Impacts of chitosan and its nanoformulations on the metabolic syndromes: a review.

A significant public health issue worldwide is metabolic syndrome, a cluster of metabolic illnesses that comprises insulin resistance, obesity, dyslipidemia, hyperglycemia, and hypertension. The creation of natural treatments and preventions for metabolic syndrome is crucial. Chitosan, along with its nanoformulations, is an oligomer of chitin, the second-most prevalent polymer in nature, which is created via deacetylation. Due to its plentiful biological actions in recent years, chitosan and its nanoformulations have drawn much interest. Recently, the chitosan nanoparticle-based delivery of CRISPR-Cas9 has been applied in treating metabolic syndromes. The benefits of chitosan and its nanoformulations on insulin resistance, obesity, diabetes mellitus, dyslipidemia, hyperglycemia, and hypertension will be outlined in the present review, highlighting potential mechanisms for the avoidance and medication of the metabolic syndromes by chitosan and its nanoformulations.

The potential mechanistic insights and future implications for the effect of prebiotics on poultry performance, gut microbiome, and intestinal morphology.

Prebiotics may modify the biological processes in the chickens' gastrointestinal tract to improve poultry performance and health. Prebiotics are natural feed additives that offer many economic advantages by decreasing mortality rates, increasing growth rates, and improving birds' feed efficiency. Prebiotic action potentially affects the degradation of indigestible dietary compounds, the synthesis of nitrogen components and vitamins, and simplifies the removal of undesirable elements in the diet. Prebiotics could also induce desirable gut microbiome modifications and affect host metabolism and immune health. It is worth mentioning that gut bacteria metabolize the prebiotic compounds into organic compounds that the host can subsequently use. It is important to limit the concept of prebiotics to compounds that influence the metabolism of resident microorganisms. Any medicinal component or feed ingredient beneficial to the intestinal microecosystem can be considered a prebiotic. In this review, the impacts of prebiotics on the gut microbiome and physiological structure are discussed, emphasizing the poultry's growth performance. The current review will highlight the knowledge gaps in this area and future research directions.

Growth, carcass characteristics, meat quality, and microbial aspects of growing quail fed diets enriched with two different types of probiotics (Bacillus toyonensis and Bifidobacterium bifidum).

The present investigation aimed to explore the impact of dietary graded levels of 2 types of probiotic bacteria (Bacillus toyonensis [BT] and Bifidobacterium bifidum [BB]) on growth, carcass traits, meat quality, and bacteriology of growing Japanese quail reared under the cage system. One thousand three hundred sixty Japanese quail day-old chicks were randomly divided into 10 groups (8 replicates each). Birds were fed a basal diet (control, T1) and the basal diet plus 0.05, 0.075, 0.10, and 0.125% BT (T2, T3, T4, and T5, respectively), 0.10% BB (T6), and the same previous doses of BT plus 0.05% BB (T7, T8, T9, and T10, respectively). Results showed a significant (P < 0.001) increase in final BW and weight gain because of probiotic supplementation (except T2 for weight gain). Both feed intake and feed conversion ratio did not differ during the overall experimental period (1-42 D of age) except feed intake that was reduced in T2 and increased in T5 and T9 groups. All carcass traits studied were significantly (P < 0.01) affected by probiotics, and the combination between BT and BB in group T8 increased all studied parameters as compared with the other treatment groups. The quail meat color of redness a∗ and L∗ values, thiobarbituric content, cooking loss, proteolysis, and total coliform were decreased (P < 0.001) by probiotic treatment. In general, supplementing BT, BB, or their combination to the basal diet delayed the proliferation of pathogenic bacteria in the diet and intestine. Using BT and BB as feed supplements enhanced growth performance and meat quality of quails as well as diminished pathogenic bacteria proliferation in their diet and intestine. As per our results, we can recommend the application of T5 and T8 to T10 levels for the best performance, carcass traits, and meat quality of growing quails.

Dietary effect of probiotics and prebiotics on broiler performance, carcass, and immunity.

This experiment was carried out to evaluate the effects of dietary addition of probiotics (Protexin) and prebiotics (active MOS, mannan oligosaccharides) on growth performance, carcasses, and antibody titer in broilers. A total number of 360-day-old Ross broiler chicks were randomly divided into 9 groups in a 3 × 3 factorial arrangement. Nine broiler starter (0-21 d) and finisher (21-35 d) diets were formulated by using 3 levels of probiotics (0, 1, and 2 g/kg of feed) and 3 levels of MOS (0, 1, and 1.5 g/kg of feed) and were randomly allotted to 9 groups. Feed intake was not affected by interaction of treatments during all phases (P > 0.05). Feed intake was improved due to the main effect of probiotic (P = 0.0001) or MOS (P = 0.005). No interaction (P > 0.05) was observed for weight gain in the starter, finisher, and overall phases. While, during the starter and finisher phases, weight gain was increased by probiotics (P = 0.028 or 0.04, respectively). Dietary supplementation of MOS improved weight gain (P = 0.01) and feed conversion ratio (FCR) (P = 0.03) during the overall period, but during starter and finisher periods, weight gain and FCR were not affected by prebiotics. Apart from dressing percentage, no interaction or individual effect of probiotics and prebiotics was observed for carcass, breast, thigh, heart, liver, and gizzard weight. Antibody titer for infectious bursal disease (IBD) was improved (P = 0.026) by the interaction effect between probiotics and prebiotics, when compared with the control group. Antibody titer against Newcastle disease (ND) was not affected by probiotics or prebiotics or their interactions (P > 0.05). It could be concluded that supplementation of prebiotics or probiotics can improve the growth performance of broilers. It may also be helpful in improving the antibody titer against IBD in broilers fed antibiotic-free diets.

Does the use of different oil sources in quail diets impact their productive and reproductive performance, egg quality, and blood constituents?

The present study investigated the impact of dietary oil sources (soybean, corn, peanut, flaxseed, olive, and sunflower oils as sources of omega 3, 6, and 9 fatty acids) on productive and reproductive traits, egg quality, hematological and biochemical blood parameters of laying Japanese quail. A total of 360 eight-week mature Japanese quail were randomly divided into 6 groups fed for 8 wk on a basal diet included with 1.5% of different oil sources. Results showed that the highest egg weights and the best feed conversion ratio (P < 0.01) were recorded for quail fed diets supplemented with 1.5% soybean and peanut oil. The highest hatchability percentages (P < 0.05) were recorded for quail fed diets supplemented with corn oil as compared to the other oils. Furthermore, diets enriched with corn, olive, or sunflower oils had higher values of blood lymphocytes (%) compared to the other treated groups. Blood total cholesterol significantly decreased in quail fed on corn, peanut, flaxseed, or olive oil sources as compared to soybean or sunflower oil groups. Immunologically, the highest levels (P < 0.001) of immunoglobulins (G and M) were recorded for quail fed on corn or olive oil sources compared to other oil sources. Quail consuming olive oil-included diets showed a significant increase in superoxide dismutase and glutathione S-transferase activities and a significant decrease on malondialdehyde level compared with those consumed the other oil sources. It could be concluded that varying the oil source can affect productive, reproductive, and health aspects of Japanese quail. Soybean oil showed good results regarding production aspects; however, olive oil was the best regarding health aspects.

Growth, carcass characteristics, and meat quality of broilers fed a low-energy diet supplemented with a multienzyme preparation.

The effect of a low-ME diet with a multienzyme (Kemzyme Plus, Kemin, Des Moines, IA) blend on performance, meat quality, and carcass traits was evaluated in Hubbard broiler chicks. A total of 120 Hubbard broiler chicks were allocated to the following 4 experimental groups and every group was separated into 6 replicates, with 5 birds per replicate: control (3,180 kcal/kg of ME), control + 0.50 g/kg diet of enzyme (Cont-Enz), low-ME diet (3,080 kcal/kg), and low-ME + 0.50 g/kg diet of enzyme (low-ME-Enz). The trail lasted for 16 D (32 to 48 D of age). No significant differences in growth parameters or carcass traits were observed among treatments. However, liver weight increased with the low-ME-Enz diet (P = 0.038). The low-ME diet recorded the highest weight for the bursa (P = 0.043) and thymus (P = 0.019). Dietary treatments had significant impacts on the length of duodenum, ileum, and cecum, as well as the weight of duodenum. The length of duodenum, ileum, and cecum increased with enzyme supplementation. The myofibril fragmentation index was lower with the Cont-Enz, low-ME, and low-ME-Enz diets than with the control diet (P = 0.043). The shear force increased with the low-ME-Enz diet (P = 0.022) than the control diet. Dietary treatments influenced breast meat yellowness (P = 0.019), whereas the low-ME diet had the lowest yellowness at the slaughtering age. The dietary treatments affected the breast meat pH (P = 0.001), with the control diet having the highest pH value after 24 hours. Thus, there was no effect of low-ME or enzyme supplementation to the control or low-ME diet on growth performance or carcass yield. However, feeding a low-ME diet or Cont-Enz preparation influenced organ and small intestine weights and meat characteristics.

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.

Humic acid as a feed additive in poultry diets: a review.

Many studies tested different feed additives, among these additives, humic substances (HS) have been used in livestock and poultry diets. Humic substances commonly present in nature as they are created from the organic matter decomposition, and are normally found in the soil and natural water. Active components of HS consist of humic acid (HA), humus, ulmic acid, fulvic acid, humin and certain microelements. Humic acid is widely used as an alternative growth promoter for antibiotics in improving poultry performance and health. Moreover, supplementation of a commercial substance as a source of HS through the drinking water or diet improved the feed consumption, feed efficiency and weight gain of broiler chickens, and also improved egg weight, egg mass, and egg production of laying hens. This review describes the useful applications and recent facets of HA including its modes of action and various valuable uses in improving the production and health safeguarding of livestock and poultry.

Effects of stock, sex, and muscle type on carcass characteristics and meat quality attributes of parent broiler breeders and broiler chickens.

This study aimed to investigate the effect of using breeder parents (434-days-old) and broiler chickens (37 D of age) from Ross 308 on meat quality parameters and carcass characteristics; sex and muscle type were also estimated. Carcass assessment involved hot carcass weight, carcass yield, and cuts (breast, legs, wings, back, and shoulder). A total of 120 birds were divided into 2 groups (60 birds from each stock), each stock contain equal number of sexes (30 males and 30 females), and further divided into 6 replicates, so that there were 5 birds in each replicate. The birds were fed ad libitum. A sample of 30 birds (male, n = 15 and female, n = 15) from each group was slaughtered for assessing carcass and physical characteristics. Sensory analysis was carried out on each group after boiling or roasting the bird. Live weight, carcass weight and yield, breast weight, legs, wings, and back weights and yield were higher (P < 0.001) for breeder parents when compared to broilers, with the exception of breast percentage. Moreover, better carcass characteristics were observed in males than in females. Parent stock had better water-holding capacity and myofibrillar fragmentation whereas broilers had more tender meat than breeders. Moreover, cooking loss and other sensory characters were not significant between the two groups; however, females had more tender pectoral muscles and more myofibrillar fragmentation than males. We concluded that parent breeders had better carcass characteristics than broiler chickens. The broiler chickens of Ross 308 and female birds had better meat quality than parent breeders.

[Advanced medical post within hospitals as possible tactical instrument for handling mass casualty incidents]. / Der Behandlungsplatz innerhalb eines Krankenhauses als mögliches taktisches Werkzeug zur Bewältigung eines Massenanfalls von Patienten.

BACKGROUND: An important instrument for handling mass casualty incidents in preclinical settings is the use of an advanced medical post. In certain circumstances, however, the establishment of such an advanced medical post on or close to the incident site is impossible. Terrorist attacks are a prime example for this. The highest priority for hospitals during mass casualty incidents is to adjust the treatment capacity to the acute rise in demand and to sustain its functionality throughout the duration of the incident. By establishing an advanced medical post within hospitals during certain types of mass casualty incidents these aims could potentially be accomplished. AIMS: The aims of this pilot study were to test the practicability of the establishment of an advanced medical post within a university hospital and to identify potential problems. The results provide the foundation of a generalized concept, which will then be integrated into the hospital emergency plans. METHODS: After the formation of a multiprofessional expert committee, different areas within the hospital were evaluated based on spatial and tactical considerations. Predefined questions were assessed and harmonized with respect to organization, vehicle management, communication, leadership and patient transport through the means of a practice run. RESULTS: The establishment and operation of an advanced medical post within the hospital were easily possible. The consequent deployment of section leaders enabled the smooth coordination of transport and an unobstructed simulated patient flow. The management of the treatment area by a senior emergency physician and a senior emergency medical service officer in close cooperation with the operational hospital lead proved to be a useful concept. Technical problems with communication within the hospital were resolved by using wireless phones and the installation of a digital radio repeater. DISCUSSION: During acute scenarios with only short prior notice, the authors prefer concepts that supplement the normal hospital operation through additional staff and material. In circumstances with prior notice of more than 60 min an advanced intrahospital advanced medical post, staffed by civil protection units, could be a concept that enables the absorption of the first patient arrivals within the first hour of a mass casualty incident without disturbing the functionality of hospitals to any great extent. Further practice runs are, however, necessary to further develop and adjust this concept to real-life circumstances.

Effect of experimental Ornithobacterium rhinotracheale infection along with live infectious bronchitis vaccination in broiler chickens.

Ornithobacterium rhinotracheale (ORT), a bacterium causing respiratory tract infection, has led to a significant problem in the intensive poultry production in Egypt. Polymerase chain reaction-amplified 784-bp specific ORT DNA fragments were found in 7 ORT isolates from lungs, air sacs, and tracheas of commercial broilers or layers in Egypt in 2015. The objective of this study was to investigate the role of the live variant IBV 4/91 with ORT infection. A total of 120 14-d-old broiler chickens (Cobb 500) were equally divided into 4 groups for experimental infection in a complete randomized design. Group 1 was infected with ORT strain and live infectious bronchitis vaccine (IBV 4/91) simultaneously; group 2 was infected with the bacterial strain alone; group 3 was vaccinated only with IBV 4/91, and group 4 was the non-vaccinated and non-infected control group. The respiratory signs, post-mortem lesions (tracheitis and pneumonia) and histopathological findings of lungs, trachea, and air sacs in the experimentally infected broiler chickens appeared to be more prominent in the chickens of group 1 than group 2. With respect to body weight, weight gain, feed conversion rate, and Ornithobacterium re-isolation, there was a difference (P ≤ 0.05) among the chickens of group 1 and the other groups. This reveals that the use of live infectious bronchitic vaccines, which is a common practice in the local Egyptian field of production, may concomitantly increase the pathogenicity of ORT in broiler chickens.

Impacts of various storage periods on egg quality, hatchability, post-hatching performance, and economic benefit analysis of two breeds of quail.

The effect of storage period on hatching and post-hatching performance of two quail breeds (brown Japanese quail (BJQ) and French white quail (FWQ)) was investigated using 940 eggs from each breed. Eggs were divided into four equal groups (235 eggs each), in each group. A total number of 210 eggs were used for incubation (with three replicates, 70 eggs each) and additional 25 eggs served as samples for egg quality parameters, each group was kept for special storage period. The first group was incubated on the same day of collection (zero day storage). Whereas the second, third, and fourth groups were stored for 4, 7, and 10 d, respectively. Increasing the storage period more than 4 d significantly decreased the relative albumen weight, yolk index, total hatchability, and fertile eggs but significantly increased the relative yolk/albumen ratio, absolute and relative egg weight loss. Moreover, FWQ eggs exhibited higher (P < 0.05) hatchability compared to BJQ eggs after 10 d of storage and yielded heavier chicks (P < 0.05) after all storage periods. The economic analysis indicated that the storage costs for FWQ eggs were significantly greater than those of BJQ at a 0 d of storage (2.42 vs. 4.81 US cent (¢); P < 0.05). Furthermore, the total costs for BJQ eggs were significantly lower than the total costs for FWQ eggs (3.0 vs. 7.0 ¢; P < 0.05). With respect to profitability, the total return represented by selling the chicks was calculated at 5.43 ¢ for BJQ and 9.01 ¢ for FWQ. The net return estimated for FWQ was significantly greater than that of BJQ (3.0 vs. 2.0 ¢; P < 0.05). However, the hatchability loss for FWQ was significantly greater than that of BJQ over different storage periods.

Comparative efficacy of commercial inactivated Newcastle disease virus vaccines against Newcastle disease virus genotype VII in broiler chickens.

Newcastle disease is still causing huge economic losses and devastating outbreaks in poultry flocks despite implementation of extensive vaccination programs. Five commercial broiler chicken groups were established as G1 (non-vaccinated, non-challenged group) and G2 (non-vaccinated, challenged group), and 3 vaccinated challenged groups as G3 (vaccinated with heterologous inactivated Newcastle disease virus (NDV) genotype II (NDV II) vaccine), G4 (vaccinated with homologous inactivated NDV genotype VII (NDV VII) vaccine), and G5 (vaccinated with bivalent (heterologous inactivated NDV II plus H5) vaccine) were used. Challenge test was done using a velogenic NDV genotype VII (vNDV VII) at 28-d olds. Respiratory signs, greenish diarrhea, and obvious post-mortem lesions of vNDV VII appeared in all the challenged birds whether vaccinated or not. In addition, the mortality rate decreased from 93.3% in G2 to 46.7%, 53.3%, and 66.7% in G4, G5, and G3, respectively. Overall, 2 wk postchallenge; body weight loss (%) had increased mainly in G2, with some improvement in chickens in G4 followed by G5 and chickens of G3 showed the least improvement. At 28 d (day of challenge), the highest hemagglutination inhibition values were 4.3 and 5.4 log2 in chickens in G4 and G5, respectively, which increased in all groups after the challenge. Cytokine (IL-6 and IFN-γ) levels were significantly higher (P < 0.05) in the vaccinated groups than that in the non-vaccinated group, especially in G5. Viral shedding in the trachea was higher than that in the cloacal swabs in all vaccinated and non-vaccinated challenged groups with peak shedding on the 6th day post challenge for both swabs, and the lowest viral shedding titers were observed in chickens in G5. Therefore, the use of homologous genotype NDV with inactivated vaccine conferred a higher clinical protection in terms of body weight loss and mortality against vNDV VII challenge in broiler chickens; however, the heterologous vaccine used in G5 induced the highest cell-mediated immune response and hemagglutination inhibition titers with the lowest viral shedding titer.

Dietary supplementation of Yucca schidigera extract enhances productive and reproductive performances, blood profile, immune function, and antioxidant status in laying Japanese quails exposed to lead in the diet.

The present study investigated the toxic impacts of lead (LD) on the productive and reproductive performances of Japanese quails and the role of Yucca schidigera extract (YSE) in reducing these impacts. A total of 360 mature Japanese quails (at 2 months of age) were used and the experiment was lasted for 8 wk. The birds were divided into 6 equal groups as follows: control (basal diet), basal diet + 100 mg LD/kg diet, basal diet + YSE (100 mg/kg diet), basal diet + YSE (200 mg/kg diet), basal diet + LD (100 mg/kg diet) + YSE (100 mg/kg diet), and basal diet + LD (100 mg/kg diet) + YSE (200 mg/kg diet). LD resulted in a significant decrease in feed intake (FI), feed conversion ratio (FCR), and egg production of birds compared with the control group. Supplementation of YSE (100 or 200) to LD containing diet could significantly improve the quail performance parameters to be comparable with the control values. Fertility and hatchability % were decreased by LD, whereas YSE at both levels (100 or 200) separately or in combination with LD showed fertility and hatchability percentages comparable to that of control. Triglycerides, cholesterol, and LDL contents in LD plus YSE100 or LD plus YSE200 groups were significantly decreased than LD alone group. LD significantly decreased superoxide dismutase and catalase activities in the serum with no effect on reduced glutathione content. Co-exposure to YSE100 or YSE200 with LD significantly increased the catalase activity and numerically increased the superoxide dismutase activity than LD alone. YSE100 or YSE200 decreased malondialdehyde contents than LD alone group. LD plus YSE100 or YSE200 groups exhibited significant improvements in the level of immunoglobulins. Co-exposure to YSE with LD significantly decreased the LD residues in egg than the LD group. The obtained results showed that YSE exhibited a potential modulatory role against the LD-induced inhibitory effects on the productive and reproductive performances of Japanese quails and YSE at 200 mg/kg diet was more effective than 100 mg/kg diet in reversing the LD-induced alterations.

Wet feed and cold water as heat stress modulators in growing Muscovy ducklings.

In an attempt to alleviate the deleterious effects of high summer temperatures, the present study investigated the effects of wet feed and cold water on the growth performance, carcass and meat quality, leg problems, physiological responses, and blood parameters of growing Muscovy ducklings. A total of 180 4-week-old ducklings was randomly divided into 6 experimental groups in a 3 × 2 factorial design that included 3 feed systems (AD: ad libitum dry; DW: diurnal wet; and AW: ad libitum wet) and 2 systems of water (TW: tap water; and CW: cold water). Access to wet feed and cold water affected the growth performance, dressed carcass, gizzard, meat quality (tenderness, juiciness, and susceptibility), tonic immobility, body temperature, and blood parameters [albumin: globulin (A: G) ratio and levels of glucose, alanine transferase (ALT), total antioxidant capacity (T-AOC), and malondialdehyde (MDA)] of the ducklings but had no significant effect on plumage condition, shank length, keel bone length, leg problems, or breast blisters. The body weight (BW) of the DW group was 1.97 and 3.12% greater than that of the AD and AW groups, respectively, and the BWG of the DW group was 6.91 and 10.72% greater than that of the AD and AW groups, respectively. Therefore, providing access to wet feed and cold water is highly recommended when raising Muscovy ducks in open houses under high-temperature conditions.

Using parabolized stability equations to model boundary-layer transition in direct and large-eddy simulations.

We examine the potential of the nonlinear parabolized stability equations (PSE) to provide an accurate yet computationally efficient treatment of the growth of disturbances in H-type transition to turbulence. The PSE capture the nonlinear interactions that eventually induce breakdown to turbulence, and can as such identify the onset of transition without relying on empirical correlations. Since the local PSE solution at the onset of transition is a close approximation of the Navier-Stokes equations, it provides a natural inflow condition for direct numerical simulations (DNS) and large-eddy simulations (LES) by avoiding nonphysical transients. We show that a combined PSE/DNS approach, where the pre-transitional region is modeled by the PSE, can reproduce the skin-friction distribution and downstream turbulent statistics from a DNS of the full domain.

Modeling boundary-layer transition in direct and large-eddy simulations using parabolized stability equations.

We examine the potential of the nonlinear parabolized stability equations (PSE) to provide an accurate yet computationally efficient treatment of the growth of disturbances in H-type transition to turbulence. The PSE capture the nonlinear interactions that eventually induce breakdown to turbulence and can as such identify the onset of transition without relying on empirical correlations. Since the local PSE solution at the onset of transition is a close approximation of the Navier-Stokes equations, it provides a natural inflow condition for direct numerical simulations (DNS) and large-eddy simulations (LES) by avoiding nonphysical transients. We show that a combined PSE-DNS approach, where the pretransitional region is modeled by the PSE, can reproduce the skin-friction distribution and downstream turbulent statistics from a DNS of the full domain. When the PSE are used in conjunction with wall-resolved and wall-modeled LES, the computational cost in both the laminar and turbulent regions is reduced by several orders of magnitude compared to DNS.

Feeding time can alleviate negative effects of heat stress on performance, meat quality and health status of turkey.

1. A total of 180 one-day-old turkeys were randomly assigned to 6 equal groups to investigate the effect of feeding time on growth performance, carcass characteristics, meat quality, leg problems and physiological responses of growing turkeys under the high temperature conditions of summer. 2. Birds of the first group were ad libitum fed and were considered as the controls (C). The second group (T1) was given 80% of diet in the morning and 20% of diet in the afternoon, the third group (T2) was given 60% of diet in the morning and 40% of diet in the afternoon, the fourth group (T3) was given 40% of diet in the morning and 60% of diet in the afternoon, the fifth group (T4) was given 20% of diet in the morning and 80% of diet in the afternoon and the sixth group (T5) was given 100% of diet in the afternoon. 3. Body weight, body weight gain and feed conversion ratio were improved with T2, T3, T4 and T5 in comparison to control or T1 under heat stress conditions. No significant impacts on carcass traits and meat quality due to changing the time of feeding were seen, except for tenderness and juiciness. 4. Feeding in the afternoon (100%) decreased body temperature and tonic immobility test score, which were positively related with the health condition of the birds. 5. The incidence of leg problems, plumage condition and breast blisters were not significantly different among the experimental groups. 6. It is concluded that feeding turkeys mainly or totally in the afternoon (T4 and T5, birds were fed with 80% or 100% of the diet in the afternoon) can be used as a strategy and a managerial tool for improving growth rate, feed utilisation, carcass and meat quality, as well as health status of growing turkeys reared under hot climate conditions.

The efficacy of using exogenous enzymes cocktail on production, egg quality, egg nutrients and blood metabolites of laying hens fed distiller's dried grains with solubles.

An experiment was performed using 120 Hisex Brown laying hens for evaluating the effects of different inclusion levels of corn distiller's dried grains with solubles (DDGS) as a replacement of soybean meal (SBM) with or without enzyme cocktail on performance, egg quality, egg nutrients and blood metabolites in laying hens through 22-42 weeks of age. A 4 × 2 factorial design experiment was performed including four substitution levels of DDGS (0, 250, 500 and 750 g/kg respectively) and two enzyme cocktail levels (0 and 250 mg/kg diet). The used enzyme in this study "Gallazyme" composed of xylanase, Trichoderma longibrachiatum (600 units/g), protease, Bacillus subtilis (8,000 units/g) and amylase and Bacillus amyloliquofaciens (800 units/g). The control diet showed the best feed efficiency followed by the intermediate levels of DDGS. The lowest value of feed efficiency was found in the group fed the highest level of DDGS. Enzyme addition improved feed efficiency and decreased laying rate. Increasing DDGS levels was associated with albumin and shell thickness increases. Dietary DDGS depressed all egg components except the organic matter which maximised in enzyme-treated groups. Increasing DDGS level was accompanied by increase in yolk cholesterol and total lipids. No significant impacts were detected with enzymes supplementation on yolk lipids profile. Excepting serum calcium and phosphorous, all serum constituents increased with increasing level of DDGS. Using enzyme markedly depressed serum ammonia by 15.02% and increased calcium by 6.44% compared with enzyme-free diets. Interaction between DDGS and enzyme was significant on most of studied parameters. It could be concluded that using enzyme cocktail in DDGS-based diets may improve feed efficiency and egg quality, in addition to lowering blood ammonia and increasing blood calcium. It is recommended to substitute SBM by DDGS up to 500 g/kg diet.

Effect of dietary supplementation of organic zinc on laying performance, egg quality and some biochemical parameters of laying hens.

This study was conducted to evaluate the effects of zinc methionine (Zn-Met) supplementation on the performance, egg quality, antioxidant status and some biochemical parameters of blood serum in laying hens from 22 to 34 weeks of age. A total of 120 Hisex Brown laying hens of 22-week-old were randomly allocated into five treatments with six cage replicates for each (four hens/replicate). Dietary treatments consisted of the basal diet with no Zn-Met supplementation (control group) and basal diet supplemented with 25, 50, 75 or 100 mg Zn-Met/kg diet. No significant differences were observed on body weight, body weight gain or feed conversion ratio due to dietary Zn-Met supplementation. However, highly significant impact was observed on daily feed intake. Egg number, egg weight and egg mass were increased in the group fed diet supplemented with the highest level of Zn-Met (100 mg/kg of diet) as compared to other groups. All egg quality traits were statistically (p > .05 or .01) affected as a response to dietary Zn-Met supplementation except egg shape index, shell percentage and yolk index. In comparison with the control group, dietary supplementation of 25, 50, 75 or 100 mg Zn-Met/kg decreased serum triglyceride and LDL-cholesterol levels. Serum cholesterol level was increased with all dietary levels of Zn-Met in comparison with the control group. Dietary Zn-Met supplementation increased the serum content of zinc, where the highest values were recorded with 50 and 100 mg Zn-Met/kg diet. Dietary Zn-Met levels did not affect the antioxidant indices in blood serum except for the activity of copper-zinc superoxide dismutase (Cu-Zn-SOD). The activity of Cu-Zn-SOD was increased with Zn-Met supplementations with no differences among supplemental zinc levels. It is concluded that dietary Zn-Met supplementation reduced serum triglyceride, LDL-cholesterol and increased Zn status and resulted in promoting antioxidant ability of laying hens, and the addition of 100 mg Zn-Met/kg to layer diet was appropriate for improving the above parameters in addition to egg production indices and Haugh unit score.