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The availability of calcium (Ca) in poultry diets is influenced by various factors, such as the feed ingredients used. This study assessed the apparent ileal digestibility (AID) and standardized ileal digestibility (SID) of Ca in barley and soybean meal (SBM) in young quail chicks using a direct method. Three diets were formulated, including a Ca-free basal diet to evaluate ileal endogenous calcium losses (IECaL), and two diets with barley or SBM as the sole Ca sources. Titanium dioxide was used as an indigestible marker for IECaL measurement. On day 30, 300 male quail chicks were distributed into the three dietary treatments, and ileal digesta samples were collected for Ca content analysis on day 34. Endogenous ileal Ca loss was determined to be 336 ± 52.7 mg/kg of dry matter intake (DMI), providing a reference for calculating SID values. The AID and SID of Ca in barley were found to be 27.9% and 39.9%, respectively, and for SBM, these values were 33.1% and 42.9%, respectively. These findings offer valuable insights into how to optimize poultry diets to ensure they receive adequate calcium, which is crucial for their overall health and productivity.

AbstractThe main goal of breeding programmes is to maximise the genetic improvement of the economic traits of farm animals. Beside the economic traits, the birds’ survival has directly influenced on the economic gain. Therefore, this study aimed to investigate the genetic relationship between survival and productive traits in Japanese quail. A total of 1854 records were collected during four generations from 2017 to 2019 in Khorasan Razavi Agricultural Research and Training Centre (KRARTC). Data were used to estimate the genetic correlations among quail survival (S) with egg weight (EW) and body weight gain (BWG) traits. Linear-threshold model was used to estimate (co)variance components, and genetic parameters of traits viathe Gibbs sampling method. The heritability of EW was 0.04, and the heritability estimates for survival at different ages ranged from 0.138 to 0.399 in joint analysis with EW. The highest negative genetic correlation between EW and S0–14(i.e. survival up to 14 d) was obtained as −0.704. The highest and lowest heritability of weight gain traits for BWG0–7and BWG7–14were 0.583 and 0.116, respectively. The analyses of BWG traits with survival at different ages revealed that the genetic correlations ranged from 0.015 (between BWG0–7and S0–14) to 0.638 (between BWG0–7and S0–7). This study showed that the genetic selection for survival at different ages could be effective. On the other hand, selection for BWG0–7could also indirectly improve the survival in quails because of the positive and high genetic correlation between BWG0–7with S0–7.HighlightsGenetic improvement of production traits in quail may lead to reduced survival in quail. Studies regarding on the survival of quail were yet not carried out.Heritability of the survival at different ages showed that genetic selection for this trait could improve the survival.Survival at different ages had a negative genetic correlation with egg weight (EW), and body weight gain (BWG) traits after 21 d of old.

An experiment was conducted to estimate the optimal calcium (Ca) requirement for growth performance and bone health in quail from 21 to 35 days posthatch. Five dietary treatments containing 0.45, 0.60, 0.75, 0.90, and 1.05 % Ca were evaluated in a completely randomized design with 6 replicates per treatment and 12 birds per pen. Body weight gain (BW gain; P= 0.04), tibia-Ca (P= 0.01), tibia ash (P= 0.01), and bone breaking strength (BBS; P= 0.01) increased quadratically with increasing dietary Ca levels, while feed conversion ratio (FCR) showed a tendency to decrease (P= 0.07). Based on the statistical model, the optimal Ca requirements for BW gain and FCR were estimated to range from 0.75 to 0.84 % and 0.74 to 0.83 %, respectively. The Ca requirements for the Seedor index, tibia mass, and tibia length were estimated to range from 0.83 to 0.87 %, 0.81 to 0.87 %, and 0.78 to 0.86 %, respectively. The corresponding values for tibia-Ca, tibia ash, and BBS ranged from 0.67 to 0.73 %, 0.68 to 0.73 %, and 0.75 to 0.83 %, respectively. The study revealed that Ca requirements for optimal bone density may exceed those for growth performance, indicating the need for dietary Ca recommendations to be influenced by bone health considerations. These findings suggest that dietary calcium levels between 0.75 % and 0.87 % are optimal for growth performance and bone health in quail during the post-hatch growth period, with higher levels potentially required to maximize bone density and strength.

Assessing nutrients’ relative bioavailability value (RBV) in poultry nutrition has been a prominent subject in the scientific literature for several decades. This method of nutritional evaluation is commonly used to appraise emerging sources of trace minerals and amino acid chelates. References outlining the method for estimating RBV have been available since the 1970s. However, a simplified approach to RBV estimation using the slope-ratio method without preceding statistical considerations to ensure validity and meet fundamental requirements may yield misleading conclusions. Using the slope-ratio method, which involves dividing the regression slope of the test ingredient by that of the reference, can cause uncertainties regarding statistical significance if the model’s probability is reported without confidence intervals (CIs) for the RBV estimates. Despite longstanding criticism regarding the misinterpretation and improper use of statistical tests and CIs, these issues persist in estimating RBV using the slope-ratio method. An additional concern is that the misuse of the slope-ratio method and the application of inappropriate statistical analyses can lead to the underestimation of the RBV of nutrients in poultry species. This means that improper application of these methods can cause inaccurately low RBV values, affecting the assessment of nutrient effectiveness. This review addresses the potential pitfalls in peer-reviewed articles within this field, with a particular focus on zinc bioavailability through a reevaluation of RBV data in broilers, laying hens, and honeybees.

Early growth traits in quails are considered as the growth performances before the inflection point which are genetically different from body weights (BW) at later stages. Moreover, in addition to growth performance, humoral immunity is moderately heritable and is considered in some breeding programs. However, estimating the direct genetic, particularly the maternal genetic correlations between growth and immunity in quail, are not studied sufficiently, which were the aims of the present study. The quails’ BW were recorded at hatch (BW0) to 25 d of age with a 5-d interval and body weight gains (BWG) were measured as average growth performance of the birds in a 5-d period. Antibody titer against Newcastle disease virus (IgN) was measured through the hemagglutination inhibition (HI) test. For titration of anti-SRBC antibodies (IgYand IgM), a hemagglutination microtiter assay was used. In general, growth records in 4,181 birds and humoral immune responses in 1,023 birds were assigned to the study. The genetic parameters were estimated by single-trait analysis via Gibb's sampling. After finding the best model for each trait, multi-trait analysis was done to estimate the direct and maternal genetic correlations. Direct heritabilities (h2) were estimated to be moderate for BW (0.481−0.551) and BWG (0.524−0.557), while h2for immune responses were low (0.035−0.079). Maternal environmental effect (c2) was only significant for BW0, BW5, and BWG0-5. Maternal heritabilities (m2) for BW and BWG were all lower than corresponding h2, ranging from 0.072 (BW25) to 0.098 (BW0). The m2for IgN (0.098) was more than 2.5 times greater than h2(0.040) for this trait. Direct (ra) and maternal (rm) genetic correlations between IgN-BW, IgY-BW, and IgY-BWG were negative, while ra and rm for IgM-BW, IgN-BWG, and IgM-BWG were positive. The rabetween humoral immune responses were low to moderate and rm was significant only for IgY-IgM (0.339). Given positive genetic correlations in BWG-IgN and BWG-IgM as well as positive genetic correlations between both IgN and IgM with IgY, it is suggested that including the BWG in the breeding programs would directly result in the improvement of the birds’ growth performance. It would also contribute indirectly to the improvement of the birds’ humoral immune responses.

In most countries, ostrich farming is considered a developing branch of the efficient poultry industry. The profitability of ostrich farm requires specific consideration of productions features such as the female fertility, egg production, hatchability, and growth performance. Hence, this study aimed to fit nonlinear functions to describe the ostrich egg production pattern to achieve the most appropriate and recommendable mathematical function for future studies. For this purpose, 14,507 daily records of 184 female ostriches in 5 production seasons (periods) during 2016 to 2021 were used. Five nonlinear functions including Incomplete gamma (Wood function), Corrected gamma (McNally), nonlinear Logistic (Yang), Logistic (Nelder), and Lokhorst were fitted for modeling the egg production curve in ostrich. The goodness of fit criteria's including Mean Square Error (MSE), Likelihood Ratio Test (LRT), Akaike Information Criterion (AIC), and Bayesian Information Criterion (BIC) were used to evaluate and selection of the best function. The results indicated that the Wood and the McNally functions with a slight difference in all fitting criteria were the best-fitted functions and the Yang function with the highest values of MSE, LRT, AIC, BIC, were the most inappropriate function to describe the ostrich egg production curve. The McNally and the Wood can be recommended as appropriate functions to describe egg production during 5 production seasons in the studied ostrich flock.

To have a better contribution to the poultry production community, the Poultry Science Association founded journals including Poultry Science(PS) at 1921. Now, after 100 yr of publishing, PS ranks between the top 10 journals in the category of “agriculture, dairy, and animal science”. One hundred years after publishing the first paper in PS, the poultry industry has been completely revolutionized. Hence, it will be interesting to establish scientometrics study of the PS development during the last century. Therefore, based on findings of the current study, among countries/authors’ collaborations, future research fronts, and possibility of hot topics in the coming years may be predictable. Accordingly, a total of 22,451 articles were retrieved. For content analyses, according to the PS categorization for subject areas, 14 different subject areas were developed, including “behavior, breeding and quantitative genetics, education and extension, health and welfare, immunology, management and environment, metabolism and nutrition, microbiology and virology, modeling, molecular biology, physiology and anatomy, production, products, processing and marketing, and reproduction”. Considering the 100-yr of PS, the most frequent subject area was “nutrition and metabolism” (14,109 articles), and “modeling” (1,114 articles) attracted less scholarly attention. However, considering the last decade (2011–2020), the most important subject area was “molecular biology” (1,420 of 2,466 articles; 57.58%), followed by “modeling” (544 of 1,144 articles; 48.88%). Moreover, the most frequent poultry species/strains were broilers (retrieved in 6,156 articles), followed by laying hens, turkeys, and quail. Considering collaboration of countries and researchers, it can be said that a total number of 108 countries contributed to PS, with the most prolific country being United States (with 9,421 articles; 43.16%), followed by China, Canada, the Netherlands, and Japan. Among the authors, Harms RH (287 articles), and Siegel PB (208) were the most prolific authors, and Siegel PB and Dunnington EA (71 articles) had more collaborations. To study keyword trends, including 3 time periods broilers was the central co-occurrent keyword, while the importance of chickens and turkeys declined during the time. Salmonellaspp. was a constant representative of poultry microbiology during 100 yr. While “nutrition and metabolism” was the most important subject area, nutrition-related keywords (major items) were not concentrated and co-occurred with a variety of keywords from different subject areas. While “molecular biology” ranked first over the past decade, the importance of “nutrition and metabolism” should not be ignored. In fact, in recent years, molecular basis of the nutrition has been studied. In big-data era and due to developing the molecular biology technologies, it seems that using mathematical modeling and computational methodologies will increase and probably remains as one of the most attractive research areas for scientists at least in the upcoming future decades.