Horacio Santiago Rostagno

Utilização do alho (Allium sativum L.) como promotor de crescimento de frangos de corte

Three experiments were carried out to evaluate garlic in broilers diets as growth promoter. In the first experiment 480 one day old chicks, sexed, were distributed in six treatments with eight replicates (four with males and four with females), with ten birds each. The treatments were: basal diet with corn , soybean meal and dicalcium phosphaate (RB1), RB1 + 0.2% garlic; RB1 + 0.4%garlic; RB1 + 0.6%garlic, RB1 + 0.01% lincomicin and RB1 + 0.0025% zinc bacitracin. In the second experiment 240 one day old chicks were distributed in three treatments with eight replicates (four with males and four with females), and ten birds each. The treatments were: basal diet with corn, soybean meal and bone and meat meal (RB2), RB2 + 0.2% garlic and RB2 + 0.4%garlic. In the third experiment 120 females broilers were used, raised up to 42 days of age, distributed in three treatments, as described for the second experiment. In all experiments feed intake, weight gain and feed convertion rate were evaluated. In the first and second experiments small intestine weight was also evaluated. There were no significant effects of tratments on the evaluated charactheristics in the three experiments. The birds presented normal performance, suggesting that the conditions they were raised were not suitable to get response due the utilization of growth promotors.

Níveis dietéticos de proteína bruta para frangos de corte de 1 a 21 e 22 a 42 dias de idade

Two experiments were carried out to determine the ideal levels of crude protein (CP) for Ross broiler chickens from one to 21 and 22 to 42 days of age, of both sexes. The parameters evaluated were weight gain (WG), feed intake (FI), feed:gain ratio (F/G) and carcass evaluation (CV). In the starting phase (1 to 21 days of age), different protein levels (20.00; 20.50; 21.00; 21.50; 22.00 and 22.50%) were used in diets containing 1.27% total lysine. In growing phase (22 to 42 days of age), the dietary protein levels were 17.50; 18.00; 18.50; 19.00 and 19.50% with 1.16% total lysine. In both experiments, were maintained ratio lysine: methionine+cystine, threonine, tryptophan and arginine, considering the ideal protein profile. In both experiments, a completely randomized block experimental design, in a 2x6 and 2x5 (two sexes and six or five dietary lysine levels) factorial arrangement, was used, with six replicates, using a total of 1440 and 1200 birds, respectively. Considering bird performance, the dietary CP requirement estimate from 1 to 21 days, for the males was 22.42% CP, while the females showed linear effect for WG and F/G. In the growing phase (22 to 42 days of age), the protein levels affected linearly males FI, F/G, breast yield and abdominal fat. Females showed quadratic effect for WG and linear effect for F/G and abdominal fat. The requirements of the crude protein estimates for male and female, respectively were: 22.4 and 22.5% CP for starting phase and 19.5 and 18.5% CP growing phase.

Exigência nutricional de treonina digestível para galinhas poedeiras no período de 34 a 50 semanas de idade

With the objective to establish the nutritional requirement of threonine for light and semi-heavy laying hens in the period from 34 to 50 weeks old, 580 laying hens (half Lohmann and half Lohmann Brown) submitted to a basal ration containing 2.850 kcal ME/kg, 14.0% CP, supplemented of five levels (0.00, 0.035, 0.07, 0.105, and 0.140%) of L-threonine, in order to provide 0.410, 0.445, 0.480, 0.515, and 0.550% of digestible threonine in the rations. A 5 x 2 (threonine level and [...]

Uso de prebióticos à base de mananoligossacarídeo em rações para frangos de corte

O experimento foi realizado com objetivo de estudar o uso de mananoligossacarideos (standard e concentrado) em racoes para frangos de corte. Foram utilizados 1.080 pintos de corte machos da marca Ross, com peso medio inicial de 42 g, distribuidos em um delineamento inteiramente ao acaso, com seis tratamentos e nove repeticoes de 20 aves por unidade experimental. As aves foram criadas em cama de maravalha reaproveitada, utilizada anteriormente por outro lote. Foram testados os tratamentos: testemunha, antibiotico (avilamicina), mananoligossacarideo alta concentracao (MOS AT), mananoligossacarideo standard (MOS ST), MOS AT + avilamicina e MOS ST + avilamicina para avaliacao do ganho de peso, do consumo de racao, da conversao alimentar, da viabilidade e do rendimento de cortes. No periodo de 1 a 21 dias de idade, nao foram encontradas diferencas significativas entre os tratamentos para as variaveis consumo de racao, conversao alimentar e viabilidade economica. Os resultados de desempenho das aves alimentadas com racao contendo MOS ST ou MOS AT, combinados ou nao com o antibiotico, nao diferiram dos obtidos nos tratamentos com avilamicina e da racao basal. No periodo de 1 a 42 dias de idade, a adicao de MOS ST, combinado ou nao com avilamicina, melhorou o ganho de peso das aves, enquanto o MOS AT afetou de forma negativa o ganho de peso. A conversao alimentar, o consumo de racao e a viabilidade economica nao foram influenciados pelos tratamentos. No entanto, o uso de aditivos em racoes para frango de corte melhorou o rendimento de cortes e reduziu a gordura abdominal.

Composição Química e Valores de Energia Metabolizável das Farinhas de Penas e Vísceras Determinados por Diferentes Metodologias para Aves

Uma serie de experimentos foi realizada com o objetivo de estabelecer o valor nutritivo de nove farinhas de visceras e de seis farinhas de penas para aves. Quatro diferentes metodologias foram utilizadas para determinar os valores de energia metabolizavel aparente corrigida (EMAn) e verdadeira corrigida (EMVn): metodo tradicional (com pintos e galos) e metodo de Sibbald (com galos inteiros e galos cecectomizados). Os valores de EMAn e EMVn da farinha de visceras estimados variaram de 3.051 a 3.621 e de 2.866 a 3.583 kcal/kg, respectivamente. Para a farinha de penas os valores variaram de 2.952 a 3.629 e de 2.703 a 3.671 kcal/kg para a EMAn e EMVn, respectivamente. Entre as metodologias realizadas para determinacao dos valores energeticos dos alimentos, as correlacoes foram baixas, portanto, as diferencas nos valores energeticos dos alimentos podem ser atribuidas a metodologia empregada.

Exigência de fósforo disponível para frangos de corte machos e fêmeas de 1 a 21 dias de idade

Ninety and sixty Hubbard one-day-old broilers chicks, half male and half female, were used at the initial phase, from 1 to 21 days of age, with initial weight of 42.5 and 42.1g, respectively. The chicks were allotted to a randomized block design, with six treatments, two sexes, four replicates per sex and twenty animals per experimental unity. The treatments consisted on deficient basal diet in available phosphorus (.15%), supplemented with available phosphorus from dicalcium phosphate (0, 0.10, 0.20, 0.30, 0.40, and 0.50%). The weight gain (GP), feed intake (CR), feed: gain (CA), bone fracture resistance (BFR), ashes (AO) and phosphorus in the bone (PO) were the evaluated variables. The available phosphorus requirements were estimated by means of the regression polynomial and linear response plateau models. The supplemented levels of available phosphorus affected the GP, CR, CA, BFR, AO and PO, for males and females. The requirement estimates of available phosphorus ranged from 0,259 (.089%/Mcal ME) to .559% (.184%/Mcal of ME), for males and from .307% (.092%/Mcal ME) to .575% (.190%/Mcal ME) for females. However, according to the biological values, for the performance and bone variables, it can be suggested that available phosphorus requirements, for male and female broilers, from 1 to 21 days of age, is .45% or .148%/Mcal ME.

Metabolizable energy values of feedstuffs obtained from poultry at different ages

Four assays were carried out to determine the apparent metabolizable energy (AME) and the corrected apparent nitrogen metabolizable energy (AMEn) of ten feeds for poultry at different poultry ages. The feeds studied were: corn grain, soybean meal, ground sorghum, wheat bran, integral rice bran, two kinds of feather meal, two kinds of poultry viscera meal and spray-dried plasma. The method of total excreta collection was used to determine the AME and AMEn values. The broiler chicks were distributed on a completely randomized experimental design, with 11 treatments, six replications, with different number of animals by replication according to the assay. In the first assay, 528 male broiler chicks in the period from 10 to 17 days of age were used, with eight animals per replication. In the second assay, 396 male broiler chicks in the period from 26 to 33 days of age were used, with six animals per replication. In the third assay, 264 male broiler chicks in the period from 40 to 47 days of age were used, with four animals per replication. In the fourth assay, 132 roosters were used, with two animals per replicate. There was an effect of age on the AME and AMEn values of the following feeds: soybean meal, ground sorghum, integral rice bran, two kinds of feather meal and spray-dried plasma, where the oldest broilers provided the highest AME and AMEn values. Wheat bran was affected by age only for the AMEn values.

Valores de energia metabolizável de alimentos determinados com frangos de corte

The chemical composition, the apparent metabolizable energy (AME) and apparent metabolizable energy corrected by nitrogen (AMEn) of six feed of vegetal origins were determined by the total excreta collection method. A total of 252 male broiler chicks of the lineage Ross with 21 days of age were distributed in a completely randomized experimental design, with seven treatments (one basal reference diet and six test diets), six replicates and six birds per experimental unit. The evaluated feeds were: corn (CO), high oil corn (HOC), whole corn germ meal (WCGM), toasted whole soybean (TWSB), soybean hulls (SH), high protein soybean meal (HPSM) with 50% crude protein. The evaluated feeds were included in the diets-test in 40% and 25% of the reference diet, for the energy and protein feeds, respectively. The values of AME, in kcal/kg of as fed, for the feeds CO, HOC, WCGM, TSB, SH and HPSM were 3.402, 3.627, 3.019, 3.419, 814 and 2.070 and the AMEn values were: 3.393, 3.595, 2.935, 3.279, 741, and 1.984, respectively.

Níveis dietéticos de lisina para frangos de corte de 1 a 21 e 22 a 40 dias de idade

Two experiments were carried out to determine the nutritional requirement of total lysine for Ross broiler chickens from one to 21 and 22 to 40 days of age, of both sexes. The parameters evaluated were weight gain, feed intake, feed conversion and carcass evaluation. In each experiment, a completely randomized experimental design, in a 2 x 6 (two sexes and six dietary lysine levels) factorial arrangement with six replicates, using a total of 1440 birds, was used. The basal diets with 1.03% total lysine, 22.0% CP and 3000 kcal ME/kg in the first experiment and 0.92% total lysine, 20.0% CP and 3150 kcal ME/kg in the second experiment, suplemented with six levels pure lysine (0.0; 0.06; 0.12; 0.18; 0.24 and 0.30%), were used. Considering weigth gain and feed conversion, the dietary requirement estimates for the experiment from 1 to 21 days were 1.303 and 1.249% total lysine and 1.183 and 1.129% digestible lysine for males and females, respectively. For the experiment from 22 to 40 days, the performance and evaluation carcass values were 1.164 and 1.143% total lysine and 1.044 and 1.023% digestible lysine for males and females, respectively.

Efeito da temperatura ambiente e da restrição alimentar sobre o desempenho e a composição da carcaça de frangos de corte

The objective of this experiment was to study the effects of environmental temperature and feeding restriction programs on performance, carcass and noble cuttings yields and fat, water and protein contents of the carcass, and also the liver glycogen content of broiler chickens under different environmental conditions. A completely randomized block experimental design, in a 5 x 2 (feeding program versus sex) factorial arrangement with two replicates within each environmental and 14 birds per experimental plot, was used. At 42 days of age, the temperature and sex negatively affected the intake and weight gain, but the feeding restriction program did not affect them. Temperature, feeding restriction programs and sex did not affect the carcass and noble cutting yields. The feeding restriction programs and the temperature did not affect the carcass fat, water and protein contents. As for sex, the females presented the highest fat contents in the carcass. The glycogen liver contents were negatively affected by the feeding restriction programs and by the sex, however were not affected by the temperature.