Asian Journal of Poultry Science - Current Issue

Effect of Source and Processing on Maize Grain Quality and Nutritional Value for Broiler Chickens 1. Heat Treatment and Physiochemical Properties

20 May, 2013

The aim of the present study was to evaluate the nutritional quality of traditional sun-dried maize grain, subjected to further heat treatment. The maize grains were obtained from three different locations, namely Moree in NSW, Emerald in QLD and Darling-Downs on the NSW-QLD border, Australia. Once received, one batch (sun-dried) was assessed without further drying. The other two batches from each source were dried artificially using a forced draught-oven at 105°C for 30 min or 24 h. The morphological structures (starch granules) of grains were changed due to heat-treatment for 30 min at 105°C and far-reaching structural changes occurred when samples were heated for 24 h. Proximate analysis of maize revealed that the DM (897.3-967.4 g kg^-1), CP (92.1-108.7 g kg^-1), EE (49.0-57.5 g kg^-1), phytate-P (1.2-2.4 g kg^-1) and ash (14.1-19.7 g kg^-1) contents of samples varied due to source and heating period. The starch, amylose, available amino acid and mineral contents increased with increasing heating duration. Variable anomeric proton peaks (¹H-NMR) were found with an increase in the oven drying period in all maize samples. In vitro digestibility of DM, starch and CP was improved due to heat-treatment at 105°C for 30 min 24 h. It may be concluded that the chemical composition, ultra-structural characteristics and energy values of maize samples varied by source and were changed through heating of low-moisture maize over varying time periods. These changes could impact on the nutritive value of the grains and animal performance.

Energy Utilization and Performance of Broiler Chickens Raised on Diets with Vegetable Proteins or Conventional Feeds

20 May, 2013

This study was undertaken to investigate the growth performance and energy utilization of broiler chickens fed on conventional diets, based on soybean or canola, with fishmeal (SBM50 and Can50, respectively) or on Vegetable Protein (VP) diets without fishmeal (SBM75 and Can75). Feed intake was highest (p<0.001) on the SBM50 and Can50 diets and lowest on SBM75 diet. Birds in the SBM50 and Can50 diet groups were heavier (p<0.001) than the SBM75 and Can75 diet groups. Birds on SBM50 and Can50 diets achieved superior Feed Conversion Ratio (FCR), while birds on Can75 diet were the poorest. Mortality of birds was unaffected (p>0.05) between dietary groups. The Apparent Metabolizable Energy (AME) intake on the SBM50 and Can50 diets was higher (p<0.001) than in the VP. Fat intake was highest (p<0.001) on Can50 diet group while protein intake was unaffected by treatment. Heat Production (HP) was identical, but net energy of production (NEp) was improved (p<0.05) in the birds on SBM50 and Can50. Whole body energy as well as fat (p<0.05) and protein contents were also increased (p<0.01) in the SBM50 and Can50 dietary groups. Birds on SBM50 and Can50 diet groups retained higher energy as fat (REf) (p<0.05) and as protein (REp) (p<0.01). The efficiencies of utilization of ME for energy (k_RE), protein (k_REp) and fat (k_REf) retentions were unaffected. The results demonstrated that birds on the conventional diets (SBM50; Can 50) utilized energy better and as such grew faster than the birds on VP (SBM75; Can75) diets.

Adding Phytase Enzyme to Low Phosphorus Broiler Diets and its Effect upon Performance, Bone Parameters and Phosphorus Excretion

20 May, 2013

A broiler growth experiment was conducted using 360 one-day old Ross 308 chicks to study the effect of reducing dietary phosphorus and adding phytase enzyme. Two diets were formulated in starting period (1-20 days): a control diet contained 0.50% Available Phosphorus (AP) and a low P diet contained 0.40% AP. Such low P diet was fed without or with phytase supplementation (500 IU kg^-1). At the growing period (21-35 days) every group of birds of the first period was divided into two sub-groups. Two grower diets were formulated, a control diet contained 0.40% AP and a low P diet contained 0.30% AP. The low AP diet was offered with phytase supplementation (500 IU kg^-1). Growth performance, bone parameters and P excretion were measured at 20 and 35 day of age. No significant differences on chick performance among dietary treatments during the starting and growing periods were observed. The best FCR value was recorded for birds fed 0.50% AP diet in the first period then grown on 0.30% AP diet+phytase. Reducing dietary AP content did significantly (p<0.05) affect bone parameters at 20 and 35 day of age. Addition of phytase did alleviate such effect. Tibia Ca and P content significantly (p<0.001) increased by phytase supplementation. Phosphorus excretion decreased more than 20% at staring period and more than 30% at growing period when broilers were fed low P diets supplemented with phytase. The results showed pronounced beneficial effect regarding the excreted P. Supplementing phytase enzyme to broiler diets renders the dietary phosphorus contents more available to the birds. Therefore, the amount of supplemental phosphorus could be remarkably reduced. It could be concluded that reducing dietary P level and using phytase enzyme could limit quantity of excreted P from broilers without adverse effect on performance. This reduces such impact in environmental pollution.

Hematological and Some Biochemical Values of Indigenous Chickens in Al-Ahsa, Saudi Arabia During Summer Season

20 May, 2013

The uses of hematological and biochemical parameters in disease diagnosis are well documented. However, sex, age and nutrition are the major factors affecting avian hematology. The measurement of these parameters in relation to age and sexes in local Saudi chickens are limited. Therefore, a total of 80 local Saudi chickens of different age and sexes in summer season were divided into 4 groups. First and second groups constitute male chicks of one and three months old (n = 20 for each). Chicks of the third and fourth groups were females of one and three months old (n = 20 for each). The collected blood and separated plasma were used for determination of hematological and some biochemical parameters, respectively. Total Erythrocyte Counts (TEC), Total Leucocytes Counts (TLC) and Packed Cell Volume (PCV) were significantly (p≤0.05) higher in male than female chicks and were not age dependant. Hemoglobin and blood indices were not significantly (p>0.05) differed in all birds. They were ranged as 9.5-11.7 g dL^-1, 97-108 m³, 30.7-34.1 pg and 28.6-34.3%, respectively. The percentage of heterophil, lymphocyte, monocyte, eosinophil and basophile were age and sex independent in addition, their values are ranged as 41.8-46.2, 43.2-48.8, 3.9-4.9 and 3.1-4.4%, respectively. The examined biochemical parameters were comparable in all birds. In conclusion, sex in local Saudi chickens in summer season influenced on TEC, TLC and PCV. These results can be a guide for scientists in the Kingdom of Saudi Arabia on changes of hematological and some biochemical value during hot the summer season.

Thai Crossbred Chickens Can Be Raised in a High Stocking Density

20 May, 2013

The purpose of this study was to assess whether the Thai crossbred chickens can be raised at a higher stocking density than that recommended in Thailand. A total 900 day-old mixed sex Thai crossbred chickens (crossbred between Thai native males and the ISA Brown commercial layer type females) were assigned as 3 replicates of 100 birds per pen, to stocking densities of 8, 12 and 16 birds m^-2, respectively. Body Weight (BW), Body Weight Gain (BWG), Feed Intake (FI), Feed Conversion Ratio (FCR) and mortality rate of birds were recorded at weekly intervals. Data on welfare indicators (leg condition, feather damage scores, tonic immobility) were obtained at the 13 weeks of age. The results showed that in this study stocking density had no significant effects on BW, BWG, FI, FCR and mortality rate of chickens at 12 weeks of age. No leg problems of chickens were found in any treatment at 13 weeks of age. Although, no perfect feather of primaries and tail were found, the total body feather damage scores were similar in all treatments. Stocking density did not significantly affect tonic immobility duration of the chickens when stocking density was increased from 8 to 16 birds m^-2. It is thus concluded that Thai crossbred chickens could be raised up to 12 weeks of age in as high density as 16 birds m^-2 without any adverse effects.

Economic Impact of Recurrent Outbreaks of Gumboro Disease in a Commercial Poultry Farm in Kano, Nigeria

20 May, 2013

The economic significance of infectious bursal disease is well known to worldwide poultry farmers. Reported cases of concern in chickens by researchers have primarily been targeted at direct mortality, secondary bacterial infections, immuno-suppression with major impacts on production efficiency and decrease responses to vaccination. This study evaluates economic losses of 3 successive recurrent outbreaks of IBD in a commercial poultry farm in Kano, Nigeria and also projected 3 year (2009-2011) economic losses. Contrary to many research findings, increased age dependence and high mortality rates were observed during the study. Spreadsheet method of disease analysis (2003) was used to project economic loss of over three billion naira during these years under study. Due to high prevalence of IBD in Nigeria, it has become necessary to attempt to quantify the economic impact of IBD so that its economic losses could be appreciated, quick decisions are made on how best to prevent, control and design research priorities. The negative impacts of IBDV can be strategically minimised by good planning, effective vaccination and sound biosecurity principles.