Microclimate parameters (ammonia, ambient temperature, heat index, and relative humidity) surrounding birds affect the production and health status of poultry. Therefore, this study aimed to evaluate the impact of adding natural zeolite to the litter of Japanese quail on improving microclimate parameters and its reflection in growth performance, blood gases, and blood biochemical parameters. A total of 1152 chicks were obtained from the same hatch at the 20th selection generation. Chicks were allocated into two groups based on the litter composition: Group 1: wheat straw as litter (untreated group); Group 2: 80% wheat straw + 20% zeolite (treated group). Each group consisted of 576 chicks: 410 selected line chicks and 166 control line chicks. Significant and favorable effects of the treatment on microclimate parameters during tested periods were found to favor the treated group. Either the treated group or the selected line had significantly better growth performance than the untreated group and control line. Zeolite-treated quails had significantly desirable blood gases and lower blood acidity and serum total iron binding capacity compared to the untreated group. Thus, adding natural zeolite to the litter enhanced the microclimate parameters that improved growth performance, blood gases, and blood biochemical parameters and reduced ammonia emission.

The world is suffering from a protein shortage due to population growth and increased food demand, increasing the pressure on poultry breeders to boost production. Additionally, Japanese quail (JQ), with their small size, rapid growth, short generational interval, and high egg production, offer a promising solution to address this challenge. A ten-generation study conducted at Fayoum University Poultry Research Center involved 17,806 JQ chicks, which were divided into two lines: one was selected for fast growth rate from 1-21 days (FGR1-21), and the other line was the control line (CL). It aimed to investigate the consequences of selection, evaluate selection effectiveness for increased early growth rate (GR1-21). All studied growth traits were significantly influenced by generation, line, and sex effects, except for body weight at hatch (BW1) and GR1-21, where sex had an insignificant effect. The interaction effect between generation and line significantly affected all studied traits, favoring the FGR1-21 line in the 8th selected generation. The cumulative response based on two different methods was in the desired direction for all studied growth traits, except for BW1. This was based on breeding values. The GR1-21 was found to be positively correlated, either genetically or phenotypically, with all correlated traits except for BW1. All studied growth traits had moderate heritability (h ² ) estimates ranging from 0.18 to 0.32. It can be concluded that continuous selection for high growth rate has resulted in a well-established paternal line of JQ specialized in meat production, which can be proposed as a sustainable solution to address food security problems.

HIS study investigated growth patterns in two selected lines for rapid growth of native chickens: normal feathering (nana) and naked-neck (NANA/Nana). Body weights (BWs) of 800 chicks (400 per line) were recorded from hatch to 126 days of age at the Poultry Farm, Faculty of Agriculture, Cairo University, Egypt. Body weight data were fitted to three nonlinear regression models (Gompertz, Richards, and Logistic growth curves). Results showed significant line effects (P<0.001) on all BWs, with the nana line consistently heavier throughout the growth period. Sex effects were evident only at later ages (70, 112, and 126 days). Among the models, the Gompertz function provided the best fit across all goodness of fit criteria, followed by the Logistic model, while the Richards model ranked last. In the Gompertz model, the NANA/Nana line exhibited higher asymptotic weight and slower maturation compared with the nana line, reaching inflection points at later ages with greater body weights. The earlier maturity of the nana line may be advantageous under heat-stressed conditions, whereas the higher mature weight of the NANA/Nana line suggests potential value in breeding programs aiming at growth improvement.

A total of 150 weaned V- Line rabbits aged five weeks were used in this study. Rabbits were randomly distributed into five equal groups of three replications 10 rabbits each at similar average of initial weight (594.68±18.22g). All rabbits housed in galvanized wire cages within well-ventilated pen under similar hygienic and husbandry conditions. The 1st group consumed the basal diet in the absence of organic acids (control, T1). The 2nd and 3rd groups consumed control diet supplemented with 0.5 and 0.25% lactic acid, respectively, the 4th and 5th groups consumed control diet supplemented with 0.5 and 0.25% citric acid, respectively. Feeding rabbits on a diet containing lactic acid at either 0.25 or 0.5% led to a significant improvement in all final growth traits, superior those received diet supplemented with citric acid and control group. Regarding carcass traits, the feeding on diets containing organic acids did not show any significant differences for the carcass characteristics. Regarding blood parameters there were no significant effects of the dietary treatments on the different blood and hematology measures, except for total lymphocytes and blood urea, which increased significantly in favor of rabbits fed lactic acid 0.5%. Economically, rabbits fed on supplemented diets with lactic acid at two levels0.5% and 0.25% had higher economic efficiency and relative economic efficiency compared to control and groups fed on citric acid at two levels

This work aimed to study the consequences of selection for fast growth rate on some laying and fitness performance in Japanese quail using 1157 females (706 for the selected line and 451 for the control line). The most important results obtained as follows:Selection generation significantly affected all egg studied traits indicating that the 4th generation (G4) had the earliest age at first egg (AFE) and age at the first ten eggs (AGE10) accompanied by the heaviest body weight at first egg (BWAFE) and desirably had lower days needed to produce the first ten eggs (DN10) and laid heavier average egg weight (AEWFM) (48.98, 60.87, 260.77, 13.12 and 11.88 respectively) and had higher number of eggs (ENFM), heavier egg mass for the first month of production (EMFM), and favorably lower pause duration length (PDL‌FM) than other generations being of 24.53, 291.32 and 1.76, respectively. Moreover, the G4 had higher fertility (88.20%) and hatchability (85.42%) associated with preferably lower early and late embryonic mortality% than other generations.The selected line attained AFE at earlier age (50.63 day) with heavier BWAFE (260.59g) and lower DN10 (14.06 day) and AGE10 (64.44 day), laid more ENFM (22.63egg), higher EMFM (263.67g), earlier age after first month of production (AGEFM, 80.63 day), larger clutch size (CSFM, 5.20) and shorter PDLFM (1.89 day) and had preferably higher fertility (80.69%), hatchability (74.14%) but undesirably higher early embryonic mortality% (2.68%) than those of the control line.Since selection for high growth rate during 1-21 days of age (GR1-21) resulted in favorable negative correlations with each of AFE, DN10, AGE10, PDLFM and AGEFM and had preferably positive rg’s with each of BWAFE, ENFM, EMFM, clutch number for the first month of production (CNFM) and CSFM, it seemed these traits can be indirectly improved through the selection for fast GR1-21.

Egg production data used in this work were obtained from records of Fayoumi chickens flock belongs to El-Takamoly poultry project at Al-Azab, Fayoum Governorate. Egg production records over a 52-wk egg laying period related to 1900 hens. All data was summarized on a weekly basis as eggs per hen per week on hen-day (survivor) basis. Regarding Wood and McNally models, (a) stands for initial egg production, (a) parameter value was very low (0.001) for both models. The increasing rate to the egg production peak (parameter b) was 2.90 for the Wood model and 2.19 for the McNally model. Similarly, parameter c, the decreasing rate of egg production from the peak, was estimated to be 0.08 for the Wood model and 0.06 for the McNally model. Depending on compartmental function m, n, p and q represent scale parameter, measure of persistency of egg production, sexual maturity rate, and age at first egg, respectively and estimated values for these parameters were 86.47, 0.01, 0.23 and 21.61, respectively, Concerning the modified compartmental model the parameters A, B, C and D represent a scale parameter, the rate of decrease in laying ability, the reciprocal indicator of the variation in sexual maturity, and the mean age of sexual maturity of the hens, respectively. In this work the estimated values of the abovementioned parameters were 75.26, 0.006, 1.14 and 24.96 for A, B ,C and D respectively. According to goodness of fit criteria, modified compartmental model was the best model for describing the egg-laying pattern of Fayoumi layers which had the lowest Akaike information criterion and Bayesian information criterion values and the highest coefficient of determination. Moreover, the modified compartmental model showed correspondence with the actual hen day of egg production (age and percentage at peak were 29.44 weeks of age and 64.16%, respectively).