Effects of dietary crude protein and calcium/ phosphorus content on growth, nitrogen and mineral retention in broiler chickens

This experiment was conducted to examine the effect of three levels of crude protein (CP) (NRC, 15% more than NRC and 15% less than NRC) and three levels of Ca and available P (Av. P) (NRC, 15% more than NRC and 15% less than NRC) on performance of broilers from hatching until 21 days of age. The experimental design was a completely randomized design (CRD), with a 3 × 3 factorial arrangement of nine dietary treatments. Each treatment combination had four replicate pens (10 birds per pen). Results of this experiment showed that CP content had no significant effect on feed and water intake. However, body weight gain (BWG) significantly reduced and FCR increased (P < 0.05) by 15% change in CP content of diet. Fifteen percent increase in mineral content of diets had no significant effect on feed intake. However, increase in Ca and Av. P significantly increased BWG and resulted in an improved feed conversion ratio (FCR) and increased water intake. There was an interactive effect of CP by Ca and Av. P levels on feed intake, BWG and FCR. A change in CP or mineral content of the diets had no significant effect on blood parameters except for potassium concentration (K+). Reducing CP, Ca and Av. P content of the diet significantly (P < 0.001) increased P, Ca and N retention. Reduction in CP content of the diet led to a decrease in length, P and tibia bone ash. There was an interactive effect of CP by Ca and Av. P on the retention of Ca, N and ash of tibia bone.Key words: Crude protein, Ca and Av. P levels, broilers, N retention

Efficacy of natural zeolite and pigments on yolk color and performance of laying hens

An in vivo study was conducted to evaluate pigment adsorptive ability of a natural zeolite in laying hens. This experiment was performed with three hundred sixty Hy-line W-36 strain of laying hens at 43 weeks of age. After a two weeks adaptation period, they received six experimental diets with a 3 × 2 factorial arrangement in a completely randomized design. The experimental groups were fed with cornsoy- wheat based diets containing three levels of natural zeolite (0.0, 1.5 and 3.0%) and 2 levels of synthetic pigment (0.0 and 0.04%) for a 6-week period. Each treatment contained 60 birds, which were randomly divided into 4 replicates of 15 birds each. The results showed that egg production, egg weight, shell thickness and the shell percent values did not significantly differ between treatments, but that the yolk color index was significantly reduced and increased by the addition of zeolite and pigment levels to the diet, respectively.Key words: Natural zeolite, pigment, yolk color, laying hens

GCHL: A grid-clustering algorithm for high-dimensional very large spatial data bases

Spatial clustering, which groups similar spatial objects into classes, is an important component of spatial data mining Han and Kamber, Data Mining: Concepts and Techniques, 2000. Due to its immense applications in various areas, spatial clustering has been highly active topic in data mining researches, with fruitful, scalable clustering methods developed recently. These spatial clustering methods can be classified into four categories: partitioning method, hierarchical method, density-based method and grid-based method. Clustering large data sets of high dimensionality has always been a serious challenge for clustering algorithms. Many recently developed clustering algorithms have attempted to address either handling data with very large number of records or data sets with very high number of dimensions. This new clustering method GCHL (a Grid-Clustering algorithm for High-dimensional very Large spatial databases) combines a novel density-grid based clustering with axis-parallel partitioning strategy to identify areas of high density in the input data space. The algorithm work as well in the feature space of any data set. The method operates on a limited memory buffer and requires at most a single scan through the data. We demonstrate the high quality of the obtained clustering solutions, capability of discovering concave/deeper and convex/higher regions, their robustness to outlier and noise, and GCHL excellent scalability

Effects of Thyme Essential Oil on Performance, Some Blood Parameters and Ileal Microflora of Japanese Quail

The ban on the use of antibiotics as growth promoters has stimulated the search for alternative feed supplements in poultry production. The active principles of thyme essential oil act as a digestibility enhancer, balancing the gut microbial ecosystem and stimulating the secretion of endogenous digestive enzymes and thus improving growth performance in poultry (Lovkova et al., 2001; Williams and Losa, 2001). A study was performed to investigate the effects of thyme essential oil (TEO) on performance, carcass characteristics, some blood parameters and ileal microflora of Japanese quail. This study lasted 35 days of age. One hundred and fifty day-old male Japanese quail chicks in a completely randomized design with two treatments (with or without 1 g/kg TEO) and five replicates of 15 birds each were used. All parameters were measured at the end of the experiment. The supplementation of TEO significantly (

Occurrence of Bacillus cereus in Beef Burger Marketed in Tehran, Capital of Iran

Background: Beef burgers made in Iran contain various compounds such as meat, cereals flour, as well as some spices which can be contaminated to Bacillus cereus, causing gastroenteritis in the consumer. This study is focused onoccurrence of B. cereus in beef burgers marketed in Tehran, capital of Iran. Methods: &nbsp;In this cross-sectional study, a total of 80 samples of different types of beef burgers marketed in Tehran, Iran were randomly collected based on their percentage of meat content, including 30% (n=25), 60% (n=40) as well as 90% (n=15). The samples were analyzed microbiologically by routine culture assay and biochemical tests to find B. cereus. Data were analyzed statistically by Microsoft Office Excel 2010. Results: Twenty-five out of 80 (31.25%) beef burger samples were contaminated by B. cereus. Based on the percentage of meat content in the samples, the beef burger with 90% meat were significantly (p<0.05) more contaminated than the others. Also, the contamination rate was significantly (p<0.05) higher in summer compared to winter. Conclusion: This survey showed that the beef burgers supplied in Iran markets is main source of B. cereus that can cause disease in Iranian consumers. More attempts must be focused on cold-chain maintenance in production, distribution, and storage of the meat products

The concentration and health risk assessment of radionuclides in the muscle of tuna fish: A worldwide systematic review and meta-analysis

Exposure to radionuclides, especially in food, can endanger the health of consumers. In this study, a systematic review and meta-analysis were performed regarding the concentration of radionuclides in tuna fish muscle. International databases including PubMed, Scopus, and Embase were searched to find articles regarding the concentration of radionuclides in tuna fish muscle from 1 January 2000 to 20 February 2021. The lowest and highest concentration of radionuclides was related to Caesium-137 (137Cs) and Potassium-40 (4 K), respectively. The rank order of radionuclides based on their pooled concentration was 4 K (370.157 Bq/kg) &gt; 210Po Polonium-210 (26.312 Bq/kg) &gt; 210Pb (5.339 Bq/kg) &gt; 226Ra (4.005 Bq/kg) &gt; 137Cs (0.415 Bq/kg). The health risk assessment based on annual effective dose indicates that consumers are at the safe range of health risk (H &lt; 1 mSv/y). The continuous monitoring concentration of radionuclides in seafood and health risk assessment should be recommended. © 2021 Elsevier Lt