Feed Intake Of Broiler Chickens Research Articles

Blood profile as a health indicator in broiler chickens fed diets of different particle sizes supplemented with multienzyme

Abstract This study evaluated the health effects of feeding diets of different feed particle sizes supplemented with multienzyme to broiler chickens. Cobb500 (n = 450) broiler chicks (as hatched) were randomly distributed to nine treatments, with each treatment consisting of five replicates of ten birds. The experiment was arranged in a 3 × 3 factorial (three feed particle sizes [3, 4, and 5 mm] and three multienzyme supplementations [0, 1, and 2 g/kg]). The blood indices of the chickens were evaluated. The data were subjected to Analysis of Variance (ANOVA), and means were compared using the Tukey Test at a 5 % probability level. The correlation between the growth performance and blood indices was also calculated. Birds fed the 3 mm particle sizes had decreased (p < 0.05) red blood cell (RBC) and lymphocyte counts with increased multienzyme at the starter phase, while the other haematological indicators increased as the multienzyme supplementation increased. Feeding the 4 mm particle size yielded similar (p < 0.05) total protein, triglyceride, and uric acid for all multienzyme inclusions. An increase in the multienzyme inclusion increased (p < 0.05) the RBC of birds fed the 5 mm particles with a decreased (p < 0.05) white blood cell (WBC) and eosinophil counts. At the finisher phase, serum albumin increased (p < 0.05) while alkaline phosphatase (ALP) decreased (p < 0.05), with increased multienzyme inclusion in birds fed the diet of 3 mm particles. Birds fed 4 mm particles had increased (p < 0.05) ALP and high-density lipoprotein (HDL) with increased multienzyme, while those fed the 5 mm particle size had increased (p < 0.05) albumin, aspartate transaminase (AST) as multienzyme supplementation increased. The correlation between growth performance and blood indices showed that feed intake (FI) has a significant (p < 0.05) impact on the blood profile of broiler chickens. The study concluded that other growth performance indicators, except the feed intake, have no impact on the blood profile of broilers. Feed particle sizes impact feed intake in broiler chickens which consequently impacts their blood composition. Therefore, the size of broiler feed particles has an impact on the health and well-being of the birds.

Effect of phased reduction of dietary digestible lysine density on growth performance, thigh meat, and biomechanical characteristics of tibia in broiler chickens.

In this study, growth performance, nutrient intake, thigh meat quality, fatty acid composition of thigh meat, and biomechanical characteristics of tibia of broiler chickens in response to phased restriction of dietary digestible lysine (dLys) were evaluated. A total of 180 male broiler chickens distributed to 3 experimental groups were fed control diets, 85% dLys diet in grower phase (GRO 85% dLys), or 85% dLys diets in grower and finisher phases (GRO-FIN 85% dLys). Feeding 85% dLys suppressed the feed intake that suppressed the growth performance, slaughter weight, and thigh weight of broiler chickens compared to control group (P < 0.05). Average daily dLys, Ca, and P intakes were suppressed in groups fed 85% dLys diets in comparison with control group (P < 0.05) due to the suppression of feed intake. While most fatty acid concentrations in thigh meat were not different among the groups, eicosanoic acid (C20:0) in thigh meat was greater in GRO-FIN 85% dLys group than control group (P = 0.002). Antioxidant status of thigh meat of broiler chickens was not affected by the phased restriction of dietary dLys compared to control group. Bone breaking strength and ultimate strength were greater in control group than 85% dLys groups (P < 0.05). In conclusion, phased dilution of dietary dLys to 85% of the required allowance yields weaker legs and tibia bones by suppressing the Ca and P intakes as a function of reduced feed intake in broiler chickens.

Growth performance, nutrient digestibility, intestinal morphology, cecal mucosal cytokines and serum antioxidant responses of broiler chickens to dietary enzymatically treated yeast and coccidia challenge

BackgroundThere is a growing search for natural feed additives to alleviate the deleterious effects of coccidia infection in poultry production. This study aimed to investigate the effect of enzymatically treated yeast (ETY) on the growth performance, nutrient digestibility, intestinal morphology, antioxidative status, and cecal mucosa cytokines of coccidia-challenged broiler chickens.MethodsFrom d 1 to 14 post hatching, 480 broiler chickens were allocated to 3 corn-soybean meal-based experimental diets with increasing concentrations of ETY (0, 1, or 2 g/kg). The experiment was designed as a randomized complete block design with body weight (BW) used as a blocking factor. On d 14 post hatching, the birds were re-randomized within each of the 3 experimental diets. Each of the 3 diet groups was split into a challenge or no-challenge group. This resulted in a 3 × 2 factorial arrangement of treatments. The coccidia challenge was administered on d 15 by an oral gavage.ResultsDietary ETY improved (P < 0.05) the G:F of birds on d 21 regardless of the challenge state and linearly increased (P < 0.01) the apparent ileal digestibility of dry matter (DM), nitrogen, and gross energy (GE). The coccidia challenge decreased (P < 0.05) BW gain and feed intake of broiler chickens and reduced (P < 0.01) the total tract retention of DM, GE, and nitrogen. The coccidia challenge increased (P < 0.01) the mRNA gene expression of TNFα, IL-1β, IL-10, and IL-6 in the cecal mucosa. There was a tendency (P = 0.08) for ETY to linearly reduce IL-1β expression. Additionally, ETY supplementation increased (P < 0.05) the gene expression of OCLN. Serum catalase increased (P < 0.05) with dietary ETY in broiler chickens on d 21. Dietary ETY linearly increased (P < 0.05) the ileal villus height to crypt depth ratio, and ileal goblet cell density in broiler chickens. The ileal and excreta oocyst counts decreased (P < 0.01) with increasing supplementation of dietary ETY in coccidia-challenged broiler chickens on d 21.ConclusionsDietary ETY enhanced nutrient utilization and augmented intestinal development in broiler chickens. However, dietary ETY did not completely attenuate the adverse effects of a coccidia challenge in broiler chickens.

Effects of intracerebroventricular injection of corticotrophin releasing factor on the gene expression of ghrelin and corticotrophin releasing factor receptors in broiler chickens.

This study aimed to investigate the effects of corticotropin-releasing factor (CRF) on the feed intake of broiler chickens and explore its influencing mechanism. The study included two trials. In trial 1, 32 male broiler chickens (Arbor Acres, Gallus gallus domesticus) were given ventricle buried tubes, and they were allowed to recover for 3 days. At 8:00 AM, intracerebroventricular (ICV) injection with CRF or normal saline was performed in 10-day-old broiler chickens, which were divided into the 5, 10, and 20 μg and control (normal saline) groups according to the dose of CRF injection. In trial 2, chickens were divided into the 10 μg and control group (physiological saline) to repeat trial 1. Results of trial 1 showed that the cumulative amount of feed intake in the 10 or 20 μg groups was considerably lower than that of the control group after ICV injection with CRF. The lowest amount of feed intake was obtained with the addition of 10 μg of CRF. In trial 2, the expression of ghrelin in the hypothalamus injected with 10 μg of CRF increased significantly, but the expression of ghrelin in various sections of the small intestine considerably decreased. The expression of CRF receptor subtypes 1 (CRFR1) in the hypothalamus and some parts of the small intestine remarkably increased, and the expression of CRF receptor subtypes 2 (CRFR2) increased only in the duodenum, whereas the expression of growth hormone secretagogue receptor (GHSR-1α) in the jejunum and ileum increased considerably after ICV injection of 10 μg of CRF. The CRF at 10 μg increased ghrelin expression in the hypothalamus and CRFR1 expression in the small intestine, and this phenomenon was related to the suppressed feed intake of broiler chickens.

Research Note: Estimation of individual feed intake of broiler chickens in group-housing systems

In most experiments, broiler chickens are group-housed and share the same feeder in a given cage or pen. Correction of feed intake in a given pen is sometimes required in the event of mortality or identification of birds within a pen as outliers. For this reason, an accurate estimation of individual feed intake (IFI) is important. The objective of this study was to compare 3 different methods of estimating the IFI of broiler chickens in group-housing systems. The methods utilized in the current study consisted of an averaging method, a ratio method, and a partitioning method. The assumption of the averaging method is that birds in a cage consume an equal amount of feed, whereas feed intake of a given bird is proportional to its BW gain in the ratio method. The partitioning method bifurcates IFI into IFI for maintenance and growth. To validate these methods, 32 male broiler chickens (initial BW = 161 ± 19 g) at d 7 post hatching were individually housed in cages. Birds were fed a corn-soybean meal-based diet for 28 d, and body weight and feed disappearance were recorded on d 14, 21, 28, and 35. Excreta were collected over the last 3 d of each week. As age of broiler chickens increased, body weight gain, feed intake, and dietary metabolizable energy both linearly and quadratically increased, whereas gain-to-feed ratio both linearly and quadratically decreased (P < 0.05). The partitioning method estimated IFI more accurately compared with the averaging method and the ratio method (P < 0.05). The current result implies that the partitioning method would accurately estimate IFI of broiler chickens in group-housing systems.

Dietary phosphorus level regulates appetite through modulation of gut and hypothalamic expression of anorexigenic genes in broiler chickens

Two experiments were designed to elucidate gut and hypothalamic molecular regulation of appetite by dietary phosphorus (P) concentration in broiler chickens. Birds (192 Cobb-500 broiler chickens) were randomly assigned to 3 experimental diets in experiment 1 (Exp. 1) and 24 broiler chickens were randomly assigned to 3 treatment groups in Exp. 2. Each diet comprised 8 replicate cages, with either 8 birds (Exp. 1) or 1 bird (Exp. 2) per replicate cage. In Exp. 1, diets contained 1.2 (P-deficient), 2.8 (P-marginal) or 4.4 (P-adequate) g/kg non-phytate P (nPP). In Exp. 2, birds fed the P-adequate diet were pair-fed (PF) to the feed consumption levels of birds fed the P-deficient diet. Feed intake and BW gain (P < 0.001) decreased in birds fed the P-deficient diet in Exp. 1. Birds fed the P-deficient diet had similar feed intake and BW gain with PF group fed the P-adequate diet (Exp. 2) but was significantly lower (P < 0.001) than birds fed the P-adequate diets. Sodium-phosphate cotransporter (NaPi-IIb) mRNA was upregulated (P < 0.05) in both experiments. Conversely, cholecystokinin (CCK) mRNA was downregulated (P < 0.01) in birds fed P-deficient diets. Anorexia-related hypothalamic cholecystokinin receptor (CCKAR) and melanocortin receptors (MC3R and MC4R) were upregulated (P < 0.05) in birds fed P-deficient diets, in both experiments. The current data show that dietary P deficiency decreases feed intake in broiler chickens by altering the expression of anorexigenic genes in the gut and hypothalamus of broiler chickens.

Effect of dietary tannins on the performance, lymphoid organ weight, and amino acid ileal digestibility of broiler chickens: A meta-analysis.

Background and Aim:Tannins are functional secondary metabolites that may provide benefits to ruminants. However, to date, their effects on broiler chickens remain inconclusive. This study aimed to evaluate the effectiveness of dietary tannin levels on the performance, body organs, and amino acid (AA) digestibility of broiler chickens using a meta-analysis.Materials and Methods:After verification and evaluation, a total of 22 articles were included in the present study. All data regarding dietary tannin dosages, performance, digestibility, and gastrointestinal physiology of broiler chickens were tabulated into a database. The database data were then statistically analyzed using mixed models, with tannin dose as a fixed effect and study as a random effect.Results:High levels of dietary tannins negatively affected the average daily gain and average daily feed intake of broiler chickens according to linear patterns (p<0.001). In addition, dietary tannins decreased drumstick and liver weights, as well as bursa of Fabricius and spleen weight (p<0.05). Meanwhile, other carcass traits (i.e., thigh, wings, and body fat) were not influenced by dietary tannins. Regarding AA digestibility, high dietary tannin concentrations induced negative responses on isoleucine, leucine, and methionine digestibility (p<0.05).Conclusion:Dietary tannins appear to have a negative effect on broiler performance, lymphoid organ weight, and AA ileal digestibility. Hence, the addition of tannins to broiler diets is not recommended.

Effects of feeding dried brewers grains to slow-growing broiler chickens

Slow-growing broiler chickens as the naked neck Label Rouge are strains that require more time to reach the market weight, and may have meat characteristics appreciated by consumers. Two studies were conducted to evaluate the inclusion of dried brewers grains (DBG) in the diet of slow-growing broiler chickens. In the first experiment (metabolism assay), a total of 180 male Label Rouge broiler chickens were assigned to 5 treatments (0, 100, 200, 300, and 400 g DBG/kg of diet) with 6 replications per treatment and 6 broiler chickens per cage, in a completely randomized design, in the period from d 14 to 24. The objective was to evaluate the energetic values of increasing DBG inclusion rates. Energetic values increased linearly (P < 0.05) with DBG inclusion. Apparent metabolizable energy (AME) of DBG, AME corrected for N, coefficient of AME (AMC), and AMC corrected for N were 2,593 kcal/kg, 2,301 kcal/kg, 57.29%, and 50.84%, respectively, these values were obtained by the inclusion of 400 g DGB/kg in the regression equation. In the second experiment, the objective was to evaluate inclusion rates of DBG in the diets of slow-growing broiler chickens and the effects on growth performance, blood metabolites, relative organs weight, meat quality, intestinal morphometry, and litter quality. A total of 980 one-day-old male broiler chickens were assigned to 7 treatments (inclusion rates of 0, 20, 40, 60, 80, 100, and 120 g DBG/kg) with 7 replications (pens) and 20 broiler chickens each, and diets were fed from d 0 to 63. There was a linear reduction (P < 0.01) in weight gain from d 0 to 21, 0 to 42, and 0 to 63, and a linear increase (P < 0.01) in feed conversion ratio as dietary DBG increased. Feed intake of broiler chickens reduced (P < 0.01) from d 0 to 42 with increased DBG inclusion. Inclusion of DBG caused a linear increase (P < 0.01) on serum glucose and total protein (P = 0.04), and a linear reduction (P = 0.03) in alanine amino transferase as dietary DBG increase. Carcass yield was not altered with DBG inclusion rates, however, Pectoralis minor yield (P = 0.04) and the relative weight of gizzard increased at d 21 (P = 0.03), and d 63 (P < 0.01) and pancreas increased at d 21 (P = 0.03), and d 63 (P = 0.05). There was a quadratic effect (P = 0.04) of DBG on villus height, but dietary DBG had no effect on litter quality. The use of DBG in the diet of slow-growing broiler chickens, in inclusion rates up to 120 g DBG/kg, reduced its growth performance.

98 The effect of mezquite pod flour in a wheat-based diet on broiler chicken growth performance

Application Inclusion of Mezquite pod flour in broiler chicken diets significantly reduced weight gain, this could inform a recommendation against the use of non-processed Mezquite in broiler chicken diets. Introduction Mezquite is an under-utilised crop and a possible alternative to soybean. Mezquite is part of the genus Prosopis, a group of leguminous trees. Their pods, containing seeds, are valued for their nutrition and are often ground into flour with 7–17% protein [1]. There are few studies looking at feeding pods to monogastric species, but Girma et al. [2] found that a 30% inclusion reduced growth and feed intake in broiler chickens, while a 10 or 20% inclusion had no significant effect. This study aimed to assess the impact of a 15% inclusion of Mezquite pod flour on broiler chicken growth and performance. Materials and Methods This trial was approved by the Animal Welfare & Ethical Review Body at the University of Nottingham. Eighty, one day old Ross 308 Broiler chickens were group housed for 6 days before being split into 20 pens of 4. Birds were fed either ad-libitum wheat-soya based diet (CON n = 40), or 15% inclusion of non-processed ground Mezquite pod (Prosopis juliflora) (MEZQ n = 40); collected from the Baringo area, Kenya. Both diets were balanced for equivalent energy and protein content, predominantly replacing wheat. Feed intake and weights were recorded twice weekly, before culling on days 35 and 36. The right breast muscle and liver were dissected and weighed. Data was analysed by one-way (treatment) or two-way (time × treatment) ANOVA (Genstat 19th edition), with significance taken as p < 0.05. Results A 15% inclusion of Mezquite pod flour in the diet negatively affected weight gain and FCR. A two-way ANOVA showed a significant interaction between time and feed for weight gain (data not shown), due to significantly higher growth of CON broilers. Mezquite inclusion therefore significantly decreased the final bodyweight (P < 0.001, one-way ANOVA). Total feed intake was similar, resulting in a significantly higher FCR for the MEZQ group (p < 0.001, one-way ANOVA). CON breast muscle weights were significantly higher (p < 0.001, one-way ANOVA). Liver weights were taken as an indication of effects on metabolic active tissues, but these were similar (Table 1). Conclusion These results suggest that Mezquite pod inclusion affects feed utilisation. This could be due to antinutritional factors, such as tannins or trypsin inhibitors, inhibiting digestion. Further study is needed to identify if antinutritional factors are responsible, and whether post-harvest processing or the use of exogenous enzymes reduces the negative impact.

Linkage between the intestinal microbiota and residual feed intake in broiler chickens

BackgroundIntestinal microbiota plays a key role in nutrient digestion and utilization with a profound impact on feed efficiency of livestock animals. However, the intestinal microbes that are critically involved in feed efficiency remain elusive.MethodsTo identify intestinal bacteria associated with residual feed intake (RFI) in chickens, male Cobb broiler chicks were individually housed from day 14 to day 35. Individual RFI values were calculated for 56 chickens. Luminal contents were collected from the ileum, cecum, and cloaca of each animal on day 35. Bacterial DNA was isolated and subjected to 16S rRNA gene sequencing. Intestinal microbiota was classified to the feature level using Deblur and QIIME 2. High and low RFI groups were formed by selecting 15 and 17 chickens with the most extreme RFI values for subsequent LEfSe comparison of the difference in the microbiota. Spearman correlation analysis was further performed to identify correlations between the intestinal microbiota composition and RFI.ResultsNo significant difference in evenness, richness, and overall diversity of the microbiota in the ileum, cecum, or cloaca was observed between high and low RFI chickens. However, LEfSe analysis revealed a number of bacterial features being differentially enriched in either high or low RFI chickens. Spearman correlation analysis further identified many differentially enriched bacterial features to be significantly correlated with RFI (P < 0.05). Importantly, not all short-chain fatty acid (SCFA) producers showed a positive association with RFI. While two novel members of Oscillibacter and Butyricicoccus were more abundant in low-RFI, high-efficiency chickens, several other SCFA producers such as Subdoligranulum variabile and two related Peptostreptococcaceae members were negatively associated with feed efficiency. Moreover, a few closely-related Lachnospiraceae family members showed a positive correlation with feed efficiency, while others of the same family displayed an opposite relationship.ConclusionsOur results highlight the complexity of the intestinal microbiota and a need to differentiate the bacteria to the species, subspecies, and even strain levels in order to reveal their true association with feed efficiency. Identification of RFI-associated bacteria provides important leads to manipulate the intestinal microbiota for improving production efficiency, profitability, and sustainability of poultry production.

Growth characteristics and meat quality of broiler chickens fed earthworm meal from Eudrilus eugeniae as a protein source

The demand and cost of animal-based protein sources for broiler chickens production like fish meal has increased in many countries. An alternative protein source can be earthworm meal (EWM). A study was conducted to evaluate the effects of supplementing broiler chickens diets with EWM derived from dried Eudrilus eugeniae on growth performance, carcass attributes, and the meat quality of broiler chickens. The starter and finisher basal diets were formulated to contain 10% fish meal and it was replaced with 0, 1, 3, 5, and 7% EWM. For the experiment, 150 one-day-old broiler chickens were randomly assigned to the 5 diets with 3 pens per diet and 10 broiler chickens per pen. Based on the data recorded in the experiment, the body weight gain (BWG), and the feed intake (FI) were computed. At 6 wk of age, 3 broiler chickens were randomly selected from each pen to assess their organ weights and sensory characteristics. Overall, there was a quadratic and cubic effect on BWG when EWM supplementation was increased (P < 0.05). There was no difference in the overall FI of broiler chickens with increase in the supplementation of EWM. As the dietary supplementation of EWM increased, the juiciness in breast meat of the broiler chickens increased quadratically (P < 0.05) while the flavor increased linearly (P < 0.05). However, there were no differences in broiler chickens meat aroma, first bite, chewiness, and the amount of residues as dietary EWM increased. Supplementation of EWM did not affect broiler chickens meat quality in terms of pH and drip loss. The EWM may be a suitable source of protein for broiler chickens production and a particularly useful substitute for fish meal. More research is required to determine the optimal inclusion rate for the most affordable, and nutritious broiler chickens diet, and to sufficiently understand the wider implications of alternative feed sources on the ecologic, economic, and environmental impact of broiler chickens production.

Dietary stevioside supplementation increases feed intake by altering the hypothalamic transcriptome profile and gut microbiota in broiler chickens.

Stevioside (STE) is a widely used sweetener. Despite the fact that chickens are insensitive to sweetness, dietary STE supplementation could increase the feed intake of broiler chickens. Stevioside might regulate the feeding behavior through functional mechanisms other than its high-potency sweetness. The present study was aimed to elucidate the potential sweetness-independent mechanism of an STE-induced orexigenic effect using the broiler chicken and considering the hypothalamic transcriptome profile and gut microbiome. The analysis of RNA-Seq identified 398 differently expressed genes (160 up-regulated and 238 down-regulated) in the hypothalamus of the STE-supplemented group compared with the control group. Cluster analysis revealed several appetite-related genes were differentially expressed, including NPY, NPY5R, TSHB, NMU, TPH2, and DDC. The analysis of 16S rRNA sequencing data also indicated that dietary STE supplementation increased the relative abundance of Lactobacillales, Bacilli, Lactobacillus, and Lactobacillaceae. Meanwhile, the proportion of Ruminococcaceae, Lachnospiraceae, Clostridia, and Clostridiales was decreased after dietary supplementation with STE. Dietary STE supplementation promoted feed intake through the regulation of the hypothalamic neuroactive ligand-receptor interaction pathway and the alteration of intestinal microbiota composition. This study provides valuable information about the sweetness-independent mechanism of the STE-induced orexigenic effect using the broiler chicken (which is insensitive to sweetness) as the animal model. © 2020 Society of Chemical Industry.

Comparison of toxic effects of dietary organic or inorganic selenium and prediction of selenium intake and tissue selenium concentrations in broiler chickens using feather selenium concentrations

The present experiment aimed to compare toxic effects of dietary organic or inorganic selenium (Se) and to predict of Se intake and tissue Se concentrations in broiler chickens based on feather Se concentrations. A total of four hundred twenty 7-day-old Ross 308 male broiler chicks were allotted to 1 of 7 dietary treatments in a completely randomized design. Each treatment had 6 replicates with 10 birds per replicate. Organic Se (selenium yeast) or inorganic Se (sodium selenite) was added to the basal diet at the levels of 5, 10, or 15 mg/kg Se. All experimental diets were fed to birds on an ad libitum basis for 28 d. Results indicated that a significant interaction (P < 0.01) was observed between Se sources and inclusion levels for the BW gain and feed intake of broiler chickens with inorganic Se at 15 mg/kg in diets showing a greatest negative effect. Increasing inclusion levels of Se in diets increased (linear, P < 0.01) plasma concentrations of uric acid. Increasing inclusion levels of Se in diets increased (linear, P < 0.01) relative liver weight. No significant interactions were observed between Se sources and inclusion levels in diets on hepatic antioxidant capacity. Increasing inclusion levels of Se in diets increased (linear, P < 0.01) Se concentrations in the liver, breast, and feather. The concentrations of Se in the breast, liver, and feather were greater (P < 0.05) for organic Se than for inorganic Se in diets. The toxic levels of organic or inorganic Se in broiler diets were near 7 or 9 mg/kg based on the BW gain, respectively. The prediction equations indicate that feather Se concentrations in broiler chickens can be used to predict both daily Se intake and Se concentrations in the liver and breast.

Prediction of maximum scaled feed intake in broiler chickens based on physical properties of bulky feeds

ABSTRACT 1. A trial was conducted to investigate the capacity of broiler chickens to consume bulky feeds during three stages of growth. These phases were from 1 to 15 d, 16 to 30 d and from 31 to 45 d. 2. A basal feed was serially diluted (0%, 2.5%, 5.0%, 10% or 15%) with one of five diluents (cellulose fibre, sawdust, rice husk, sand or vermiculite) to produce 25 feeds which were supplied on an ad libitum basis to the birds in each phase. Cobb 500® strain chicks were used, and, within each phase, each feed was given to nine individually-caged birds, 225 in total, distributed in a completely randomised design. 3. Intake increased initially, and then declined, as the proportion of each diluent increased. The consumption of feeds that limited intake were directly proportional to metabolic body weight and so a scaled feed intake, expressed as g/BW0.67 per day, was calculated. There were large effects of feed type on intake, in the short term, with consumption of a bulky feed leading to higher intakes. 4. It was concluded the Water Holding Capacity (WHC) content of the feeds could be appropriate measurement of ‘bulk’ responsible for limiting intake and could be used to predict maximum feed intake capacities of broiler chickens fed bulky diets.

Genetic parameters for body weight and different definitions of residual feed intake in broiler chickens

BackgroundThe objectives of this study were to (1) simultaneously estimate genetic parameters for BW, feed intake (FI), and body weight gain (Gain) during a FI test in broiler chickens using multi-trait Bayesian analysis; (2) derive phenotypic and genetic residual feed intake (RFI) and estimate genetic parameters of the resulting traits; and (3) compute a Bayesian measure of direct and correlated superiority of a group selected on phenotypic or genetic residual feed intake. A total of 56,649 male and female broiler chickens were measured at one of two ages ({text{t}} or {text{t}} - 6 days). BW, FI, and Gain of males and females at the two ages were considered as separate traits, resulting in a 12-trait model. Phenotypic RFI ({text{RFI}}_{text{P}}) and genetic RFI ({text{RFI}}_{text{G}}) were estimated from a conditional distribution of FI given BW and Gain using partial phenotypic and partial genetic regression coefficients, respectively.ResultsPosterior means of heritability for BW, FI and Gain were moderately high and estimates were significantly different between males and females at the same age for all traits. In addition, the genetic correlations between male and female traits at the same age were significantly different from 1, which suggests a sex-by-genotype interaction. Genetic correlations between {text{RFI}}_{text{P}} and {text{RFI}}_{text{G }} were significantly different from 1 at an older age but not at a younger age.ConclusionsThe results of the multivariate Bayesian analyses in this study showed that genetic evaluation for production and feed efficiency traits should take sex and age differences into account to increase accuracy of selection and genetic gain. Moreover, for communicating with stakeholders, it is easier to explain results from selection on {text{RFI}}_{text{G}} than selection on {text{RFI}}_{text{P}}, since {text{RFI}}_{text{G}} is genetically independent of production traits and it explains the efficiency of birds in nutrient utilization independently of energy requirements for production and maintenance.

The effects of dietary 1-alpha-hydroxycholecalciferol individually or in combination with different levels of cholecalciferol on growth performance and tibia criteria in broiler chickens

This study was conducted to evaluate the effects of 1 alpha-hydroxycholecalciferol (1-α(OH)D3) individually or in combination with different concentrations of cholecalciferol on growth performance and tibia criteria of 3-day-old broiler chickens fed diets deficient in Ca and phosphorus P. A total of 300 hatched broiler chickens were weighed and randomly allotted to 5 treatments with 4 pens and 15 broiler chickens/pen. The vitamin premix that included in the diets did not contain cholecalciferol. The dietary treatments were as follows: Ca–P deficient diet + phytase (basal diet); basal diet + 5 μg of 1-α(OH)D3/kg of diet; basal diet + 5 μg of 1-α(OH)D3 and 1500 IU of cholecalciferol/kg of diet; basal diet + 5 μg of 1-α(OH)D3 and 3000 IU of cholecalciferol/kg of diet; basal diet + 5 μg of 1-α(OH)D3 and 5000 IU of cholecalciferol/kg of diet. Final body weight (BW) of broiler chickens supplemented with 1-α(OH)D3 and 1500 IU of cholecalciferol/kg of diet and 1-α(OH)D3 and 3000 IU of cholecalciferol/kg of diet was greater (P < 0.05) than those fed basal diet, basal diet supplemented with 1-α(OH)D3 alone and basal diet supplemented with 1-α(OH)D3 and 5000 IU of cholecalciferol/kg of diet. In the whole experiment, feed intake of broiler chickens fed basal diet was greater (P < 0.05) than those fed basal diet supplemented with 1-α(OH)D3 alone, basal diet supplemented with 1-α(OH)D3 and 1500, 3000, and 5000 IU of cholecalciferol/kg of diet. Feed conversion ratio of broiler chickens fed basal diet supplemented with 1-α(OH)D3 and 1500 or 3000 IU of cholecalciferol/kg of diet were significantly better than those fed basal diet, basal diet supplemented with 1-α(OH)D3 alone or basal diet supplemented with 1-α(OH)D3 and 5000 IU of cholecalciferol/kg of diet. Broiler chickens fed basal diet had lower tibia length and diameter than those in other groups (P < 0.05). Broiler chickens fed basal diet supplemented with 1-α(OH)D3 and 3000 and 5000 IU of cholecalciferol/kg of diet had greater (P < 0.05) tibia weight than those fed basal diet or basal diet supplemented with 1-α(OH)D3 alone, but did not differ from broiler chickens fed basal diet supplemented with 1-α(OH)D3 and 1500 IU of cholecalciferol/kg of diet that were intermediate. Broiler chickens fed basal diet supplemented with 1-α(OH)D3 alone had greater (P < 0.05) tibia ash than those in other groups. In conclusion, addition of 1-α(OH)D3 alone to the Ca-and P-deficient diet could maximize bone mineralization, but it couldn't maximize growth performance and growth performance criteria including BW and feed efficiency were maximized in broiler chickens fed dietary containing 1-α(OH)D3 in combination with 1500 IU cholecalciferol/kg of diet.

Supplemental boric acid does not prevent the development of footpad dermatitis in broilers subjected to high stocking density

The present study was conducted to evaluate the protective effect of dietary boric acid supplementation on the development of incidence and severity of footpad dermatitis (FPD) in broiler chickens subjected to normal or high stocking densities (NSD or HSD). A total of 576 1-day-old ROSS 308 broiler chickens were randomly allocated to 4 treatments (8 replicate pens per treatment) in a 2 × 2 factorial arrangement of dietary boric acid (0 and 60mg/kg) and stocking density (NSD 14 birds/m2 and HSD 22 birds/m2). Basal diets were formulated for starter, grower, and finisher phases. Growth performance, litter quality (litter pH, moisture, temperature, and NH3 volatilization), serum and litter boron levels, and incidence and severity of FPD were recorded. The HSD affected the body weight gain and feed intake of broiler chickens during all phases and 0 to 42 (P < 0.05), whereas feed conversion ratio (FCR) was poor at 0 to 21 days only. Dietary boric acid had no effect on the growth performance of broiler chickens. Litter pH, moisture, and NH3 volatilization were higher in broiler chickens subjected to HSD (P < 0.05). Thus, the incidence and severity of FPD increased in response to HSD (P < 0.05). Dietary boric acid reduced the litter pH and NH3 volatilization on day 42 of experiment (P < 0.05). However, dietary boric acid supplementation had no effect on the incidence and severity of FPD. Boric acid supplementation in broiler diets increased the serum and litter boron levels at day 42 in broiler chickens subjected to NSD or HSD (P < 0.05). In conclusion, HSD resulted in poor growth performance, litter quality, and greater incidence and severity of FPD in broiler chickens. Dietary boric acid was ineffective against FPD in broiler chickens although it improved the litter quality by lowering the litter pH and NH3 volatilization.

Effects of dry whey powder alone or combined with calcium butyrate on productive performance, duodenal morphometry, nutrient digestibility, and ceca bacteria counts of broiler chickens

Abstract Prebiotics and organic acids have been proposed as safe additives in poultry feeding to promote performance and health. The purpose of this study was to assess the influence of supplementing corn-soybean diets of broiler chickens with dry whey powder (WP), fat-coated calcium butyrate (CaB), and a mixture of both on apparent ileal digestibility (AID), pH of gastrointestinal content at various segments, productive performance, duodenal histomorphometry, and ceca microbial counts. The experiment consisted of a 2 × 2 factorial arrangement, with 2 WP inclusion rates (0 and 60 g/kg of diet) and 2 CaB rates (0 and 1 g/kg of diet). One-day-old male broiler chickens were randomly allocated to floor pens and assigned to 1 of 4 treatments. In Trial 1, 120 broiler chickens were allocated to 4 treatments with 3 pens per treatment and 10 broiler chickens per pen during 21 d. With the addition of WP, the AID of dry matter, crude protein, Ca, and P increased, and cecum pH decreased only when CaB was also added (CaB × WP, P 0.046). In Trial 2, 1200 broiler chickens were allocated to the 4 treatments with 10 pens per treatment and 30 broiler chickens per pen during 42 d. With the dietary supplementation of WP, average daily gain and feed intake of broiler chickens increased during starter, grower-finisher periods, and the entire feeding period only when CaB was also added ( P P P 0.017), while the supplementation of WP increased Bifidobacterium spp. counts only when CaB was not added (CaB × WP, P = 0.049). Results obtained in the present study indicate that the supplementation of WP without CaB addition improved the FCR of broiler chickens. However, the supplementation of WP together with CaB improve duodenal development, increases nutrient AID, and the weight and ingestion of broiler chickens.

Effect of ethanolic extract of propolis as an alternative to antibiotics as a growth promoter on broiler performance, serum biochemistry, and immune responses.

Aim:An in vivo experiment was conducted to investigate the effect of different levels of ethanolic extract of propolis, on growth performance, carcass traits, serum biochemistry, and humoral immune responses of chickens, as compared with the antibiotic flavophospholipol.Materials and Methods:312 1-day-old as-hatched broiler chicks (Ross 308) were randomly allotted to 6 treatments with 4 replicate pens per treatment. The 6 dietary treatments fed for 42 days consisted of a corn-soybean meal basal diet (control); control plus 4.5 mg/kg flavophospholipol, and control plus 50, 100, 200, and 300 mg/kg ethanol extracts of propolis, respectively.Results:Neither propolis nor antibiotic affected the performance criteria; however, dietary treatments tended to enhance to enhance body weight and daily feed intake of broiler chickens compared with control group (p>0.05). None of the dietary treatments significantly altered feed: Gain though; broilers fed diet supplemented with 200 mg/kg propolis had better feed: gain values compared with other groups in starter, and grower phases as well as the whole experimental period (p>0.05). Carcass yield and internal organ relative weights were not affected by treatments on day 42, except for abdominal fat pad weight that decreased in broilers supplemented with antibiotic. None of the treatments significantly affected humoral immune function. Dietary treatments failed to induce any significant effect on serum biochemistry (p>0.05); though broilers receiving 100 mg/kg propolis had greater high-density lipoprotein-cholesterol and lower triglyceride concentrations compared with other groups.Conclusion:In conclusion, the results indicated that addition of ethanolic extract of propolis to routine dietary components of broilers, such as corn and soybean, seems not to have a positive influence on performance criteria.

Effect of anti-nutritional factors of oilseed co-products on feed intake of pigs and poultry

Soybean, canola, camelina and flaxseed co-products from the oilseed industry are used to formulate pig and poultry feeds. However, these co-products contain various anti-nutritional factors (ANF). The major ANF in soybean and potentially co-products is trypsin inhibitor (TI). Pigs and poultry can tolerate TI levels up to 3.00 and 4.00TIU/mg in the diet, respectively. Solvent-extracted soybean meal has low TI activity (<14.0TIU/mg); most TI is destroyed during the desolventising-toasting stage of oil extraction. Thus, inclusion of soybean meal in diets for pigs and poultry does not affect feed intake and nutrient utilization. However, soybean or expeller-pressed soybean co-products can contain considerable amounts of TI (>50.0TIU/mg), implying that the raw soybean or expeller-pressed soybean co-products should be sufficiently heated to inactivate most of the TI before feeding. The major ANF in canola co-products are glucosinolates. Poultry and pigs can tolerate up to 2.00 and 2.50μmol/g of glucosinolates in their diets. Total glucosinolate content in most canola co-products is moderate (<10μmol/g). Thus, while co-products from modern canola cultivars do not affect feed intake, dietary inclusion of original canola co-products (with total glucosinolate content of ≤35μmol/g) reduced feed intake of grow-finish pigs by 80g/day and of broiler chickens in the starter phase by 4g/day. Glucosinolates and TI are the major ANF in camelina co-products. In camelina co-products, total glucosinolate content ranged from 34.4 to 36.3μmol/g and TI activity from 12 to 28TIU/mg. Camelina co-products are not solvent-extracted and thus have high TI activity. Dietary inclusion of camelina co-products reduced feed intake of broiler chickens in the starter phase by 3.4g/day. Cyanogenic glucosides are the major ANF in flaxseed co-products. Flaxseed meal contained 127mg cyanogenic glucoside/kg. Dietary inclusion of flaxseed meal reduced feed intake by poultry by 3.4g/day. In conclusion, soybean, canola, camelina and flaxseed co-products contain various ANF that reduce feed intake by pigs and poultry.