Journal of Livestock Science and Technology
Volume:2 Issue: 2, Nov 2014

The objective of this research was to investigate the efficacy of dietary inclusion of probiotics Primalac® and Bactocell® and prebiotic Fermacto® on broiler’s performance and immune response, individually or in combination. A total of 540 one-d-old male Ross 308 broiler chicks were allocated into 6 experimental treatments with 6 replicates of 15 birds per replicate from 1 to 42 d of age. The birds received a basal diet (control) or the basal diet supplemented with probiotic Primalac® (PP), probiotic Bactocell® (PB), prebiotic Fermacto® (Pre), probiotic Bactocell® prebiotic Fermacto® (PBPre) or probiotic Primalac® prebiotic Fermacto® (PPPre). Performance parameters were measured from 1-42 d of age. A suspension of sheep red blood cells (SRBCs) was injected into the breast of 3 birds from each replicate on d 22, and the antibody titer was measured on d 30. At d 22, blood samples (from 3 birds per replicate) were taken for measuring the white blood cells (WBCs), heterophil (HE) percent, lymphocyte (LY) percent, and the ratio of heterophil:lymphocyte (H/L). No significant differences were found between the control and supplemented groups in average daily gain (ADG), average daily feed intake (ADFI), antibody titer against SRBCs, HE percent, LY percent and H/L. Addition of PBPre or PPPre to the diet improved FCR by 8.5 and 12.7%, respectively, compared with the control group, and PBPre supplementation resulted in an increase in WBCs compared to other treatment groups.

This study was conducted to investigate the effects of different levels of zinc sulfate and chromium picolinate on performance, body temperature, carcass characteristics, tibia ash and serum biochemical parameters of Japanese quails under heat stress condition. The birds (n = 540; 7-d-old) were randomly assigned to 9 treatment groups consisting of 3 replicates of 20 birds each in a 3 × 3 factorial arrangement of treatments (zinc; chromium). Birds were kept in floor cages in a temperature controlled room at either thermoneutral zone or heat stress for 8 h/d (0900 to 1700 h) until the end of the study, and fed a basal (control) diet or the basal diet supplemented with either 40 or 80 mg of Zn as ZnSO4 and 500 or 1000 g Cr as CrPic/kg of diet. A linear decrease in feed intake and improvement in feed conversion ratio were found in Zn and Cr supplemented quails reared under heat stress conditions. Chromium supplementation increased daily weight gain linearly.Quails body temperature before and during heat stress tends to decrease linearly as dietary Zn and Cr supplementation increased. Supplementation with Zn decreased the relative weight of the small intestine, rectum, and weight to length ratio of the small intestine. Tibia ash was increased with Zn and Cr supplementation. Supplementation of quail's diet with Zn and Cr did not have any effect on serum biochemical parameters. The results of this study revealed positive effects of Zn and Cr supplementation on the performance, body temperature, carcass characteristics and tibia ash of quails under heat stress. It seems that supplementation of the quail's diets with 80 mg/kg ZnSO4 and 1000 g/kg CrPic can be greatly helpful for improving the adverse effects of heat stress.

Chukar partridge raising is a profitable business. New feed additives of plant origin may be an alternative to antibiotic growth promoters. This study was carried out to determine the effect of different levels of Pistacia atlantica oil on performance and pathological conditions in chukar partridge. One-day-old chukar partridge chicks were assigned to three dietary treatments of 40 birds each. Each treatment consisted of four replicates. The control diet (A) was formulated according to the nutrient requirements of chukar partridge chicks. Diets B and C were supplemented with 2.5 and 7 g/kg Pistacia atlantica oil, respectively. The birds fed diet supplemented with 7 g/kg Pistacia atlantica oil recorded the best value (pPistacia atlantica oil to the diet was improved body weight and feed conversion ratio when compared to the control group. Pathological evaluation did not show any alterations between experimental groups. In conclusion, Pistacia atlantica oil could be considered as a natural alternative to antibiotic growth promoter for chukar partridge breeding without causing any pathological effect.

Genetic diversity is a key component of ecosystems. The aim of the present study was to evaluate the genetic diversity of Iranian native honeybee colonies (Apis mellifera meda L.) located in the northern region. Colonies from 24 locations have been analyzed using microsatellite markers. Samples were collected from Caspian Sea southern area (north of Iran). Six microsatellite markers (A28, A29, A113, A24, A76, and A43) amplified them. Amplification was successful in four loci but not for A76 and A43. Polymorphism and diversity indices were high for all amplified loci and for total population. Average heterozygosity and average number of alleles were significantly high in these colonies. The phylogenies also revealed a genetic distance among colonies of this area. The results showed a reliable genetic diversity among Apis mellifera meda L. populations in the north of Iran (southern area of Caspian Sea). Based on the microsatellite genotypes, the honeybee population in the southern area of Caspian Sea can be clustered into two distinct subpopulations located in Gilan and Mazandaran area. These results support the previous morphological and biochemical evidences.

An F2 Japanese quail population was developed by crossing two strains (wild and white) to map quantitative trait loci (QTL) for performance and carcass traits. A total of 472 F2 birds were reared and slaughtered at 42 days of age. Performance and carcass traits were measured on all of the F2 individuals. Parental (P0), F1 and F2 individuals were genotyped with 3 microsatellites from quail chromosome 5. Based on five quantitative genetic models analyzed, QTL affecting carcass efficiency, breast percentage, femur percentage, back weight and back percentage, head weight, gizzard weight, uropygial weight, liver weight and liver percentage and neck percentage were mapped. The results provided an important framework for further genetic mapping and the identification of quantitative trait loci controlling performance carcass traits in the Japanese quail.

The LEPR is a glycoprotein expressed mainly in hypothalamus, where it takes part in energy homeostasis and in regulation of the activity of the secretory organs. A transition mutation in this gene results in substitution of cytosine by thymine leading to the substitution of threonine by methionine in the intracellular domain of the LEPR-b isoform. This study investigated the impact of polymorphism located in the LEPR (T945M) gene on milk yield and age at first calving traits. The analysis was conducted on 395 randomly Holstein dairy cows. In the association studies, traits of interest were analyzed using the GLM procedure of SAS; means of the LEPR genotypes were compared by the LSMeans test. Statistical analyses showed no significant difference between the SNP and selected traits. Regarding the association revealed, theT945M SNP may not be as a possible candidate for marker – assisted selection in the Iranian dairy cattle breeding program.

In this study test-day records of milk (kg), fat (g), and protein (g) yields, somatic cell score (SCS, cells/ML) collected by Animal Breeding Center of Iran during 2007 and 2009 were used to estimate genetic parameters using random regression model. Models with different order of Legendre polynomials were compared using Bayesian information criterion (BIC).For milk, fat yield and SCS genetic and permanent environmental effects were modeled with 3th order of Legendre polynomials and for protein yield genetic and permanent environmental effects were modeled with 4th and 3rd order of Legendre polynomials, respectively. The mean heritability for milk, fat, protein yield and SCS were 0.24, 0.12, 0.23 and 0.07, respectively. For all the traits except for SCS, the estimated heritabilities were lowest at the beginning and higher at the end of the lactation period. Around peak yield (DIM 50 to 150), heritability was lowest for all traits and then increased to the end of lactation. Phenotypic correlations were high between adjacent yields and small between yields at the extremes of the lactation curve. Negative genetic correlations were observed between tests at the beginning and at the end of lactation in this research. The present study showed clear evidence for the benefits of using a random regression TD model for management decisions.

The aim of this study was to determine the effect of marker density, level of heritability, number of QTLs, and size of training set on the genomic accuracy over three generations. Thereby, a trait was simulated with heritability of 0.10, 0.25 or 0.40. For each animal, a genome with 20 chromosomes, 1 Morgan each, was simulated. Different marker densities (2000, 4000 and 6000 markers) and 400 and 600 randomly distributed QTLs were simulated. Marker density, size of training set, and heritability level significantly affected the genomic accuracy (P