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The number of eggs produced in a given period (egg production rate) is an important trait in layers that change over time and can be presented as a curve. This study aimed to fit the weekly egg production data of Khazak indigenous hens using non-linear regression models and to select an appropriate model for describing the egg production curve for this bird. Biweekly egg production of 144 laying hens over 52 weeks of egg production was used to evaluate the egg production curve. Seven non-linear models (Gamma, McNally, Compartmental II, Nelder, Yang, Lokhorst, and Narushin-Takma) were fitted to egg production data. The four goodness fit criteria (Akaike' s information criterion, Mean square error, Log Likelihood, and Bayesian information criterion) were used to compare the models. The results of the goodness of fit criteria showed that the Narushin-Takma and Yang models were the best and worst models, respectively, for describing the egg production curve of Khazak hens. The time and egg production at the peak with the Narushin-Takma model was similar to the actual values, and this model was significantly better than other studied models. The correlation between actual and predicted egg production indicated that the Narushin-Takma model could accurately predict the egg production of this breed. As a result, the Narushin-Takma model can be used to predict the egg production curve of Khazak hens in breeding programs and nutritional management. [ABSTRACT FROM AUTHOR]

Lysozyme activity is one of the nonspecific immunity parameters measured by changing the amount of adsorption at different times. The objective of the present study was to compare five non-linear models including Gompertz, Richards, Logistic, Lopez, and Weilbull to describe the cumulative plasma lysozyme activity in quails. In total 1364 plasma samples (1004 females and 360 males) were collected and the cumulative lysozyme activity was calculated by turbidimetric method assay in Micrococcus luteus. The goodness-of-fit of models was compared according to different criteria of Maximum loglikelihood, Akaike information criterion, Mean square error, and Bayesian information criterion. The results showed that the Gompertz model was the best model for describing of decreasing cumulative pattern of lysozyme activity in female and male quails and provided satisfactory predictions of lysozyme activity at different times (30, 60, 90, 120, 150, 180, 210, 240, 270, 300 seconds). The parameters of all models were higher in females than males except for the k parameter which was greater in the males. Male quails had higher values for time and lysozyme activity than females at inflection points, whereas the absolute growth rate in 30, 150, and 300 seconds was predicted higher in female quails. In conclusion, the Gompertz model can be used accurately to evaluate cumulative lysozyme activity patterns in both sexes of quails. [ABSTRACT FROM AUTHOR]

The present study was conducted to evaluate aflatoxin B1 (AFB1) detoxification effects of some medicinal plants under both in vitro and in vivo. The in vitro experiment was performed with 25 treatments in 5 replications. The samples of medicinal plants were incubated with AFB1 for 72 h, and the toxin residual in the supernatant was determined. The highest aflatoxin elimination was found to be related to peppermint (81%). Thereafter, in vivo experiment was conducted to investigate the effects of peppermint dried leaves, essential oil, and menthol on liver, bone, and meat, as well as the performance of growing Japanese quail fed diet contaminated with AFB1. A total of 640 7-day-old Japanese quails were assigned using a completely randomized design as 2 × 4 factorial arrangement with two levels of AFB1 (including 0 and 2.5 mg/kg diet) and four treatments (including no additive; peppermint powder, 20 g/kg; peppermint essential oil, 800 mg/kg; and menthol powder, 400 mg/kg). Those birds fed AFB1-contaminated diet with no additives showed the worst liver health status by considering super oxide dismutase (P = 0.0399), glutathione peroxidase (P = 0.0139), alanine aminotransferase (P < 0.0001), and aspartate aminotransferase levels (P = 0.0512). However, the supplementation of AFB1 contaminated diet with additives improved their liver health status. Menthol receiving birds showed the highest tibia strength, while the birds fed with AFB1-contaminated diet with no additives had the weakest bone strength (P < 0.0001). A significant increase was also observed in malondialdehyde level of meat by dietary inclusion of AFB1, which was well-repressed by the dietary supplementation of peppermint essential oil and menthol (P = 0.0075). Body weight gain dramatically decreased by adding AFB1 to the diet, which was recovered with the dietary supplementation of additives (P = 0.0585). According to the results of the current study, peppermint and its derivatives can be used to suppress aflatoxin effects on the liver, bone, and meat quality and to improve the performance of Japanese quails. [ABSTRACT FROM AUTHOR]

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., Competing Interests: Declaration of competing interest The authors whose names are listed immediately below certify that they have NO affiliations with or involvement in any organization or entity with any financial interest (such as honoraria; educational grants; participation in speakers’ bureaus; membership, employment, consultancies, stock ownership, or other equity interest; and expert testimony or patent-licensing arrangements), or non-financial interest (such as personal or professional relationships, affiliations, knowledge or beliefs) in the subject matter or materials discussed in this manuscript., (Copyright © 2024. Published by Elsevier Inc.)