نشریه علوم دامی (پژوهش و سازندگی)
پیاپی 86 (بهار 1389)

Broiler production is one of the main sources of the food in Iran. in order to calculation of production factors productivity of broiler industry in west Azarbaijan 49 broiler farm units from 7 city with systematic random sampling selected. For determination of main factors in farms product function method (Cobb – Dauglas) and marginal analysis used. The results indicate that five main factors are effective in production process. These factors are: feed، hygienics costs، capacity، mortality and feed conversion ratio. Estimated coefficients showed that feed has the highest coefficient of production. (1. 026). The mean of total factor Productivity (TFP) was 1. 97 Infact with spending 1 unit (rials) in farm units، they obtain 1. 97 (rials) as income. There wasn،t relation between management factors (such as: Experience، technology education and extension) and total factor productivity Also TPF of large farms is less than small units.

This experiment was conducted to determine the effects of Non-Starch Polysaccharides (ß-Glucan) content of hull-less barley on viscosity and metabolizable energy in cockerels. A number of 44 intact and caecectomized adult cockerels were used in this study. A significant differences (p<0. 05) was observed between varieties in viscosity of feed and feces. Varieties 20 (1/635 CPS) and 6 (2/505 CPS) respectively showed the minimum and maximum feed viscosity and varieties 4 (14/215 CPS) and 1 respectively had the maximum and minimum viscosity of feces. The study showed that there was a significant (p<0. 05) differences between the varieties in metabolismable energy. The average of AME، AMEn، TME and TMEn of the 20 varieties were 2879/8، 2879/8، 2993/3 and 2993/3 kcal/kg respectively. Variety 2 had the minimum (2481/5، 2481/5، 2613/5، 2613/4 kcal/kg) and variety 15 had the maximum (3341/2، 3341/2، 3441/1، 3441 kcal/kg) metabolismable energy. There was no difference between the intact and cecectomised cokerols in the quantity of received ß-Glucan but the difference in metabolizable energy and fecal viscosity was significant (p<0. 05) in such a manner that the intect cockerels showed more metabolismable energy values and less facal viscosity than the caecectomized adult cockerels. The results showed that there was a significant (p<0. 05) differeces between hull-less barley، barley and wheat in viscosity and metabolizable energy. The viscosity of excreta from hull-less barley was more as compared to wheat (8. 39 vs 4. 34 cps). Metabolismable energy of wheat was greater than of hull-less barley and barley. It is concluded that hull-less barley can be used in the diet of poultry nutrition but more investigation should be paied on it in the plant breeding programs.

Milk samples are monthly collected from each registered cow by Dairy Herd Improvement (DHI) center to analyze milk components. Adequate air bubbling through the milk in an on-farm weigh jar requires ensuring homogeneity before taking representative samples. This experiment was conducted to determine the effect of air bubbling time on milk fat percentage. The milk samples (n=960) were taken from 120 lactating Holstein cows at second meal of milking during 2 sequential days. After each cow milking، the sampler valve was opened to allow air to enter and mix the milk. Four samples serially were taken from the same weigh jar at 0، 10، 20 and 30 seconds air bubbling. Milk components were determined at DHI laboratory. The results showed، least square means of milk fat percentage was lower (p<0. 01) for control group (2. 58±0. 076) compare to the others. There were not significant differences between 10، 20، 30 seconds air bubbling (3. 5±0. 074، 3. 57±0. 074 and 3. 66±0. 074، respectively). There were no differences between air bubbling times when a weigh jar contains lower than 6 kg milk. In conclusion، 10 seconds air bubbling through the milk in a weigh jar could be enough before milk sampling.

This experiment was conducted to determine the effect of different levels of sodium bicarbonate and potassium bicarbonate (0. 5،0. 7،1% in dite) on performance broilers at cyclic heat stress (18-330c). 420 commercial broiler (male and female) at 21 day–old for four weeks were randomly allocated to 7 dietary treatment. The experiment followed a compeletly randomized design with seven treatments and three replicate (21 plot) in which 20 chicks were reared on the litter. Weight gain، feed intake، feed conversion، final weight and abdominal fat percentage were significantly different (P<0. 05) among treatments. dietary supplement of NaHCo3 gave significantly (P<0. 05) better feed conversion، weight gain، feed intake and final weight than supplement of Potassium bicarbonate (KHCO3).

In the present study، the effect of incomplete sire’s pedigree on variance component، genetic parameters and accuracy of selection for a quantitative trait in sheep were studied using computer simulation. Two populations with heritability’s of 0. 15 and 0. 30 for a hypothetic quantitative trait were simulated. Data including animal ID، Sire ID، Dam ID، phenotypic values، additive genetic values and environmental values were saved for two populations. Sire numbers were deleted with proportions of 0، 10، 20، ….. ، 100 percentage of total pedigree. Deletion of sire numbers were done randomly and sequentially and the resulted files in each case were saved. In order to estimation of variance components and genetic parameters and prediction of breeding values، data were analyzed with simple animal model using DFREML package. In population 1 (h2=0. 15) and the case of random deletion، phenotypic variance was approximately constant as the deletion percentage of sires increased. Additive genetic variance decreased and error variance increased partially. Consequently، h2 reduced، but the changes were not significant (P>0. 05). The accuracy of selection () were significantly reduced from 0. 666 (complete pedigree) to 0. 483 (without sires pedigree). The trend of variance components and heritability’s in population 2 (h2=0. 30) were the same as population 1، but the changes of heritability’s were significant. The accuracy of selection () were significantly reduced from 0. 850 (complete pedigree) to 0. 685 (without sires pedigree) in population 2. In case of sequential deletion of sire’s pedigree، the trend of variance components and heritability was approximately constant in population 1. The estimates of heritability were non significantly reduced based on increasing of deletion percentages of sire’s pedigree. Generally، the results of this study showed that the amount of sire’s pedigree deletion affected variance components، heritability and the accuracy of selection.

An experiment was conducted to determine the sulfur amino acid (SAA) requirement for broiler breeder in peak of egg production. The experiment was carried out in Babolkenar pure line breeding center with 196 broiler breeder hen. The experimental groups were consisting of 6 levels of methionine (0. 2، 0. 25، 0. 3، 0. 35، 0. 4 and 0. 45%)، in 4 replicate with 8 hens in each replicate from 25 to 35 weeks. The hens were selected according to body weight (2932±15) for maximum uniformity in treatments groups. Amino acid profile and protein of ingredients were analyzed and these results were used for diet formulation. The diets form was plate. The results showed that different level of methionine had no significant effects on egg weight، double yolk eggs، small and settable egg (p>0. 05). Egg production (%)، egg mass (g/h/d) and feed conversion had a significant different (p<0. 05). Two-slope، quadratic broken-line analysis were used for determination of requirement. Broken line regression analysis indicated the methionine requirement for egg mass (g/h/d)، feed conversion and settable egg (%) were 424،429 and 476 (mg/d) respectively. According to result sulfur amino acid requirement for egg mass (g/h/d)، feed conversion and settable egg (%) were 843،848 and 894 (mg/d) respectively. According to result methionine requirement for egg mass (g/h/d)، feed conversion and settable egg (%) were 0. 26، 0. 266 and 0. 296 percentages in diet respectively.

Due to growing concerns about antibiotic resistance and a ban for antibiotic growth promoters، this study was conducted in order to determine the effects of two types of prebiotic components as alternatives to antibiotics on growth performance and carcass characteristics of male broiler chickens. A total of 192 male broiler chicks (day-old Hubbard strain) were distributed into a completely randomized design. Experimental treatments (8 treatments with three replicates and 8 birds in each replicate) were: one control diet (without any growth promoter)، one level of antibiotic virginiamycin، and two types of low-digestible carbohydrates ingredients including inulin (1. 5، 3 and 4. 5 % of the diets) and mannan-oligosaccharide (MOS، 0. 1، 0. 2 and 0. 3 % of the diets). For 6 weeks، the birds were fed ad libitum with the mash feed mixtures. Mean body weight and feed intake were recorded weekly. At the end of experiment (on days 43)، two birds were randomly selected from each pen and individually weighed and slaughtered. Then، carcass weight and weight of gastrointestinal parts (including: pancreas، gizzard، liver، proventriculus، heart، intestine and abdominal fat pad) were determined. The SAS General Linear Models (GLM) procedure was used for statistical analysis of data. Based on the results of this experiment، the most feed consumption was related to the inulin-supplemented birds. The highest and the lowest feed consumption were related to the birds fed diets with 4. 5% inulin and 0. 3% MOS، respectively (P<0. 001). Inulin- supplemented birds also had greater body weight gain compared to the control and the birds fed diets supplemented with MOS (P<0. 001). Diets supplementation with inulin led to an improvement in feed conversion which was statistically significant (p<0. 05). There was statistically significant differences between dietary treatments based on abdominal fat pad percentage (p<0. 05). Chicks fed diets supplemented with inulin had significantly lower amounts of abdominal fat pad deposition (p<0. 05). The relative weight of ileum and jejunum (g/cm of segment length) were higher in chicks fed inulin-supplemented diets (p<0. 05).

The study was conducted to investigate the effect of urea treatment method of wheat straw on degradability، digestibility and the fattening performance of male calves fed treated straw. In a completely randomized experiment with 3 treatments، 18 Holstein bulls (with average body weight 224. 72 ± 20. 45 kg) was assigned to 1 of 3 treatments: 1) 40% normal untreated straw; 2) 40% whole bale treated straw with 5% urea (WSBP); or 3) 40% chopped straw treated with 5% urea (OSBP). The average DM degradability of untreated and treated straw at zero time was 16، 20 and 22%، respectively that were significantly different (p<0. 05) between the treatments. The treatment resulted in a significant increase (p<0. 05) in effective rumen degradability of DM at various outflow rates. The average apparent digestibility of DM was 44. 9، 48. 4 and 48. 8% in treatments 1، 2 and 3 respectively that was not significantly different between treatments. The average daily gain (698، 881 and 882 g/d، respectively) and daily DMI (8. 8، 10. 2 and 10 kg/d، respectively) were significantly (p<0. 05) higher for WSBP and OSBP compared with un-treated straw diet. Further، the required time to achieve 200 kg weight gain reduced. In general، considering the similar results of treating straw on the diet digestibility and animals performance، and being easy of whole bale straw treating، this method is recommended for farmers.

The present research was conducted to identify polymorphism of 5 microsatellite markers including: MCW5، MCW16، MCW18، ADL210 and ADL225 in Sistan native chickens. Thirty individuals were randomly selected in Sistan region. All loci deviated from Hardy-Weinberger equilibrium (0. 05). In this population، MCW5 and ADL225 loci had the lowest (0. 7448) and the highest (0. 8210) heterozygosity، respectively. Within populations، the average observed heterozygote frequency was 0. 7860. ADL225 and MCW5 loci had shown the highest (0. 79) and the lowest (0. 70) of PIC، respectively. Results of this study show that ADL225 had the lowest PI (0. 004386) and the highest PD (0. 9957) and MCW5 had highest PI (0. 008) and the lowest PD (0. 992). These results suggest that the Sistan native chicken has the property genetic diversity and this good level of diversity will contribute to breeding programs.

Two experiments were conducted to evaluate the nutritive value of white mulberry (Morus alba) fruits waste and its use in broilers nutrition. In first experiment protein، gross energy، ash، ether extract، crude fiber، calcium and phosphorus of white mulberry fruits were measured، then in a trail the apparent metabolisable energy (AME)، apparent metabolisable energy corrected to nitrogen retention (AMEn)، true metabolisable energy (TME) and true metabolisable energy corrected to nitrogen retention (TMEn) content of some feed stuff for poultry were determined by Sibbald (1989) methods. The result showed that mulberry fruits can be used as an energy sources. The AME، AMEn، TME and TMEn of its were 3104، 3255، 4096 and 3976 Kcal / Kg dry matter respectively. Second experiment consist of 4 treatments (0، 5، 10، 15 % mulberry fruits) and 4 replicates. A total of 400 day-old chicks were randomly assigned to 16 litter floor pens. The diets formulated according to cobb 500 nutritional recommendation guideline for broiler chickens. In experimental period (7-42 days) feed consumption (g/d)، mortality (%)، weight gain (g/d) and feed conversion were measured weekly. Finally at the age of slaughter (42d) 2 chicks were selected randomly from each replicate and then carcass quality، carcass weigh، breast، leg، abdominal fat، liver، kidney and heart were measured. The results showed that using different level of mulberry fruits had no significant effect on feed intake. Weight gain (g/d) in 5، 10 and 15 % mulberry fruits groups were 19. 52، 6. 98 and 17. 41 % lower than controls. According to result، control group had the best feed conversion in comparison with other groups (p<0. 05). The livability carcass، leg، breast، heart and abdominal fat didn’t affect by level of mulberry. When the level of mulberry fruits increased، kidney weight was increased and its percentage for 15% mulberry was 0. 969 vs. 557 in control groups. With increasing of mulberry fruits، liver weight was increased.