The use of organic Zn sources has been claimed to reduce the environmental impact of poultry production and improve broiler performance and the quality of products. This study investigated the effects of three organic Zn supplementation strategies (i.e., TRE, total replacement; PRE, partial replacement; OTS, on-top supplementation) on tibia and blood biochemistry characteristics of broilers at high altitudes. Male Cobb 500 chicks were distributed in 54 floor pens (22 birds each) and assigned to nine experimental treatments. Birds were fed mash diets under three feeding phases until 42 days and following the standard Ecuadorian high-altitude production standard practices. The treatments were a basal diet supplemented with three inclusion rates of ZnSO4 and the same diets including or not Zn from one of two organic Zn sources (i.e., ZPR, Zn proteinate; ZAC, Zn amino acid complex). Basal diets were analyzed for Zn concentration. Tibia ash and Zn concentrations and serum biochemistry variables were determined at 21 and 42 days. The strategies to supplement organic Zn were compared with the reference treatment containing 100 ppm Zn as ZnSO4 (the standard practice; STD) using mixed models, being the block (i.e., the replication) as a random factor. The interaction of the strategy with the organic Zn source was assessed with the ANOVA and multiple comparisons. The organic Zn sources were compared considering the feed intake a random factor, and their interaction with the dietary Zn level was assessed using multiple regression. No overall effect of the Zn supplementation strategy was observed other than the reduced Zn concentration at 21 days in TRE birds. At 21 days, PRE and TRE increased the serum protein and phosphorus concentrations, respectively. At that age, TRE also increased insulin concentration, but only in the ZAC-fed birds. However, TRE produced the opposite effect on serum protein at 42 days. At the same age, ZAC-fed birds showed lower serum phosphorus concentration than ZPR-fed ones regardless of the dietary Zn supplementation level or the Zn intake. Also, ZAC under TRE produced no effect on tibia Zn concentration compared to STD, but ZPR increased it. The ZPR increased the tibia Zn concentration when fed under PRE or TRE, but not under OTS. In conclusion, the results showed no adverse effect of PRE or TRE strategies on tibia characteristics. The data indicate likely different effects of PRE and TRE on protein metabolism and a possible negative interaction of the organic Zn with a high Zn content as ZnSO4.

Feeding broilers with organic chemical sources of Zn has recently been recommended to improve performance, immune system, carcass yield, and reduce environmental contamination. However, its use under proposed supplementation strategies (i.e., total replacement, partial replacement, on-top) needs further investigation. This study assessed the effect of total replacement, partial replacement, and on-top supplementation strategies to feed organic Zn sources and the effect of two organic chemical forms on performance and Zn excretion in broilers at high altitudes. Twenty-two male Cobb 500-day-old chicks were placed in each of 54 floor pens and raised for up to 42 days under a three-phase feeding program and following the Ecuadorian highland production system. Pens were assigned to one of nine experimental treatments consisting of a basal diet supplemented with 0, 33, and 100 ppm of Zn from ZnSO4 and added or not 40 ppm Zn from Zn proteinate or Zn amino acid complex. A Completely Randomized Block Design was considered, being the block the replication. The Zn concentration of the basal diet was determined. Feed intake, BW, BW gain, feed conversion ratio, and European Production Efficiency Factor were assessed at 21 and 42 days of age, and the Zn excretion was estimated accordingly. Each supplementation strategy was compared with the standard practice (100 ppm Zn as ZnSO4) using contrasts and mixed models, and the interaction with the chemical form was assessed considering the P-values of the ANOVA and the multiple comparisons between the corresponding treatments. The effects of the organic Zn forms and their interactions with the dietary Zn level were assessed considering the responses were linear functions of the organic Zn source, the feed intake, the Zn intake, the Zn supplementation level, and the block, as corresponding. None of the strategies to supplement a Zn organic source, or the organic sources themselves, showed overall detectable effects on performance. However, interactions were observed between the supplementation strategy and the organic Zn source and between the organic source and the dietary Zn levels or the Zn intake. Under the on-top supplementation strategy, the Zn organic sources showed different feed conversion ratios at 21 days. In addition, totally or partially replacing the ZnSO4 with a Zn organic form reduced the Zn excretion. In conclusion, although no overall effect of the supplementation strategies was detected, the assessed organic Zn forms showed different effects on the feed conversion ratio at 21 days.

Data, scripts, and figures of the article "Evaluation of oregano essential oil in broilers challenged with a mixed Eimeria spp. and high dietary protein model of subclinical coccidiosis" to be published in the journal Animal - Open Space.

This data set contains the data, JMP scripts, and figures of the article titled "The effect of oregano essential oils on Feed Passage Syndrome in broilers: 1. Assessment under field conditions" to be published in the journal Animal - Open Space.

Abstract The effect of nutritional density on performance and egg quality has not been stablished in hens at high altitudes. This study evaluated the effect of different nutritional densities on performance and egg quality of laying hens at high altitude. Sixty 45-weeks old Hy-Line Brown hens distributed in 12 cages (5 birds each) and assigned to one of three dietary treatments (i.e, low nutritional density, LND; medium nutritional density, MND –control diet; high nutritional density, HND) were fed during four weeks and assessed during the las one. Feed intake, egg production rate, egg mass, feed conversion ratio, and external and internal egg quality were evaluated. No differences were observed in performance, egg weight, egg length, egg width, egg surface area, and egg shape index (P > 0.05). Shell weight, thickness, and weight per unit of surface area were higher in the LND and MND diets compared to the HND (P = 0.003, P = 0.017, and P = 0.031, respectively). While dense albumen length was greater in the control diet (MND) compared to LND and HND (P = 0.049), no other internal quality trait showed differences (P > 0.05). In conclusion, laying hens fed LND and MND diets showed better shell integrity (greater shell weight and thickness).

Feed Passage Syndrome (FPS) in broilers is a multifactorial condition characterized by wet excreta and decreased feed efficiency, which can be triggered by various contributing factors. Alternatives to antimicrobials, including phytogenics, are being studied to control this process. This study assessed oregano essential oil (OEO) in broilers subjected to a FPS challenge model. Three treatments (negative control, neomycin-fed positive control, and OEO-fed group) were included. All treatments were challenged with reused litter, inoculums of Eimeria spp. and Clostridium perfringens, and excess dietary CP. OEO-fed birds showed improved performance, better excreta characteristics, lower frequency of congested mucosa, reverted hyperplasia of the bursa of Fabricius, better antioxidant status, and higher breast and carcass weights and dietary protein and energy efficiencies. The OEO treatment was shown to influence the growth pattern of the broilers. In conclusion, the OEO showed positive effects in broilers challenged with a FSP model.

This data set contains the data, JMP scripts, and figures of the article titled "Processing weights of chickens determined by Dual-Energy X-Ray Absorptiometry. 1. Weight changes due to fasting, bleeding, and chilling" to be published in the journal Animal - Open Space.

A considerable opportunity exists in evaluating the dynamics of the carcass and the processing cut-up weights of broilers across the whole grow-out period as influenced by intervention factors. However, no fast and objective tool exists up to date to make such determinations. This study aimed to develop models to predict the unchilled and chilled weights of the carcass and cut-up pieces of broilers using Dual-Energy X-ray Absorptiometry (DEXA) and feathered non-fasted birds. Highly diverse (BW and body composition) broilers (n = 291) between 4 and 79 days of age were euthanized, DEXA-scanned, and manually processed to determine the weights of the carcass and cut-up pieces. Correction factors were applied to obtain the fasted BW and the corresponding bled and chilled weights. A database was built up, including all the weights recorded and the DEXA-reported indexes. A stratified random data-splitting with a refitting approach was applied. Multiple least-squares linear regressions were fitted for each unchilled and chilled variable on the training dataset using JMP Pro 16. Natural log and square root transformations were applied to predictor variables as convenient, and outliers were removed. Candidate models were screened for normal distribution and homoscedasticity of residuals and collinearity among predictors. The highest precision (adjusted R2) and the lowest error (RMSE) were selection criteria. Once model overfitting and prediction performance was tested on the validation dataset, the models were refitted with all the data in the original dataset. Prediction models with high (unchilled and chilled carcass and cut-up weights, feet, and head; R2 > 0.99) and acceptable (abdominal fat; R2 > 0.69) precision were obtained. In conclusion, these results support the use of DEXA to determine the processing weights of broilers. Its application to the study of growth curves of cut-up pieces as influenced by nutrition, genetics, environment, and management opens a new spectrum of opportunities for the industry.

Dual-Energy X-ray Absorptiometry (DEXA) has been shown to predict the processing weights of the carcass and cut-up pieces of the chicken. This study aimed to validate models to predict processing weights using DEXA that were previously developed. An experiment was conducted with broilers grown up in 80 floor pens randomly subjected to one of five dietary treatments. On day 41, all birds were weighed, seven were randomly selected per pen, and their weights were recorded. After a feed withdrawal period, five selected birds per pen were transported to a processing plant, and the rest of the birds were fed again. The carcass was weighed before and after chilling for one hour. The chilled carcass was cut up, the weights of each commercial piece were recorded (breast fillet, tenders, wings, leg quarters, total white meat, and ready-to-cook parts), and the corresponding unchilled weights were calculated. On day 43 or 44, the other two birds selected per pen were weighed, DEXA-scanned without fasting, and their fasted weights were determined by applying a previously developed equation. Predicted processing weights were obtained by entering DEXA-reported values into a set of models previously developed. All the data were adjusted to the same BW basis. The pen mean observed processing weights and the DEXA-predicted ones were used to validate the models. The linear regression between predicted and observed values was calculated, and the R2 was used as a precision index. The parallelism of the predicted and observed response curves across dietary treatments, and the model prediction error and accuracy were determined. The validation criteria were based on the validation R2, the change in R2 from development to validation, the parallelism of response curves, and the prediction accuracy. The validation R2 of all tested models predicting the weight of cut-up pieces was > 0.84, and their prediction errors were ≤ 5.85 %, except for the model predicting the weight of the wings (prediction error > 10 %). All traits showed parallel trends when the response curves across treatments obtained with the DEXA-predicted values or the processing plant data were compared. In conclusion, all models but the one predicting the weight of wings satisfied the evaluation criteria and were validated, supporting the use of DEXA to determine the processing weights of broilers and its application to the study of nutrition interventions to improve breast meat production.

An experiment was conducted to evaluate the effect of feeding post-weaned piglets different levels of a commercial amoxicillin plus norfloxacin formula (Respirend) on the performance, clinical evidence of sickness, and the cost:benefit ratio. 454 PIC x Camborough female and castrated male, weaned at 21 d of age, with an average initial weight of 6.19 kg, were used in this experiment. Treatment 1 consisted in feeding a basal diet supplemented with 1000 g of a commercial tilmicosin product (Pulmotil) per metric tonne of feed (control group, from 21 to 35 d of age) and Treatments 2), 3) and 4) consisted in feeding the basal diet supplement with 500, 300 y 100 g of Respirend per metric tonne of feed, respectively, from 21 to 42 d of age. The results did not show significant differences (P<0.05) in mortality nor in parenteral medicine administration cost in none of the periods. Nevertheless, 500 g of Respirend per metric tonne of feed improved significantly (P<0.05) the general health status in the period between 21 and 35 d of age. For the whole evaluation period (21 to 42 d of age), this level improved significantly (P<0.05) the final body weight, the average daily weight gain, the average daily feed intake, the feed:gain ratio and optimized the cost:benefit ratio.

The present study evaluated In vitro effect of gentamicin sulfate and ceftiofur sodium on the viability of the Marek's disease virus. The titer of cell associated turkey herpesvirus (HVT) vaccine was not appreciably reduced when incubated with 50 mg/ml of gentamicin sulfate or ceftiofur sodium. Statistic difference was not found between the number of plaqueforming units (PFU) of reconstituted vaccine associated with both antibiotics 0, 15, 30 and 60 minutes after reconstitution of vaccine. The antibiotics did not considerably alter the pH values. There was a significative decrease of the titer of all vaccinal solutions when they were inoculated 30 and 60 minutes after the reconstitution of the vaccine. Nevertheless, these titers are higher than the required titers to protectect against the Marek disease.

The study of neurochemical-based interkingdom signaling and its impact on host-microbe interaction is called microbial endocrinology. Neurochemicals play a recognized role in determining bacterial colonization and interaction with the gut epithelium. While much attention has been devoted to the determination of neurochemical concentrations in the mammalian gut to better understand tissue and region-specific microbial endocrinology-based mechanisms of host-microbe interaction, little is known regarding the biogeography of neurochemicals in the avian gut. Greater resolution of avian gut neurochemical concentrations is needed especially as recent microbial endocrinology-based investigations into bacterial foodborne pathogen colonization of the chicken gut have demonstrated neurochemicals to affect Campylobacter jejuni and Salmonella spp. in vivo and in vitro. The aim of the present study was to determine the concentrations of stress-related neurochemicals in the tissue and luminal content of the duodenum, jejunum, ileum, cecum, and colon of the broiler intestinal tract, and to investigate if this biogeography changes with age of the bird. While all neurochemicals measured were detected in the intestinal tract, many displayed differences in regional concentrations. Whereas the catecholamine norepinephrine was detected in each region of the intestinal tract, epinephrine was present only in the cecum and colon. Likewise, dopamine, and its metabolite 3,4-dihydroxyphenylacetic acid were found in the greatest quantities in the cecum and colon. Serotonin and histamine were identified in each gut region. Region-specific age-related changes were observed (P < 0.05) for serotonin, its metabolite 5-hydroxyindole acetic acid as well as for histamine. Several neurochemicals, including norepinephrine, were found in the contents of each gut region. Epinephrine was not detected in the gut content of any region. Salsolinol, a microbial-produced neuroactive compound was detected in the gut content but not in tissue. Together, our data establish a neurochemical biogeography of the broiler chicken intestinal tract. By providing researchers with a region-by-region map of in vivo gut neurochemical concentrations of a modern broiler chicken breed, this neurochemical map is expected to inform future investigations that seek to utilize avian enteric neurochemistry.

This data set contains the data, JMP scripts, and figures of the article titled "The fasting heat production of broilers is a function of their body composition" to be published in the journal Animal - Open Space.

This study aims to model the relationship among performance, whole body composition, and processing yield through meta-regression. Scientific papers found in Scopus and Google Scholar were included if they reported results and variability values of an actual experiment in the three mentioned groups of variables using a single broiler genetic line. Weighted mean effect sizes were determined with a random model, the risk of bias was determined, and heterogeneity was considered an indicator of usefulness. Meta-regressions considered the effect sizes of the response variable and the percent change in one or more variables as predictors. A 78-row database was built from 14 papers, including nine factors tested on 22,256 broilers. No influencing bias was found, and the data was determined useful. Meta-regressions showed that the changes in body weight gain (BWG) are inversely related to the effects in feed conversion ratio (FCR) (p < 0.001) and that the changes in FCR and effects in protein-to-fat gain (PFG) are directly related (p < 0.001). The changes in PFG and the effects on carcass conformation or the market value of birds are directly related (p < 0.001). In conclusion, body composition predicts carcass conformation and its market value, supporting its use to predict the economic value of broilers.

Poultry researchers have used mathematical models to explain some laying bird responses. There are many equations of the egg characteristics, but their validity has not yet been confirmed. Therefore, the aim of the current study was to assess the accuracy of the equations proposed to predict egg characteristics in laying hens. A total of one hundred forty-eight prediction equations of egg characteristics were collected from different studies. A total of 781 eggs from 75-week-old Hy-Line laying hens were gathered to measure egg quality characteristics, and other egg characteristics were calculated using these measurements. The residuals of the difference of observed and predicted values were used to calculate accuracy measurements like mean absolute deviation (MAD), mean squared error of prediction (MSEP), mean absolute percentage error (MAPE) and root mean squared error of prediction (RMSEP). RMSEP was used to estimate the error of the model (EM) with a 12% as the maximum level of validation of the egg characteristics prediction equation and 1.2% only for specific gravity. Nine egg characteristic prediction equations were validated with great accuracy because validated equations showed a value of MAD, MSEP, MAPE and RMSEP very low and EM less than 12%. Equations validated for external egg characteristic used easy-to-measure traits (i.e., egg weight, egg length, and egg width) as predictor variables. Fifteen egg characteristic prediction equations were validated with considerable accuracy. These equations might shorten the process of egg quality determination, reduce the waste of eggs, and thereby saving time and money.

The increasing breast weight of modern broilers highlights the convenience of studying the dynamics of processing weights across the grow-out period. For models predicting these traits to work with non-fasted live birds under longitudinal studies, it is necessary to determine the changes in the weights of birds due to fasting and bleeding and carcasses due to chilling. This study aimed to develop a model to predict the fasting weight loss of broilers, determine the weight changes due to bleeding and chilling, and assess the percentage of gizzard fat in the abdominal fat. Models were fitted to fasting BW loss data from literature. A bleeding BW loss value obtained in a pilot study was compared to literature. This one and a single-source percent gizzard in the abdominal fat value were used as reference values. Birds from two experiments were selected at different ages to determine the following variables: non-fasted and fasted BW, bled weight, unchilled and chilled carcass weights, and gizzard fat and abdominal fat pad weights. Predicted and reference values were compared to the observed data based on their 95% confidence intervals, and the fitted model and reference values were validated if no statistical differences were inferred. The fasting BW loss model was refitted to the data from experiments, and the estimates of the model fitted to both datasets were compared. The fasting BW loss followed a three-parameter exponential model with reducing values as the bird aged, and the predicted and observed values showed no statistical difference (P > 0.05). The reference bleeding BW loss (2.76%) and gizzard fat percentage (18%) values showed no difference (P > 0.05) to data from broiler experiments, and a chilling carcass weight gain of 2.79% was determined. The scale and relative growth rate estimates of the fasting BW loss model showed no difference (P > 0.05) between datasets, and the asymptote showed a possible but negligible difference. The fasting BW loss model, the bleeding BW loss coefficient, and the gizzard fat percentage were validated. The model and coefficients obtained herein will not only be applied to predict processing weights using Dual-Energy X-ray Absorptiometry but also may be used in other modeling approaches.

The objective of this study was to determine the effect of feeding an antimicrobial association to males broiler chickens from 0 to 14 days of age on the performance and clinical signs of bacterial processes. Two treatments were tested: a control treatment without Respirend-M, and a treatment with the antimicrobial (300 g/t Respirend-M, 0-14 d). 398 male Cobb 500 chicks were randomly assigned to two treatments and four replications per treatment. Body weight at 14 d, body weight gain, feed intake, feed conversion ratio, and health status were evaluated. The results showed feeding 300 g/t Respirend-M significantly (P<0.05) improved the final body weight, the body weight gain and the feed intake. No statistically significant (P>0.05) effect was detected on the feed conversion ratio.

The fasting heat production (FHP; net energy expenditure under maintenance) is a key value to determine the net energy value of the feed and is calculated from measurements in respiratory chambers or predicted as a function of the metabolic BW (MBW). This study aimed to determine the influence of body composition on the FHP of broilers through a modeling approach. Six experiments (Exp 1–6) were conducted to develop (Exp 1–4) and externally validate (Exp 5 and 6) predictive models. In Exp 1–4, broilers of a single genetic line in floor pens were subjected to three dietary treatments to induce differences in body composition. The FHP (calorimetry chambers) and the body protein-to-fat ratio (PFR; Dual-Energy X-ray Absorptiometry) were recorded at nine time points between 7 and 55 days. Linear models were adjusted (considering the pen as the experimental unit), starting with a model containing the MBW as the sole predictor. Further modifications were tested by including the PFR and the age of the birds. A random split with a refitting approach was applied. Four models were internally validated and refitted to the whole data. They considered the FHP a function of the MBW (or BW) and the PFR, including or not the age of the birds, and showed high precision (R2 > 0.98) and accuracy (error < 2.5%). All models demonstrated that birds at the same BW and age have higher FHP the leaner they are. Body protein and fat are positively and negatively correlated to FHP, respectively. In Exp 5, broilers of two genetic lines fed three dietary treatments were tested for FHP and body composition at 22 and 41 days. In Exp 6, broilers fed continuous dietary treatments in a dose–response design were tested for FHP and body composition at 17, 20, and 41 days. The models were tested on the data from Exp 5 and 6 considering the treatments as the validation unit. The four selected models showed high prediction precision (validation R2 > 0.92) and accuracy (model prediction error < 3%) and were validated externally. In conclusion, at the same age and BW, the higher the PFR, the higher the FHP. Including the PFR improved the strength of the models.

The food production system needs to be sustainable including poultry sector to feed the increasing global population. An accepted economical and environmental approach of broiler production is to produce larger broilers faster while using less feed. Broiler production is aimed at producing consumable meat and meat products. The global broiler meat market has evolved over the years with increasing selection pressure shifted toward attaining yield characteristics for increased cut-up parts such as breast and thighs. There is a shift toward a big bird market in the U.S. with approximately 70% of the broiler meat produced from large birds (>2.72 kg). Genetic selection of broilers for quantitative traits such as growth rate and lean muscle mass without increasing the fat mass has altered broiler physiological homeostasis to adapt toward the larger rates of muscle protein turnover. Physiological stresses created due to selection pressures in broilers have produced several muscle myopathies including an emerging one called woody breast myopathy. The sustainable broiler production practice may require humane consideration of raising broilers in less stressful grow-out regimes that will have minimal impact on broiler metabolic health. Another sustainability approach of broiler production toward feed efficiency lies on understanding dietary formulation approach of amino acids and energy that promote optimal nutrient utilization and minimal nutrient output to environment while also fulfilling the growth demands and body composition changes associated with increased protein gain in current meat broilers brought by the genetic progress.