|Genre:||Health and Food|
|Published (Last):||2 October 2008|
|PDF File Size:||18.45 Mb|
|ePub File Size:||16.29 Mb|
|Price:||Free* [*Free Regsitration Required]|
Email: hederdavila yahoo. Background: methionine is considered essential for maintenance, growth, and feather development. Methionine supply during the growth phase can influence the weight at sexual maturity and egg size. A basal diet formulated to meet all nutrient requirements was added with graded levels of DL-methionine replacing glutamic acid. A quadratic effect was observed for feed conversion and uniformity at 40 days of age, and percentage of feathers did not vary. A linear increase occurred in the laying phase for feed intake and weight gain of the birds.
No effects of the assessed ratios were observed on the other variables. Conclusion: a 0. Keywords: Coturnix japonica , ideal protein, productive performance, sulfur amino acids. Antecedentes: la metionina es esencial para el mantenimiento, crecimiento y desarrollo de las plumas. O fornecimento nutricional de metionina durante a fase de crescimento pode influenciar fatores como peso corporal para maturidade sexual e tamanho do ovo.
Quail farming is very important for providing jobs and producing high quality protein at a low cost. Nutrition during the growing phase of the birds can influence their performance during the production phase. Most research has focused on the nutritional requirements of quails during the laying phase and there is little information about requirements during the growing phase.
Quails are characterized by early sexual maturity 40 days , demanding feeding programs that maximize growth by combining body development with sexual maturity, thus allowing uniformity of breeding stock and productivity Pinto et al. The ideal protein concept implies feeding the best ratios between lysine and other amino acids, thus reducing the crude protein content of the diet.
This is possible due to the availability of industrial amino acids in the market. Methionine, the first limiting amino acid for quails Mandal et al. High protein ingredients e. Nevertheless, this practice increases production costs, deviate amino acids for functions not related to growth, worsens environmental conditions, and increases pollution.
The use of synthetic amino acids is an interesting alternative to minimize those problems Silva and Costa, A total of one-day-old female Japanese quails Coturnix japonica were used body weight 7. The experimental unit consisted of 20 birds per cage, with 10 replicates. One sixty-watt light bulb was placed in each cage to warm the birds until they reached 15 days of age.
The cages were set inside a shed. They were made of galvanized wire and covered and managed under a raffia curtain for the first 15 days of the birds' life to keep the place warm. This was also achieved by hanging curtains on the laterals of the shed. One glass pressure drinker was installed per cage. Quails were guided to the water right after being housed. The glass pressure drinkers were replaced by nipple drinkers at 12 days of age. One tray feeder diameter: 18 cm was used per cage until birds were 12 days of age and was then replaced by a gutter feeder placed in the front of the experimental units.
The units had 24 hours a day of artificial light with the same light bulbs used for warmth until birds were 15 days old. Then, only natural light was provided until birds were 40 days old to avoid premature sexual maturity. Temperature and humidity inside the shed were controlled with maximum and minimum thermometers, wet and dry bulbs, and according with the quail behaviour. Temperature was recorded at p. The diets were iso-caloric and iso-nitrogen. When quails reached 40 days they had their beaks trimmed before moving them to egg laying cages.
Birds were moved to laying cages at 41 days of age keeping the same birds from each experimental unit together to evaluate growth and development during the laying phase.
The experimental units were 50 x 34 cm galvanized wire cages in a ladder arrangement, equipped with gutter feeders in the front section and corresponding nipple drinkers. The stocking density per experimental unit was Light was provided 16 hours a day during the experimental period. Light supply was controlled with a timer, allowing the lights to be turned on and off at night and early morning, in accordance with common procedures in commercial poultry farms.
Temperature and humidity inside the shed were daily recorded. The quails were fed a single diet based on corn and soybean Table 2 in the laying phase. This diet was formulated to meet the nutritional requirements proposed by Rostagno et al. Feed intake was weekly measured and the average intake of died birds was subtracted to calculate the real consumption per experimental unit. All birds were weighed at the beginning and at the end of the growing phase and at the laying phase to determine weight at 40 and days, and weight gain in each phase.
Mortality was daily recorded to determine bird viability in the growing and laying phases. On reaching 40 days, two birds that were within the average weight of each experimental unit were slaughtered. Birds were dry-plucked and feathers were weighed for feathering calculations. Next, birds were eviscerated, cooled, frozen, and ground to determine the contents of dry matter, ether extract and crude protein according to the AOAC Body fat and protein deposits were calculated by slaughtering an additional group of 50 one-day-old quail.
They were compared to body fat and protein deposits of the quail slaughtered at the end of the growing phase.
For the calculation of body fat and protein deposits, the value found in the sample was compared with the average weight of the live animal in each experimental unit, according to Pinto et al. All the intact eggs produced per replicate in the last three days of each week were weighed and total weight was divided by the number of eggs weighed. The average weight of eggs was multiplied by the total number of eggs produced in the period.
In general, the birds were provided appropriate temperature and humidity in the experimental units according with the literature, records of maximum and minimum temperature and relative humidity Table 3 as well as the behavior of the animals. Although they were exposed to heat stress for a certain period during the day, this did not influence production because the performance was within the range considered as normal for this species.
This limit was not exceeded in the experimental units after birds presented complete feathering, thus preventing them from any potential negative environmental influence on performance. Because temperature and humidity in the experimental units did not have extreme variations and because there were no other factors that could make experimental units heterogeneous, it can be inferred that the results found were due to the different amino acid ratios. Low ratios were related to low weight of the animals, increased feed ingestion, and greater weight gain during the production phase.
Therefore, at the end of the growing period, lighter birds had greater diet intake during the laying stage, resulting in a compensatory gain with greater feed intake so all birds reached a similar weight at days of age.
Similarly, Pinto et al. According to these authors, a ratio lower than 0. Total dietary protein and amino acids such as cystine, methionine, arginine, isoleucine, leucine, valine, lysine, serine, threonine, histidine, phenylalanine, tyrosine, and tryptophan are associated to feather formation.
A deficiency in crude protein could result in deficient feathering of birds. This allows us to infer that the protein reduction in this study with amino acids supplementation in isonitrogenic diets did not affect maintenance and feathering.
Although a similar response was noted in this study, the best result for feathering was obtained using a lower ratio than that required for weight gain and feed conversion. Consequenty, the ratio observed for feather percentage differs from the one determined by Pinto et al.
Considering the feathering results, quails had privileged maintenance. Since methionine is an important sulfur amino acid in the translation of messenger RNA, being the first amino acid incorporated in the N-terminal position of all proteins, methionine requirement for maintenance and synthesis of feather proteins is as important as the need for body protein synthesis.
Quails fed greater ratios presented better development and weight gain, resulting in greater carcass weight and carcass protein deposition, which was also followed by greater fat deposition.
Pinto et al. The 0. Thus, quails fed diets with the lowest ratios delayed to start the egg-laying phase, presenting a production equal to the others only from the third production week. Feed conversion per dozen eggs was worst for quails fed the lowest ratios 0. The best ratio for uniformity of quails was 0. This ratio is higher than 0. In conclusion, the 0. The authors declare they have no conflicts of interest with regard to the work presented in this report.
Ideal ratio of digestible methionine plus cystine to digestible lysine for growing Japanese quails. Rev Colomb Cienc Pecu ; Official methods of analysis, 17nd ed. Leeson S, Summers JD.
Commercial poultry nutrition. Guelph Ontario : University Books Publishers; Diferentes pesos corporais ao final da fase de recria sobre o desempenho produtivo de codornas japonesas.
Encicl Biosf ; Effect of enzyme supplementation on the metabolizable energy contento of solventextracted rapeseed and sunflower seed meals for chicken, guinea fowl and quail. Br Poult Sci ; Nutrient requirements of poultry. Oliveira BL.
Lavras: UFLA; Rev Bras de Zoot ; Reis LFSD. Lisboa: Agros Publishers; Version 9. Cary: SAS Institute, Tabelas para codornas japonesas e europeias.
La Cria de Codornices: Coturnicultura. (Registro nro. 22230)