Shokufeh Hasanvand; Ali Khatibjoo; Hassan Shizadi; Yahya Mohamadi; Mohammad Amir Karimi Torshizi; Drakhshanda Rahimhi
Volume 25, Issue 3 , October 2023, , Pages 325-341
Abstract
Introduction: Exposure of poultry birds to extreme temperature stressor modulates the immune responsiveness and haemato-biochemical parameters of birds. Cold temperature can increase ascites susceptibility by increasing both metabolic oxygen requirements and pulmonary hypertension. Biochar is an ash ...
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Introduction: Exposure of poultry birds to extreme temperature stressor modulates the immune responsiveness and haemato-biochemical parameters of birds. Cold temperature can increase ascites susceptibility by increasing both metabolic oxygen requirements and pulmonary hypertension. Biochar is an ash substance that is produced from the burning of biological material via pyrolysis. This study was carried out to investigate the effects of wet Litter Biochar on performance of cold-stressed broiler chickens.
Material and Methods: In this experiment, the effect of wet litter biochar (WLB), probiotic and zeolite on performance, blood metabolites and small intestine morphology of broiler chickens reared under cold stress were investigated. In a completely randomized design 350 Ross-308 broiler chickens (one-day-old, mixed sexes) were allocated to seven treatments, five replicates and 10 birds in each replicate. Experimental treatments included: 1) positive control (basal diet in recommended temperature), 2) negative control (basal diet+ cold stress), 3) negative control+ %0.5 WLB, 4) negative control+ %0.75 WLB, 5) negative control+ 1% WLB, 6) negative control+ 0.02% probiotic Ecobacto-P, and 7) negative control+ 1% zeolite. In cold stress groups, house temperature decreased to 17° C from 7 d until end of the experiment (42 d).
Results and Discussion: As compared to group reared in recommended house, cold stress significantly decreased broiler chickens feed intake, body weight gain (BWG), carcass and abdominal fat percentages, serum triglyceride concentration, activity of aspartate transaminase and alanine aminotransferase enzymes as well as villous width of jejunum and ileum while increased total and ascitic mortality, ileal and jejunal villous height and crypt depth to villous length ratio (P<0.05). Inclusion of 0.5 and 1% WLB and probiotic increased broiler chickens BWG, ileal and jejunal villous length and surface area, but decreased feed conversion ratio as compared to negative control group (P<0.05).
Conclusion: Generally, although addition of wet litter biochar and probiotic led to improvement in performance and small intestine morphometry of cold-stressed broiler chickens, but they did not completely catch-up negative effects of cold stress on broiler chickens.
Yahya Mohammadi; Mohammad Mahdi Shariati; Saeed Zerehdaran; Mohammad Razmkabir; Mohammad Bagher Sayyadnejad; Mohammad Bagher Zandi
Volume 18, Issue 1 , April 2016, , Pages 1-11
Abstract
Genomic Selection (GS) is a tool for prediction of breeding values for quantitative traits. For a successful application of GS, accuracy of predicted genomic breeding value (GEBV) is a key issue to consider. Here we investigated the accuracy of GEBV in 345 genotyped Iranian Holstein cattle. The study ...
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Genomic Selection (GS) is a tool for prediction of breeding values for quantitative traits. For a successful application of GS, accuracy of predicted genomic breeding value (GEBV) is a key issue to consider. Here we investigated the accuracy of GEBV in 345 genotyped Iranian Holstein cattle. The study was performed on milk, fat, protein yield and somatic cell count. Four methods G-BLUP, Bayes B, Reproducing kernel Hilbert Spaces (RKHS) and Neural Networks (NN) were used to predict genomic breeding values and their accuracies. The GEBV accuracies varied between 0.39 for somatic cell count to 0.73 for fat yield. Bayes B gave the highest accuracies among methods. Bayes B and non- parametric methods tended to produce inflated predictions (slope of the regression of GBV on EBV greater than 1). However, in all traits, lower estimates of MSE were obtained using G- BLUP. Bayes B regression model are of interest for future applications of genomic selection in this population, but further improvements are needed to reduce deflation of their predictions.