Poultry Science Journal
Volume:9 Issue: 2, Summer -Autumn 2021

This review article provides a general overview of advanced molecular techniques and their implementation in the genetic improvement of poultry and presents the potential application of these techniques in developing countries. Advances in molecular genetics have contributed to a significant rate of genetic progress in domestic fowl, especially for traits that are difficult to improve through conventional breeding methods. Compared to developed nations, however, the application of molecular techniques for the genetic improvement of poultry is limited in most developing countries due to a lack of infrastructure, capital, and human resources. This does not mean that it is an impossible task. To implement molecular techniques in developing countries, the potential merit of using these tools for the genetic improvement of poultry should be evaluated in terms of economic costs and benefits of the technology compared with conventional breeding. The existence of conventional genetic evaluation and selection programs is also a prerequisite, along with well-established research institutions and well-trained human resources. More important are the cooperation and partnership with academic and research institutions in developed countries to address challenges in applying molecular tools and associated infrastructures to implement genomic selection in developing countries.

Discarded as waste with the production of several tonnes per day, eggshell is a solid waste from poultry industry. Eggshell waste disposal pollutes the ecosystem by being accumulated in landfills, invites insects,   which involves high management cost. Given its beneficial effects, eggshells are valuable when transformed to new values. In other words, eggshell contains a high amount of calcium component, which contributes several benefits to human beings as well as the ecosystem. In tablet form, for instance, it supplements human health by strengthening bones to treat osteoporosis and protect teeth  stabilization. As a food additive, eggshell powder finds its place in cuisines and confectionaries. it also acts a catalyst in biodiesel production, acts as an absorbent in heavy metal removal in soil and water and is a stabilizer in civil industry. Eggshells are potentially utilized as a UV protectant in nylon and polystyrenes and are potentially used in cosmetic industry for several anti-aging skin care formulations. For sustainable agriculture, eggshells act as manure or soil stabilizer to enhance plant health.  The current review details the utilization methods of eggshell by transforming it into new forms.

One experiment was carried out to investigate the effect of low crude protein (CP) diets supplemented with crystalline essential amino acids (EAAs) on growth performance, meat quality, and nitrogen retention in Japanese quails reared from 1 to 35 days of age. A total of 840 unsexed one-day-old quail chicks were used in a completely randomized design consisting of seven treatments with six replicates and 20 birds in each. In addition to the control diet, two negative control diets were also adjusted to contain 10 and 20% lower CP than the control (LP10 and LP20 diets, respectively). The EAAs/CP ratio was similar to that of the control diet. Also, four rations supplemented with amino acids were formulated to contain 10% (LP10+EAAs10 and LP20+EAAs10) or 20% (LP10+EAAs20 and LP20+EAAs20) higher EAAs than LP10 and LP20. Crude protein digestibility was determined using the total collection method at 21 and 35 d of age. After slaughtering at 21 and 35 d of age, whole-breast meats were dissected out to determine meat quality indices. During 1 - 21d of age, 10 or 20% reduction in CP significantly decreased body weight gain and increased feed conversion ratio; however, amino acid supplementation significantly improved body weight gain and feed conversion ratio (P < 0.05). During 1- 35 d of age, reduction of CP to 20% led to decreased body weight gain in EAAs supplemented and un-supplemented diets. Dietary treatments did not have any significant effect on the breast meat quality variables except for pH. At 35d of age, 20% reduction in dietary CP significantly reduced nitrogen retention percentage. Overall, a 10% reduction in dietary CP without EAAs supplementation had no adverse effect on the growth performance of Japanese quails during the 1 to 35d of age.

In this experiment, the effect of fermented sesame meal or its combination with probiotics was evaluated on performance, carcass traits, blood parameters, and humoral immunity of Japanese quails. In a completely randomized design, 480 seven-day-old Japanese quails were assigned to eight treatments, four replicates, and fifteen chicks per replicate. Treatments were corn-soybean meal diet as a basal or control group (1), and basal diet containing  35% of sesame meal (2), 35% of fermented sesame meal with Saccharomyces cerevisiae (3), 35% of sesame meal + Saccharomyces cerevisiae probiotic (4), 35% of fermented sesame meal with Bacillus subtilis (5), 35% of sesame meal + Bacillus subtilis probiotic (6) 35% of sesame fermented meal with Lactobacillus sakei (7), and 35%  of sesame meal + Lactobacillus sakei probiotic (8). The study results indicated that treatments with sesame meal, compared to control treatment, had no significant effects on the performance and blood parameters of Japanese quails. Birds fed with a diet containing 35% of fermented sesame meal with Saccharomyces cerevisiae had a lower relative liver weight than the control treatment, whereas birds fed with a diet containing 35% sesame meal plus Lactobacillus sakei probiotic had a greater relative liver weight (P < 0.05). Treatment with fermented sesame meal with Saccharomyces cerevisiae had a higher level of antibody produced against sheep red blood cells and Newcastle virus than those of the control group (P < 0.05). Findings revealed that up to 35% of sesame meal not only does not impair the performance of Japanese quails, and fermenting of this protein supply but can also improves the birds’ health.

Dielectric properties (dielectric constant & dielectric loss factor) of chicken manure in the temperature range of 10-70  and moisture contents of 15%, 25%, 35%, and 40% (wet basis), were determined using Agilent high temperature open-ended coaxial probe coupled with vector network analyzer in the frequency range 10 MHz to 14 GHz. It is observed that the dielectric constant and dielectric loss factor decrease with an increase of frequency at all temperatures. Moreover, these properties increase smoothly with temperature and moisture content up to ~40  and beyond it, values increase abruptly at all frequencies. The penetration depths of the electromagnetic field in chicken manure samples were calculated at ISM (industrial, scientific and medical) frequencies of 13, 27, 40, 915, 2450, and 5800 MHz by making use of measured dielectric properties and it was observed that these depths decrease with increase in frequency at all moisture content and temperatures. The data of dielectric properties and penetration depths presented in this paper helps to develop the radio frequency/microwave applicators for providing dielectric heat treatment to chicken manure for various applications such as drying, disinfestation, pasteurization etc.

A number of 144 male Ross-308 broiler chicks (18-day old) were used to investigate the effects of extra nutritional vitamin D3 levels on the physiological response of broiler chicks exposed to lactic acidosis stress. Effects of the six experimental treatment consisting subcutaneous (SC) injection of 0 (control- and control+), 20000, 30000, 40000, and 50000 IU of vitamin D3 were examined in four replicates of six birds in a complete randomized block design during days 21 to 29 of age. Lactic acidosis is a form of metabolic acidosis that begins when a bird overproduces or underutilizes lactic acid, and their body is not able to adjust to these changes. Liver fat percentage decreased in the birds receiving 50000 IU of vitamin D3 compared with the control birds (P < 0.036). Administration of 30000 IU vitamin D3 enhanced serum concentration of creatinine by 18.52 percent compared with the control+ birds (P < 0.0001). Injection of 50000 and 40000 IU vitamin D3 decreased serum concentration of lactate dehydrogenase by 24.99 and 19.81 percent, respectively, compared with the control+ birds (P < 0.0003). The mean serum activity of alanine aminotransferase in the birds receiving 20000 IU vitamin D3 was greater by 28.57, 18.84, and 17.32 percent, compared with the control+ birds and those received 40000 and 50000 IU, respectively (P < 0.008). It was concluded that administration of extra nutritional vitamin D3 up to 50000 IU per bird resulted in broad but inconsistent changes in the blood biochemical and enzymatic parameters in birds exposed to lactic acid. No firm evidence was found to suggest a protective effect vitamin D3 on the incidence of sudden death syndrome in broilers during lactic acidosis.

The effect of different levels of Scrophularia striata extract in normal and challenged conditions with E. coli on performance, carcass characteristics, cellular immune response, blood antioxidant status, intestinal histo-morphometry, and microbial population (E.coli and Lactobacillus) of Cobb 500 broilers were evaluated. The experiment was performed in a complete block design with a 2 × 4 factorial arrangement with five replications of 10 birds each for 35 days in two separated halls [include challenge (C) and non-challenge (N)] with similar experimental conditions. Experimental treatments in two breeding halls were: 1) basal diet or control (CONT), 2) basal diet + 0.1 g/kg of herbal extract (EXTR 1), 3) basal diet +0.2 g/kg of herbal extract (EXTR 2), 4) Basal diet +0.1 g/kg an antibiotic (Oxytetracycline) (ANTB). On the 16th and 24th days of the experiment, one dose of 1×107 CFU K99 E. Coli was gavaged to chickens in a challenged conditioned hall. The results showed that average body weight and daily weight gain in the whole period (days 35 and 1-35) in EXTR 2 was better than the control treatment (P < 0.05). The percentage of breast weight in the ANTB was significantly different from the control treatment (P < 0.05). Glutathione peroxidase (GPX) in EXTR 2 was better than the control treatment (P < 0.05). Malondialdehyde (MDA) in EXTR 1 was significantly lower than the control group (P < 0.05). The values of E. coli in the treatment ANTB were less than control treatment (P < 0.05). Lactobacillus value in treatment EXTR 2 was higher than control treatment (P < 0.05). The value of total immunoglobulin in 28 days in ANTB, EXTR 1, and EXTR 2 were significantly higher than that of control treatment (P < 0.05). The length of villi was affected by treatments (P < 0.05). In conclusion, dietary inclusion of 0.2 g/kg of Scrophularia striata extract may improve the health status of the birds during E. coli challenge.

This study was performed to evaluate the decisions of the contracted broiler enterprises for the integrated company selection in terms of 5 criteria (C1: Stability, C2: Crisis management, C3: Profitability C4: Flexibility, C5: Supply). In this study, 68 enterprises were selected with stratified random sampling among the broiler enterprises, operating in Sakarya (12.0%), Bolu (11.0%) and Ankara (3.2%) those constitute 24.2%  of contracted broiler enterprises in Turkey in 2017. The research was conducted with two large scales (A and B) and two small scales (C and D) integrated companies in the broiler sector, where broiler enterprises produce under a contract. According to these 5 criteria, the optimum selection of integrated companies of broiler enterprises among A, B, C, and D was analyzed using Analytical Hierarchy Process (AHP). As a result of the analysis, the importance level of C1, C2, C3, C4, and C5 criteria among 5 criteria was found strategically significant at 46.0%, 20.0%, 18.0%, 10.0% and 6.0%, respectively. Thus, C1 criterion was determined as the most dominant criterion. The selection weights of integrated companies A, B, C, and D were 34.5%, 36.7%, 12.6% and 17.1%, respectively. This result shows that working with large-scale A and B integrated companies is strategically advantageous for broiler enterprises.

Chicken meat is one of the main sources of cheap, great quality, and nutritious protein. The purpose of this study was to analyze the strengths, weaknesses, opportunities, and threats (SWOT) chicken meat safety for practical solutions during the COVID-19 pandemic. A cross-sectional mixed-method study was designed. First, semi-structured, face-to-face interviews were conducted with 14 experts in the chicken meat industry. They were selected through purposive sampling. Then, an online questionnaire with the characteristics of participants in knowledge, attitude, and practice about the safety of chicken meat during the COVID-19 pandemic was sent through WhatsApp Messenger to 179 households in Tehran, Iran. The quantitative data were analyzed by the SPSS, and then SWOT analysis was done based on both qualitative and quantitative findings. Five categories and eight themes with 35 subthemes were extracted about safety challenges in the chicken meat industry according to the views of stakeholders. In the second phase, the majority of participants had moderate knowledge (65.5%), a positive attitude (64.8%), and acceptable practice (67%) toward the safety of chicken meat. The SWOT analysis showed the up-to-date strategy and regulations (S), mismanagement (W), privatization and export of chicken (O), and sanctions (T) as the most important factors influencing the safety of chicken meat from production to consumption in Iran. The chief weaknesses of the poultry industry are mismanagement and lack of policy and planning in all sectors. The government must sustain a continuous plan for the allocation of poultry inputs. This will assist the associated supervisors in designing and offering strategies to develop the chicken meat industry. Policymakers can use the SWOT analysis results for practical solutions and potential future strengthening actions of chicken meat safety to increase public health during the COVID-19 pandemic.

This study aimed to evaluate the effects of dietary Nutrition Bio-Shield Superfood® (NBS) supplement on the growth performance, intestinal morphology, immune response, and blood metabolites in broiler chicks. A total of 360 one-day-old Ross 308 broilers were used in a 42-d experiment. Based on a completely randomized design, the birds were allotted to 5 dietary treatments with 5 floor pen replicates of 12 birds each. Treatments included supplementation of 0, 0.5, 1, 1.5, and 2 g/kg of NBS to a basal diet. Feed conversion ratio (FCR) during 25-42 d and 1-42 d were linearly improved (P ≤ 0.05) with increasing levels of dietary NBS. During these periods, FCR in groups that received 1 and 2 g/kg of NBS was significantly lower than the control group (P < 0.05). Dietary supplementation of NBS at 1 and 1.5 g/kg of the diet increased serum IgM level compared to all other treatments. Villus height (VH) and VH to crypt depth (CD) ratio showed a quadratic response to the treatments (P = 0.05 and P = 0.04, respectively), decreasing with the supplementation of 1.5 and 1 g/kg of NBS, respectively. The thickness of the muscle layer in the jejunum was increased by 2 g/kg of NBS compared to the control group. Feeding NBS had no significant effect on carcass traits and blood metabolites. In general, dietary NBS supplementation improves FCR, immune status, and jejunum histomorphology in broiler chickens.

Past studies have shown a link between maternal condition or resource availability, and the resultant sex ratio of offspring in avian species, both wild and domesticated. This study utilized 200 male and 400 female chicks from a W-36 white leghorn parent stock and assessed the effects of three diets with different caloric and protein concentrations on the sex ratios of the Hy-Line W-36 laying hens. As expected, the development of both parent and filial generations was significantly affected by diet or egg composition, respectively. Sex ratio was not significantly different from an assumed population proportion of 0.50 across all experimental groups, but did approach significance among offspring of parents switched from “High” to “Control” diets at 17 weeks of age. Results suggest that continual availability of either high- or low-nutrient density feed resources does not predispose hens to bias the sex ratio of their offspring; however, a sudden change in diet, particularly to one of lower protein concentration, may influence such an effect. Further trials are needed to assess the efficacy of diet alteration prior to reproductive maturity as a means of sex allocation manipulation.

Egg productivity and quality are essential quantitative traits controlled by many genes, including those encoding bone morphogenetic receptor 1B (BMPR1B) and prolactin (PRL). This study aimed to identify the polymorphisms of BMPR1B and PRL and their association with egg productivity and quality traits in Japanese quail. The phenotypes of 73 female quails raised under an individual cage system were investigated, and their blood samples were analyzed. The phenotypes investigated included egg production, body weight at 1 to 6 weeks, egg weight, egg index, eggshell weight, eggshell thickness, albumen index, yolk index, yolk score, yolk weight, albumen weight, yolk ratio, albumen ratio, and Haugh unit. The polymorphisms of BMPR1B in exon 9 and intron 10 were investigated using the polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method, while a 24 bp indel of PRL located in promoter region was directly detected by examining the size of the PCR products (154/130 bp). The association between BMPR1B and PRL polymorphisms with egg productivity and quality traits was analyzed using an independent sample t-test. The result showed that the BMPR1B did not have polymorphisms. On the other hand, two genotypes, DD and ID, were found for the 24 bp indel of PRL. Moreover, the t-test analysis results indicated no association between the 24 bp indel of PRL and egg productivity and quality (P > 0.05). In conclusion, BMPR1B was monomorphic, and PRL polymorphisms did not affect the egg productivity and quality traits of Japanese quails.