Does the gradual increase in dietary zinc oxide supplementation can affect egg quality, serum indices, and productive performance of laying hens?

This study was conducted to evaluate the influence of increased supplementation of zinc oxide (ZnO) on performance, quality of egg, blood chemistry, and antioxidant ability in serum of laying chickens (Hisex Brown) reared from 22 to 34 weeks of age. Seventy-two 22-week-old laying hens (Hisex Brown) were haphazardly separated into 3 handling collections of 24 chickens (6 replicates per treatment and four laying hens per replicate). Dietary treatments included basal diet without zinc addition for control group while the 2nd and 3rd groups contained basal diet with 25 or 75 mg ZnO/kg diet. Results showed that the higher level of ZnO (75 mg ZnO/kg diet) elevated (P < 0.01) feed intake during all studied periods compared with the control group and other groups that contained ZnO. The handling groups supplied with 75 mg ZnO/kg diet gave the worst feed: egg ratio within the whole period and the intervals compared with the control and other ZnO levels. Supplementation of zinc decreased egg number and egg output when compared with the control groups. Egg quality traits were statistically differed due to dietary ZnO supplementation except egg shape index, yolk %, and albumin %. Supplementation of zinc decreased triglyceride (P = 0.001) of laying hens. The low-density lipoproteins (LDL) cholesterol level in serum was decreased with 75 mg ZnO/kg in comparison with all treatment groups. Zinc supplementation increased the level of serum zinc without differences in supplemented zinc levels. Dietary supplemental zinc did not affect antioxidant parameters in the serum. It is concluded that dietary zinc supplementation up to 75 mg/kg used as effective supplement to enhance zinc status and antioxidant ability and activities in laying hens.

Influence of PEG induced drought stress on molecular and biochemical constituents and seedling growth of Egyptian barley cultivars.

In order to investigate the effects of drought stress on germination components of barley cultivars, a laboratory experiment was conducted in a factorial randomized complete design with four replications. The controlled experiment included ten of Egyptian barley cultivars namely; (Giza 123, 124, 125, 126, 127, 129, 130, 134, 135 and 2000) as first factor. The second factor included 4 levels of drought stress inducer by applying 0, 5, 10 and 20% of polyethylene glycol-6000 (PEG) which is equivalent to four osmotic potential levels including -0.001, -0.27, -0.54 and -1.09 MPa, respectively. The results showed that, the highest reduction was related to the drought level of 20% PEG among the barley cultivars. The best cultivars in terms of germination traits were Giza 134, Giza 127, and Giza 126 this indicate their tolerance to drought stress and Giza 130, 135, 2000 cultivars was moderately tolerance and remaining is less tolerance. The protein band 27 kDa and 78 kDa showed high intensity after stress in almost all cultivars. Those two protein bands their exciting was very clear in treated barley leaf tissue. It could be related to dehydrine and oxygen evolving enhancer protein 2 (OEE2) which involved in drought stress tolerance response. Cultivars Giza 127, 130 and 134 showed highest tolerance response under drought stress. The antioxidant enzymes PAGE pattern of Peroxidase (POX), Sodium dismutase (SOD) and Ascorbate peroxidase (APX) for Barley cultivars under drought stress revealed a high activities for Giza 126, 127, 134, 136 and 2000 under -0.5 MPa osmotic stress by PEG in most of their isoforms. Based on similarity coefficient values the highest values were 1.0 with 100% similarly between tolerant cultivars Giza 130 and Giza 127. Similarly between the susceptible cultivars 125 and Giza 129 was 60%.These data confirmed by the growth parameters which we ranked as tolerant to drought stress.

Influence of dietary inclusion of untreated or heat-treated Jatropha meal on productive and reproductive performances and biochemical blood parameters of laying Japanese quail.

Jatropha meal (JM) has been characterized as a potential animal feedstuff due to its high crude protein content and high levels of essential amino acids. However, it contains anti-nutritive and toxic compounds that may hinder its use. The present study was conducted to evaluate the effects of a dietary inclusion of raw Jatropha meal (RJM) and heat-treated Jatropha meal on the growth and production of laying Japanese quail using productive, reproductive, and biochemical blood parameters. A total number of 180 mature Japanese quail at 2 months of age (120 females and 60 males) was randomly divided into 4 treatment groups: control (0% JM); 3.5% RJM; 3.5% JM heated in an oven at 100°C for 24 h (JM24); and 3.5% JM heated in oven at 100°C for 48 h (JM48). After 8 wk on treatment diets, the inclusion of RJM to quail diets reduced (P < 0.05) feed intake, feed efficiency, egg number, and egg mass compared with the control diet. There was no difference between the heat-treated Jatropha (JM24 and JM48) treatments and the control. Fertility and hatchability percentages were improved (P < 0.001) with JM24 and JM48 compared with the RJM group. Feeding of 3.5% RJM or JM24 in quail diets led to significant decrease (P < 0.05) in serum total protein, albumen, globulin, γ-glutamyl transpeptidase, total and HDL-cholesterol, immunoglobulin (IgG and IgM), and increased serum alanine transaminase (ALT) and creatinine along with the mortality rate when compared with birds fed JM48. In conclusion, heat treatment of JM is essential to eliminate its hepatotoxic and nephrotoxic effects and, when properly heat-treated, can be used in laying Japanese quail diets without detrimental effects on production, reproductive performance, and health status.