Immobilization and docking studies of Carlsberg subtilisin for application in poultry industry.

Carlsberg subtilisin from Bacillus licheniformis PB1 was investigated as a potential feed supplement, through immobilizing on bentonite for improving the growth rate of broilers. Initially, the pre-optimized and partially-purified protease was extracted and characterized using SDS-PAGE with MW 27.0 KDa. The MALDI-TOF-MS/MS spectrum confirmed a tryptic peptide peak with m/z 1108.496 referring to the Carlsberg subtilisin as a protein-digesting enzyme with alkaline nature. The highest free enzyme activity (30 U/mg) was observed at 50°C, 1 M potassium phosphate, and pH 8.0. the enhanced stability was observed when the enzyme was adsorbed to an inert solid support with 86.39 ± 4.36% activity retention under 20 optimized conditions. Additionally, the dried immobilized enzyme exhibited only a 5% activity loss after two-week storage at room temperature. Structural modeling (Docking) revealed that hydrophobic interactions between bentonite and amino acids surrounding the catalytic triad keep the enzyme structure intact upon drying at RT. The prominent hygroscopic nature of bentonite facilitated protein structure retention upon drying. During a 46-days study, supplementation of boilers' feed with the subtilisin-bentonite complex promoted significant weight gain i.e. 15.03% in contrast to positive control (p = 0.001).

A review of recent studies on the enrichment of eggs and poultry meat with omega-3 polyunsaturated fatty acids: novel findings and unanswered questions.

Studies from our laboratory over the past decade have yielded new information with regard to the dietary enrichment of eggs and poultry meat with omega-3 (n-3) polyunsaturated fatty acids (PUFA) but have also generated a number of unanswered questions. In this review, we summarize the novel findings from this work, identify knowledge gaps, and offer possible explanations for some perplexing observations. Specifically discussed are: 1) Why feeding laying hens and broilers an oil rich in stearidonic acid (SDA; 18:4 n-3), which theoretically bypasses the putative rate-limiting step in the hepatic n-3 PUFA biosynthetic pathway, does not enrich egg yolks and tissues with very long-chain (VLC; ≥20 C) n-3 PUFA to the same degree as obtained by feeding birds oils rich in preformed VLC n-3 PUFA; 2) Why in hens fed an SDA-rich oil, SDA fails to accumulate in egg yolk but is readily incorporated into adipose tissue; 3) How oils rich in oleic acid (OA; 18:1 n-9), when co-fed with various sources of n-3 PUFA, attenuates egg and tissue n-3 PUFA contents or rescues egg production when co-fed with a level of docosahexaenoic acid (DHA; 22:6 n-3) that causes severe hypotriglyceridemia; and 4) Why the efficiency of VLC n-3 PUFA deposition into eggs and poultry meat is inversely related to the dietary content of α-linolenic acid (ALA; 18:3 n-3), SDA, or DHA.

Interactions of zinc with phytate and phytase in the digestive tract of poultry and pigs: a review.

Phytase supplementation is gaining importance in animal nutrition because of its effect on phosphorus (P) digestibility and the increasing relevance of P for sustainable production. The potential inhibitors of phytase efficacy and phytate degradation, such as calcium (Ca) and zinc (Zn), have been a subject of intense research. This review focuses on the interactions of Zn with phytate and phytase in the digestive tract of poultry and pigs, with an emphasis on the effects of Zn supplementation on phytase efficacy and P digestibility. In vitro studies have shown the inhibitory effect of Zn on phytase efficacy. However, relevant in vivo studies are scarce and do not show consistent results for poultry and pigs. The results could be influenced by different factors, such as diet composition, amount of Zn supplement, mineral concentrations, and phytase supplementation, which limit the comparability of studies. The chosen response criteria to measure phytase efficacy, which is mainly tibia ash, could also influence the results. Compared to poultry, the literature findings are somewhat more conclusive in pigs, where pharmacological Zn doses (≥ 1000 mg kg-1 Zn) appear to reduce P digestibility. To appropriately evaluate the effects of non-pharmacological Zn doses, further studies are needed that provide comprehensive information on their experimental setup and include measurements of gastrointestinal phytate degradation to better understand the mechanisms associated with Zn and phytase supplements. © 2023 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Accentuating the positive and eliminating the negative: Efficacy of TiO2 as digestibility index marker for poultry nutrition studies.

Inert digestibility index markers such as titanium dioxide are universally accepted to provide simple measurement of digestive tract retention and relative digestibility in poultry feeding trials. Their use underpins industry practice: specifically dosing regimens for adjunct enzymes added to animal feed. Among these, phytases, enzymes that degrade dietary phytate, inositol hexakisphosphate, represent a billion-dollar sector in an industry that raises ca. 70 billion chickens/annum. Unbeknown to the feed enzyme sector, is the growth in cell biology of use of titanium dioxide for enrichment of inositol phosphates from extracts of cells and tissues. The adoption of titanium dioxide in cell biology arises from its affinity under acid conditions for phosphates, suggesting that in feeding trial contexts that target phytate degradation this marker may not be as inert as assumed. We show that feed grade titanium dioxide enriches a mixed population of higher and lower inositol phosphates from acid solutions. Additionally, we compared the extractable inositol phosphates in gizzard and ileal digesta of 21day old male Ross 308 broilers fed three phytase doses (0, 500 and 6000 FTU/kg feed) and one inositol dose (2g/kg feed). This experiment was performed with or without titanium dioxide added as a digestibility index marker at a level of 0.5%, with all diets fed for 21 days. Analysis yielded no significant difference in effect of phytase inclusion in the presence or absence of titanium dioxide. Thus, despite the utility of titanium dioxide for recovery of inositol phosphates from biological samples, it seems that its use as an inert marker in digestibility trials is justified-as its inclusion in mash diets does not interfere with the recovery of inositol phosphates from digesta samples.

Phytase dose-dependent response of kidney inositol phosphate levels in poultry.

Phytases, enzymes that degrade phytate present in feedstuffs, are widely added to the diets of monogastric animals. Many studies have correlated phytase addition with improved animal productivity and a subset of these have sought to correlate animal performance with phytase-mediated generation of inositol phosphates in different parts of the gastro-intestinal tract or with release of inositol or of phosphate, the absorbable products of phytate degradation. Remarkably, the effect of dietary phytase on tissue inositol phosphates has not been studied. The objective of this study was to determine effect of phytase supplementation on liver and kidney myo-inositol and myo-inositol phosphates in broiler chickens. For this, methods were developed to measure inositol phosphates in chicken tissues. The study comprised wheat/soy-based diets containing one of three levels of phytase (0, 500 and 6,000 FTU/kg of modified E. coli 6-phytase). Diets were provided to broilers for 21 D and on day 21 digesta were collected from the gizzard and ileum. Liver and kidney tissue were harvested. Myo-inositol and inositol phosphates were measured in diet, digesta, liver and kidney. Gizzard and ileal content inositol was increased progressively, and total inositol phosphates reduced progressively, by phytase supplementation. The predominant higher inositol phosphates detected in tissues, D-and/or L-Ins(3,4,5,6)P4 and Ins(1,3,4,5,6)P5, differed from those (D-and/or L-Ins(1,2,3,4)P4, D-and/or L-Ins(1,2,5,6)P4, Ins(1,2,3,4,6)P5, D-and/or L-Ins(1,2,3,4,5)P5 and D-and/or L-Ins(1,2,4,5,6)P5) generated from phytate (InsP6) degradation by E. coli 6-phytase or endogenous feed phytase, suggesting tissue inositol phosphates are not the result of direct absorption. Kidney inositol phosphates were reduced progressively by phytase supplementation. These data suggest that tissue inositol phosphate concentrations can be influenced by dietary phytase inclusion rate and that such effects are tissue specific, though the consequences for physiology of such changes have yet to be elucidated.

Effect of growth medium nitrogen and phosphorus on nutritional composition of Lemna minor (an alternative fish and poultry feed).

Duckweed (Lemna minor L.) is an aquatic macrophyte and grows profoundly on the surface of polluted water reservoirs of Pakistan. The plant can be used as a potential alternative for the fish and poultry industry to meet the promptly growing demand for feed. Our study investigates the effect of varying concentrations (ppm) of nutrients like N, P, and their combination, NP on biomass production, carbohydrate, lipid, protein, and mineral (Ca, Mg, Fe, Mn & Zn) contents of L. minor. The varying concentrations of N and P substantially affected the above-stated parameters. The highest biomass yield was recorded in the 30 ppm NP tank as 172 g/m2 day in comparison with the control tank. Higher protein, lipid, and carbohydrate contents were recorded for 30 ppm NP, 20 ppm NP, and 10 ppm NP respectively. Minerals like Ca, Mg, Fe, Mn & Zn increased in 20 ppm P and all N concentrations. The combined application of NP was more effective in boosting the protein, carbohydrate, and lipid content whereas less effective in increasing the mineral contents. A rise in the concentration of N and P showed a positive correlation with the nutritional composition of L. minor.

Functional role of branched chain amino acids in poultry: a review.

This review provides insight into the effects of the branched-chain amino acids (BCAA: leucine, isoleucine, and valine) on the growth, production performance, immunity, and intestinal health of poultry. Besides providing nitrogen substrates and carbon framework for energy homeostasis and transamination, BCAA also function as signaling molecules in the regulation of glucose, lipid, and protein synthesis via protein kinase B and as a mechanistic target of the rapamycin (AKT-mTOR) signaling pathway that is important for muscle accretion. The level of leucine is generally high in cereals and an imbalance in the ratio among the 3 BCAA in a low protein diet would produce a negative effect on poultry growth performance. This occurs due to the structural similarity of the 3 BCAA, which leads to metabolic competition and interference with the enzymatic degradation pathway. Emerging evidence shows that the inclusion of BCAA is essential for the proper functioning of the innate and adaptive immune system and the maintenance of intestinal mucosal integrity. The recommended levels of BCAA for poultry are outlined by NRC (1994), but commercial broilers and laying hen breed standards also determine their own recommended levels. In this review, it has been noted that the requirement for BCAA is influenced by the diet type, breed, and age of the birds. Additionally, several studies focused on the effects of BCAA in low protein diets as a strategy to reduce nitrogen excretion. Notably, there is limited research on the inclusion ratio of BCAA in a supplemental form as compared to the ingredient-bound form which would affect the dynamics of utilization in different disease-challenged conditions, especially those affecting digesta passage ratio. In summary, this review encompasses the role of BCAA as functional AA and discusses their physiological effects on the productivity and health of poultry. The observations and interpretations of this review can guide future research to adjust the recommended levels of BCAA in feeding programs in the absence of subtherapeutic antibiotics in poultry.

Hepatic fatty acids profile, oxidative stability and egg quality traits ameliorated by supplementation of alternative lipid sources and milk thistle meal.

This study assessed the effects of different levels of milk thistle (Silybum marianum) meal (MTM) on egg quality traits, oxidative stability, blood biochemical parameters and liver health indices in laying hens receiving diets supplemented with lipid from different sources. For this purpose, Leghorn laying hens (Hy-Line W-36) were randomly assigned to 12 experimental treatments with eight replicates of five birds each. Dietary treatments consisted of four dietary fat sources (fish oil, sunflower oil, poultry oil and fat powder, each with different fatty acid profiles) and three levels of MTM (0.0, 15 and 30 g/kg) offered through 10 days of adaptation and 70 days of main recording. Results showed that dietary inclusion of polyunsaturated fatty acids, including fish or sunflower oils, reduced serum cholesterol content but increased blood malondialdehyde (MDA) concentration (p < 0.05). While fish oil improved the yolk colour index and Haugh unit (p < 0.05), it decreased yolk cholesterol concentration (p < 0.01). The highest hepatic glycogen content and tissue integrity as well as the lowest liver lipid percentage and MDA content were observed in birds fed diets supplemented with poultry oil. On the other hand, feeding 30 g/kg of MTM reduced not only hepatic lipid percentage but also aspartate aminotransferase (AST) and alanine aminotransferase (ALT) activities (p < 0.01), while it improved eggshell strength and thickness (p < 0.05). Supplementation of fat powder enhanced hepatic C16:0 content, while addition of poultry, sunflower or fish oil increased C18:1, C18:2 or C20:5 concentrations respectively (p < 0.01); nonetheless, feeding the highest level of MTM reduced hepatic ΣSFA but increased Σn-3 fatty acids (p < 0.01). The interaction effects indicated that fish or sunflower oil supplementation increased the MTM level required to reduce not only serum or egg cholesterol concentrations (p < 0.05) but also blood or hepatic MDA content (p < 0.01). It was concluded that fish oil and MTM (30 g/kg) supplements might improve internal egg quality traits and eggshell quality respectively. The hepatic fatty acid profile was also found strongly correlated with dietary fatty acids. Finally, the best hepatic health indices and the highest oxidative stability were achieved when the birds were fed diets supplemented with poultry oil and 30 g/kg of MTM.

The immune status, oxidative and epigenetic changes in tissues of turkeys fed diets with different ratios of arginine and lysine.

In the present experiment, it was assumed that the appropriate dietary ratio of arginine (Arg) to lysine (Lys) can improve the immune status and growth performance of turkeys. The aim of this study was to evaluate the effects of two inclusion rates of Arg relative to Lys in turkey diets with Lys content consistent with National Research Council (NRC) recommendations or 10% higher on the immune status of birds and indicators of protein and DNA damage due to oxidation, nitration or epigenetic changes. Another goal was to determine which dietary Arg:Lys ratio stimulates the immune response of turkeys vaccinated against Ornithobacterium rhinotracheale. The experiment was performed on 576 turkeys randomly assigned to four groups with two levels of Lys (low = NRC recommendation or high = NRC + 10%) and two levels of Arg (95% or 105% Arg relative to the content of dietary Lys). It was found that the Lys content of turkey diets should be 10% higher than that recommended by the NRC and combined with the higher Arg level (105% of Lys). Although the above Arg:Lys ratio did not improve the growth performance of birds, it stimulated their immune system and reduced protein nitration as well as protein and DNA oxidation.

Limitations of an in vitro model of the poultry digestive tract on the evaluation of the catalytic performance of phytases.

BACKGROUND: The study aims to investigate the limitation of a poultry digestive tract model developed by Menezes-Blackburn et al. [J Agric Food Chem 63: 6142-6149 (2015)] on the evaluation of the bioefficacy of phytases. RESULTS: It was confirmed that the in vitro model does not mimic the in vivo situation in the birds sufficiently well to identify the best phytase product under real conditions, or to draw conclusion on the effect of phytate concentration, phytate source or feed composition on the bioefficacy of phytase. Addition of calcium ion (Ca2+ ) up to a concentration of 10 g kg-1 to the feed substrate, for example, did not affect enzymatic phytate dephosphorylation in the in vitro model in contrast to the observation in poultry. CONCLUSION: The in vitro approach was shown to be applicable as a complementary tool in the pre-selection of promising phytase candidates, resulting in a reduction in the number of feeding trials in the initial screening phase. © 2020 The Author. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Microbiota and metabolome responses in the cecum and serum of broiler chickens fed with plant essential oils or virginiamycin.

This study investigated the cecal microbiota and serum metabolite profile of chickens fed with plant essential oils (PEO) or virginiamycin (VIRG) using high-throughput 16S rRNA gene sequencing and untargeted metabolomics approach. The main aim of this work was to explore the biochemical mechanisms involved in the improved growth performance of antibiotics and their alternatives in animal production. The results showed that both PEO and VIRG treatment significantly increased the relative abundance of phyla Bacteroidetes and decreased the abundance of phyla Firmicutes and genus of Lactobacillus in cecal microbiota of chickens. Compared to the control group (CT group), the relative abundance of genus of Alistipes, unclassified Rikenellaceae, Roseburia, and Anaeroplasma was enriched in the PEO group; that of genus Bacteroides, Lachnospiraceae, and unclassified Enterobacteriaceae was enriched in the cecal microbiota of the VIRG group. Untargeted metabolomics analyses revealed that the PEO treatment modified 102 metabolites and 3 KEGG pathways (primary bile acid biosynthesis and phenylalanine metabolism) in the cecal microbiota, and 81 metabolites and relevant KEGG pathways (fructose and mannose metabolism, biosynthesis of unsaturated fatty acids, and linoleic acid.) in the serum of the chicken. Compared to the CT group, VIRG treatment group differed 217 metabolites and 10 KEGG pathways in cecal contents and 142 metabolites and 7 KEGG pathways in serum of chickens. Pearson's correlation analysis showed that phyla Bacteroidetes and genus of Bacteroides, Alistipes, and unclassified Rikenellaceae (in the VIRG and PE group) were positively correlated with many lipid metabolites. However, phyla Firmicutes and genera Lactobacillus (higher in the CT group) were negatively correlated with the lipid and thymine metabolism, and positively correlated with hydroxyisocaproic acid, cytosine, and taurine. This study shows that dietary supplementation with PEO and VIRG altered the composition and metabolism profile of the cecal microbiota, modified the serum metabolism profile.

Myo-inositol: its metabolism and potential implications for poultry nutrition-a review.

Myo-inositol (MI) has gained relevance in physiology research during the last decade. As a constituent of animal cells, MI was proven to be crucial in several metabolic and regulatory processes. Myo-inositol is involved in lipid signaling, osmolarity, glucose, and insulin metabolism. In humans and rodents, dietary MI was assessed to be important for health so that MI supplementation appeared to be a valuable alternative for treatment of several diseases as well as for improvements in metabolic performance. In poultry, there is a lack of evidence not only related to specific species-linked metabolic processes but also about the effects of dietary MI on performance and health. This review intends to provide information about the meaning of dietary MI in animal metabolism as well as to discuss potential implications of dietary MI in poultry health and performance with the aim to identify open questions in poultry research.

The use of yellow mealworm (T. molitor) as alternative source of protein in poultry diets: a review.

Protein sources are known to be the second largest component in the poultry sector. Traditionally, fish and soya-bean meals are known to supply very good protein; however, these are restricted in supply and more expensive than energy sources. The prices of soya-bean meal are currently high and tend to fluctuate with changes in climatic conditions and social situations in the countries where it is produced. Developing countries like South Africa have made enormous investments in soya-bean production, despite that the country still imports considerable volumes of this crop and is not self-sufficient. This then means that there is an urgent need to seek for alternative and cost-effective protein sources that can provide the same nutrients as soya-bean and fish meal for poultry production. Tenebrio molitor L. which is commonly known as yellow mealworm has a huge potential to substitute commonly used protein sources in poultry diets. Mealworms are easy to breed and do not require large area for production. Moreover, they have high nutritional value comparable to that of soya-bean and fishmeal. However, the only limiting nutrient for mealworms is calcium which can be easily supplemented in the diets. Therefore, this review sets out to explore the importance of replacing soya bean with mealworms in poultry diets. Furthermore, the life cycle of meal worms will also be discussed.

Effects of selenium source and level in diet on glutathione peroxidase activity, tissue selenium distribution, and growth performance in poultry.

Today, a few differing sources of selenium (Se), i.e. inorganic, organic, and nano forms of Se, are used as feed supplements for poultry. Published research indicates that nano-Se and organic Se possess comparable efficiency to inorganic Se in increasing GSH-Px activity of plasma and various tissues, but they deposit at higher rates in various tissues. However, there are principal differences in absorption mechanisms, metabolism, and efficiency of these three forms of Se. The aim of this review was to analyze the available literature on the effects of different Se sources and levels in the diet on glutathione peroxidase (GSH-Px) activity, tissue Se distribution and growth performance in poultry. Higher levels of Se increase GSH-Px activity in the body, but this reaches a plateau even if Se concentrations in diet increase further, while the deposition of Se in tissues increases as Se content in diet increases. In addition, many studies have shown the positive effects of adding Se to diet on growth performance in poultry. Optimal Se supplementation is necessary not only for good poultry health but also to ensure and preserve meat quality during storage and to provide human beings with this microelement.

Supplementation of broiler breeders with fat sources and vitamin e: carry over effect on performance, carcass yield, and meat quality offspring / Suplementação de matrizes de frangos de corte com fontes de gordura e vitamina E: transferência dos efeitos sobre a performance, o rendimento da carcaça e a qualidade da carne da progênie

The aim of this study was to evaluate two sources of oil (soybean and fish) and four additional levels of vitamin E (0, 150, 250 and 350mg/kg diet) in breeder diets between the 42nd and 56th week of age and its effect on performance and meat quality of offspring. The supplementation of fish oil in the maternal diet increased the deposition of DHA and CLA in egg yolk. From 1 to 35 days of age, intermediate levels of vitamin E resulted in lower weight gain and feed intake. To feed conversion, the best result was obtained supplementing the maternal diet with soybean oil, regardless of vitamin inclusion. In addition, the evaluation of meat quality, the fish oil-supplemented-diet resulted in lower moisture loss of the breast fillets. For maternal diet supplemented with fish oil, the inclusion of vitamin E resulted in a linear increase of the pH value of the meat. Greater levels of vitamin E in the maternal diet influenced the functional properties of meat according to the type of oil that was added to the diet. The deposition of different fatty acids in the embryonic egg yolk can directly influence the meat quality of offspring.(AU)

O objetivo deste estudo foi avaliar duas fontes de óleo (soja e peixe) e quatro níveis adicionais de vitamina E (0, 150, 250 e 350mg/kg dieta), em dietas de matrizes entre a 42º e a 56º semana de idade, sobre o desempenho e a qualidade de carne da progênie. A suplementação de óleo de peixe na dieta das matrizes aumentou a deposição de DHA e CLA na gema dos ovos. Entre um e 35 dias de idade, níveis intermediários de vitamina E resultaram em menor ganho de peso e consumo de ração. Para a conversão alimentar, o melhor resultado foi obtido suplementando a dieta materna com óleo de soja, independentemente da inclusão vitamínica. Dietas suplementadas com óleo de peixe resultaram em menor perda de umidade nos filés de peito. Para a dieta materna suplementada com óleo de peixe, a inclusão de vitamina E resultou em um aumento linear do valor de pH da carne. Níveis mais altos de vitamina E na dieta materna influenciaram as propriedades funcionais da carne de acordo com o tipo de óleo adicionado à dieta. A deposição de diferentes ácidos graxos na gema de ovos embrionados pode influenciar diretamente a qualidade da carne da progênie.(AU)

Modification and application of an in vitro assay to examine inositol phosphate degradation in the digestive tract of poultry.

BACKGROUND: An in vitro assay was modified to study the disappearance of inositol hexakisphosphate (InsP6 ) and the formation of lower inositol phosphate (InsP) isomers in the poultry digestive tract, and three experiments investigated the influence of diets with different ingredients and additives. Using the poultry diet as a matrix, the assay simulated the conditions (e.g. pH, temperature, proteolytic enzymes, water content, and retention time) of the crop, stomach, and small intestine, and extraction and analysis of InsP isomers were immediately conducted. RESULTS: The assay produced highly reproducible results with coefficients of variation ≤10% for an InsP isomer concentration ≥0.4 µmol g-1 DM (n = 3), and it was sensitive to the factors that varied in the three experiments. CONCLUSION: The described assay is a suitable tool that can be used to screen feed enzymes and to investigate the effects of supplements in the absence of endogenous phytases. The ease of handling and high reproducibility of the assay indicated that the assay is a rapid and feasible method that can be used to examine the degradation pathway of phytate in feed under gastrointestinal conditions. © 2017 Society of Chemical Industry.

Aflatoxin B1 Induced Systemic Toxicity in Poultry and Rescue Effects of Selenium and Zinc.

Among many challenges, exposure to aflatoxins, particularly aflatoxin B1 (AFB1), is one of the major concerns in poultry industry. AFB1 intoxication results in decreased meat/egg production, hepatotoxicity, nephrotoxicity, disturbance in gastrointestinal tract (GIT) and reproduction, immune suppression, and increased disease susceptibility. Selenium (Se) and zinc (Zn), in dietary supplementation, offer easy, cost-effective, and efficient ways to neutralize the toxic effect of AFB1. In the current review, we discussed the impact of AFB1 on poultry industry, its biotransformation, and organ-specific noxious effects, along with the action mechanism of AFB1-induced toxicity. Moreover, we explained the biological and detoxifying roles of Se and Zn in avian species as well as the protection mechanism of these two trace elements. Ultimately, we discussed the use of Se and Zn supplementation against AFB1-induced toxicity in poultry birds.

Hypocholestrolic effect of spent black tea leaves replaced with wheat bran in broiler ration.

Black tea leaves (Camellia sinensis) have been known for many years in lowering cholesterol level. The purpose of the present study was to find the effects of spent black tea leaves as a substitute of wheat bran on cholesterol reduction in broiler chicks. For this purpose a total of hundred & fifty (150), day old broiler poultry chicks were purchased from the local market. The spent black tea leaves were collected from tea stalls. Chicks were randomly distributed into 5 main groups according to spent black tea leaves and wheat bran supplementation. Group R0 was kept as control, containing 120 g/kg wheat bran but no spent black tea leaves supplementation; group R30 received spent black tea leaves supplemented feed at the rate of 30 g/kg plus 90 g/kg wheat bran; group R60 received spent black tea leaves supplemented feed at the rate of 60 g/kg plus 60 g/kg wheat bran, group R90 received spent black tea leaves supplemented feed at the rate of 90 g/kg plus 30 g/kg wheat bran and group R120 received the spent black tea leaves supplemented feed at the rate of 120 g/kg plus 0 g/kg wheat bran respectively. Each group was carrying three replicate (10 chicks/replicate). The data was statistically analyzed, using completely randomized design. Mean liver cholesterol per chick on diet R30, R60, R90, and R120 was 102.22, 93.55, 76.22, 60.78 and 51.55 mg/100 g. Breast cholesterol per chick on diet R30, R60, R90, and R120 was 61.89, 51.33, 44.78, 37 and 32.77 mg/100 g. It was concluded that the addition of spent black tea leaves at the rate of 120 g/kg has significant effect on cholesterol reduction and over all performance of broiler chicks and recommended that expensive wheat bran can be effectively replaced by these spent black tea leaves in broiler poultry ration.

Reduction of nitrogen excretion and emission in poultry: A review for organic poultry.

Organic poultry is an alternative to conventional poultry which is rapidly developing as a response to customers' demand for better food and a cleaner environment. Although organic poultry manure can partially be utilized by organic horticultural producers, litter accumulation as well as excessive nitrogen still remains a challenge to maintain environment pureness, animal, and human health. Compared to conventional poultry, diet formulation without nitrogen overloading in organic poultry is even more complicated due to specific standards and regulations which limit the application of some supplements and imposes specific criteria to the ingredients in use. This is especially valid for methionine provision which supplementation as a crystalline form is only temporarily allowed. This review is focused on the utilization of various protein sources in the preparation of a diet composed of 100% organic ingredients which meet the avian physiology need for methionine, while avoiding protein overload. The potential to use unconventional protein sources such as invertebrates and microbial proteins to achieve optimal amino acid provision is also discussed.

Biomassa de Rubrivivax gelatinosus na criação de frangos de corte: desempenho animal e cor dos produtos / Biomass of Rubrivivax gelatinosus in broiler chicken feeding: animal performance and color of products

A bactéria Rubrivivax gelatinosus tem sido utilizada experimentalmente no tratamento despoluente de efluentes industriais de abatedouros de aves e peixes, originando uma biomassa contendo pigmentos carotenoides, substâncias que possuem a capacidade de conferir cor aos alimentos e proteger contra reações oxidativas. Este trabalho teve por objetivo verificar o efeito da biomassa de R. gelatinosus adicionada à alimentação de frangos de corte sobre o desempenho animal e a cor de carne e pele. Duzentos pintos machos Cobb 500 foram distribuídos aleatoriamente em 20 boxes para receber, do 36º ao 45º dia de criação, quatro tratamentos com diferentes quantidades de biomassa na ração (T1 [controle] - 0g/kg; T2 - 1g/kg; T3 - 2g/kg; T4 - 3g/kg), em cinco repetições. As pesagens de aves e rações para a análise de desempenho foram feitas no início da criação e ao fim de cada período de crescimento. Ao final do experimento (45 dias), 20 aves de cada tratamento foram abatidas para a determinação da cor objetiva (L - luminosidade, C - saturação, h - tom) em pele e carne de peito e coxa. Os resultados obtidos foram submetidos à ANOVA, teste t para a comparação múltipla de médias e análise de regressão com nível de significância de 5%. O ganho de peso e o consumo das aves não diferiram estatisticamente entre si (P>0,05), enquanto o índice de conversão alimentar foi superior para o T1. A luminosidade da carne e da pele aumentou significativamente nos tratamentos que receberam a biomassa. O tom da cor em carne e pele aumentou em direção ao amarelo até a concentração de 2g de biomassa por kg de ração, ao passo que, na concentração de 3g/kg, o aumento foi em direção à tonalidade vermelha. Somente na carne da coxa a saturação da cor sofreu influência da presença da biomassa na dieta. Concluiu-se que, até a proporção de 3g/kg, a biomassa não prejudicou o desempenho e foi eficiente em pigmentar a pele e a carne de frangos de corte...

The phototrophic bacterium Rubrivivax gelatinosus has been used experimentally for the depollution of industrial effluents from broiler and fish slaughterhouses, resulting in a biomass containing oxycarotenoids, substances that impart color and protection against to oxidative reactions. This work aimed to check the effect of R. gelatinosus biomass added into broiler chickens' feed on animal performance and meat/skin color. Two hundred Cobb 500 male chicks were randomly divided into 20 boxes to receive, from the 36th to the 45th day of rearing, 4 treatments with different amounts of biomass in the diets (T1 [control] - 0g/kg; T2 - 1g/kg; T3 - 2g/kg; T4 - 3g/kg), in 5 replicates. Chickens and rations were weighted at the beginning of the rearing time and at the end of each growth phase to assess animal performance. At the end of the experiment (45 days), 20 birds from each repetition were slaughtered for the evaluation of the objective color (L - lightness, C - chroma, h - hue) on skin and meat of breast and thigh. Statistical analyses comprised ANOVA, t test for means comparison and regression analysis, at 5% significance level. Weight gain and feed consumption did not differ statistically (P>0.05), while feed conversion was better for T1. Lightness of meat and skin increased significantly in the treatments with the biomass supplementation. Hue angle of meat and skin increased towards yellow until 2g biomass/kg and towards red at 3g/kg. Chroma was only influenced by the presence of the biomass in thigh meat. It was concluded that the addition of the biomass up to 3g/kg was not harmful to birds' performance and was efficient to cause changes in the color of broiler skin and meat...