Effect of Monovalent Copper Oxide and Potentiated Zinc Oxide on Growth Performance and Gut Morphology of Broiler Chickens Challenged with Coccidiosis.

An experiment was conducted to evaluate the effect of copper oxide (Cu2O) and potentiated zinc oxide (ZnO) on performance, intestinal morphology, oocyst excretion, coccidial lesion scores, and antioxidant properties in broilers during an Eimeria spp. challenge. A total of 288 1-day-old male broiler chickens (Ross 308) were divided into 18 treatments. Treatments included three levels of Cu (0, 15, or 150 mg/kg) from Cu2O and three levels of Zn (0, 80, or 160 mg/kg) from potentiated ZnO which were added to the basal diet and fed to broilers with or without challenge, using a completely randomized design in a factorial arrangement for 42 days. Live body weight, feed intake, mortality, and the cause of death were recorded weekly and histomorphology of jejunum was measured at the end of the experiment. Results showed that birds fed Cu and Zn linearly decreased (P < 0.0001) oocyst shedding. The number of excreted oocysts was reduced eight times in broilers fed a diet containing 150 mg/kg copper from Cu2O and 160 mg/kg zinc from potentiated ZnO, compared to the infected group without Cu and Zn supplementation (P < 0.0001). Microscopic features of both non-challenged and challenged broiler jejunum revealed significant improvement along with increased Cu2O and potentiated ZnO doses. Supplementation of Cu2O and potentiated ZnO decreased the jejunum structure damages and intestinal lesion score (P < 0.002). Eimeria caused a decrease (P < 0.006) in total antioxidant capacity. Superoxide dismutase increased by dietary zinc supplementation (P < 0.05). Results suggested that a combination of Cu2O and potentiated ZnO could exhibit efficient anticoccidial activity.

Comparison of absorption kinetics and utilisation of DL-methionine (DL-Met), Met-Met product (AQUAVI® Met-Met), and protein-bound methionine (PB-Met) by female broiler chickens.

1. Two experiments were conducted to determine the effects of different methionine (Met) sources regarding their absorption kinetics and utilisation in female single-meal-fed broiler chickens.2. A total of 340, one day old female Ross 308 broiler chickens were fed commercial starter and grower diets for 38 d. Birds were then allocated to treatment diets in two experiments as a completely randomised design with four replicates of five chicks per each until 60 d of age. In experiment 1, a 2 × 5 factorial design was used to investigate the effect of two sources (DL-Met and AQUAVI®Met-Met) and five equimolar levels (0.4, 0.8, 1.2, 1.6, and 2 g/kg) in the diet. In experiment 2, different proportions of protein-bound methionine (PB-Met) to DL-Met (0.4:1.6, 0.8:1.2, 1.2:0.8: 1.6:0.4, and 2:0 g/kg) were incorporated into a basal diet deficient in Met. During the experiment, chickens received 90 g of pelleted feed for a time period of 17 ± 2.5 min, once daily.3. The results indicated that chickens fed diets supplemented with DL-Met and Met-Met showed a rapid rise in plasma Met 1 h after feeding, with a sudden drop at 2 h after feeding. In contrast, chickens fed PB-Met substituted diets showed a gradual plasma peak at 1 and 2 h postprandial (P < 0.01). Plasma homocysteine (HCY) content increased to 34.38 and 40.43 µmol/l with DL-Met2.0 and Met-Met2.0 diets, while it decreased to 25.68 µmol/l with PB-Met2.0(P ≤ 0.01). Chickens that received the PB-Met2.0 diet had higher (P ≤ 0.01) protein utilisation (0.54 g/g) and lower excreta nitrogen content (4.04 g/100 g excreta), which demonstrated the benefits of feeding a protein-bound Met source. The efficiency of Met utilisation was 0.69 g/g in chickens fed PB-Met2.0 diet, but only 0.36 and 0.41 g/g in those fed DL-Met2.0 and Met-Met2.0 (P ≤ 0.01).4. The observed utilisation coefficient of DL-Met and Met-Met for single-meal meat-type chickens was lower than expected. The synchronisation of intestinal Met absorption maintained the efficiency of utilisation, which was related to the sources of added Met, with protein-bound Met showing the best utilisation and least excretion.

Comparison of the Immunogenicity of Four Infectious Bursal Disease Intermediate Vaccines in Commercial Broiler Flocks in Iran: A Field Trial Study.

Infectious bursal disease (IBD) is a highly contagious disease in young chickens worldwide. The major strategy for the prevention and control of IBD virus (IBDV) is vaccination. Therefore, the present study aimed to compare the immunogenicity of four commercially available IBD vaccines on broilers (Ross 308) that were raised in areas with very virulent IBDV infection history. Two commercial broiler farms with four standard poultry houses were selected in Alborz (n=6,250 birds per house) and Khorasan Razavi (n=8,000 birds per house) provinces of Iran. In each farm, the houses were randomly assigned to one of the four IBD intermediate vaccine brands including Dn, Vc, Ch, and Razi. The birds in Alborz were vaccinated against IBDV via drinking water at 18 and 22; and 15 and 21 days of age in Alborz and Khorasan Razavi flocks, respectively. The enzyme-linked immunosorbent assay antibody titers against IBDV were measured in 20 birds per group at 1, 28, 35, and 42 days of age. In addition, production attributes including body weight, feed conversion ratio, mortality, and production index were measured during the research period. According to the findings, the IBD antibody titers were not affected by the vaccine brands at 28, 35, and 42 days of age (P&gt;0.05). Following the second IBD vaccination, an increasing trend in IBD antibody titers was noted in the Razi vaccine as well as other brands at days 35 and 42 compared to the previously recorded titers (P&lt;0.05). Moreover, the production attributes of the flocks receiving various IBDV vaccine brands were not different (P&gt;0.05). Regarding the productivity indices and high immunogenicity levels, the results indicated that the potential of the IBD Razi vaccine was comparable to the other investigated brands of commercial IBD vaccines, and nominated it as an immunogenic candidate vaccine for use in commercial broilers.

The effect of dietary coenzyme Q10 on plasma metabolites and hepatic gene expression in broiler breeder hens.

1. This study was performed to evaluate the effects of dietary supplementation of coenzyme Q10 (CoQ10) on laying rate, body weight, plasma metabolites and some liver gene expression in broiler breeder hens. 2. A total of 128 broiler breeder hens (Arbor Acres Plus, 47 weeks of age) were randomly distributed to four dietary groups supplemented with different levels of CoQ10 (0, 300, 600 or 900 mg/kg diet) with four replicates of eight hens each. During 47-54 weeks of age, laying rate, egg mass and body weight were recorded weekly. To assay plasma biochemical indicators, blood samples were collected at 54 weeks of age. At the end of the experiment, for evaluating the abdominal fat weight, liver weight and expression of the adiponectin and proliferator-activated receptor-α (PPAR-α) genes in the liver, eight hens per treatment were selected, weighed and humanely killed by decapitation. 3. Dietary supplementation of CoQ10 linearly decreased abdominal fat weight, alanine aminotransferase (ALT) and aspartate aminotransferase (AST) activities by increased levels of CoQ10. The plasma levels of glucose, cholesterol and alkaline phosphatase (ALP) activity were quadratically decreased by increased levels of CoQ10. The best plasma levels of glucose, cholesterol and ALP activity were estimated at 562.5, 633.3 and 517.8 mg CoQ10/kg diet, respectively. Adiponectin and PPARα gene expression exhibited a linear increased by increased levels of CoQ10. 4. In conclusion, addition of CoQ10 to the diet influenced lipid metabolism and expression of the adiponectin and PPAR-α genes, which might be partially due to the improvement in mitochondrial metabolism and energy production. However, further studies are necessary to determine the effects of CoQ10 on these indicators in broiler breeder hens during ageing.

Changes in broiler breeder hen's immunity by zinc oxide and phytase.

BACKGROUND: The immune response of aged broiler breeder hens is influenced by many factors including obesity and aged lymphatic organs, but may improve by increasing the bioavailability of various nutrients such as zinc (Zn). Dietary supplementation of phytase can improve Zn availability in senescent broiler breeder hens. AIMS: The aim of this study was to investigate the effect of supplementary zinc oxide (ZnO) and phytase in a maize-soybean meal-based diet on immune responses of broiler breeder hens. METHODS: In a 2 × 4 factorial arrangement, a total of 128 hens were randomly assigned into eight groups. The birds received two levels of phytase (0 or 300 U/kg diet) and four levels of ZnO (30, 60, 90, and 120 mg/kg diet) for 13 successive wk (59-72 wk of age). RESULTS: Results showed that phytase supplementation significantly increased immunoglobulin M (IgM), cutaneous basophil hypersensitivity (CBH) responses, total number of leukocytes, percentage of lymphocytes, and heterophil to lymphocyte ratios. The percentage of basophils and monocytes, however, decreased with phytase supplementation. Supplementation of ZnO increased anti-sheep red blood cells (SRBC) antibody titer, IgM, CBH responses, the total number of leukocytes, and the percentage of lymphocytes. Dietary supplementation of ZnO decreased the percentage of heterophil, and heterophil to lymphocyte ratio. A significant interaction effect of phytase and ZnO was found on the total number of leukocytes and percentage of lymphocytes. CONCLUSION: Dietary supplementation of ZnO (90 mg/kg diet) and phytase had some positive effects on improving immune responses in broiler breeder hens.

Comparison of single- and multi-strain probiotics effects on broiler breeder performance, egg production, egg quality and hatchability.

1. This study was conducted to investigate the effect of multi-strain probiotic (containing Lactobacillus acidophilus 2.5 × 107 cfu/g, Lactobacillus casei 2.5 × 107 cfu/g, Bifidobacterium thermophilum 2.5 × 107 cfu/g and Enterococcus faecium 2.5 × 107 cfu/g) and single-strain probiotic (Pediococcus acidilactici 1 × 1010 cfu/g) on broiler breeder performance and gastrointestinal health. 2. A completely randomised trial was conducted using 300 broiler breeder hens (Ross 308) aged 51 weeks old which were randomly allocated to 1 of 5 dietary treatments with 6 replicates per treatment in a 10 week trial. Treatments included (1) the basal diet a negative control, (2) basal diet supplemented with 0.1 g/kg multi-strain probiotic (MS), (3) basal diet supplemented with 0.1 g/kg single-strain probiotic (SS), (4) basal diet supplemented with 0.1 g/kg of both of probiotics (MS+ SS) and (5) positive control basal diet supplemented with 0.5 g/kg oxytetracycline antibiotic (OX). 3. Body weight, egg production, yolk weight, eggshell thickness and weight, Haugh unit, fertility and hatchability were determined. Results showed that dietary treatments had no significant effect on total hen house or total hatching egg production, egg weight, yolk colour index, shell weight, mortality, body weight, fertility, hatchability, oviduct and stroma weight or number of large and small yellow follicles (P > 0.05). None of the jejunum morphological parameters, apparent ileal digestibility of protein and ileal Lactobacillus population were influenced by supplemental probiotics (P > 0.05), although ileum Escherichia coli count was reduced by inclusion of dietary probiotics (P < 0.05). 4. It was concluded that although both probiotic treatments reduced coliforms, they did not improve broiler breeder performance or gastrointestinal tract (GIT) function.

The effect of n-6/n-3 fatty acid ratios on broiler breeder performance, hatchability, fatty acid profile and reproduction.

This experiment was conducted to study the effect of dietary omega6 (n-6) to omega3 (n-3) fatty acid (FA) ratios on performance and reproduction of broiler breeders. In experiment 1, 400 females and 40 males (30 week age) of Ross 308 broiler breeder (20 females and two males in each pen) were randomly assigned to one of the four diets with n-6/n-3 FA ratios of 4, 6, 8 and 16 (control). As a measure of hatchability, fertility of eggs and general incubation traits, 1,200 eggs (60 eggs from each pen) were collected and incubated for 21 days and embryo liver and brain fatty acid profile in 14 and 21 days were determined. In experiment 2, 48 males (three males in each pen) randomly assigned to one of the four diets with n-6/n-3 FA ratios of 4, 6, 8 and 16 (control). Semen was collected twice weekly, and semen volume, spermatozoa concentration and motility and alive and dead spermatozoa were estimated. Egg production and egg mass were decreased by n-6/n-3 FA ratios of 4:1 and 6:1 (p < .05). There were no significant differences between treatments on breeder's body weight, eggs fertility and hatchability, embryonic mortality and semen features. Linolenic acid, eicosapentaenoic acid, docosahexaenoic acid and total n-3 of egg yolk, semen, testis and liver and brain of embryo and day-old chicken were increased while concentration of linoleic acid, arachidonic acid and docosatetraenoic acid of mentioned tissues were decreased by increasing n-6/n-3 FA ratios (p > .05). In conclusion, absolute amount of n-3 and n-6 FAs in broiler breeder diet may be more important than n-6/n-3 FA ratios and to consider reproductive and performance traits of breeders, it is necessary to supply higher levels of n-3 and n-6 FA with respect to n-6/n-3 FA ratios.

Effect of feeding guanidinoacetic acid and L-arginine on the fertility rate and sperm penetration in the perivitelline layer of aged broiler breeder hens.

Two experiments were conducted to evaluate the effects of feeding guanidinoacetic acid (GAA) and L-arginine (ARG) on fertility and sperm penetration (SP) rate of broiler breeder hens. In the first experiment, a total of 200 broiler breeder hens (Ross 308) aged 53 weeks were randomly allotted to four dietary treatments (0, 0.6, 1.2 and 1.8 g GAA/kg diet) with five replicates of 10 birds each. In the second experiment, 320 broiler breeder hens (Ross 308) were used from 53 to 62 weeks of age in a 2 × 4 factorial arrangement (0 or 1.2 g GAA/kg diet along with 0, 3, 6 or 9 g ARG/kg diet). The hens received a diet containing 2800 kcal ME/kg and 14% CP. Sixteen sexually mature Ross 308 breeder roosters (34 weeks old) were used to artificially inseminate the hens. Fertility of the hens was determined in 61 and 62 weeks of age. The sperm penetration holes in the inner perivitelline layer (IPL) overlying the germinal disc were enumerated on days 3 and 7 following each insemination. Adding GAA to the breeder diet increased the number of SPs in the IPL and fertility in both experiments (p < 0.01). The interactive effect of ARG and GAA on the SP and fertility was significant. Supplementary ARG increased the SP rate in the IPL (p < 0.01). In conclusion, dietary supplementation of GAA and ARG might be potentially used to improve the fertility of broiler breeder hens at the later phase of the egg production period.

The effect of increasing feeding frequency on performance, plasma hormones and metabolites, and hepatic lipid metabolism of broiler breeder hens.

An experiment was conducted to study the effects of feeding regimens on reproductive performance, plasma hormone and metabolite levels, and hepatic lipid metabolism of Cobb 500 broiler breeder hens from 26 to 38 wk of age. Seventy-two birds were used in a completely randomized design with 3 treatments, each replicated 4 times. Treatments were as follows: 1) once a day feeding, in which birds were fed once a day at 0615 h (control), 2) twice a day feeding, in which daily allocated feed was fed in 2 equal meals at 0615 and 1215 h, and 3) thrice a day feeding in which daily allocated feed was offered in 3 equal meals at 0615, 1215, and 1815 h. Through 38 wk of age, total hen-day egg production in the hens fed twice and thrice a day was greater (67.1 and 67.2 vs. 62.2 eggs/hen, P < 0.01). Similarly, egg weight was higher (P < 0.01) in birds fed more than once a day. Multi-meal-fed birds had significantly lower plasma triiodothyronine and glucose at 32 wk and also lower glucose and cholesterol, and higher 17ß-estradiol levels at 38 wk than those fed once a day (P ≤ 0.05). Hepatic expression of malic enzyme, fatty acid synthase, acetyl-CoA carboxylase, and ATP citrate lyase relative to ß-actin decreased (P < 0.05) in birds fed twice and thrice a day compared with birds fed once a day at peak egg production (32 wk). In contrast, feeding regimens did not affect the hepatic gene expression of lipogenic enzymes after peak egg production at 38 wk. Stearoyl-CoA desaturase 1 (SCD1) gene expression was constant over dietary regimens. There was no difference in malic enzyme activity in multi-meal-fed birds at 38 wk. In summary, feeding broiler breeder hens 2 or 3 meals per day improved the reproductive performance during the early lay cycle. Implementing twice or thrice a day feeding regimens altered hepatic lipogenic gene expression in broiler breeder hens only at peak egg production, which indicated a short-term effect of increasing feeding frequency on hepatic lipid metabolism.

Arginine, soy isoflavone and hydroxypropylmethylcellulose have protective effects against obesity in broiler breeder hens fed on high-energy diets.

1. The present study was undertaken to determine the effects of arginine, soy isoflavone (ISF) and hydroxypropylmethylcellulose (HPMC) on obesity in broiler breeder hens. 2. A total of 320 Cobb 500 hens, 45 weeks of age, were assigned to 64 floor pens. The experiment was conducted as a completely randomised design in a factorial arrangement (2 × 2 × 2 × 2) with 4 replicates of 5 hens in each pen. Factors included two concentrations of HPMC (0 and 1%), two concentrations of arginine (8.4 and 12 g/kg), two concentrations of ISF (zero and three times more than that present in basal diets) and two contents of energy (11.7 and 14.6 MJ/kg). Performance criteria and blood characteristics of hens were measured during the experimental period. Expression of genes involved in lipid metabolism was determined in the liver at 55 weeks of age. 3. Hens given high-energy diets showed increased BW (body weight), ovary weight and abdominal fat pad and enhanced plasma glucose, triglyceride (TG), cholesterol, haemoglobin, haematocrit and low lymphocyte percentages. The expression of malic enzyme, peroxisome proliferator-activated receptor-α (PPARα), peroxisome proliferator-activated receptor-γ (PPARγ) and inducible nitric oxide (iNOS) increased and sterol regulatory element binding protein-1c (SREBP1c) decreased with increasing energy content of diets. Arginine addition decreased TG, cholesterol and A1-c haemoglobin concentration and increased PPARα, PPARγ and iNOS expression. Inclusion of ISF and HPMC decreased BW, egg weight, plasma TG, cholesterol and increased egg production and also enhanced PPARγ and iNOS expression. Significant interactions were observed between energy concentration and ISF and HPMC on BW. 4. The results of the current study revealed that ISF, HPMC and arginine have beneficial effects on controlling the metabolism of obese broiler breeder hens and using a mix of these products minimises the harmful effects of obesity.

Effects of feeding regimen, fiber inclusion, and crude protein content of the diet on performance and egg quality and hatchability of eggs of broiler breeder hens.

A 12-wk experiment was conducted to study the effects of feeding regimen, inclusion of a fiber source, and CP content of the diet on performance of broiler breeder hens. In total, 360 hens and 60 males, 43 wk of age, were assigned to 60 floor pens (6 hens and 1 male each). There were 12 treatments arranged factorially with 2 feeding regimens [restricted (R) and liberal feeding (close to ad libitum consumption; LIB)], 3 sources of fiber (0, 3% inulin, and 3% cellulose), and 2 levels of CP (14.5 and 17.4%). No interactions among main effects were observed for any of the traits studied, and therefore, only main effects are presented. Body weight, liver weight, and abdominal fat weight were higher (P < 0.001) for the LIB than for the R-fed hens. However, egg production (P < 0.001), fertility index (P < 0.05), and percentage of hatch (P < 0.01) were lower for LIB than for R hens. The weights of ovaries (P < 0.05) and the size of the first preovulatory follicle (P < 0.05) were higher for the LIB than for the R hens. Also, egg yolk, egg weight, and BW of the hatching chicks were higher (P < 0.001) for the LIB hens. The inclusion of a fiber source in the diet decreased (P < 0.05) feed intake, BW gain, absolute liver and abdominal fat weight, and egg yolk weight, with effects being more pronounced (P < 0.05) with cellulose than with inulin. Hens fed additional fiber produced more (P < 0.05) eggs that were more fertile (P < 0.05) than control hens. Crude protein content of the diet did not affect hen performance but reduced (P < 0.01) the relative weight of the liver, ovary, and abdominal fat. It is concluded that the inclusion of inulin or cellulose in the diet improved hen performance and that an increase in dietary CP reduced obesity in broiler breeder hens.

Dietary fibers and crude protein content alleviate hepatic fat deposition and obesity in broiler breeder hens.

The effects of inclusion of cellulose or inulin as a source of dietary fiber and CP content of the diet on hepatic fat deposition were investigated in hens fed restricted or close to ad libitum consumption. There were 12 dietary treatments forming a 2 × 3 × 2 factorial with 2 feeding regimens [restricted and liberal (close to ad libitum consumption; LIB)], 3 fiber sources (control, 3% inulin, and 3% cellulose), and 2 levels of CP (14.5 and 17.4%). Hens were assigned in groups of 6 to 60 floor pens. From 43 to 55 wk of age, hens fed LIB showed increased activity of the hepatic malic enzyme (MalE; P < 0.01), which led to an increase (P < 0.001) in liver weight and hepatic lipid deposition and was associated with enhancements (P < 0.05) in plasma levels of glucose, triglyceride, total cholesterol, and low-density lipoprotein cholesterol. Abdominal fat deposition and BW of the hens increased (P < 0.001) with liberal feeding. Inclusion of inulin in the diet reduced (P < 0.05) liver and abdominal fat weight, whereas cellulose inclusion decreased (P < 0.05) feed intake, abdominal fat, and BW. An increase in CP content of the diet from 14.5 to 17.4% reduced MalE activity (P < 0.001), liver weight (P < 0.001), and the accumulation of lipids and cholesterol in the liver, as well as plasma triglyceride concentration and abdominal fat pad weight (P < 0.05). It is concluded that fiber inclusion reduced abdominal fat and liver weight, with effects being more pronounced with cellulose than with inulin. An increase in dietary CP reduced MalE activity and alleviated hepatic and plasma lipid concentration; therefore, it might be a practical approach to reduce the incidence of obesity-linked problems in broiler breeder hens. The combination of high-CP diets and the inclusion of a fiber source did not suppress liver lipid content over that observed with the high-CP diet, exclusively.

Effects of wheat inclusion and xylanase supplementation of the diet on productive performance, nutrient retention, and endogenous intestinal enzyme activity of laying hens.

An experiment was conducted to study the effects of inclusion of a wheat cultivar (high in nonstarch polysaccharides) and xylanase supplementation of the diet on productive performance, pH of the gastrointestinal tract, nutrient retention, and intestinal enzyme activity of Hy-Line W-36 laying hens from 25 to 47 wk of age. The experiment was completely randomized with 8 treatments arranged factorially with 4 levels of wheat (0, 23, 46, and 69%) that corresponded to a dietary arabinoxylan content of 3.0, 3.3, 3.6, and 3.9%, with or without xylanase supplementation. Each treatment was replicated 5 times. For the entire experimental period, egg weight (P < 0.05) and egg mass (P < 0.01) were reduced and the feed conversion ratio was hindered (P < 0.05) with increased levels of wheat in the diet, but ADFI and egg production were not affected. Xylanase supplementation improved egg production (P < 0.05), egg mass (P < 0.01), and the feed conversion ratio (P < 0.01). Diet did not affect egg quality at any age, except for shell thickness at 47 wk that was improved with xylanase supplementation (P < 0.05). Digesta pH of the different organs of the gastrointestinal tract was not affected by wheat inclusion or xylanase supplementation. Ileal viscosity increased (P < 0.001) with wheat inclusion and decreased (P < 0.001) with xylanase supplementation at all ages. Fat digestibility (P < 0.001) decreased with increased levels of wheat but AME(n) content of the diets (P < 0.05) and nitrogen retention were not affected. Wheat inclusion increased (P < 0.001) amylase (33 wk), lipase (33 wk), and aminopeptidase (47 wk) activity in the duodenum as well as lipase activity in the jejunum at 47 wk of age. However, xylanase supplementation did not affect the activity of any of the enzymes studied. It is concluded that most of the negative effects of wheat inclusion in the diet were reduced or even disappeared with xylanase supplementation. Wheat with a high nonstarch polysaccharide content (Pishtaz cultivar) can be used at levels of up to 69% in laying-hen diets without negatively affecting bird performance, provided that feeds are supplemented with xylanase.

Black cumin seeds, Artemisia leaves (Artemisia sieberi), and Camellia L. plant extract as phytogenic products in broiler diets and their effects on performance, blood constituents, immunity, and cecal microbial population.

Two experiments were conducted to evaluate the effects of using black cumin seeds (BCS), Artemisia leaves (AL), and Camellia L. plant extract (CLE) in the diets of broiler chicks. Experiment 1 was conducted as a completely randomized design in a factorial arrangement (2 × 2) with 8 replicates of 4 chicks in each battery cage. Factors included 2 levels of BCS and AL (0 and 1%). Experiment 2 was conducted as a completely randomized design with 4 treatments (control, 0.3 and 0.5 g/kg of CLE, and 0.5 g/kg of mannanoligosaccharide) of 8 replicates and 4 chicks in each. Body weight and cumulative feed intake were measured at 21, 35, and 42 d of age. Antibody response against SRBC was measured on d 28 and 42. Blood characteristics, relative weight and length of different parts of the carcass, gastrointestinal pH, villi length, and crypt depth were measured at 42 d of age. Artemisia addition did not affect BW and feed conversion ratio (FCR) but decreased feed intake significantly up to 21 d of age (P ≤ 0.01). Black cumin significantly increased BW (P ≤ 0.05) at 21 and 42 d of age and decreased FCR throughout the experimental period (P ≤ 0.01). Artemisia significantly increased monocytes but had no effect on gastrointestinal pH, antibody response, and relative weight and length of different parts of the carcass. Black cumin increased red blood cells, hematocrit, hemoglobin, gizzard relative weight, and pH but decreased antibody response and monocytes percentage (P ≤ 0.01). Artemisia did not affect plasma lipid profile but decreased coliform and Escherichia coli populations of ceca significantly (P ≤ 0.01 and P ≤ 0.05, respectively). Addition of 0.5 g/kg of CLE decreased BW, feed intake, and FCR throughout the experiment (P ≤ 0.01). Camellia increased gizzard and proventriculus pH, villi length, and crypt depth (P ≤ 0.01) but decreased primary antibody response, total white blood cell count, and cholesterol concentration (P ≤ 0.05). The results of this experiment showed that using BCS alone or mixed with AL improved broiler health and performance but CLE negatively affected broiler BW and feed intake and is not a good alternative to commercial mannanoligosaccharide.

The effect of dietary n-6:n-3 ratio and sex on broiler breeder immunity.

A study was conducted with male and female adult broiler breeders to determine the effect of feeding a fish oil supplement on selected immune activities. The fish oil was added to the diet such that the n-6:n-3 ratios could meet certain levels. Four hundred Ross 308 broiler breeder hens and 48 Ross 308 broiler breeder roosters at 30 wk of age were randomly assigned to diets containing 3.5% fat with n-6:n-3 ratios of 4, 6, 8, and 16. As a measure of cell-mediated immunity, thickness of the toe web was measured at 4, 8, 24, and 48 h after injection of phytohemagglutinin-P (PHA-P) at 32 wk of age. Total antibodies were quantified 6 and 9 d after the injection of SRBC at 33 wk of age. Blood lymphocyte proliferation was assayed after in vitro stimulation with PHA-P at 34 wk of age. The fatty acid profile of the spleen was determined in roosters. The effects of dietary n-6:n-3 ratios on total antibodies and in vitro lymphocyte proliferation were not significant (P > 0.05). However, the birds fed diets containing an n-6:n-3 ratio of 8 showed the greatest toe web thickness (P < 0.05). Total antibodies in hens at 9 d after SRBC injection were significantly greater than those of roosters. Conversely, toe web thickness in roosters was greater than that of hens (P < 0.05). Although the increase in the dietary n-6:n-3 ratio of polyunsaturated fatty acids significantly decreased the concentrations of eicosapentaenoic acid, docosahexaenoic acid, total n-3 (P < 0.05), linoleic acid, arachidonic acid, and total n-6, the n-6:n-3 fatty acid ratios of the entire spleen were significantly increased (P < 0.05). Results indicated that under the conditions of this study, the n-6:n-3 ratios seemed to influence the toe web response to PHA-P, but not the antibody response or the cell proliferation response in vitro.

Genetic parameters for feed utilization traits in Japanese quail.

Feed costs substantially affect the efficiency of poultry operations, justifying genetic improvement of feed utilization by selection. The current research was conducted to estimate genetic variance for the 4-wk feed conversion ratio (FCR) and its genetic correlations with BW, BW gain (WG), feed intake (FI), and residual feed intake (RFI) in Japanese quail. The data analyzed originated from a line selected for low FCR for 3 generations. In each generation, 35 sires and 70 dams were used as parents for the next generation. Body weight and WG were recorded on a total of 1,226 individuals, whereas FCR, RFI, and FI were recorded on 505 family groups. The results showed that heritability estimates (±SE) of BW at 28 d of age and WG between 7 and 28 d of age were 0.22 ± 0.05 and 0.28 ± 0.06, respectively. For FI, FCR, and RFI, significant genetic variances were estimated. Genetic correlations of FCR between 7 and 28 d of age with WG and FI between 7 and 28 d of age were -0.45 ± 0.09 and 0.24 ± 0.08, respectively. This implies that a low FCR is genetically related to a high WG and low FI. The genetic correlation between FCR from 7 to 28 d of age and RFI from 7 to 28 d of age was 0.26 ± 0.08, indicating that the 2 alternative feed efficiency traits are genetically different traits, and that the correlated genetic response in one of them in response to selection on the other is likely to be only moderate. Genetic correlations of RFI from 7 to 28 d of age with WG and FI between 7 and 28 d of age were 0.08 ± 0.04 and 0.74 ± 0.11, respectively. This reflects the fact that RFI is phenotypically independent of WG, which tends to make the genetic correlation between RFI and WG low as well. In conclusion, all the traits analyzed displayed significant genetic variance, allowing their genetic improvement by selection, yet the alternative feed utilization traits, FCR and RFI, displayed different genetic characteristics.

Efficacy of combined or single use of Lactobacillus crispatus LT116 and L. johnsonii LT171 on broiler performance.

1. The objective of this research was to investigate the efficacy of combined or single use of Lactobacillus crispatus LT116 and Lactobacillus johnsonii LT171 on broiler performance. 2. A total of 320 one-d-old male Ross broiler chicks were allocated in 4 experimental treatments for 6 weeks. The experimental treatments received a maize-soybean meal basal diet that was supplemented as follows: 'control', with no other additions; 'LJ', 1 × 10(6) CFU of L. johnsonii LT171; 'LC', 1 × 10(6) CFU of L. crispatus LT116; and 'LCJ', 0·5 × 10(6) CFU of L. johnsonii LT171 + 0·5 × 10(6) CFU of L. crispatus LT116/g of the diet. A suspension of sheep red blood cells (SRBC) was injected into the breast of 8 birds from each treatment on d 14 and 30, and the antibody titre was measured on d 20, 26, 36 and 42. 3. Body weight was improved when compared with control for broilers fed diets supplemented with LCJ. The feed conversion ratio (FCR) decreased in LC and LCJ groups compared with control. The number of coliforms in the ileum of LJ, LC and LCJ birds was lower than that from the control birds. However, only the LCJ treatment significantly decreased the number of coliforms in the caecum. The LCJ group had greater villus height in the duodenum than the LC group, and both LCJ and LC groups showed increased villus height in the duodenum and jejunum relative to the control. Antibody titre against SRBC was higher for the LCJ group than for the LJ and control groups in terms of secondary immune response (mean of 36 and 42 d). 4. This study showed, compared with the control, that the combination of Lactobacillus spp. could positively affect body weight, coliform numbers in the caecum and immune response.

Response to selection for feed conversion ratio in Japanese quail.

We investigated the effect of selection for 4-wk feed conversion ratio (FCR) on genetic improvement of FCR, BW, weight gain (WG), feed intake (FI), and residual FI (RFI) in Japanese quail. The F line was selected for reduced FCR and the C line was maintained as a randombred control. In each generation, 35 sires and 70 dams were used as parents for the next generation. Three generations of selection were performed. Realized heritability for FCR was calculated as the ratio of cumulative selection response to the cumulative selection differential, and additionally, genetic response was quantified as the difference between the means of selection and control lines. The results showed that realized heritability for FCR after 3 generations of selection was 0.67. The mean FCR in F line and C line in the last generation was 2.13 and 2.61, respectively. This is 18.4% cumulative genetic improvement, or 6.1% improvement per generation. In the last generation, the means of F and C lines were 193 and 166 g for BW at age 28 d (16.4% total increase, or 5.5% per generation), 184 and 158 g for WG (17.2% total higher gain and 5.7% per generation), 393 and 413 g for FI (4.9% total higher consumption and 1.6% per generation), and -24.5 and 10.2 for RFI (-34.7 g of cumulative gain; -11.6 g per generation), respectively. These results show that selection to decrease FCR increases BW and WG and decreases FI and RFI as a correlated response.

A twice-a-day feeding regimen optimizes performance in broiler breeder hens.

To evaluate the effects of different methods of feed allocation on performance, plasma hormone concentration, and ovarian morphology, an experiment was conducted using 32 Cobb 500 broiler breeder hens. The experiment was started at 27 wk and lasted to 39 wk of age. Feeding regimens included: i) hens with an ad libitum feeding program, ii) hens that received their restricted feed once a day, iii) hens that received their restricted feed twice a day, and iv) hens that received their restricted feed 3 times a day. Each hen was assumed as an experimental unit and treatments were replicated 8 times. Daily egg production, BW, and egg and yolk weights were measured. Two blood samples were taken 3 and 6 h after the first feed allocation every 2 wk. Plasma samples were assayed for glucose, triacylglycerol (TAG), cholesterol, as well as leptin-like concentration, glucagon, triiodothyronine, thyroxine, progesterone, estradiol, and testosterone. Liver, abdominal fat pad, and ovary were collected at necropsy. Ovaries were weighed and follicles were characterized as large yellow follicles, small yellow follicles, and large white follicles. Results showed inferior egg production in ad libitum-fed birds along with high levels of plasma glucose, TAG, cholesterol, leptin-like concentration, and testosterone. Twice-a-day-fed birds produced more egg in the entire production period than once-a-day-fed birds. Better performance of twice-a-day-fed hens was associated with lower plasma glucose, TAG, and leptin-like concentration, whereas their estradiol and glucagon were higher than once-a-day-fed hens. Results obtained in our study suggest that allocation of restricted feed 2 times a day may alleviate or delay lipotoxicity development and improve reproductive performance in broiler breeder hens.

Impact of dietary crude protein and amino acids status on performance and some excreta characteristics of broiler chicks during 10-28 days of age.

A study was conducted in a completely randomised design to evaluate the effects of providing almost all important essential amino acids (EAA) in low-crude protein (CP) diets equal to that of higher CP diets in broiler chickens. Also the effects of additional mixture of glycine (Gly) and glutamic acid (Glu) or supplementation of excess EAA to low-CP diets on the live performance and excreta characteristics including pH, moisture, nitrogen, uric acid and ammonia concentration were measured to ascertain the optimum CP concentration for the maximum performance and reduced excreta ammonia concentration. Male, broiler chickens growing from 10 to 28 days of age were fed eight experimental diets. Reducing dietary CP below 19% negatively affected performance. Adding the Gly and Glu mixtures to 17% CP diets improved live performance. Reducing CP to 19% with a normal amino acids status declined N, ammonia, uric acid, moisture and pH of excreta significantly. These findings suggest that diminishing dietary CP from 23% to 19% while maintaining adequate EAA levels during 10-28 days of age results in not only a significant decline in N emission, but also a probable reduction in the NH(3) volatilisation because of reduction in pH and moisture. Contrary to expectations, reduction of dietary CP below the minimum level (19%) resulted in more ammonia. All these factors may improve on litter and air quality within the housing facility and reduce the ventilation rate required to emit the elevated ammonia gas concentrations.