the highest economic feed efficiency (EFE %) as compared to other treatment groups, reflecting the highest relative EFE to the control birds. Males showed higher EFE than females.
6. Histological study:
Histological examination of breast, thigh muscle and liver sections from different treatment groups showed that the intermediate level of betaine (1.5g/kg) was the best for enhancing muscles growth (breast and thigh muscles) and liver histogeneses in turkeys.
In conclusion, growth performance parameters, body measurements, carcass traits and economic efficiency of grower turkey were improved without adversely effects on protein metabolism, lipid metabolism, enzyme activity and the histological structure of the muscles and liver by supplementing diet with betaine at level of 1.5 g/kg as compared to lower (0.75 g/kg) or higher (2.25 g/kg) betaine levels.
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| Publication year |
2012
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| Pages |
PP. 130
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| Availability location |
مكتبة معهد بحوث الانتاج الحيوانى-شارع نادى الصيد- الدقى- الجيزة
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| Availability number |
1234
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| Organization Name |
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| Country |
Egypt
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| Author(s) from ARC |
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| Agris Categories |
Animal physiology - Nutrition
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AGROVOC
TERMS |
Betaine.
Blood composition.
Carcass composition.
Economic analysis.
Muscles.
Performance testing.
Turkeys.
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| Publication Type |
Master Thesis
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