Estimate of choline nutritional requirements for chicks from 1 to 21 days of age.

Choline is an essential nutrient in poultry diets because it performs various important metabolic functions. The objective of this study was to re-evaluate the choline requirements of male broiler chickens from 1 to 21 days of age at two levels of methionine. Two assays using 2,160 Cobb® chickens (1,080 in each assay) were conducted. The study design was completely randomized and consisted of six treatments and six replicates, with 30 animals per experimental unit. The semipurified basal diet was formulated with corn, soya bean meal, soya protein concentrate, starch and sugar, providing 390 mg/kg choline and 0.593% digestible methionine (requirement level) in Assay 1 and a reduction of about one-quarter in the requirement level of digestible methionine (0.440%) in Assay 2. Choline chloride (62.5%) was added by a supplementation technique to both basal diets to compose crescent levels of choline supplementation (715, 1,040, 1,365, 1,690 and 2,015 mg/kg). The weight gain responses were fitted using quadratic polynomial (QP) and broken-line (BL) models. The ideal intake of choline (mg/bird.day) was estimated from the first intercept of the QP with the BL plateau (BL + QP). The results showed that the diet with the 25% reduction in digestible methionine limited the maximum weight gain by approximately 10%. The choline requirements of broilers from 1 to 7, 1 to 14 and 1 to 21 days of age were 27,013, 44,458 and 62,535 mg/bird.day, respectively, for the requirement level of digestible methionine and 26,796, 41,820 and 56,578 mg/bird.day for the broilers receiving the diet with the 25% reduction in digestible methionine.

Optimal in-feed amino acid ratio for broiler breeder hens based on deletion studies.

An ideal amino acid ratio (IAAR) for breeder hens is needed for maximum nitrogen retention (NR) taking into account nitrogen deposition in body (NDB ), feathers (NDF ) and egg mass (NEM) to improve dietary protein efficiency. Thus, the aim of this study was to apply the deletion method to derive the IAAR for broiler breeder hens. The nitrogen balance trials were performed from 31 to 35 weeks and from 46 to 50 weeks. Twelve treatments with eight replicates and one hen per cage were used. A balanced diet (BD) was formulated to meet the requirement of all nutrients. The other diets were formulated diluting 55% of BD with corn starch and refilled with amino acids (AAs) and other ingredients, except the AA tested. Each trial lasted 25 days. Feather losses, egg production and egg weight were recorded daily, and the samples were stored to further determine NEM and nitrogen in feather losses (NDFL ). At the start and the end of each period, a group of birds were slaughtered to further determine NDB and NDF . The NR was calculated as the sum of NDB , NDF , NDFL , NEM and the nitrogen maintenance requirement (NMR). The deletion of valine greatly depressed the NR in peak production (31 to 35 weeks) while the deletion of the isoleucine greatly depressed the NR of the hens from 46 to 50 weeks of age. The percentual reduction in NR and the per cent of the AA to delete from the BD were used to calculate the AA requirement. The average IAAR was Lys 100, Met+Cys 86, Trp 23, Thr 80, Arg 113, Val 90, Ile 91, Leu 133, Phe+Tyr 108, Gly+Ser 94 and His 35. The IAAR was in line with the recommendation from the literature, validating deletion method with the advantages from a rapid and low-cost procedure.

Maintenance valine, isoleucine, and tryptophan requirements for poultry.

Poultry maintenance requirements for valine, isoleucine, and tryptophan were measured by nitrogen balance using different unit systems. The nitrogen balance trial lasted 5 d with 48 h of fasting (with roosters receiving only water+sucrose) and the last 72 h for feeding and excreta collection. Forty grams of each diet first-limiting in valine, isoleucine, or tryptophan was fed by tube each day (3 d) to give a range of intakes from 0 to 101, 0 to 119, and 0 to 34 mg/kg BW d of valine, isoleucine, and tryptophan, respectively. A nitrogen-free diet containing energy, vitamins, and minerals, meeting the rooster requirements, was offered ad libitum during these three d. To confirm that the amino acids studied were limiting, a treatment was added with a control diet formulated by adding 0.24 g/kg of L-valine, 0.21 g/kg of L-isoleucine, and 0.10 g/kg of L-tryptophan to the diets with lower amino acid level. Excreta were collected during the last 3 d of the balance period and the nitrogen content of the excreta was analyzed. For each amino acid, a linear regression between nitrogen retention (NR) and amino acid intake was performed. The equations from linear regression were: NR=-98.6 (±10.1)+2.4 (±0.2)×Val, NR=-46.9 (±7.1)+2.3 (±0.1)×Ile, NR=-39.5 (±7.7)+7.3 (±0.4)×Trp; where Val, Ile, and Trp are the intakes of valine, isoleucine, and tryptophan in mg/kg body weight per d, respectively. The valine, isoleucine, and tryptophan required to maintain the body at zero NR were calculated to be 41, 20, and 5 mg/kg body weight per d, respectively. For the system unit mg per kg of metabolic weight, the intake of valine, isoleucine, and tryptophan was 59, 32, and 9, respectively. Considering the degree of maturity of the animal and body protein content (BPm (0.73)×u), the amounts of valine, isoleucine, and tryptophan required for maintenance were calculated to be 247, 134, and 37 mg per unit of maintenance protein (BPm (0.73)×u) per d. Maintenance requirement is more adequately expressed as body protein content.

Establishing an essential amino acid profile for maintenance in poultry using deletion method.

This study aimed to estimate the essential amino acid profile and the ideal ratio for the maintenance of poultry by deletion method. A nitrogen balance (NB) trial was conducted using 198 adult roosters, housed individually in metabolic cages. The treatments were 33 purified diets being 11 diets with an amino acid mixture providing high protein intake of 500 mg N/BWkg (0.75) per day, 11 diets providing medium protein intake of 250 mg N/BWkg (0.75) per day (in each diet, one amino acid tested was diluted 50%) and 11 diets providing low protein intake of 125 mg N/BWkg (0.75) per day (made by omitting the amino acid tested). Each treatment had six replicates. After 48 h of fasting receiving water plus sucrose, the roosters were fed 40 g of the diets by tube once a day for 3 days. The excreta were collected within 72 h after the first feeding. The diets and excreta were analysed for nitrogen content. For each amino acid studied, a linear regression was fitted by NB and amino acid intake (AAI). The maintenance requirements were estimated as the AAI to maintain the NB equal to zero. The daily amino acid requirements for maintenance were estimated to be Lys 11, Met 29, Thr 23, Trp 5, Arg 50, Val 29, His 6, Gly 54, Phe 49, Leu 78 and Ile 21 mg/BWkg (0.75) per day. Therefore, the amino acid ratio for maintenance was concluded to be Lys 100, Met 276, Thr 220, Trp 48, Arg 467, Val 275, His 60, Gly 511, Phe 467, Leu 735 and Ile 198% independent of the scale. The essential amino acid profile and the ideal ratio for the maintenance of poultry estimated in this study contributed to improve the factorial model for estimating essential amino acid requirements for poultry.

A low-cost fermentation medium for thermophilic protease production by Streptomyces sp. 594 using feather meal and corn steep liquor.

Protease production by Streptomyces sp. 594 was obtained after submerged fermentation (SF) and solid-state fermentation (SSF) using feather meal (FM) and corn steep liquor (CSL) as sole sources of carbon and nitrogen. Enzyme productions were 13.4 U ml(-1) in SF and 21.5 U g(-1) in SSF; these values were approximately 86% and 39% higher, respectively, than those obtained previously when yeast extract was used in place of CSL. The proteases, which belong to the serine and metalloproteinase classes, were active at high temperatures (55 degrees C to 90 degrees C) and over a wide range of pH values (5.0 to 10.0). Thus, these thermophilic proteases have shown interesting properties for industrial purposes. As far as we are concerned, this is the first contribution toward the microbial production of thermophilic proteases by a streptomycete using a low-cost medium composed of industrial poultry (FM) and corn processing by-products (CSL).

Thermophilic protease production by Streptomyces sp. 594 in submerged and solid-state fermentations using feather meal.

AIMS: Protease production by Streptomyces sp. 594 in submerged (SF) and solid-state fermentation (SSF) using feather meal, an industrial poultry residue, and partial characterization of the crude enzyme. METHODS AND RESULTS: Streptomyces sp. 594 produced proteases in SF (7.2 +/- 0.2 U ml(-1)) and SSF (15.5 +/- 0.41 U g(-1)), with pH increase in both media. Considering protease activity, values obtained in the liquid extract after SSF (6.3 +/- 0.17 U ml(-1)) were lower than those from SF. The proteases, which belong to serine and metalloproteinase classes, were active over a wide range of pH (5.0-10.0) and high temperatures (55-80 degrees C). Strain 594 was also able to degrade feather in agar and liquid media. Keratinase activity (80 U l(-1)) also confirmed the keratin degrading capacity of this streptomycete. CONCLUSIONS: Proteases produced using residues from poultry industry have shown interesting properties for industrial purposes. SIGNIFICANCE AND IMPACT OF THE STUDY: As far as we are concerned, this is the first contribution towards the production of thermophilic protease by a streptomycete in SSF using a keratinous waste.

[Non-adherence to tuberculosis treatment: a study on perceptions and knowledge of the disease and evaluation of health services from the patient perspective]. / Estudo de casos sobre abandono do tratamento da tuberculose: avaliação do atendimento, percepção e conhecimentos sobre a doença na perspectiva dos clientes (Fortaleza, Ceará, Brasil).

This research was developed in 1995-1996 in the Oliveira Pombo Health Center (CSOP), Fortaleza, Ceará, Brazil. The aim was to explore factors influencing non-adherence to tuberculosis treatment. Specific objectives were: dynamics of tuberculosis notification and treatment of non-adherence cases at the CSOP; demographic, social, economic, and cultural profiles of clientele (social actors); default reasons that interrupt treatment; and knowledge and perception of the disease. The methodological approach was based on descriptive epidemiology and on sociological interpretivism. A semi-structured interview was used for questions related to the social actors, such as: demographic, social, economic, cultural, and behavioral factors; knowledge and perceptions of tuberculosis and treatment; impact of the disease on patients' lives; and perspectives concerning health service attendance. Results show that treatment non-compliance involved multiple and complex interrelated factors.