Different Strains Of Chickens Research Articles

Effect of Various Feed Additives on Carcass and Meat Quality of Two Different Strains of Chickens

Assorted feed additives for broiler chickens, including prohibited antibiotics, are widely sold in the market. The objective of incorporating supplement in feed is to improve broilers’ performance and meat quality. This study conducted an experiment to 60 DOC broilers from each Cobb and Lohmann strains. The experiment was conducted in a 2x4 factorial CRD. The treatments were feed additives, i.e. antibiotics, probiotics, acidifiers and phytobiotics. Each treatment was repeated 3 times. The measured variables were carcass and non-carcass percentage as well as physical quality of broiler meat. Analysis of variance showed that feed additives did not significantly affect (P>0.05) carcass and non-carcass percentage and meat physical quality of the two broiler strains. Conclusively, probiotics, acidifiers and phytobiotics are the potential alternatives as a substitute for antibiotics for Cobb and Lohmann broiler chickens as reflected from the carcass percentage and meat quality.

Comparative Staging of Blastoderm Development at Oviposition in Eggs from Layer and Broiler Grandparent Breeder Flocks

Recent decades were characterized by genetic selection of broiler and layer chickens for enhanced growth rate and meat yield or intensified egg production, respectively. It is to be expected that genetic selection for various traits would also influence embryo development. The effects of different strains of chickens on egg weight, stage of blastoderm, variation of the blastoderm development and Pearson correlation between egg weight and stage of blastoderm at oviposition were studied in the current study. Hatching eggs were randomly collected from three layer chicken lines (Layer-1, Layer-2, and Layer-3) raised in Poultry Research Institute, and two broiler grandparent flocks (Female and Male) from Aviagen Anadolu. The age of all chicken lines was 36 week. A total of 30 eggs in each line were used, and egg weight and the blastoderm development of the embryos were determined at oviposition time. At the end of the research, significant difference in egg weights (P0.05). The mean stage of blastoderm development in male grandparent line eggs significantly lower than other four genetic lines (P

A novel chicken model of fatty liver disease induced by high cholesterol and low choline diets

Fatty liver diseases, common metabolic diseases in chickens, can lead to a decrease in egg production and sudden death of chickens. To solve problems caused by the diseases, reliable chicken models of fatty liver disease are required. To generate chicken models of fatty liver, 7-week-old ISA female chickens were fed with a control diet (17% protein, 5.3% fat, and 1,300 mg/kg choline), a low protein and high fat diet (LPHF, 13% protein, 9.1% fat, and 1,300 mg/kg choline), a high cholesterol with low choline diet (CLC, 17% protein, 7.6% fat with additional 2% cholesterol, and 800 mg/kg choline), a low protein, high fat, high cholesterol, and low choline diet (LPHFCLC, 13% protein, 12.6% fat with additional 2% cholesterol, and 800 mg/kg choline) for 4 wk. Our data showed that the CLC and LPHFCLC diets induced hyperlipidemia. Histological examination and the content of hepatic lipids indicated that the CLC and LPHFCLC diets induced hepatic steatosis. Plasma dipeptidyl peptidase 4, a biomarker of fatty liver diseases in laying hens, increased in chickens fed with the CLC or LPHFCLC diets. Hepatic ballooning and immune infiltration were observed in these livers accompanied by elevated interleukin 1 beta and lipopolysaccharide induced tumor necrosis factor mRNAs suggesting that the CLC and LPHFCLC diets also caused steatohepatitis in these livers. These diets also induced hepatic steatosis in Plymouth Rock chickens. Thus, the CLC and LPHFCLC diets can be used to generate models for fatty liver diseases in different strains of chickens. In ISA chickens fed with the CLC diet, peroxisome proliferator-activated receptor γ, sterol regulatory element binding transcription factor 1, and fatty acid synthase mRNAs increased in the livers, suggesting that lipogenesis was enhanced by the CLC treatment. Our data show that treatment with CLC or LPHFCLC for 4 wk induces fatty liver disease in chickens. These diets can be utilized to rapidly generate chicken models for fatty liver research.

Development of a Chicken Model of Nonalcoholic Fatty Liver Disease Induced by High Cholesterol and Low Choline Diet

Non‐alcoholic fatty liver disease (NAFLD), a most common liver disease in human, is one of the primary causes of the laying hen death in chicken farming. It leads to a great commercial loss in agricultural sector. Therefore, reliable chicken models of NAFLD is required for the research of NAFLD etiology and prevention in chickens. To generate rapid chicken models of NAFLD, 7‐week‐old ISA chickens were fed with control diet (18% dietary protein, 4.72% fat, and 1300 mg/kg choline), low protein and high fat diet (LPHF, 13% dietary protein, 8.95% fat, and 1300 mg/kg choline), high cholesterol with low choline diet (CLC, 18% dietary protein, 4.72% fat, 2% cholesterol, and 800 mg/kg choline), or low protein, high fat, low choline, and high cholesterol diet (LPHFCLC, 13% CP, 8.95% fat, 2% cholesterol, and 800 mg/kg choline) for 4 weeks. Compared with control group, CLC and LPHFCLC treatments significantly elevated the level of plasma triglyceride and cholesterol. The appearance and the histological sections of the livers showed that CLC and LPHFCLC treatments significantly led to the accumulation of fat in the livers. The symptoms of steatohepatitis, hepatic ballooning and immune infiltration, were presented in the livers in CLC and LPHFCLC groups. In addition, the levels of dipeptidyl‐peptidase 4, a biomarker of fatty liver hemorrhagic syndrome in laying hens, were also increased in the plasma of CLC and LPHFCLC treatments. These data indicated that the diet with 2% cholesterol and 800 mg/kg choline was sufficient to induce hepatic steatosis and steatohepatitis. Moreover, the genes related to lipogenesis (PPARG, SREBP1C, and FASN) and pro‐inflammation cytokines (TNFA and IL1B) were elevated in the CLC group, further confirming the effects of CLC treatment on laying hens. Interestingly, CLC treatment also induced non‐alcoholic fatty livers in Plymouth Rock broiler chickens. It suggested that CLC treatment may induce non‐alcoholic fatty liver disease in different strains of chickens. Therefore, our data suggested that CLC treatment may induced rapid and reliable non‐alcoholic fatty liver disease in chickens. Accordingly, de novo lipogenesis is primary occurred in the livers both in chicken and human. This model can be expected to be utilized for the screening of functional components to prevent or improve fatty livers in chickens and human.

Hatch rate of laying hen strains provided a photoperiod during incubation

Implementing a photoperiod during incubation has been shown to be a potential next step to removing one more stressor for newly hatched poultry species. The distribution of hatch over time is a parameter that may be influenced by photoperiod that could benefit from a photoperiod but has not been studied at this time and is the objective of this paper. The impact on hatch rate for three strains of chicken, Barred Plymouth Rock (BR), Lohmann Brown (LB) and Lohmann Lite (LL), was measured following the provision of a 12L : 12D (12 h light : 12 h dark) photoperiod starting at 0, 9 or 17 days of incubation and compared with incubation in the dark. The cumulative number of chicks hatched eggs at four points in time (489, 498, 507 and 516 h of incubation) was analysed using repeated measures analysis in a 3 × 4 factorial arrangement of treatments. Repeated measures analysis was done to determine the main and interaction effects of photoperiod and bird strain, and a regression analysis was used to determine how these effects evolved over time. Lohmann Brown embryos provided a 12L : 12D photoperiod throughout incubation were first to reach 50% of total chicks hatched and rate of hatch from 50% to 75% of total chicks hatched as well. As the LB chicks did not begin to hatch earlier or finish later, the LB strain was the most synchronised when provided a 12L : 12D photoperiod from the beginning of incubation. Similar results were found for LL, but no difference on the percentage hatched over time was found when provided the 12L : 12D photoperiod at the beginning of incubation or at day 9. The BR strain only showed a significant difference in hatch window synchronisation when provided a 12L : 12D photoperiod at day 9 of incubation. These results indicate that the strain of chicken impacts the hatch window, and each strain responds to a photoperiod during incubation differently. This information could be useful for hatchery managers to deal with different strains of chicken for incubation.

Effect of Thermal Conditioning on the Production Performance of different Strains of Chicken

An experiment was conducted to investigate the effect of different thermal conditioning on the production performances of Aseel, Nandanam Broiler – 3, Nandanam Chicken – 4 and Nacked Neck. A total of 360 chicken (90 chicken from each strain) were randomly assigned in to three treatment with three replicates and each replicate contain 30 chicks. The first treatment served as a control group where birds reared under ambient temperature, birds in second treatment were exposed to heat stress at 37oC for 4 hours and birds in third treatment were exposed to 39oC for 2 hours from day old to 14 days and 29 to 42 days of age, apart from exposure period birds were reared at ambient temperature. The results showed a significantly (P

Analysis of Genetic Polymorphisms in Four Marker Sites of PEPCK-C Gene in Different Strains of Chickens

Analysis of Genetic Polymorphisms in Four Marker Sites of PEPCK-C Gene in Different Strains of Chickens

Sex-biased mortality analysis in chick embryos during the entire period of incubation

SUMMARY From 50,129 fertile eggs, a total of 1,712 dead chick embryos were collected from 5 different strains of chickens: ai-Jiao (233), Xing-Xing (143), HuBei-local (894), Hy-line (212), and Zhu-Si (230). the embryos were collected during the early (1 to 7 d), middle (8 to 14 d), and late (15 to 21 d) stages of incubation. Sex-biased embryonic mortality was analyzed during the different stages. We found that the overall mortality of female embryos was significantly higher than that of males in different stages of incubation (P < 0.05). We then analyzed the data by strain. In Hy-line, HuBei-local, and Zhu-Si chickens, female mortality was significantly higher (P < 0.05) during the early stage. During the middle stage, female mortality in HuBeilocal chickens was significantly greater than that of males (P < 0.005). During the late stage, female mortality was significantly lower (P < 0.05) in ai-Jiao chickens but was significantly higher (P < 0.01) in HuBei-local chickens. thus, more females died during the entire period of incubation, especially in the early and middle stages. Mortality was variable among strains during the late stage of incubation. In strains with smaller egg sizes, more females died, whereas in strains with larger egg sizes, more males died.

Effects of age and strain on the expression of leptin receptor, neuropeptide Y and pro-opiomelanocortin in the hypothalamus of young chickens

1. An experiment was conducted to study changes in the expression of the hypothalamic leptin receptor, neuropeptide Y (NPY) and proopiomelanocortin (POMC) with age during the early neonatal period in two different strains of chickens: Beijing-You (BY) and Arbor Acres (AA). 2. Compared with BY chickens, AA chickens ate more, and grew faster. Hypothalamic NPY concentrations of both strains increased with age until d 7 followed by a decline. Hypothalamic NPY of BY chickens on d 7 was lower than in AA chickens at the same age. 3. No difference with age was observed in hypothalamic α-melanocyte-stimulating hormone (α-MSH) of BY chickens, while hypothalamic α-MSH in AA chickens on d 0 was higher than on the other days. Compared with AA chickens, BY chickens showed lower hypothalamic α-MSH on d 0. 4. Similar developmental changes between two strains were observed in the expression of leptin receptor, NPY or POMC genes in the hypothalamus. Hypothalamic mRNA of leptin receptor on d 0 was higher than on d 1 and 7. Unlike NPY, hypothalamic NPY mRNA on d 0 was higher than on the other days. 5. Hypothalamic POMC mRNA decreased gradually with age until 7 d followed by a slight increase. 6. The results showed that the developmental changes of hypothalamic signal molecules varied with age and strain. NPY, α-MSH and leptin receptor might be involved in the early programming of feed intake in newly hatched chickens.

A detailed paraxial schematic eye for the White Leghorn chick.

We studied the normal ocular development of the chick (Gallus gallus domesticus, White Leghorn) up to 15days of age using both longitudinal and cross-sectional methods. The change in refractive error, corneal curvature and axial ocular distances were used to construct schematic eyes. Equations are presented which allow prediction of refractive error changes associated with changes in vitreous chamber depth. The mean refractive error was +3.2D at hatching, which reduced by 66% over the first 3days and stabilized by 11days of age. The lens thickened and the anterior chamber deepened from hatching, but vitreal elongation and corneal flattening were delayed until after the first 3days, suggesting that normal eye growth may be initially inhibited or inactive during an initial emmetropization period, and subsequently activated in response to myopic defocus arising from the continually expanding lens. Finally, when compared with published data on other chick strains, we find differences in the degree of hyperopia at hatching due to differences in lens thickness. However, the rate of ocular and vitreal expansion and the developmental changes in corneal power are similar, making the schematic eyes presented here generally applicable to different strains of chickens.

Comparison of the Chemical Composition, Textural Characteristics, and Sensory Properties of North and South Korean Native Chickens and Commercial Broilers

The objective of this study was to compare the quality characteristics of chicken breast and thigh meat from North Korean native chickens (NKNC), South Korean native chickens (SKNC, woorimotdak), and commercial broilers (CB). NKNC thigh meat had a higher crude protein content than CB. In addition, the breasts of NKNC and CB had higher pH values than that of SKNC, but the cooking loss was higher in NKNC. The surface color of the breast and thigh meat of NKNC was darker and redder than that of SKNC and CB. The total collagen content of the breast and thigh muscles was the highest in NKNC, followed by SKNC and CB. A similar trend occurred with breast meat hardness. The content of arachidonic and docosahexaenoic acids was higher in both the breast and thigh muscles of NKNC than in those of the other groups, while the concentrations of linoleic and linolenic acids were higher only in thigh meat. Sensory evaluation did not show any differences among the three different strains of chicken except for the meat color. Sensory panelists preferred thigh meat from SKNC and CB to that of NKNC due to the strong dark color of the NKNC. Based on these results, NKNC had harder breasts based on texture, as well as a darker surface color and higher composition of long chain polyunsaturated fatty acids than CB. The quality characteristics of SKNC tested in this study were intermediate between NKNC and CB; however, SKNC may have a better chance of acceptance by Korean consumers due to the undesirable color of NKNC.

Effect of Chronic Heat Stress on Performance and Oxidative Damage in Different Strains of Chickens

Heat stress (HS) causes poor growth, immunosupression and high mortality, through physiological dysfunction. We have reported that ‘acute’ HS increases mitochondrial reactive oxygen species (ROS) and oxidative damage in the skeletal muscle of broiler chickens (Cobb), but that this is not for the case for males of the laying-type white leghorn (WLH) strain of chickens (Mujahid et al., 2005b). We have now studied the effects of ‘chronic’ HS on performance and oxidative damage to skeletal muscle in different strains of chickens. Meat-type male chickens (Ross and Cobb) and male laying-type chickens (WLH) of 14d of age were arranged according to a factorial design (3 strains×4 conditions): control (24°C), cyclic (32-24-32°C: 32°C for 8h/d, 32-24-32HS), constant (32 and 34°C, 32HS and 34HS, respectively) for 14d. Feed consumption and body weight gain were measured. Thiobarbituric acid reactive substances (TBARS) content in skeletal muscle was measured colorimetrically with BHT (butylated hydroxytoluene) and expressed as malondialdehyde (MDA) equivalent. Body weight gain and feed consumption for the 3 strains (Ross, Cobb and WLH) were decreased by 32HS and 34HS, but not by 32-24-32HS. The decrease in weight gain of WLH chickens for the 32HS and 34HS conditions was smaller than for broiler chickens (Ross and Cobb). The 32HS and 34HS groups showed slightly enhanced MDA levels (P<0.05) in the skeletal muscle of all 3 strains, but not for the 32-24-32HS group. The results suggest that depression in growth performance due to chronic heat stress is more evident in meat-type chickens (Ross and Cobb) than male laying-type chickens (WLH), and that reduction in the performance are associated with enhancement of oxidative damage to skeletal muscle.

Evaluation of Growth Traits and Short-Term Laying Performance of Three Different Strains of Chicken in the Derived Savannah Zone of Nigeria

Growth evaluation and short-term egg laying performance of 360 commercial layers of thre e different strains, Brown shaver (BRS), Nera black (NB) and Black shaver (BLS) were studied at day old, 4, 8, 12, 16 and 20 weeks. Parameters measured were bodyweight, body length, breast girth and keel length. Body weight and other body dimensions were significantly (P<0.05) influenced by strain of chickens. Nera black layers consistently had the highest body parameters at all ages. Generally, body parameters increased with increasing age of the birds. The correlation coefficients amongst the body parameters revealed positively high and significant (P<0.05) relationship. Traits considered for egg laying performance were egg number and egg weight. Strains significantly (P<0.05) affected mean egg number and egg weight at weeks 4, 7 and 8; and 12, 13 and 15 respectively. BRS laid more eggs per bird than other genotypes, followed by NB and BLS, the least. Egg weight was highest in BRS, NB and BLS in that order. Estimates of correlation coefficient showed that the traits being considered are mostly positive but with low correlation of egg number to egg weight for BRS and BLS. Phenotypic correlations of egg traits were found to be negative between egg number and egg weights in NB.

Teratogenicity of ethanol in different chicken strains.

This study investigated the teratogenicity of ethanol in several different strains of chickens. The chick embryo provides a useful model for studying the fetal alcohol syndrome. Two broad classifications of chicks, each containing many strains, are commercially available for use: broilers and layers. Teratogenicity of ethanol in broilers and layers was studied by examining three different parameters: embryo weight, ratio of torso weight to head weight, and embryo viability. Broilers and layers experienced similar ethanol-induced reductions in embryo weight, Broiler embryos experienced a preferential ethanol-induced suppression of head growth. Differences in viability between different strains were found, but no clear pattern between broilers or layers could be determined, possibly due to environmental conditions. The data presented here suggest that the strain of chick and the handling of the eggs are important considerations when studying the teratogenicity of ethanol. An ethanol dose-response test should be periodically performed as a check on environmental conditions affecting the eggs--conditions that are beyond the control of the researcher.

Effects of aflatoxin B1 on liver microsomal enzymes in different strains of chickens

Administration of Aflatoxin B1 (AFB1) with safflower seed oil to hubbard chickens caused a significant increase in liver microsomal protein, electron transport components, and drug metabolizing enzymes. No alteration was observed in the activity of alanine and aspartate aminotransferases. AFB1 treatment with dimethylsulfoxide (DMSO) as a vehicle caused a significant decrease in electron transport components, drug metabolizing enzymes, and a significant increase in the activity of aspartate aminotransferase. Higher inhibition was observed at 1.5 mg/kg dose level of AFB1. Inhibition by AFB1 was maximal after 24 hr of treatment and decreased thereafter. AFB1 treatment with DMSO caused no significant change in electron transport components and drug metabolizing enzymes in Rhode Red Island (RRI) strain. Vancob male chickens showed significant decrease in electron transport components and drug metabolizing enzymes, while a significant increase was observed in vancob females. Results suggest that the effects of AFB1 depend on treatment vehicle, strain and sex of chickens.

Differences in eye growth and the response to visual deprivation in different strains of chicken

Several laboratories studying visual deprivation myopia in the domestic chick report varying degrees of axial elongation and myopia induced by similar visual deprivation techniques. In this study we tested the hypothesis that in different strains of chick the eyes respond differently to visual deprivation. We compared under identical conditions two strains of White Leghorn chick commonly used in ocular development research--the Cornell-K strain (K) and Washington H & N Strain (H/N). The normal development of the eye was found to vary significantly between these strains of White Leghorn chicks. The K strain normally develops flatter corneas, thicker lenses, and larger eyes than the H/N strain. The response to visual deprivation also varies significantly between strains. For example, we find that 2 weeks of visual deprivation in the K strain results in less elongation of the vitreous chamber and flattening of the cornea yielding lower levels of induced myopia compared to the H/N strain. Our results show that while visual experience clearly affects normal ocular development in both strains of chick, the nature of the effect depends upon not only the type and duration of the experience but the genetics of the subject population as well.

The Haugh Unit Correction for Egg Weight is not Adequate for Comparing Eggs from Chickens of Different Lines and Ages

The Haugh unit is the accepted commercial and research standard for measuring albumen quality of chicken eggs. This unit has been criticized because it assumes a fixed relation between egg weight and albumen height. However, the amount of albumen in an egg differs between genetic strains and changes with the age of the hen. Data are presented to show that no fixed regression is adequate for comparing eggs from hens of different strains of chickens. With the increasing age of the hen, the weight of the egg increases in a quadratic fashion while the albumen height decreases linearly. The Haugh unit also declines more rapidly than does the actual albumen height because of the overcompensation for egg weight in the Haugh unit calculation. Correlation coefficients between Haugh unit, albumen height, and the log of the albumen height were very high. When comparing eggs from diverse groups of hens, the Haugh unit correction for egg weight will likely introduce more error than it will eliminate.

Characterization of very virulent Marek's disease viruses isolated in Japan

Pathogenicity of two isolates of Marek's disease virus (MDV), MS1 and MS2, from chickens was examined in two genetically different strains of chickens, MD-susceptible P-2 chickens and less susceptible PDL-1 chickens. The isolates induced an early mortality syndrome unassociated with lymphoproliferative lesions in P-2 chickens. There were no significant differences in pathogenicity between our isolates and the Md/5 strain of very virulent MDV (vvMDV) in both P-2 and PDL-1 chickens. Protective indices of turkey herpes virus (HVT) vaccine against challenge with MS1 or MS2 in P-2 chickens were 54% and 28%, respectively, whereas HVT gave more than 80% protection in PDL-1 chickens. These results indicate that the two isolates could be classified as vvMDV. In contrast, a bivalent vaccine composed of HVT and serotype 2 MDV, and CVI988 vaccine gave good protection against challenge with the isolates in P-2 chickens; however, the best protection was given by the CBI988 vaccine. This is the first report of isolation of vvMDV in Japan.

Exposure of Chicken Embryos to Selected Magnetic Fields

Tests were made to determine whether the development of chicken embryos was altered by exposure to time-varying magnetic fields. Unipolar square waves with periods of 100μs, 1, 10, 20, and 30ms, and 20ms bipolar square and sinusoidal waves were tested. The nominal peak strength for each experiment was 1μT. Neither the morphogenesis of the embryo nor the temporal aspects of development was altered by any tested field. Fertile eggs of several different strains of chickens were also tested to determine whether strain sensitivity to certain magnetic fields can account for the reports of positive effects of magnetic fields upon development. No significant alterations were noted in the embryos of any of the tested strains. Published reports of alterations in development following exposure to similar low level magnetic fields have not been confirmed in this laboratory.

Cytotoxic T lymphocytes in reticuloendotheliosis virus‐infected chickens

Cytotoxic T lymphocytes were functionally demonstrated in spleen cells from chickens 7 days post inoculation with reticuloendotheliosis virus using a Cr-release assay. Major histocompatibility complex (MHC)-restricted cytotoxicity was demonstrated using effector and target cells from two different strains of chickens of known avian MHC haplotype. Anti-viral specificity was shown and in vivo generation of MHC-restricted cytotoxicity was evaluated. Cytotoxic T cells were distinguished from macrophages and natural killer cells. Their cytotoxicity was not antibody dependent. Higher levels of cytolysis were found with cytotoxic T cells from embryonally bursectomized vs. intact chickens over a large range of effector to target cell ratios. Using monoclonal antibodies, cytotoxic T cells were further defined as Ia+ T cells by immunofluorescence, antibody plus complement-mediated lysis of effector cells and blocking of cytolysis in the Cr-release assay.