G.S.S. Corrêa

Efeito de antibiótico e probióticos sobre o desempenho e rendimento de carcaça de frangos de corte

A completely randomized design with five replicates and 150 chicks per experimental unity were used to evaluate the effect of growth promoters on feed intake, weight gain and feed:weight gain ratio of broilers. The experimental diets were: 1- initial diet (20.2% of crude protein and 2931kcal of metabolizable energy) from 1 to 20 days of age (ID) and final diet (18.5% of crude protein and 2993kcal of metabolizable energy) from 21 to 40 days of age (FD); 2- ID plus 0.02% of Calsporin10 probiotic and FD plus 0.02% of Calsporin10 probiotic; 3- ID plus 2.0% of probiotic Estibion and FD plus 0.63% of probiotic Estibion; 4- ID plus 0.013% of Zinc bacitracin and FD plus 0.013% of Zinc bacitracin. During the initial period broilers fed on probiotic diets showed lower feed intake and better feed:weight gain ratio. However growth promoters have no effect on the studied traits in the final and total periods. Higher thigh yields were observed for male fed on poliprobiotic diets.

Uso de redes neurais artificais na predição de valores genéticos para peso aos 205 dias em bovinos da raça Tabapuã

Data from 19,240 Tabapua animals from 152 farms located in different states of Brazil, born from 1976 to 1995, were used to predict the genetic value of body weight at 205 days of age (BV_P205) of Tabapua beef cattle using Artificial Neural Networks (ANN) and LM algorithm - Levenberg Marquardt training for data entry. Due to the use of networks with supervised learning, the predicted breeding values for P205 from BLUP were used as desired output. The breeding values for P205 obtained from RNA and those predicted by BLUP were highly correlated. The ranked breeding values for body weight at 205 days through RNA and those predicted by BLUP (VG_P205_RNA) showed a variation in the classification of animals indicating risks in the use of ANNs procedure for genetic evaluation of this trait. Insertions of new animals require new training data always dependent on BLUP.

Efeito da interação idade da matriz x peso do ovo sobre o desempenho de codornas de corte

The effect of female breeder age x egg weight interaction was evaluated on the performance of meat type quails (Coturnix coturnix coturnix) at 21st and 42nd days of age. For every female breeder age class (70, 205, and 280 days of age), 600 eggs were classified according to egg weight class (class 1: 11.0-12.9; class 2: 13.0-14.9, and class 3: 15.0-16.9g). A total of 225 quails of both genders, totaling 75 quails for every egg weight class were used in this study. A completely randomized experimental design with five replicates of 15 quails was used. The experimental diets were formulated to contain 28% crude protein and 2,900 kcal of metabolizable energy (ME). Weight gain, body weight, feed consumption, and weight gain: feed consumption ratio from hatch to 21st day and from hatch to 42nd day of age were recorded. Both egg weight and female breeder age classes affected body weight, weight gain, and feed consumption at 21st and 42nd days of age. Quails from heavier egg weight class and female breeder age classes 205 and 280 days of age showed higher performance (P<0.05). Quail viability was affected by egg weight class, i.e. quails from lighter eggs showed lower viability at 21st and 42nd days of life. Heavier eggs originated heavier quails at hatch (P<0.05)

Desempenho e características bioquímicas de leitões submetidos a dietas com aditivos probióticos, prebióticos, simbióticos e antibióticos

The experiment was conducted to evaluate the performance and biochemical parameters in weaned piglets using alternative supplements to replace antibiotics. A total of 480 male pigs were used, randomly distributed in delineation with five treatments. The feed was based on corn, soybean meal and a commercial core for piglets. The treatments were T1: diet without supplements or basal diet, T2: basal diet with antibiotics, T3: basal diet with added probiotic, T4: basal diet with added probiotic and T5: basal diet with addition of symbiotic. In the experiment we evaluated performance characteristics, body weight, weight gain, feed intake and feed conversion. In the second part of the experiment, we evaluated the biochemical parameters of piglets used in the first experiment, fifty blood samples, ten samples of each treatment, were taken, and after separation of the clot, the serum was frozen at -20°C. Subsequently we analyzed the serum levels of total protein, albumin, globulin, albumin/globulin, ALP, creatinine, alanine aminotransferase, aspartate aminotransferase, gamma glutamyltransferase, cholesterol, urea, calcium, phosphorus and calcium/phosphorus ratio. No significant differences in biochemical parameters or in the performance of piglets submitted to different diets were found.

Exigência de metionina + cistina para codornas de corte durante a fase de crescimento

The effect of the methionine+cystine level on the performance of European quail during two phases in the growing period (from hatch to 21 days of age and from hatch to 35 days of age) was evaluated in a completely randomized experimental design with six levels of total methionine+cystine (.73; .79; .85; .91; .97 and 1.03%), and four replicates and 12 quails per experimental unit. Body weight, weight gain, feed intake and feed:weight gain ratio were evaluated in both phases. Significant and quadratic effects of methionine+cystine on the performance traits recorded from hatch to 21 days of age were observed. The highest body weight and weight gain and lowest feed intake and feed:weight gain ratio were estimated for quails fed .95% and .94% diets. Significant and quadratic effects of metionine+cystine on body weight, weight gain and feed intake from hatch to 35 days of age were estimated for quails fed .93%; .93%; and .94% diets, respectively. Weight gain methioninine+cystine requirement from hatch to 21 days is .95%, and from hatch to 35 days of age is .93%.

Exigência de fósforo disponível para suínos machos castrados selecionados para deposição de carne magra, dos 30 aos 60kg

An experiment was carried to determine available phosphorus requirement of crossbred barrows (Agroceres-Pic), using 60 animals in a completely randomized block design with five dietary treatments - 0.1; 0.2; 0.3; 0.4; and 0.5% of available phosphorus, six replicates, and two animals per experimental unit. On the 21st day of the experiment and at its end, blood samples were collected from orbital plexus of fasting animals to analyze and register alkaline phosphatase and serum phosphorus values. Quadratic effect of available phosphorus level on average daily gain, daily feed intake, serum phosphorus on the 21st day of the experiment, serum phosphorus at the end of the experiment, and feed conversion ratio were observed. Minimum feed conversion ratio was estimated for animals fed diets containing 0.39% available phosphorus. There was a linear effect of available phosphorus level on daily phosphorus intake, alkaline phosphatase on the 21st day and alkaline phosphatase at the end of the experiment. Dietary available phosphorus requirement for 30 to 60kg high lean barrows was 0.39%, which corresponds to an available phosphorus intake of 9.11g/day.

Cálcio, fósforo e proteína total no sangue de frangos de corte em função de níveis de balanço eletrolítico da ração

Determinaram-se os melhores valores do balanco eletrolitico (BE) de dietas para frangos quanto aos teores de calcio, fosforo e proteina total no sangue de frangos de corte aos 42 dias de idade. Foram utilizadas 1728 aves de marca comercial, machos. As aves foram alimentadas com duas dietas basais, 20 ou 23% de proteina bruta (PB), na fase inicial, e uma unica racao basal, 20% de PB, na fase de crescimento, combinadas com niveis de balanco eletrolitico de 0; 50; 100; 150; 200; 250; 300 e 350mEq/kg. Foi utilizado delineamento experimental inteiramente ao acaso, em arranjo fatorial, com seis repeticoes de 18 aves cada e 96 unidades experimentais. Foi escolhida uma ave em cada unidade experimental para a coleta de sangue. Foram avaliados os teores de calcio, fosforo e proteinas totais no sangue dessas aves aos 42 dias de idade. Os melhores valores de BE estimados para o teor de proteina total no sangue foram de 101 e 131mEq/kg da dieta, para planos nutricionais de 20-20% e 23-20% de PB, respectivamente. Para os teores plasmaticos de calcio e fosforo, nao foram encontradas diferencas entre os niveis de BE estudados.

Desempenho de frangos de corte alimentados com altos valores de balanço eletrolítico em região de clima quente

A trial was carried out to determine the best electrolyte balance value (EB) for broilers performance from 1 to 7, 1 to 14, 1 to 21 and 1 to 42 days of age. A total of 720 one-day-old chicks, males, were reared in the floor covered with shaving woods and fed corn-soybean base diets combined with 200; 250; 300; 350 e 400mEq/kg of EB. A completely randomized experimental design with six replicates of 24 chicks each and 36 experimental units was used. Weigh gain (WG), feed intake (FC) and feed efficiency (FE) were evaluated at 7, 14, 21 and 42 days of age. The best values of EB estimated for the WG at 21 and 42 days was 70mEq/kg, estimated by a quadratic regression model. No differences among treatments were observed for the other studied traits. The results suggested EB should be around 270 up to 300mEq/kg in high temperature regions, for broiler chicks in inicial and growth phases.

Teores de glicina+ serina total em dietas de baixa proteína bruta para de frangos de corte de 22 a 35 dias de idade

A completely randomized experimental design was carried out to evaluate the effects of total glycine+serine (gly+ser) levels in low crude protein (CP) diets on performance and body composition of male broiler from 22 to 35 days of age (growing phase). A total of 750 broilers were randomly allotted to five treatments and five replicates of 30 chickens per replication. The birds were fed from 1 to 21 days of age, a common diet formulated to meet bird requirements in all nutrients. From 21 days the diets contained 17% CP and gly+ser levels of 1.50; 1.75; 2.00 and 2.25%; and a control diet with 21%CP. The gly+ser levels showed linear effect on feed: weight gain ratio during the growing phase. There was no effect of gly+ser level on carcass or main carcass part yields. Increasing levels of gly+ser decreased linearly the carcass dry matter content.

Digestible lysine for broiler chickens with lower genetic potential grown on free-range system

Determining the actual lysine requirement is crucial as it is an essential amino acid and plays animportant role in the metabolism of broilers. In addition, it is the second limiting amino acid for broilers fed with rations formulated basedon corn and soybean meal. The aim of this study was to determine the digestible lysine requirement for male broilers with lower genetic potential for growth in a semi-confined system as well as to evaluate the effects of different values of digestible lysine on performance and carcass characteristics. A total of 300 broiler chickensfrom a commercial lineage EMBRAPA 041 were used with an average initial weight of 987 g. The broilers were distributed into 20 experimental units in a completely randomized design with five treatments (0.586; 0.746; 0.906; 1.066, and 1.226% digestible lysine), four replicates and 15 broilers per experimental unit.In both periods, there were linear effect of digestible lysine values on the lysine intake and lysine utilization efficiency and quadratic effect on final body weight, weight gain and feed: gain ratio.There was a quadratic effect on the absolute weight of carcasses, breast, thigh + drumstick and income gizzard.For rearing of male broilers with lesser genetic growth potential reared in semi-confinement, rations with 1.040% and 1.103% digestible lysine can be recommended for maximum weight gain in periods from 35 to 70 and 35 to 84 days of age, respectively.