Comparative Effects of Including Inorganic, Organic, and Hydroxy Zinc Sources on Growth Development, Egg Quality, Mineral Excretion, and Bone Health of Laying Quails.

The purpose of this study was to determine the effects of the dietary addition of zinc (Zn) in the form of sulphate (Zn-S), glycine (Zn-G), and hydroxychloride (Zn-H) on quail performance, eggshell quality, antioxidant status, mineral excretion, biomechanical properties and mineralization of bone. A total of 75 female quails (10-weeks-old) were randomly distributed into 3 groups with 5 replications, each with 5 female quails. Treatment groups were set up by adding Zn-S and Zn-H as the inorganic form and Zn-G as the organic form of zinc to the corn-soybean basal diet (34.14 mg/kg Zn) to obtain 50 mg/kg Zn and the feeding experiment lasted for 12 weeks. Performance parameters and egg production were not impaired by the Zn source (P > 0.05). The inclusion of Zn-S in the diet produced a reduction in eggshell thickness, while an improvement in yolk antioxidant capacity (measured as MDA concentration) was detected compared to the other Zn sources (P < 0.05). Shear strength and cortical bone area increased (P < 0.05) with Zn-G supplementation, however, the mineral concentration of the tibia was higher (P < 0.01) in those quails who had received Zn-H. Lower levels of mineral excretion were observed in both types of supplementations compared to Zn-S. Therefore, it can be stated that Zn-G or Zn-H supplementation in the diet of laying quails could be an interesting strategy to reduce mineral excretion and improve bone mineralization without affecting performance compared to Zn-S. However, further studies are needed to determine the differences between Zn-G and Zn-H.

Does the addition of choline and/or betaine to diets reduce the methionine requirements of laying quails? Assessment of performance and egg antioxidant capacity.

The purpose of the present study was to assess the performance, quality of eggs internally and externally, and antioxidant capacity of yolks in laying quails with the administration of choline and betaine to diets containing reduced methionine levels. A total of 150 Japanese laying quails (Coturnix coturnix japonica) at the 10-wk age were randomly assigned to 6 experimental groups, each consisting of 5 replicates and 5 birds for 10 wk. The treatment diets were designed by adding the following substances: 0.45% methionine (C), 0.30% methionine (LM), 0.30% methionine + 0.15% choline (LMC), 0.30% methionine + 0.20% betaine (LMB), 0.30% methionine + 0.075% choline + 0.10% betaine (LMCB1), 0.30% methionine + 0.15% choline + 0.20% betaine (LMCB2). The treatments did not affect performance, egg production, or egg internal quality (P > 0.05). No significant effect was determined on the damaged egg rate (P > 0.05), but the egg-breaking strength, eggshell thickness, and eggshell relative weight decreased in the LMCB2 group (P < 0.05). Regarding lipid peroxidation, treatments did not affect the yolk 2,2 diphenyl-1-picrylhydrazyl value (P > 0.05), although the lowest thiobarbituric acid reactive substances value was observed in the LMB compared to the control group (P < 0.05). It may be summarized that methionine can be decreased to levels of 0.30% for laying quail diets with no negative effect on performance, egg production, or egg internal quality, whereas the combination of methionine (0.30%) and betaine (0.2%) could improve antioxidant stability of eggs over the 10-wk experimental period. These findings provide useful information to the traditional recommendations on the requirements of laying quail. However, further studies are needed to test whether these effects persist throughout extended study periods.

Effect of increasing valine level in the diet on performance, egg quality, and serum components in laying quails.

This research was conducted to determine the effect of increasing dietary valine level on performance parameters, egg quality criteria, and blood and serum components. In the study, 120 female Japanese quails at the age of 10 weeks (241.4 ± 8.6 g) did randomly allocate to six experimental groups contained five subgroups. Treatment diets were prepared to contain 0.93% (control), 1.00%, 1.10%, 1.20%, 1.30%, or 1.40% valine. The egg mass decreased linearly with the increasing level of valine in the diet, while egg weight decreased in both linear and quadratic manner (P < 0.05). Increased levels of dietary valine increased eggshell breaking strength in cubic manner (P < 0.05). The administration of the valine to the diet caused a linear decrease in the albumin index and Haugh unit (P < 0.05). Other egg quality parameters were not affected (P > 0.05). Serum glucose and triglyceride concentrations of laying quails were reduced by the increasing dietary valine levels; the effect on serum glucose was linear, while both linear and quadratic effects were significant on triglyceride concentration (P < 0.05). White blood cell, lymphocyte, and neutrophil counts increased with the increasing dietary levels of valine (P < 0.05). Both linear and quadratic effects were significant on white blood cells and lymphocytes, while the effect on neutrophil counts was linear. However, erythrocyte and haematocrit (P < 0.05) decreased quadratically with increment in the dietary levels of valine. In conclusion, the increased valine levels in the diet adversely affected the egg weight, egg mass, and Haugh unit. but it reduced the serum triglyceride and glucose. Results may suggest that dietary valine at 0.93% level is sufficient for egg production and egg quality in laying quails, but positive effects of increased dietary valine levels on white blood cells may worth to investigate further.

Performance, Egg Quality, and Yolk Antioxidant Capacity of the Laying Quail in Response to Dietary Choline Levels.

The current study determined the ideal dose of choline in the diet of laying quails based on egg development, egg quality, and antioxidant capacity. A total of 120 female quails (244.7 ± 10.38 g) were randomly assigned to 6 experimental groups with 5 replicates of 4 quails each. In the 10-week trial, treatment diets were formed by adding 6 choline chloride−60% concentrations providing 1500 (control), 2000, 2500, 3000, 3500, and 4000 mg/kg of choline. The feed intake of quails was quadratically affected (p < 0.05) by the choline level of the diet, in other developmental parameters, and by egg quality among these treatments. The feed intake was reduced to 2500 and 3000 mg/kg levels of choline in the diet compared to the control group. Free radical scavenging capacity (DPPH) of the yolk increased linearly (p < 0.001) with dietary choline levels. In contrast, the thiobarbituric acid reactive substances (TBARS) value decreased as dietary choline levels increased, except for 4000 mg/kg levels. Based on the findings of the current study, 1500 mg/kg of dietary choline is adequate to maintain performance parameters and egg quality in laying quails. However, to increase egg antioxidant capacity, in terms of the DPPH value, the dietary choline dose needs to be increased to 3500 mg/kg.

Use of Maca Powder (Lepidium meyenii) as Feed Additive in Diets of Laying Quails at Different Ages: Its Effect on Performance, Eggshell Quality, Serum, Ileum, and Bone Properties.

Using additives can reduce the negative effects of aging on factors affecting profitability, such as the availability of nutrients, production, and egg quality. Maca is an herbaceous plant rich in protein, crude oil, essential acids, and pharmacological compounds. Maca has positive effects on different health parameters. In this study, the effect of adding Maca powder to the diets of young and old laying quails at the end of the 10-week trial was investigated. In total, 150 laying Japanese quails (Coturnix japonica) (209.1 ± 10.0 g) were randomly distributed to a 2 × 3 factorial arrangement with two ages (10 weeks and 30 weeks) and three Maca powder levels (0, 1, or 2 g/kg), with five subgroups per treatment. According to the study, eggshell quality, total cholesterol, triglyceride, progesterone, and testosterone concentrations of serum were lower in old quail than in young quail, while egg weight, feed intake, and follicle-stimulating hormone increased significantly as quail aged. (p < 0.05). Furthermore, aging negatively affected the histomorphology of the ileum and cortical bone thickness (p < 0.05). Additional findings show that adding 1 g/kg Maca powder to the diet of quail significantly improved eggshell, ileum, and bone traits that deteriorate with age, without affecting performance, and adding 2 g/kg Maca powder to the diet significantly reduced serum total cholesterol levels (p < 0.05). Incorporating Maca powder into the diet of aged birds could reduce the negative effects of aging.

Effect of maca powder supplementation to growing quail diets on performance, carcass, serum constituents and hormones, and bone and ileum characteristics.

The aim of this study was to investigate the effects of different levels of maca powder supplementation (0.0, 0.5, 1.0, 1.5, 2.0, and 2.5 g/kg) in the diet on performance, carcass characteristics, serum biochemical constituents and hormone concentrations, bone biomechanical properties, and ileum histomorphology in growing Japanese quails. In this 42-day trial, a total of 480 mixed sex Japanese quail chicks, aged 1 day, were randomly distributed among six experimental groups. Each experimental group contained four replicates of 20 chicks each. The addition of 2.0 g/kg of maca powder to the diet significantly decreased body weight, body weight gain compared to the control group (P < 0.05). In addition, with the 1.5 g/kg level of maca powder, feed efficiency improved considerably (P < 0.05). The testis weight increased significantly with the addition of maca powder at 1.0 g/kg level to the diet, and testesteron concentration of serum in male quails was also increased significantly at 1.5 g/kg level of maca powder compared to control group (P < 0.05). The addition of 2.5 g/kg level of maca powder significantly reduced the cholesterol concentration of serum in male quails compared to the control group (P < 0.05). The administration of 2.0 g/kg level of maca powder to the diet caused a decrease in shear force (P < 0.05). The addition of maca powder to the diet significantly increased crypt depth and villus surface area at 0.5 g/kg level, villus width at 1.0 g/kg level, and villus height at 2.0 g/kg level in growing quails (P < 0.05). According to the results obtained from the present research, it can be said that the addition up to 2.0 g/kg maca powder to growing quail diets could improve feed efficiency, testesteron concentration of serum, and ileum properties.