Ross Broiler Chicks Research Articles

Differential expression of intestinal nutrient transporters and host defense peptides in Eimeria maxima-infected Fayoumi and Ross chickens

Fayoumi chickens are believed to be more disease resistant compared to commercial broiler chickens. The objective of this study was to compare mRNA expression of intestinal nutrient transporters, digestive enzymes, and host defense peptides (HDP) between Eimeria maxima-challenged Fayoumi and Ross broiler chickens. At 21 d of age, Ross broilers and Fayoumi lines M5.1 and M15.2 were challenged with 1,000 E. maxima oocysts. Control birds were not challenged. Duodenum, jejunum, and ileum were sampled (n = 6) at 7 d post challenge. Gene expression was analyzed using relative quantification PCR. Data were analyzed by ANOVA and significance level was set at P < 0.05. There was numerical, but not statistically significant, differential weight gain depression for Ross (15%) and Fayoumi lines M5.1 (21%) and M15.2 (22%) and significant line-specific changes in gene expression. For nutrient transporters, there was downregulation of mRNA for the brush border membrane, amino acid transporters b0,+AT/rBAT, BoAT, and EAAT3 in different segments of the small intestine of Ross and both lines of Fayoumi chickens, indicating that E. maxima challenge likely caused a decrease in nutrient uptake. For HDP, there was downregulation of avian beta defensin (AvBD) 1, 6, 10, 12, and 13 mRNA in the jejunum of the 2 Fayoumi lines, but no change in the Ross broilers. In the duodenum, there was upregulation of AvBD10 mRNA in the Ross and both Fayoumi lines and additionally upregulation of AvBD11, 12, and 13 mRNA in only Fayoumi line M15.2. Liver expressed antimicrobial peptide 2 (LEAP2) mRNA was downregulated in the duodenum and jejunum of Ross and Fayoumi line M5.1 but not in Fayoumi line M15.2. The homeostatic, non-challenged levels of AvBD mRNA were greater in Fayoumi line M15.2 than Ross and Fayoumi line M5.1 in the duodenum and ileum. This study demonstrates tissue- and genetic line-specific transcriptional responses to E. maxima, highlights novel potential candidate genes for response to coccidiosis, and confirms a role for several previously reported genes in response to coccidiosis.

Effects of chronic thermal stress on growth performance, carcass traits, antioxidant indices and the expression of HSP70, growth hormone and superoxide dismutase genes in two broiler strains

The objective was to investigate the effects of genetic type and the duration of chronic thermal stress (36 °C) on the growing efficiency, carcass traits, antioxidant status, and the expression of liver heat shock protein 70 (HSP70), growth hormone (GH) and superoxide dismutase (SOD) genes. Two hundred and seventy one-day-old chicks (135 male chicks of each breed; Ross 308 and Cobb 500) were used in this work. On the 21st day of age, birds were allocated randomly into 3 equal groups till the 42 days of age (CON:raised in a thermoneutral condition; HS1 and HS2 groups were subjected to 4 and 6 h of daily thermal stress, respectively). Regardless of genetic type, thermal stress decreased the dressing percentage in broilers when compared with the thermoneutral conditions (p = 0.039). In both broiler strains, thermal stress for 6 h (HS2) increased the heterophil to lymphocyte ratio (p = 0.036) and the serum albumin, cholesterol and triglyceride levels (p = 0.023, 0.012 and 0.005, respectively) compared with the thermoneutral group. Under the thermonuteral and heat stress conditions, the Ross broiler chickens showed a significant lower serum triiodothyronine level compared with the Cobb boilers (p = 0.042). It is interesting to note that the expression of HSP70 in the liver of heat-stressed Ross broilers, either 4 or 6 h, was significantly (p = 0.002) higher than that reported in the heat-stressed Cobb broilers. In both broiler strains, the thermal stress for 6 h up-regulate the expression of SOD gene (p = 0.001), but down-regulate the expression of GH gene (p = 0.021) when compared with the CON group. In conclusion, chronic thermal stress down-regulate the mRNA expression of liver GH, concomitantly with an increase in the expression of HSP70 and SOD genes in both broiler strains. This could be useful in the identification of molecular genetic markers to assist in selecting broilers that are more tolerant to heat stress.

EFFECTS OF DIETARY PROTEIN LEVELS WITH OR WITHOUT SYNTHETIC AMINO ACIDS AND ENZYME SUPPLEMENTATION ON PERFORMANCE OF BROILER CHICKENS

This experiment was conducted to study the effect of using two levels of (recommended (R), R-2%) crude protein (CP) supplemented with or without the requirements of methionine and lysine (Met. and Ly.) and each with two levels (0.00 and 0.10%) of Avizyme 1500 in 2 x 2 x 2 factorial arrangement (giving eight dietary treatments) on growth performance of broiler chickens (Ross strain). Accordingly, a total numbers of 192 one-day old unsexed Ross broiler chickens were initially fed a control diet for five days. At six days of age, chicks were randomly allotted to the dietary treatments, birds were divided into eight treatments (24 birds each), each treatment contained three replicates of eight birds each. Results obtained could be summarized in the following: The main effects of level of CP had insignificant effect on live body weight (LBW), live body weight gain (LBWG), feed intake (FI), feed conversion (FC) and performance index (PI) during finisher (25 to 41) and overall experimental periods (6 to 41 days). Level of CP had significant effect on crude protein conversion (CPC) during the period from 6 to 41 days, chicks fed diet containing R had the worst CPC during same period. Chicks fed adequate amounts of amino acids (AA) supplement diets recorded significantly higher PI value during the period from 6 to 41 days, while, recorded significantly the worst values of FC and CPC during the same period. Level of AA had insignificant effect on LBW, LBWG and FI during overall experimental period. Neither enzyme addition nor interaction between level of CP, AA and enzyme addition had any significant effect on LBW, LBWG, FC, CPC and PI during the period from 6 to 41 days. No significant differences due to level of CP or AA on blood constituents, except, red blood cells count (RBCs) which was significantly affected. Chicks fed diet containing R-2% CP or diet containing inadequate amounts of AA had higher value of RBCs. No significant differences due to enzyme addition and interaction effect of dietary treatments on blood constituents, except, interaction effect on neutrophils% (segment) which was significantly affected. Neither level of CP and enzyme addition nor interaction between level of CP, AA and enzyme addition had any significant effect on slaughter parameters% and tibia weight and ash% at the end of the finishing period. Level of CP, AA and interaction between level of CP, AA and enzyme addition had insignificantly affected chemical composition of broiler meat. Chicks fed diet containing R-2% supplemented with the requirements of Met. and Ly. with 0.10% of Avizyme had the best economical and relative efficiency values during the period from 6 to 41 days of age, as compared with those fed the control diet and other treatments. It can be concluded that, CP can be reduced from the recommended level by 2% and supplement these diets with either Met. and Ly or Avizyme without affecting performance. Besides, using such diets reduces feed cost and N pollution.

A DNA prime/protein boost vaccine protocol developed against Campylobacter jejuni for poultry

Vaccination of broilers is one of the potential ways to decrease Campylobacter intestinal loads and therefore may reduce human disease incidence. Despite many studies, no efficient vaccine is available yet. Using the reverse vaccinology strategy, we recently identified new vaccine candidates whose immune and protective capacities need to be evaluated in vivo. Therefore, the goal of the present study was to develop and evaluate an avian subunit vaccine protocol for poultry against Campylobacter jejuni. For this, flagellin was used as vaccine antigen candidate. A DNA prime/protein boost regimen was effective in inducing a massive protective immune response against C. jejuni in specific pathogen free Leghorn chickens. Contrastingly, the same vaccine regimen stimulated the production of antibodies against Campylobacter in conventional Ross broiler chickens harbouring maternally derived antibodies against Campylobacter, but not the control of C. jejuni colonization. These results highlight the strength of the vaccine protocol in inducing protective immunity and the significance of the avian strain and/or immune status in the induction of this response. Nevertheless, as such the vaccine protocol is not efficient in broilers to induce protection and has to be adapted; this has been done in one of our recent published work.

Histological and biochemical evaluation of supplementing broiler diet with β-hydroxy-methyl butyrate calcium (β-HMB-Ca).

Two hundred and sixteen day-old Ross-308 broiler chicks were allocated into 4 groups to study the impacts of different concentrations (0.0, 0.1, 0.15 and 0.2%) of β-hydroxy-methyl butyrate calcium (β-HMB-Ca), on values of tri-iodothyronin (T3) and tetra-iodothyronin (T4) hormones, liver enzymes [aspartate aminotransferase (AST) and alanine aminotransferase (ALT)], uric acid, peroxide, malondialdihyde (MDA), fatty acids and some histological parameters of small intestine (thickness of mucosa, height of villi, thickness of villi, depth of epithelial crypts and epithelial height). The biochemical results did not show any significant effect on T3 and T4 hormones and ALT while there was significant (P<0.01) decrease of AST in groups 2 and 3 and significant (P<0.05) decrease in uric acid in groups 2, 3 and 4 in comparison to control. In the liver, peroxide value (PV) and free fatty acids (FFA) were significantly (P<0.05 and P<0.01 respectively) decreased in groups 2 and 3 compared to control. The histological changes indicate significant values (P<0.05) in all parameters of duodenum in group 2 and 3, while those parameters of jejunum showed significant values (P<0.05) in most parameters of groups 2 and 4. In conclusion, the addition of β-HMB-Ca to the broiler diet from age 1 to 35 days has improved the levels of liver function enzymes and uric acid in the serum and lowered the parameters of oxidation in the liver with improved the maturity, performance and secretory activities of the small intestine in broiler chickens.

Increased bioavailability of tylosin phosphate as in-feed medication formulated for long-action pellets in broiler chickens

Circadian variation of serum concentrations of tylosin in broiler chickens after in-feed medication prompted a comparison study of the serum profiles of this drug after in-feed medication with standard tylosin phosphate (Tprf reference formulation group), and after in-feed medication with a sustained-release pellet formulation (Tpsr group), based on Patent No.MX/a/2012/013222 and PCT/MX2013/000137, in broiler chickens. Six hundred 4-week-old Ross broiler chickens were in-feed medicated with tylosin phosphate at an approximate dose of 25.2 mg/kg/d, based on daily feed consumption values and a final concentration of tylosin in feed of 200 mg/kg of feed. Approximately 2 to 3 mL of blood were obtained per 5 chickens every 2 h, avoiding the sampling of a bird more than once and during 72 h after making medicated feed available for the first time. Serum concentrations of tylosin were determined by HPLC. Gaussian multi-peak regressions were then fitted to serum concentration vs. time profiles. Day by d areas under the serum concentration vs. time profiles (AUC0–24), as well as overall AUC0–72, were statistically higher for the Tpsr group (P < 0.001). Also, maximum serum concentrations obtained and relative bioavailability for the Tpsr formulation were statistically higher (382.8%) as compared to the Tprf group (P < 0.01). Considering the referred improved values of AUC observed in the Tpsr formulation, as well as the fact that tylosin is a time-dependent antibacterial drug, better clinical responses are postulated with this pharmaceutical preparation intended for chickens. Tissue deposition studies for this new formulation of tylosin are required.

Histopathological Study of Chick Intestine: Effect of Probiotic and Lead Acetate

This work was conducted to evaluate the histopathological effects of probiotic (Biomin) and the toxic action of lead acetate on the intestine of one day old forty Ross broiler chicks. The probiotic was used in recommended dose (1.5g/Kg diet), lead acetate was used in toxic dose of (320mg/kg diet). Results show that the histopathological changes of animal group that was treated with lead acetate in toxic dose for 28 days represent the presence of necrosis at the apex of villi with desquamation and hyperplasia in the epithelium of villi and intestinal gland, while sections of chick intestine that were treated with lead acetate at toxic dose and probiotic at recommended dose for 28 days show the infiltration of lymphocyte in submucosal layer and focal area of coagulative necrosis in muscular layer. The group taken probiotic alone shows mild vascular degeneration when compared with the control group.

EFFECT OF DEFFERENT LEVELS OF TURMERIC SUPPLEMENTATION WITH DIET ON HUMORAL IMMUNE RESPONSE TO NEWCASTLE AND INFECTIOUS BURSAL DISEASE VIRUS AND HISTOPATHOLOGICAL CHANGES OF SOME INTERNAL ORGAN OF BROILER CHICKENS

In this study, evaluated the effect of turmeric dietary addition on immune response against the Newcastle disease virus (NDV) and Infectious bursal disease (IBDV). and histopathological changes in some internal organs was evaluated in 42 day old broiler chicks. ninety-six Ross broiler chicks were reared from 1 to 42 days old and divided randomly into four groups, Feed and drinking water were offered ad libitum. Group1 (G1) received turmeric (0.2%), while group2 (G2) received turmeric (0.4%), Group3 (G3) received turmeric (0.6 %) and group4 (G4) was the control positive received basal diet . At the end of the trial five birds from each treatment were slaughtered for assessment of histological section, take same of organ (liver , spleen , and bursa of Fabricius) at 42 day. Results of ELISA test titer revealed differences among various treatment groups at the end of the experiment. mean ELISA test values of G2 revealed a higher significant at (P&lt; 0.05) in antibody titers in comparsion with other groups and control. specimen from liver ,spleen and bursa of fabricius were dissected out for histopathological examination and results of microscopic section showed increase in immune response of G2 chicken : of microscopic sections of G2 histopathological changes in the liver tissue revaled mamefisted by focal mononuclear cells aggregation and proliferation of kupffers cells and slight congestion of blood sinusoids and congestion of portal bloob vessels with few infiltration of inflammatory cells .The intrahepatic bile ductless exhibited dilation and hyperplasia of their epithelial linings with slight per portal fibrosis compared with G1,G3 which showed no clear histopathological changes. The microscopic examination of the spleen revaled range from mild (G1 and G3) to moderate hyperplasia of lymphoid follicles in (G2) . histopathological changes in the bursa of fabricius were characterized by moderate follicular hypertrophy especially in G2 as compared with other treated group's and control .

EFFECT OF USING BIOAKTIV OXYGEN ACTIVATED SODIUM CHLORIDE AS A NOVAEL ALTERNATIVE TO ANTIBIOTIC IN DRINKING WATER ON PERFORMANCE AND ENZYMES ACTIVITY OF BROILER CHICKS.

The study was designed to examine effects of using graded levels of oxygen activated sodium chloride (BioAktiv)in comparison to antibiotic on performance, serum metabolites and digestive enzymes activity in broiler chicks. One hundred eighty, one day old Ross broiler chicks were randomly allocated to four groups. The first group was control without water supplementation. While, the 2nd and 3rd groups received 0.5 and 1gm / 1L drinking water BioAktiv, respectively. The 4th one was given 500 ppm streptomycin (commercial streptomycin 5%) antibiotic. Chicks received the 4 experimental treatments up to the age of 35 day of age. Chicks given different levels of BioAktiv, recorded higher live body weight (LBW) and body weight gain (BWG) ,better feed conversion ratio (FCR) comparable to both antibiotic and control groups. The highest (p<0.01) digestive enzyme activities (amylase, protease) were reported for chicks given NaCl gm/1L BioAktiv, followed by those of antibiotic and the control groups. Highly significant increase (p<0.01) in the serum concentration of total proteins and globulin was observed in groups received the different levels of BioAktiv compared to those of the untreated and antibiotic ones , Likewise, the levels of serum T3 and T3/T4 ratio;recorded higher level with treated groups, however, T4 value was insignificantly differed among all groups. Beyond, watery BioAktiv addition had hypolipemic and hypocholesterolemic effects, but had no effect on liver and kidney functions. These findings imply that, BioAktivmight be considered as a safe water-added antibiotic alternative having affirmative effect on growth performance, gastrointestinal tract (GIT) health and the physiological homeostasis of broiler chicks.

Promising new vaccine candidates against Campylobacter in broilers.

Campylobacter is the leading cause of human bacterial gastroenteritis in the European Union. Birds represent the main reservoir of the bacteria, and human campylobacteriosis mainly occurs after consuming and/or handling poultry meat. Reducing avian intestinal Campylobacter loads should impact the incidence of human diseases. At the primary production level, several measures have been identified to reach this goal, including vaccination of poultry. Despite many studies, however, no efficient vaccine is currently available. We have recently identified new vaccine candidates using the reverse vaccinology strategy. This study assessed the in vivo immune and protective potential of six newly-identified vaccine antigens. Among the candidates tested on Ross broiler chickens, four (YP_001000437.1, YP_001000562.1, YP_999817.1, and YP_999838.1) significantly reduced cecal Campylobacter loads by between 2 and 4.2 log10 CFU/g, with the concomitant development of a specific humoral immune response. In a second trial, cecal load reductions results were not statistically confirmed despite the induction of a strong immune response. These vaccine candidates need to be further investigated since they present promising features.

ISOLATION AND IDENTIFICATION OF GRAM NEGATIVE OXIDASE POSITIVE BACILLI ISOLATED FROM BROILER CHICKENS

Miscellaneous Gram negative bacteria are seriously affecting broiler chickens and poultry industry in Egypt. The present study aimed to isolate and completely identify oxidase positive Gram negative bacterial pathogens recovered from different pathological lesions in broiler chickens by conventional biochemical tests, API20NE and microbact24e system. Samples were taken from 200 Hubbard and Ross broiler chickens of different ages (3-5weeks), from different farms in Beni-Suef and El-Fayoum Governorates during the period from January 2016 to April 2016. Bacteriological examination showed that Gram negative bacteria were 165 (82.5%) of isolates of which 105 isolates (52.5%) were oxidase positive while 60 isolates (30%) were oxidase negative. The most prevalent bacterial isolates were Pseudomonas aeruginosa (43 isolates), Aeromonas hydrophila (35 isolates), Pasteurella gallicida (12 isolates), Plesiomonas shigelloides (10 isolates), and Vibrio vulnificus (5 isolates) with incidences of 21.5%, 17.5%, 6% 5%, and 2.5%, respectively.

Performance of broiler chickens fed South African sorghum-based diets with xylanase

Two experiments were conducted to determine the influence of sorghum variety and xylanase on performance of broiler chickens. In Experiment 1A, a total of 240 day-old Ross broiler chickens were assigned to a 2 (sex) × 3 (sorghum variety) × 2 (with or without xylanase) factorial arrangement in a completely randomized design with 20 chickens per treatment. Gross performance measurements were assessed at 7, 14, and 21 days of age. Carcass yield and visceral organ weights were measured at day 21. In Experiment 1B, a total of 108 female Ross 308 broiler chickens were randomly assigned to a 3 (sorghum variety) × 2 (with or without xylanase) factorial arrangement in a completely randomized design with 6 treatments replicated 6 times. On day 25, all birds were euthanazed by intravenous injection of sodium pentobarbitone and digesta contents from the distal ileum were collected to determine the nutrient digestibility. Broiler chickens offered sorghum variety Pan8816 supplemented with xylanase had higher feed intake, weight gain, and similar feed conversion ratio at 1 - 7 days of age. Breast meat of broiler chickens was not affected by variety or xylanase. The small intestine was heavier in the Pan8625 and Pan8816 groups with xylanase than in the similar Pan8906 group. Enzyme inclusion increased the crude protein digestibility. When xylanase was included in all sorghum varieties, numerically, starch digestibility tended to improve. Sorghum variety affected the growth performance of broiler chickens. Furthermore, nutrient digestibility was affected by the differences in variety. Keywords : Digestibility, tannin, poultry, visceral organs, xylanase

The effects of pre-transport supplementation with electrolytes and betaine on performance, carcass yield and meat quality of broilers in summer and winter

Abstract The consequences of high ambient temperature for broiler chickens collectively results in poorer productivity, prostration and even death. As they approach processing weight, broilers are particularly sensitive to heat stress as they produce large amounts of metabolic heat. Transport from farm to the processing site is a stress for broilers. So, the combination of high ambient temperature prior to transport and the stress associated with transport to processing have unwanted effects on broiler performance and meat quality. In two experiments (summer and winter) the effect of supplementing the water of Ross-308 broiler chickens with electrolytes, with or without betaine for 2 days before processing, on performance and breast muscle meat quality were investigated. In the summer experiment broilers were exposed to a cyclic high temperature protocol over the two days (9 h at 28–29 °C and 14 h at 22–24 °C). In the winter experiment the shed temperature ranged between 14 and 18 °C. The growth performance of birds during supplementation and then the breast muscle meat quality 24–72 h post-mortem were determined. In both experiments betaine had no effect on any performance or meat quality measure and the electrolyte supplementation had no effect on growth performance. In the summer experiment, electrolyte supplementation had significant effects on some measures of meat quality. Breast muscle from supplemented birds had lower 24 h post-mortem pH and based on meat ‘lightness’, lower levels of PSE meat. The 72 h drip loss was significantly lower in meat from birds that had been supplemented with electrolytes. The electrolyte supplements had no effects on meat ‘redness’ or ‘yellowness’, on shear force or cooking losses. In the winter experiment, the electrolyte supplementation had no effect on growth performance or breast muscle meat quality. In this experiment, the average shed temperature was approximately 16 °C with peak values of approximately 18 °C. The growth rate of the birds was approximately 40% higher than that identified in industry performance standards for the Ross-308 strain. The data suggest that the temperature for best performance of the Ross-308 is lower than the 18–24 °C currently accepted as ideal. In all experiments there were significant effects of bird gender on performance and meat quality measures. While electrolyte supplementation supported improvements in meat quality during periods of moderately high ambient temperature, the commercial benefit of these would need to be assessed. The value of electrolyte supplementation is likely to be more substantial when broiler chickens experience heat wave conditions with temperatures > 32 °C, but this remains to be evaluated.

Effects of chromium picolinate on fat deposition, activity and genetic expression of lipid metabolism-related enzymes in 21 day old Ross broilers.

ObjectiveThis experiment was conducted to investigate the effects of chromium picolinate (CrP) on fat deposition, genetic expression and enzymatic activity of lipid metabolism-related enzymes.MethodsTwo hundred forty one-day-old Ross broilers were randomly divided into 5 groups with 4 replicates per group and 12 Ross broiler chicks per replicate. The normal control group was fed a basal diet, and the other groups fed the same basal diet supplemented with 0.1, 0.2, 0.4, and 0.8 mg/kg CrP respectively. The experiment lasted for 21 days.ResultsAdded CrP in the basal diet decreased the abdominal fat, had no effects on subcutaneous fat thickness and inter-muscular fat width; 0.2 mg/kg CrP significantly decreased the fatty acid synthase (FAS) enzymatic (p<0.05); acetyl-CoA carboxylase (ACC) enzymatic activity decreased in all CrP groups (p<0.05); hormone-sensitive lipase (HSL) enzymatic activity also decreased, but the change was not significant (p>0.05); 0.4 mg/kg CrP group significantly decreased the lipoprotein lipase (LPL) enzymatic activity. FAS mRNA expression increased in all experimental groups, and the LPL mRNA expression significantly increased in all experimental groups (p<0.05), but not 0.2 mg/kg CrP group.ConclusionThe results indicated that adding CrP in basal diet decreased the abdominal fat percentage, had no effects on subcutaneous fat thickness and inter-muscular fat width, decreased the enzymatic activity of FAS, ACC, LPL and HSL and increased the genetic expression levels of FAS and LPL.

Higher bioavailability of doxycycline in broiler chickens with a novel in-feed pharmaceutical formulation

Bioavailability of a new, long-acting (LA) pharmaceutical preparation for administering doxycycline as in-feed medication to broiler chickens was compared to the standard in-feed administration of doxycycline. A commercial poultry house harboring Ross-308 broiler chickens, weighing 450 g, was divided into 7 sections as follows: doxy-FOLA group (n = 6,000 chickens divided into 3 replicates) medicated with 10% doxycyline, long-acting pellets at a dose of 400 g of doxycycline HCl/ton of food, resulting in a calculated dose of 48 mg/kg for 5 d; doxy-ref group (n = 6,000, divided into 3 replicates) medicated as for doxy-FOLA, but using a 20% commercial preparation of doxycycline. A third group of 300 broiler chickens (divided into 3 replicates), received a single IV dose of 48 mg/kg from a 2.4% solution of doxycycline HCl under ketamine anesthesia. Blood samples were obtained at designated times, serum was harvested, and doxycycline concentrations determined by high-performance liquid chromatography (HPLC). Bioavailability values were 156% and 227% on d 1 and 5 for doxy-FOLA and 13% and 23% for doxy-ref, on the same days. Mean residence time (MRT) and elimination half-life (T½β) were statistically different (P < 0.05) in doxy-FOLA group as compared to doxy-ref group (MRT: 26 h and 5.2 h; and T½β: 18 h vs 3 h, on the first day for doxy-FOLA and doxy-ref, respectively). Based on 3 levels of bacterial sensitivity of E. coli derived from a small survey carried out (i.e., 1.0, 2.0, and 4.0 μg/mL) and considering pharmacokinetic/pharmacodynamic (PK/PD) ratios required for this time-dependent antibacterial drug, it is possible to postulate that doxy-FOLA outstrips the reference preparation maintaining higher and more prolonged serum concentrations of doxycycline and consequently complying better with PK/PD ratios regarded as optimal for this drug. The advantages of using doxy-FOLA in poultry medicine include a more comprehensive use of the active principle, which in turn should have a better impact on bacterial diseases. Yet, a longer withdrawal time is anticipated based on an almost 4-fold increment in the MRT value.

Effect of phytase superdosing, myo-inositol and available phosphorus concentrations on performance and bone mineralisation in broilers.

A total of 2,376 one-day-old Ross broiler chickens were used to investigate the effect of myo-inositol (MYO) and phytase supplementation on performance and bone mineralization variables in broilers fed diets formulated to have varying concentrations of available phosphorus (P). The trial was designed as a 2 × 2 × 3 factorial; with and without phytase superdosing (0 or 1,500 FTU/kg), MYO (0 or 3 g/kg), and dietary P (low, moderate or high). At 21 d, dietary phytase and MYO had no consistent benefit on bone mineralization variables. Bone ash reduced by 4.7% from the medium to low P diet (P < 0.01), with no effect of phytase supplementation. Superdosing improved bone P content by 6% in birds fed the low P diet, signifying an interaction between dietary P concentrations and phytase (P < 0.05). Dietary MYO addition resulted in a numerical reduction in bone ash and a significant reduction in bone strength (P < 0.05). At 42 d, the beneficial effect of phytase superdosing on feed intake and body weight gain was evident in the low P diet. Superdosing reduced feed conversion rate (FCR) at all P levels (P < 0.05), although this effect was more pronounced on the low P diet, suggesting that sufficient P being released from the phytase itself to re-phosphorylate MYO and hence improve FCR. The significant improvement in FCR was greater with superdosing than with MYO alone, and the combination led to no further improvement in FCR compared with superdosing alone, signifying a phytase and MYO interaction (P < 0.05). From these results, it can be estimated that MYO is providing around 30% to 35% of the total response to superdosing.

Efficacy of 1,3-diacylglycerol as a fat emulsifier in low-density diet for broilers

An experiment was conducted to study the effects of dietary supplementation of 1,3-diacylglycerol (DAG) as an emulsifier in a low-density diet on growth performance, nutrient digestibility, blood characteristics, and meat quality in broilers. A total of 480 1-day-old male 308 Ross broiler chicks were randomly allocated into 1 of the following 5 treatments: Control, fed a basal diet (CON), basal diet minus 100 kcal ME diet (LE), T1 (LE + 0.075% 1,3-DAG), T2 (LE + 0.10% 1,3-DAG), and T3 (LE + 0.15% 1,3-DAG).The supplementation of low energy diet to broilers reduced (P < 0.05) feed intake compared to CON diet during wk 1 of the experiment. The supplementation of LE diet with 0.075, 0.10, and 0.15% 1,3-DAG linearly increased (P = 0.09) body weight gain (BWG) and decreased (P = 0.08) feed intake (FI) during wk 1. During wk 2 to 3 and overall (0 to 5 wk), there was linear increase (P < 0.05) in BWG and decrease in feed conversion ratio (FCR) in LE diet supplemented with graded levels of emulsifier. The LE diet reduced (P < 0.05) dry matter (DM) and energy digestibility (P = 0.07) compared with CON diet. Supplementing energy-reduced diet with different levels of 1,3-DAG linearly increased (P < 0.05) DM, and energy digestibility, but no significant differences were observed in blood profiles, meat quality (except drip loss) of broilers.In conclusion, DAG positively affected growth performances and nutrient digestibility in broilers. However, meat quality and serum profiles were unaffected in broilers fed an energy-reduced diet supplemented with DAG.

Performance of Broilers Supplemented With Peppermint ( Mentha piperita L.) Powder.

This study was conducted to determine the effects of dietary supplementation of peppermint (Mentha piperita L.) on the performance of broiler chicks. 500 Ross broiler chicks were divided into 5 treatment groups of 4 replications in a completely randomized design format. The diets were ISO-caloric and ISO-nitrogenous ones and contained 1.5, 3, 4.5, and 6 g/kg of peppermint powder. At start, growing, and end periods, the effects of peppermint powder on average daily weight gain, feed conversation ratio, and mortality rate were studied. The results of the present study showed that over a production period of 42 days peppermint had a significant effect on average daily weight gain and feed conversation ratio when compared with the control group (P < .05). The level of 4.5 g/kg had the highest average daily weight gain (52.78 g), and control treatment with 46.98 g had the least average daily weight gain among different levels of peppermint. The level of 4.5 g/kg and 6 g/kg of peppermint had the least mortality compared to control treatment during training period (P < .05). From this experiment, we can conclude that treatment with 4.5 g/kg peppermint powder has better performance and carcass characteristics in broilers.

The effect of Rosemary (Rosmarinus officinalis L.) extract supplemented into broiler diets, on performance and blood parameters

This experiment was carried out to determine the effect of dietary supplementation of Rosemary (Rosmarinus officinalis) ethanol extract, on performance and blood parameters of broilers. One hundred twenty 1-day-old male Ross-308 broiler chicks were used in this experiment. The chickens were divided into 3 groups, including one control and 2 treatment containing 40 birds each. Each group was divided into four replicates and the study lasted 42 days. Group 1 (Control group) was fed with only basal diets. Group 2 (ROE 100mg/kg) was fed basal diet supplemented with 100 mg/kg R. officinalis L. Group 3 (ROE 200mg/kg), was fed basal diet supplemented with 200 mg/kg R. officinalis L. At the end of experiment blood samples collected. Body weight gain (P

Avaliação de extratos de plantas sobre a resposta imune, o desempenho produtivo e a morfometria intestinal de frangos de corte desafiados com Eimeria sp.

RESUMO O objetivo foi avaliar o efeito do uso de extrato de plantas sobre a resposta imune, o desempenho produtivo e a morfometria intestinal de frangos de corte desafiados com a vacina contra coccidiose. Foram utilizados 720 pintos de corte, machos, distribuídos em um delineamento inteiramente casualizado com quatro tratamentos e nove repetições de 20 aves cada. A partir dos 14 dias, as aves passaram a receber os tratamentos experimentais compostos por A – Dieta basal + Antibiótico promotor do crescimento (APC) ; B - Dieta basal + APC + desafio vacinal; C - Dieta basal + extrato de plantas, e D - Dieta basal + extrato de plantas + desafio vacinal. As aves dos tratamentos B e D receberam vacina oral contra coccidiose (vinte vezes a dose individual recomendada pelo fabricante). A adição de extrato de plantas à dieta de aves desafiadas com oocistos de Eimeria sp aumentou (p &lt;0,05) a secreção de IgA pela mucosa intestinal. As lesões microscópicas da mucosa intestinal não foram influenciadas (p &gt;0,05) pelo desafio ou pelo uso do extrato de plantas. O desafio com oocistos de Eimeria sp ou associado ao extrato de plantas resultou em menor (p &lt;0,05) ganho de peso e pior conversão alimentar apenas na semana seguinte à inoculação. Os resultados obtidos mostraram que a adição de extrato de plantas à dieta de aves submetidas ao desafio vacinal aumentou a secreção de IgA pela mucosa intestinal e que a inclusão do extrato de plantas ou de melhorador de desempenho resultou em desempenho produtivo semelhante.