24-Hour postnatal total serum protein concentration affects the health and growth performance of female Holstein dairy calves.

BACKGROUND: Total serum protein (TSP) within the first few days of life in the neonatal calf has predictive value for subsequent growth and production in calves before and after weaning. INTRODUCTION: The objective of this study was to evaluate the effect of TSP concentration 24-h after birth (24-h) on the performance and health of Holstein dairy calves. METHODS: A total of 152 female calves were enrolled in this study. Blood samples were collected at 24-h, and TSP concentration was measured with a refractometer. Calves based on TSP concentration at 24-h were allocated into three groups: 1 - TSP ≤6.5 g/dL, 2 - TSP between 6.6 and 6.9 g/dL and 3 - TSP ≥7 g/dL. The weighing was done at birth and at days 30 and 60. Starter feed intake was recorded from day 3 to weaning, and body structures were measured at birth and weaning day. RESULTS: Calves with TSP >6.5 g/dL had greater body weight at days 30 and 60 than calves with TSP ≤6.5 g/dL. Average daily gain during 1-30 and 1-60 days of life increased as TSP increased. Furthermore, starter feed intake during the first 60 days of life was greater in calves with TSP ≥7 g/dL than calves with TSP <7 g/dL. The TSP concentration influenced structural growth, and >6.5 g/dL calves had greater heart girth, hip width and body length than ≤6.5 g/dL calves. Moreover, odds ratio for pneumonia decreased as TSP increased, whereas diarrhoea was unaffected. CONCLUSION: The TSP at 24-h is an important contributing factor for the variation in growth performance and health of preweaning calves, and strategies to improve calf immunity and increase TSP lead to better animal health during preweaning period. IMPLICATIONS: These results indicated that TSP ≥6.5 g/dL possibly was associated with greater performance, and this concentration could be considered a baseline for future analyses.

Laying performance, egg quality, fertility, nutrient digestibility, digestive enzymes activity, gut microbiota, intestinal morphology, antioxidant capacity, mucosal immunity, and cytokine levels in meat-type Japanese quail breeders fed different phytogenic levels.

A total of 180 female Japanese quail breeders were allocated to 5 treatments with 6 replicates of 6 birds and fed a diet supplemented with 0, 125, 250, 500, or 1000 mg/kg of a phytogenic feed additive (PFA) in a 9-wk experiment. Egg weight, feed efficiency, shell breaking strength and calcium content, specific gravity, Haugh unit, and percentages of fertile eggs increased with increasing PFA levels (P < 0.05). Increasing of PFA levels increased nutrient digestibility, dietary AMEn, and activities of digestive enzymes in the pancreas and intestinal digesta (P < 0.05). Supplementation of PFA reduced Escherichia coli (P < 0.05), Clostridium spp. (P < 0.05) and Salmonella spp. counts (P < 0.05), while increased Lactobacillus and Bifidobacterium spp. counts in the ileal and cecal contents (P < 0.05). Dietary PFA increased jejunal villus height and decreased ileal crypt depth (P < 0.05). Serum diamine oxidase activity and D-lactate level were decreased with increase in PFA level (P < 0.05). Increasing PFA levels increased glutathione peroxidase activity in the pancreas, small intestine, and cecal tonsil, but decreased malondialdehyde contents (P < 0.05). Birds fed PFA exhibited increased levels of secretory IgA in the intestinal mucosa (P < 0.05), and increased the percentage of CD3+ T cells, ratio of CD4+/CD8+ T cells, and cytokine concentrations in the cecal tonsils (P < 0.05). In conclusion, PFA could improve gut health and nutrient utilization and, therefore, benefit productivity, egg quality, and fertility in quails.

The Effects of Phosphorylation and Microwave Treatment on the Functional Characteristics of Freeze-Dried Egg White Powder.

The effects of phosphorylation pre-treatments at 1.5, 2.5, and 3.5% levels, as well as microwave application at 200, 400, and 700 watts levels for 2 min, on the functional parameters of egg white powder obtained by the freeze dryer procedure were investigated. P1.5-M200 had the highest oil-holding capacity, emulsion stability, and emulsion activity, while P2.5-M200 had the highest foam capacity. The P2.5-M400 had the largest particle size, and P3.5-M200 had the highest degree of phosphorylation and protein solubility. On the other hand, P3.5-M200 had the highest solution viscosity by 1% (w/v), water-holding capacity, and foam stability, in the treatments that used phosphorylation and microwave treatment simultaneously. FTIR spectroscopy of the unfolding structure of egg white protein revealed changes in the protein's secondary structure, such as the development of ß-sheets and ß-turns, as well as the binding of negatively charged phosphate groups on the serine, threonine, and tyrosine side chains. The phosphorylation and microwave treatments reduced the particle size of the egg white protein powder while increasing the surface area of the protein molecules, according to SEM analyses.

Effects of Replacing Inorganic with Organic Iron on Performance, Egg Quality, Serum and Egg Yolk Lipids, Antioxidant Status, and Iron Accumulation in Eggs of Laying Hens.

This study compared the effects dietary organic (ferrous glycine [FG]) versus inorganic (ferrous sulfate [FS]) iron in laying hens on performance, egg quality, serum and egg yolk lipids, antioxidant status, and iron enrichment of eggs. A total of 378 Shaver White layers were allotted to 7 treatments with 6 replicates (9 birds each) from 30 to 42 weeks of age. A basal diet (19 mg iron/kg) served as control, while the other six diets were supplemented with either FS or FG to provide 30, 60, and 120 mg/kg of added iron. Dietary FG and FS treatments improved (P < 0.05) laying rate, egg weight, and egg quality of layers, relative to the control, albeit eggshell strength and eggshell calcium also deteriorated with the highest level of FS (P < 0.05). The iron treatment groups exhibited a lower serum and egg yolk levels of triglycerides, total cholesterol, and low-density lipoprotein cholesterol that accompanied by higher levels of high-density lipoprotein cholesterol and greater activities of superoxide dismutase (SOD) and glutathione peroxidase (GPx) as compared with the control (P < 0.05). The contents of malondialdehyde and protein carbonyl were conversely related to the activities SOD and GPx (P < 0.05). The serum and egg fractions (yolk, albumen, and shell) displayed gradually increases in iron contents as the level of iron increased in the diet (P < 0.05), while FG was superior to FS at all tested levels (P < 0.05). To summary, FS can be replaced by FG, with more favorable impacts on egg quality and iron enrichment.

Efficacy of dietary supplemental insoluble fibrous materials in ameliorating adverse effects of coccidial challenge in broiler chickens.

The current experiment was designed to examine effects of dietary supplemental sunflower hulls (SH) and rice hulls (RH) on growth performance, carcass traits, intestinal morphology, lesion score and oocyst shedding in broiler chickens exposed to coccidial challenge. A total of 540 broiler chickens (Ross 308) were assigned to six dietary treatments based on a factorial arrangement (2 × 3) across 1-14, 14-28 and 28-42-d periods. Experimental treatments consisted of broiler chickens without or with coccidial challenge each offered with three different diets: a basal diet or basal diet supplemented with either RH or SH at 40 g/kg diet, respectively. Infection with Eimeria impaired daily weight gain (DWG) and feed conversion ratio (FCR) of broiler chickens during growing period (p < 0.05) while supplementation of SH or RH reduced the adverse effect of coccidiosis so that birds had similar DWG to those fed the basal diet without infection. However, only dietary SH improved the FCR of broilers challenged with coccidiosis. Regardless of coccidial challenge, dietary access to insoluble fibre improved performance of broilers across the growing period (p < 0.05); however, this effect was not observed during the entire rearing period. Relative weights of liver and pancreas were increased in birds subjected to coccidial challenge on d 21 of age (p < 0.05). Moreover, relative weights of the intestinal segments were enhanced (p < 0.05). Furthermore, gizzard weights were higher in birds receiving diets added with fibre (p < 0.05). Infection with coccidiosis decreased villus height and villus height to crypt depth ratio in duodenum of broilers which received the basal diet compared with those fed the same feed without coccidial challenge (p < 0.05). However, supplemental SH could decrease the negative effect of infection on the noted intestinal morphometric attributes. Similarly, a marked reduction was observed for lesion score and faecal oocyst excretion of challenged broilers fed on dietary supplemental fibre (p < 0.05). In conclusion, supplementation of insoluble fibre could ameliorate negative effects of coccidial challenge on DWG of broiler chickens and inclusion of SH in diet of birds exposed to Eimeria infection could be recommended.

Effects of dietary fiber and threonine on performance, intestinal morphology and immune responses in broiler chickens.

The present experiment was conducted to investigate the effects of fiber and threonine (Thr) on growth performance, intestinal morphology and immune responses of broiler chickens. A total of 420 one-day-old mixed sex broiler chicks (Ross 308) were randomly divided into 6 experimental diets and 5 replicates of 14 chicks based on a factorial arrangement (2 × 3) from 1 to 42 d of age. Experimental factors included dietary supplemental fiber type (no supplemental fiber [NSF], 30 g/kg sugar beet pulp [SBP] or 30 g/kg rice hull [RH]) and Thr inclusion level (100% or 110% of Thr requirement recommended by breeder company [Ross 308]). Growth performance of broilers was assayed at different periods of the experiment. Intestinal morphometric features were measured at 21 d of age. Antibody titer against sheep red blood cells (SRBC), Newcastle and influenza disease viruses were measured on d 30 of trial. Dietary inclusion of SBP and RH significantly decreased feed intake and weight gain during the entire rearing period (P < 0.05). Interaction of fiber and Thr had no beneficial effects on the performance of chickens across the entire rearing phase. Dietary supplementation of 110% Thr required level improved jejunal morphometric features (P < 0.05), whereas its inclusion with fibrous materials failed to show the same effects. Dietary supplemental Thr together with SBP significantly increased antibody production against SRBC (P < 0.05). In conclusion, although supplemental 30 g/kg fibrous materials impaired growth performance, inclusion of SBP along with 110% Thr level improved the humoral immunity in broiler chickens.

Evaluation of Calendula officinalis L. (marigold) flower as a natural growth promoter in comparison with an antibiotic growth promoter on growth performance, carcass traits and humoral immune responses of broilers.

The objective of this experiment was to investigate the effects of dried powder of Calendula officinalis L. (marigold) flower as an antibiotic growth promoter substitute on growth performance, organ weights, and immunological parameters in broilers. A total of 240 mixed sex broilers (Ross 308) at 1 d of age were individually weighed and randomly assigned to 4 treatments with 4 replicates of 15 birds for 6 wk. The dietary treatments were: 1) a basal diet (control); 2) control plus 4.5 mg flavophospholipol/kg of diet; 3) control plus 5 g marigold/kg of diet; 4) control plus 10 g marigold/kg of diet. Antibody responses against Newcastle (NDV), influenza (AI) viruses, and sheep red blood cells (SRBC) were measured. Supplementing 4.5 mg flavophospholipol/kg of diet enhanced body weight (BW) of broilers at 14 and 28 d of age (P < 0.05), but final BW at 42 d was not markedly affected. At 14 and 28 d of age, broilers fed diets supplemented with 10 g marigold/kg of diet had significantly lower BW compared with broilers fed the basal diet supplemented with antibiotic or 5 g marigold/kg of diet. During the starter period, broilers fed diets supplemented with antibiotic had significantly (P < 0.05) better FCR compared with broilers supplemented with 10 g marigold/kg of diet, but did not differ from broilers fed the basal diet or basal diet supplemented with 5 g marigold/kg of diet. There were no significant differences in FCR between treatments, during grower, finisher phases as well as for the whole experiment. Carcass yield was significantly (P < 0.05) higher in broilers supplemented with 5 g marigold/kg of diet compared with broilers in other groups. The treatments failed to induce any marked effect on immune parameters. In conclusion, the results of this experiment showed that supplementation of 5 and 10 g dried powder of marigold/kg of diet has no affirmative influence on growth performance of broilers.

Effects of dietary 1 alpha-hydroxycholecalciferol in calcium and phosphorous-deficient diets on growth performance, tibia related indices and immune responses in broiler chickens.

This experiment was conducted to investigate the effect of dietary 1α-hydroxycholecalciferol (1α-OH-D3) in calcium (Ca)- and phosphorous (P)-deficient diets on growth performance, carcass characteristics, tibia related parameters, and immune responses of broiler chickens. A total of 280 one-day-old broiler chickens (Ross 308) were assigned to 20 floor pens and 4 dietary treatments with 5 replicates. Dietary treatments consisted of starter diets (starter diet of treatment A: 1% Ca, 0.73% total phosphorus [tP]; starter diet of treatment B: 0.85% Ca, 0.64% tP + 5 µg/kg of 1α-OH-D3; starter diet of treatment C: 0.85% Ca, 0.59% tP + 5 µg/kg of 1α-OH-D3; starter diet of treatment D: 0.85% Ca, 0.54% tP + 5 µg/kg of 1α-OH-D3), grower diets (grower diet of treatment A: 0.86% Ca, 0.68% tP; grower diet of treatment B: 0.73% Ca, 0.59% tP + 5 µg/kg of 1α-OH-D3; grower diet of treatment C: 0.73% Ca, 0.55% tP + 5 µg/kg of 1α-OH-D3; grower diet of treatment D: 0.73% Ca, 0.50% tP + 5 µg/kg of 1α-OH-D3) and finisher diets (finisher diet of treatment A: 0.81% Ca, 0.64% tP; finisher diet of treatment B: 0.68% Ca, 0.56% tP + 5 µg/kg of 1α-OH-D3; finisher diet of treatment C: 0.68% Ca, 0.52% tP + 5 µg/kg of 1α-OH-D3; finisher diet of treatment D: 0.68% Ca, 0.48% tP + 5 µg/kg of 1α-OH-D3). Results showed that body weight gain (BWG) and feed intake (FI) of broilers in treatment B were similar to those of broilers in treatment A at the end of the trial (P < 0.05). Broilers in treatments C and D had lower BWG and FI than those in treatment A during the whole trial (P < 0.05). Feed conversion ratio, carcass traits and relative weight of lymphoid organs were not affected by dietary treatments (P > 0.05). Dietary treatments had no significant effect on antibody titers against Newcastle and Influenza disease viruses as well as sheep red blood cells. Dietary treatments had no significant effects on tibia ash and tibial dyschondroplasia score. Broilers fed Ca-P deficient diets had lower tibia Ca and P than those in treatment A (P < 0.05). In conclusion, results indicated that broilers fed Ca-P deficient diets supplemented with 5 µg/kg 1α-OH-D3 failed to achieve the same tibia Ca and P values as broilers fed nonphytate phosphorus adequate diets.

Evaluation of one-alpha-hydroxy-cholecalciferol alone or in combination with cholecalciferol in Ca-P deficiency diets on development of tibial dyschondroplasia in broiler chickens.

This experiment was conducted to determine whether dietary cholecalciferol will alleviate a calcium and phosphorous (Ca-P) deficiency when one-alpha-hydroxy-cholecalciferol, 1α(OH)D3, is supplemented, and to determine the effects of adequate and inadequate Ca-P when 1α(OH)D3 is supplemented and vitamin D3 is adequate. A total of 144 one-d-old broiler chicks (Ross 308) were allocated to 3 treatments. The dietary treatments were as follows: treatment A, adequate Ca-P + cholecalciferol + 5 µg/kg 1α(OH)D3; treatment B, inadequate Ca-P + cholecalciferol + 5 µg/kg 1α(OH)D3; treatment C, inadequate Ca-P + 5 µg/kg 1α(OH)D3. All diets were mixed with 500 FTU/kg of phytase, and cholecalciferol was provided in 5,000 IU/kg except for treatment C that fed diets without vitamin D3. The Ca-P levels in the adequate diets were 0.90% Ca, 0.66% total phosphorus (tP); 0.75% Ca, 0.59% tP; 0.69% Ca, 0.54% tP for the starter, grower and finisher periods. At d 42 of age, broilers were inspected for incidence and severity of tibial dyschondroplasia (TD). The results showed that inadequate Ca-P supplementation with cholecalciferol significantly decreased the incidence of TD, score and tibia ash compared with broilers fed the same diet in the absence of cholecalciferol (P < 0.05). The broilers fed inadequate Ca-P diets with cholecalciferol were unable to achieve the same tibia ash and incidence of TD as those fed Ca-P adequate diets (P < 0.05). In conclusion, this trial suggests that broilers fed an inadequate Ca-P diet with 1α(OH)D3 and adequate level of cholecalciferol are unable to sufficient bone formation. There was no indication that 1α(OH)D3 in the absence of cholecalciferol was effective in reducing TD whereas it could improve tibia ash.

Cotreatment of IGF1 and Fadrozole Upregulates the Expression of RSPO1, SOX9, and AMH in Chicken Embryos.

Insulin-like growth factor-1 (IGF1) and anti-aromatase synergistically increase the rate and stability of female-to-male sex reversal as well as pre- and postnatal weight gains in hatched chickens. This study aimed at assessing gene expression profiles of chicken embryos treated with IGF1 and fadrozole. Day 3.5 fertile eggs were in ovo injected with one of IGF1, fadrozole anti-aromatase, combined IGF1 and fadrozole, or sham injection. The expression profile was studied on day 6 and day 11 of the embryonic development following gonadal differentiation. On day 6 of embryonic development, simultaneous injection of IGF1 and fadrozole significantly upregulated the expression of RSPO1, AMH, and SOX9 in genetically female embryos compared to single injections and control groups. Also, a higher expression of ESR1 and BMP4 was observed in genetically male embryos on day 6 compared to the control group. In day 11 embryos, a higher expression of BMP4 was detected in both males and females of the IGF1 and fadrozole-administered group compared to the sham injection cohort. In conclusion, the results of this study indicate that combined effects of IGF1 and fadrozole induce female-to-male sex reversal by increasing the expression of testis developmental factors rather than attenuating ovary developmental factors.

Influence of drinking water containing Aloe vera (Aloe barbadensis Miller) gel on growth performance, intestinal microflora, and humoral immune responses of broilers.

AIM: The risk of bacteria resistance to specific antibiotics possibly by continuous subtherapeutical administration of antibiotic growth promoters (AGPs) in poultry feed led to a ban on the use of AGP in poultry production. As a result of this ban, alternative substances for poultry growth promotion and disease prevention are being investigated, among which phytogenic and herbal products have received increased attention as natural additives because they have been accepted by consumers as natural additives. The effect of water supplementation of Aloe vera (AV) as an AGP substitute on performance, intestinal microflora, and immune responses of broilers. MATERIALS AND METHODS: The five experimental treatments were allocated to four replicates. The following treatments were applied (1) a basal broiler diet (C) and normal drinking water, (2) 0.5% AV gel in drinking water, (3) 0.75% AV gel in drinking water, (4) 1% AV gel in drinking water, and (5) diet C supplemented with flavophospholipol at 4.5 mg/kg and drinking normal water. Vaccines against influenza disease and sheep red blood cell (SRBC) were administrated to immunological stimuli. The populations of Lactobacilli spp. and coliforms were enumerated in ileum. RESULTS: Body weight of broilers supplemented with different levels of AV increased compared with control group (p<0.05). Birds supplemented with antibiotic had the best feed-to-gain ratio (F:G) in different periods. Supplementation of 0.5% and 0.75% AV improved F: G entire experimental period compared with control group (p<0.05). Coliform bacteria were reduced in broilers supplemented with different levels of AV or antibiotic (p<0.05). The Lactobacilli spp. population in birds supplemented with 0.75%, 1% AV or antibiotic significantly was higher than other groups (p<0.05). Supplementation with 1% AV led to greater antibody titers against SRBC compared with other groups (p<0.05). CONCLUSION: These findings demonstrated a possibility of supplementing broiler drinking water with 1% AV gel as an alternative for AGP substitution.

Is passive transmission of non-viral vectors through artificial insemination of sperm-DNA mixtures sufficient for chicken transgenesis?

DNA uptake in the post-acrosomal region of the spermatozoa takes place exclusively in immotile spermatozoa that are naturally unable to fertilize eggs. The present study aimed to assess whether passive transmission of non-viral vectors to the surrounding areas of chicken embryos could be an alternate mechanism in chicken sperm-mediated gene transfer. First, the presence of nucleases in rooster seminal plasma was evaluated. Semen ejaculates from five roosters were centrifuged and the supernatant was incubated with pBL2 for 1 h. A robust nuclease cocktail was detected in the rooster semen. To overcome these nucleases, plasmid-TransIT combinations were incubated with semen for 1 h. Incubation of exogenous DNA in the lipoplex structure could considerably bypass the semen nuclease effect. Then, intravaginal insemination of 1 × 10(9) sperm mixed with lipoplexes (40 µg pBL2:40 µl TransIT) was carried out in 15 virgin hens. Neither the epithelial tissue from the inseminated female reproductive tracts nor the produced embryos following artificial insemination showed the transgene. To remove any bias in the transgene transmission possibility, the plasmid-TransIT admixture was directly injected in close vicinity of the embryos in newly laid eggs. Nonetheless, none of the produced fetuses or chicks carried the transgene. In conclusion, the results of the present study revealed a nuclease admixture in rooster seminal plasma, and passive/active transmission of the non-viral vector into close vicinity of the chicken embryo was inefficient for producing transgenic chicks.

Effect of various fiber types and choice feeding of fiber on performance, gut development, humoral immunity, and fiber preference in broiler chicks.

Two experiments were conducted to investigate the effect of fibrous materials with one single diet or by choice feeding on performance, intestinal morphology, immunity, and fiber preference in broiler chicks. In experiment 1, 240-day-old chicks (Ross 308) were assigned to one of 4 treatments, comprising 5 replicates per treatment in a completely randomized design. Dietary treatments included: a basal diet (control) or 30 g/kg sugar beet pulp (SBP), 30 g/kg rice hull (RH), or 30 g/kg equal combination of them (SBP/RH) added to the basal diet. Results showed SBP and SBP/RH impaired daily weight gain (DWG) in the growing period compared with control (P < 0.05). Additionally, chickens that received SBP had deteriorated FCR across the entire rearing period (P < 0.05). In comparison to control and SBP, supplementing SBP/RH significantly increased antibody titer against Newcastle disease virus (NDV; P < 0.05) at 23 d of age. Furthermore, SBP reduced duodenal and ileal villus height compared with control at 21 d of age. In experiment 2, a total of 240 chicks were allotted to 4 experimental treatments of feeding: 1) control; or choice feeding between 2) control and SBP (C-SBP); 3) control and RH (C-RH); 4) control and SBP/RH (C- SBP/RH). Results indicated that chicks had a tendency to use separate sources of fiber. RH was consumed lower than C-SBP/RH and C-SBP in starter and growing periods, respectively (P < 0.05). Chickens choice fed RH and SBP/RH had greater daily feed intake than control across 14 to 28 d of age (P < 0.05). However, DWG reduced in all fiber fed birds (P < 0.05) and resulted in impaired FCR in broilers of the C-SBP group (P < 0.05). In addition, choice feeding of SBP/RH increased antibody titer against NDV as compared with control and SBP (P < 0.05). In conclusion, fiber inclusion in both experiments impaired growth performance but an equal combination of fiber improved immunity. In addition, broilers had a tendency to use separate sources of fiber.

Evaluation of kefir as a potential probiotic on growth performance, serum biochemistry and immune responses in broiler chicks.

This experiment was conducted to evaluate the effect of milk or molasses kefir as a probiotic on growth performance, carcass traits, serum biochemistry and humoral immune responses in broiler chickens. A total of 192 one-d-old as hatched broiler chicks (Ross 308) were randomly allotted to 4 treatments, each with 4 replicate pens of 12 chicks. The following treatments were applied: 1) a basal diet (C) and normal drinking water, 2) 2% milk kefir in drinking water, 3) 2% molasses kefir in drinking water, and 4) the diet C supplemented with commercial probiotic. At d 42, eight birds per treatment were killed for determination of carcass traits. Broilers at 28 days of age were bled for measuring antibody titers against Newcastle disease virus (NDV) and avian influenza virus (AIV), at 30 days of age for antibody titers against sheep red blood cell (SRBC), and at 42 days of age for biochemical analysis. Supplementing 2% milk kefir increased body weight of broilers at 28 and 42 days of age (P < 0.05). Supplementing 2% molasses kefir improved feed conversation ratio (FCR) of broilers during growth period (P < 0.05), but FCR of broilers in other periods was not affected. Daily feed intake, internal organ weights, and carcass traits were not influenced by the treatments except for small intestine and ceca length. Small intestinal length significantly decreased in broilers supplemented with milk and molasses kefir (P < 0.05). Molasses kefir supplementation significantly (P < 0.05) increased antibody titer against SRBC at 31 days of age but other immune related parameters were not statistically different among treatments. Biochemical parameters including serum protein, albumin, and triglyceride concentrations were not statistically (P > 0.05) influenced. Broilers supplemented with molasses kefir, had a significantly lower concentration of serum total cholesterol, low density lipoprotein cholesterol and elevated high density lipoprotein cholesterol at 42 days of age (P < 0.05). In conclusion, the results indicated that inclusion of 2% milk kefir in drinking water would improve growth performance of broiler chickens.

Synergistic effect of fadrozole and insulin-like growth factor-I on female-to-male sex reversal and body weight of broiler chicks.

The aim of this study was to investigate the effects of Fadrozole hydrochloride and recombinant human insulin-like growth factor I (rhIGF-I) on female-to-male sex reversal, hatching traits, and body weight of broiler chickens. On the third day of incubation, fertile eggs were randomly assigned to five experimental groups comprising (i) Fadrozole (0.1 mg/egg), (ii) rhIGF-I (100 ng/egg), (iii) Fadrozole (0.1 mg/egg) + rhIGF-I (100 ng/egg), (iv) vehicle injection (10 mM acetic acid and 0.1% BSA), and (v) non-injected eggs. Eggs in the rhIGF-I-injected groups showed the mode of hatching time at the 480th hour of incubation, 12 hours earlier compared to the other groups, with no statistically significant difference in mortality and hatchability. On Day 1 and 42 of production, 90% of genetically female chicks were masculinized using Fadrozole treatment, while 100% female-to-male phenotypic sex reversal was observed in the Fadrozole+rhIGF-I group. Fadrozole equalized the body weight of both genders, although rhIGF-I was effective on the body weight of male chicks only. Interestingly, combined rhIGF-I and Fadrozole could increase the body weight in both sexes compared to the individual injections (P<0.05). These findings revealed that (i) IGF-I-treated chicken embryos were shown to be an effective option for overcoming the very long chicken deprivation period, (ii) the simultaneous treatment with Fadrozole and IGF-I could maximize the female-to-male sex reversal chance, (iii) the increase in the body weight of masculinized chickens via Fadrozole could be equal to their genetically male counterparts, and (iv) the IGF-I effectiveness, specifically along with the application of aromatase inhibitors in female chicks, indicates that estrogen synthesis could be a stumbling block for the IGF-I action mechanism in female embryos.

Chromium supplementation can alleviate the negative effects of heat stress on growth performance, carcass traits, and meat lipid oxidation of broiler chicks without any adverse impacts on blood constituents.

This study was conducted to determine the effects of dietary supplementation with Cr nicotinate and Cr chloride and their optimum inclusion rate on performance, carcass traits, meat oxidative stability, serum metabolites, hematological parameters, and liver chromium concentration in heat-stressed broilers. A total number of 420, 1-day-old male broiler chicks were randomly assigned to seven treatments with four replicates of 15 chicks. The dietary treatments consisted of the basal diet supplemented with 0 (control), 500, 1,000, and 1,500 µg/kg Cr in the form of Cr nicotinate and Cr chloride. Chicks were raised for 6 weeks in heat stress condition (33 ± 2°C). Supplements of organic and inorganic Cr particularly at 1,500 µg/kg incorporation increased feed consumption (P < 0.05) and body mass gain of broilers (P < 0.01). Cr supplementation increased carcass yield and decreased abdominal fat (P < 0.01). Supplementation of 1,500 µg/kg Cr nicotinate (P < 0.05) enhanced liver Cr concentration. Storage time increased lipid oxidation of meat (P < 0.01). Cr decreased lipid oxidation of breast and thigh muscles over 2 (P < 0.01) or 6 (P < 0.05) days of storage time. Birds fed 1,500 µg/kg Cr nicotinate, had lower concentration of serum glucose and triglyceride at 21 days (P < 0.05). Hematological parameters tested at 21 and 42 days, were not influenced. The results suggested that dietary Cr supplementation regardless of its source have a positive effect on productive, and carcass traits, also enhances oxidative stability of refrigerated meat in broilers reared under heat stress conditions.

Assessment of growth performance, immune responses, serum metabolites, and prevalence of leg weakness in broiler chicks submitted to early-age water restriction.

The objective of this study was to evaluate the effects of two methods of early-age water restriction on performance, some immune responses, serum metabolites, and prevalence of leg weakness in broiler chicks. One-hundred-eighty-seven-day-old chicks (Ross 308) were allocated to three treatments with four replicates based on a completely randomized design. Treatments included the control group, where birds had free access to water, and water-restricted groups, where access to water was limited to three 2-h periods (WRT1) or a 12-h period (WRT2) per day from days 7 to 17. Chicks in the control group were significantly heavier (P < 0.05) at 17 and 46 days of age compared to the restricted birds. In the WRT2 group, feed intake decreased significantly over the 17- to 28-day period while feed conversion ratio was poorer during water restriction (P < 0.05). Antibody titers against Newcastle and SRBC were higher (P < 0.05) for chicks with ad libitum access to water. Birds in the restricted groups exhibited a higher heterophil to lymphocyte ratio compared to the control group (P < 0.05). The treatments had no significant impact on serum metabolites including protein, triglyceride, total cholesterol, high-density lipoprotein and low-density lipoprotein cholesterols, calcium, and phosphorus concentrations. Walking ability, tibial dyschondroplasia, foot pad, hock burn, and valgus/varus angulation were not significantly influenced by water restriction. In conclusion, the current results indicate that early-age water restriction negatively influenced productive traits and immunological responses of broiler chicks and failed to have any favorable impacts on leg health.

Effect of diets supplemented with different levels of manganese, zinc, and copper from their organic or inorganic sources on egg production and quality characteristics in laying hens.

This experiment was conducted to evaluate the effect of zinc, manganese, and copper sources (inorganic vs. organic) in the diet on laying performance and eggshell quality characteristics. One hundred and eighty Hy-Line W-36 layers at 38 weeks of age were allocated to 36-layer cages of five hens each. Each six cages were randomly assigned to one of the six experimental diets fed from 38 to 53 week of age. In three experimental treatments, the basal diet was supplemented with 65-75-7 or 65-75-7 or 40-40-7 mg/kg of Zn, Mn, and Cu, respectively, from their oxide or sulfate sources. Three other groups were fed diets supplemented with 20-20-3.5 or 40-40-7.5 or 60-60-10.5 mg/kg of organic forms of Zn, Mn, and Cu, respectively. Dietary treatments significantly did affect feed intake (P < 0.001), feed conversion ratio (P < 0.001) and percentage of broken eggs (P < 0.05). Substitution of Zn and Mn oxides (65 and 75 mg kg(-1), respectively) with equal amounts of their sulfate forms significantly improved feed intake, feed conversion ratio, percentage of broken eggs, and Haugh Unit (P < 0.05). In addition, laying hens maintained their performance when substitution of Zn and Mn oxides and Cu sulfate (65, 75, and 7 mg kg(-1), respectively) reduced up to 20, 20, and 3.5 mg kg(-1) by amino acid complexes of the microelements. The results showed that a corn-soybean diet supplemented with the organic forms of Zn, Mn, and Cu at a dosage 50% to 75% lower than NRC recommendation is sufficient to maintain laying performance and can improve eggshell and albumen qualities of the egg in laying hens.