Effect of digestible protein on intermediate metabolism, hepatic enzyme activities, energy reserves, and growth performance of pacu (Piaractus mesopotamicus) in the finishing growth phase.

This study investigated the effect of different levels of digestible protein (DP) on blood metabolites, hepatic enzyme activity of glycolysis and amino acid metabolism, energy reserves, and the production characteristics of pacu (Piaractus mesopotamicus) during the finishing growth phase. Six semi purified and isoenergetic diets, containing 16.3, 20.

Coccidiosis infection and growth performance of broilers in experimental trials: insights from a meta-analysis including modulating factors.

An infection by protozoa Eimeria spp. can cause coccidiosis, which negatively affects broiler chicken performance and causes economic and production losses. To understand the effect of coccidiosis on broilers' performance, we evaluated the independent variables and their interactions on the severity of coccidiosis in broilers that cause variation (Δ) of average daily feed intake (ADFI), average daily gain (ADG), and gain per feed (G:F) of broiler chicks using a meta-analysis approach.

Description and Validation of Flow-Through Chambers of Respirometry for Measuring Gas Exchange in Animal Trials.

Indirect calorimetry (IC) is a widely used method to study animal energy metabolism by measuring gas exchange. The accuracy of IC depends on detecting variations in signals reflecting the metabolic response, which can be challenging due to measurement noise and external factors. This study proposes a methodology to validate IC systems, including an easy-to-use spreadsheet for data computing, to verify accuracy and detect whole-system leaks.

The Response to Dietary Leucine in Laying Lens.

This study aimed to estimate the standardized ileal digestible leucine intake (SID-Leu, mg) in laying hens for maintenance, and to describe the response in laying hens to SID-Leu, thereby providing the information required to determine the optimum economic intake of SID-Leu for laying hens. Two nitrogen balance series, one balanced and the other unbalanced with respect to leucine (Leu), were used to estimate the SID-Leu requirement for maintenance using 36 roosters per series. The roosters were randomly distributed among the six levels of Leu with each level being replicated six times.

Responses of broilers challenged by Eimeria maxima fed with different levels of dietary balanced protein.

This study aimed to evaluate the effects of different dietary balanced protein (BP) levels on the gut health, amino acid apparent ileal digestibility (AID), footpad dermatitis lesions, and litter quality in broiler chicks infected with Eimeria maxima. A total of 2400 male 14-day-old Cobb500 broilers were randomly allotted into 10 treatments with six replications containing 40 birds each in a factorial design of 5 × 2. The treatments consisted of five levels of BP (6.

A novel consensus bacterial 6-phytase variant improves the responses of laying hens fed an inorganic phosphorus-free diet with reduced energy and nutrients from 23 to 72 wk of age.

The objective of this study was to evaluate the effect of a novel consensus bacterial 6-phytase variant (PhyG) on egg productivity, eggshell quality, and body composition of laying hens fed inorganic phosphate-free diets with reduced energy and nutrients from 23 to 72 wk of age. Five treatments were randomly assigned, performing 28 replicates per treatment with 4 hens each, totaling 560 Hy-Line W80 birds. A positive control (PC) feed was formulated to contain adequate levels of energy and nutrients.

Response of Laying Hens to Repletion and Depletion in Dietary Balanced Protein.

This study was carried out to investigate the response of laying hens given a repletion or depletion in dietary balanced protein (BP) during the laying phase period. At the beginning of the rearing period (eight w-old), four-hundred pullets were equally distributed and received one of two experimental feeds: 1-Low BP (L) and 2-High BP (H). For the laying period (19 to 102 w-old), four feeding programs were designed based on the same treatments for rearing phases (LL, HH, LH, HL), where subsequent letters indicate the feed received during the rearing and laying period, respectively.

Dynamics of Growth and Egg Traits in Three Dietary Balanced Protein Scenarios Applied for Laying Hens.

The objective of this study was to evaluate laying hens from 8 to 102 weeks old, regarding their changes in performance, body composition, and egg components produced in three scenarios of nutrition. Three treatments designed to contain different levels of balanced protein (BP) were randomly assigned to the experimental units, performing ten replicates per treatment with 20 birds each. A standard feed was formulated to meet hen requirements and the ideal ratio between essential amino acids.

Effect of feed restriction on the maintenance energy requirement of broiler breeders.

Objective: This study aimed to evaluate the effect of the ad libitum and restricted feeding regimen on fasting heat production (FHP) and body composition.

Methods: Twelve Hubbard broilers breeders were selected with the same body weight and submitted in two feeding regimes: Restricted (T1) with feed intake of 150 g/bird/d and ad libitum (T2). The birds were randomly distributed on the treatments in two runs with three replications per treatment (per run).

Modelling Broiler Requirements for Lysine and Arginine.

Six assays were conducted to investigate male and female broiler responses to standardized ileal digestible (SID) lysine (Lys) and arginine (Arg). Response data were modeled to estimate the efficiency of utilization () of both amino acids and adjust factorial models to predict bird intake for SID Lys and SID Arg. In each assay, 1280 Cobb 500 broilers (640 male and 640 female) were randomly assigned to one of sixteen dietary treatments with four replicates of 20 birds.

Threonine incorporation in tissues of growing broiler chickens using L-[ N] threonine.

Most amino acid requirement trials appear for whole-body responses, but there is little information concerning amino acid incorporation in individual tissues, which may vary according to the age. L-[ N] threonine was used to evaluate its incorporation rate and distribution among broiler tissues in different ages. Seventy-two male broiler chickens were distributed into three different phases: starter (4 to 9 days old), grower (18 to 23 days old) and finisher phase (32 to 37 days old).

Supplemental phytase derived from E. coli in different concentrations on performance, bone mineralization and cost of broilers diets.

The trial was conducted to evaluate the supplementation of E. coli phytase on performance, weight and ash of bones, as well as to determine the bioavailability of P and cost/benefit of its use in diets. A total 1,890 Cobb male day old chicks were assigned to six treatments and seven replicates with 45 birds each, distributed in a completely randomized design.

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

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.

Efficiency of methionine and cystine utilization by broiler chickens using stable isotopes.

The aim of this study was to develop a method to determine the efficiency of utilization of Met and Cys using stable isotopes in order to reduce the number of sacrificed animals relative to the comparative slaughter technique. Met and Cys efficiencies were obtained separately and as total SAA values. Twenty-one 14- to 28-day-old broiler chickens were fed experimental diets containing different Met:Cys ratios (44:56, 50:50 and 56:44).

Nitrogen maintenance requirements and potential for nitrogen retention of pullets in growth phase.

Experiments were conducted to estimate daily N maintenance requirements (NMRs) and the genetic potential for daily N retention (NR T) of pullets in growth phase. Three nitrogen balance trials were conducted, and a total of 48 Hy-line W-36 pullets were used in each trial in age periods (starter: 14-28, grower: 56-70 and developer: 98-112 days). The treatments consisted of six graded levels of nitrogen in the diets (L1 = 8, L2 = 16, L3 = 24, L4 = 32, L5 = 40 and L6 = 48 g N/kg of feed), formulated using the dilution technique.

Factorial models to estimate isoleucine requirements for broilers.

The objective of this work was to determine the efficiency of utilization (EU) and produce factorial models for optimal isoleucine (Ile) intake. Six dose-response trials were carried out, three for males and three for females, with 640 Ross 308 in each studied phase. The initial (1-14 days), grower (15-28 days) and finisher (29-42 days) phases were evaluated to cover the growing phase of the broiler chicken.

Bacillus amyloliquefaciens CECT 5940 alone or in combination with antibiotic growth promoters improves performance in broilers under enteric pathogen challenge.

A study was conducted to investigate the effects of Bacillus amyloliquefaciens CECT 5940 as a direct-fed microbial (DFM) alone or in association with bacitracin methylene disalicylate (BMD) in broilers under enteric pathogen challenge. A total of 1,530-day-old male Cobb500 chicks were randomly assigned to 5 treatments, with 9 replicate pens with 34 birds each. Treatments included positive control (PC, basal diet without additives or challenge); negative control (NC, basal diet without additive and challenged birds); NC + 0.

Partitioning the efficiency of utilization of amino acids in growing broilers: Multiple linear regression and multivariate approaches.

Determining the efficiency of amino acid (AA) utilization in growing animals is crucial to estimate their requirement accurately. In broiler chickens, the composition of AA in feather is different from feather-free body and the proportion of feathers will change along broiler's growth, which may impact the efficiency of utilization on AA consumed. Therefore, in order to establish a method that predicts the efficiency of utilization for feather-free body and feather, two approaches were evaluated: a multiple linear regression and a multivariate analysis.

Optimal in-feed amino acid ratio for laying hens based on deletion method.

A total of 56 Hy-line W-36 hens from 28 to 30 weeks were used on nitrogen balance (NB) trial to estimate daily N maintenance requirements (NMR) and the genetic potential for daily N retention (NR T). The treatments consisted of six graded levels of nitrogen in the diets (N1 = 8; N2 = 16; N3 = 24; N4 = 32; N5 = 40; and N6 = 48 g N/kg of feed), formulated using the dilution technique. The regression analyses between nitrogen intake and excretion were performed to fit the exponential function and to determine the NMR = 292 mg/BW , which was applied for further calculation of NR T = 1,883 mg/BW .

Methionine to cystine ratio in the total sulfur amino acid requirements and sulfur amino acid metabolism using labelled amino acid approach for broilers.

Background: Assuming that part of Methionine (Met) is converted into Cystine (Cys), but ignoring the rates with which such phenomenon occurs may lead to an excessive supply of Met in poultry diets. Such inconvenient could be easily avoided with the knowledge of the ideal Met:Cys/Total sulfur amino acids (TSAA) ratio and the rates of Met conversion into Cys.

Results: Met sources did not affect performance.

Prediction of crude protein digestibility of animal by-product meals for dogs by the protein solubility in pepsin method.

Animal by-product meals have large variability in crude protein (CP) content and digestibility. In vivo digestibility procedures are precise but laborious, and in vitro methods could be an alternative to evaluate and classify these ingredients. The present study reports prediction equations to estimate the CP digestibility of meat and bone meal (MBM) and poultry by-product meal (PM) using the protein solubility in pepsin method (PSP).

Sugarcane fibre may prevents hairball formation in cats.

Hair ingested by licking during cat grooming can eventually coalesce into solid masses in cat gastrointestinal tract. It is believed that dietary fibre might reduce formation of these trichobezoars (hairballs). The effects of two insoluble fibre sources added to kibble diets were evaluated with respect to trichobezoar faecal excretion.

Molecular identification and characterization of ileal and cecal fungus communities in broilers given probiotics, specific essential oil blends, and under mixed Eimeria infection.

Broiler digestive tract fungal communities have gained far less scrutiny than that given corresponding bacterial communities. Attention given poultry-associated fungi have focused primarily on feed-associated toxin-producers, yeast, and yeast products. The current project focused on the use of pyrosequencing and denaturing gradient gel electrophoresis (DGGE) to identify and monitor broiler digestive fungal communities.

Use of pyrosequencing and denaturing gradient gel electrophoresis to examine the effects of probiotics and essential oil blends on digestive microflora in broilers under mixed Eimeria infection.

A protective digestive microflora helps prevent and reduce broiler infection and colonization by enteropathogens. In the current experiment, broilers fed diets supplemented with probiotics and essential oil (EO) blends were infected with a standard mixed Eimeria spp. to determine effects of performance enhancers on ileal and cecal microbial communities (MCs).