J. Radünz Neto

The impact of feeding growing-finishing pigs with daily tailored diets using precision feeding techniques on animal performance, nutrient utilization, and body and carcass composition.

The impact of moving from conventional to precision feeding systems in growing-finishing pig operations on animal performance, nutrient utilization, and body and carcass composition was studied. Fifteen animals per treatment for a total of 60 pigs of 41.2 (SE = 0.5) kg of BW were used in a performance trial (84 d) with 4 treatments: a 3-phase (3P) feeding program obtained by blending fixed proportions of feeds A (high nutrient density) and B (low nutrient density); a 3-phase commercial (COM) feeding program; and 2 daily-phase feeding programs in which the blended proportions of feeds A and B were adjusted daily to meet the estimated nutritional requirements of the group (multiphase-group feeding, MPG) or of each pig individually (multiphase-individual feeding, MPI). Daily feed intake was recorded each day and pigs were weighed weekly during the trial. Body composition was assessed at the beginning of the trial and every 28 d by dual-energy X-ray densitometry. Nitrogen and phosphorus excretion was estimated as the difference between retention and intake. Organ, carcass, and primal cut measurements were taken after slaughter. The COM feeding program reduced (P < 0.05) ADFI and improved G:F rate in relation to other treatments. The MPG and MPI programs showed values for ADFI, ADG, G:F, final BW, and nitrogen and phosphorus retention that were similar to those obtained for the 3P feeding program. However, compared with the 3P treatment, the MPI feeding program reduced the standardized ileal digestible lysine intake by 27%, the estimated nitrogen excretion by 22%, and the estimated phosphorus excretion by 27% (P < 0.05). Organs, carcass, and primal cut weights did not differ among treatments. Feeding growing-finishing pigs with daily tailored diets using precision feeding techniques is an effective approach to reduce nutrient excretion without compromising pig performance or carcass composition.

Teores de proteína bruta em dietas práticas para juvenis de carpa capim

The response of grass carp (Ctenopharyngodon idella) juveniles to crude protein (CP) levels in practical diets was evaluated in an experiment with 120 juveniles and 80 days of feeding. The diets containing porcine meat meal, soybean meal, corn and wheat meal, with 22, 30, 36, or 44% CP. Ten juveniles (153.0±1.5 g) per tank (850L) were fed twice daily with pelleted feed (3% of biomass). Linear effect of CP on final weight, weight gain, specific growth rate, carcass and fillet yield, coefficient of protein retention, protein efficiency rate, deposition of fat and protein, and hematocrit were observed. It was also observed effect on triglycerides and total cholesterol in blood, indicating that dietary protein was being used as energy source. Feed conversion ratio and fat content in whole fish showed quadratic effect, with maximum points at 40.6 and 37.1% CP, respectively. The best CP content for grass carp in growing phase was 44%, and the variation of protein content in diet changed the metabolism of grass carp juveniles, reflected in blood and carcass parameters.

Desempenho reprodutivo de fêmeas de jundiá alimentadas com diferentes fontes protéicas

Two trials were carried out to evaluate the reproductive performance of jundia females fed during 71 days with different protein sources. In the first trial soybean meal was associated to meat and bone meal (CS), sugar cane yeast (LS) and fish meal (PS). In the second trial the effect of replacement of meat and bone meal by soybean meal was evaluated to the levels 0, 35 and 70% of the CS diet (CS0, CS35 e CS70, respectively). The spawning of females were induced with carp hypophysis extract. In the trial 1, embryonic development was higher in the eggs from females fed CS and PS. In the trial 2, embryonic, vitelinic and larval development were higher in CS0 treatment. This concluded that meat and bone meal and soybean meal used as protein sources showed good option in the feeding of reproductive jundia females.

Enzimas digestivas de juvenis de carpa capim alimentados com forragem e ração

Objetivou-se avaliar a atividade de enzimas digestivas de 240 juvenis (20,15±0,23 g) de carpa capim (Ctenopharyngodon idella) alimentadas com capim teosinto e racao durante 45 dias e criados em sistema de recirculacao de agua, composto por 12 tanques (20 peixes/tanque). Os tratamentos foram: C= somente capim teosinto; SD= capim teosinto+racao diariamente (3% PV); SA= capim teosinto+racao a cada dois dias (3% PV); R= somente racao (3% PV). Apos o periodo de alimentacao, 6 peixes por tratamento foram aba- tidos para analise (na porcao anterior e posterior do trato) das enzimas digestivas amilase, maltase, tripsina e quimiotripsina. Tambem foram avaliados os pesos do figado, do trato digestorio, comprimento do trato e ganho em peso relativo. A associacao de capim e racao, diariamente, resulta em maior peso do figado, ganho em peso relativo e menor atividade de maltase. A atividade de amilase, o peso e comprimento do trato digestorio nao variaram (p>0,05). A atividade das proteases alcalinas e menor quando juvenis de carpa capim sao alimentadas exclusivamente com racao.

Crescimento de juvenis de jundiá (Rhamdia quelen) com diferentes proporções de amilose:amilopectina na dieta

The growth and carcass traits of jundia (Rhamdia quelen) after 60 days being fed with different amylose:amylopectin ratio in diet were evaluated. Two hundred and forty fish (initial weight of 34.3±4.3g) were raised in water re-use system with 12 units of 280L. Three diets were tested with amylose:amylopectin ratios: T417 = 26% amylose, T416 = 16% amylose and TMOCHI = 0% amylose. The fish were fed twice a day at 8:30 and 16:00h. Every 15 days the amount of food offered was ajusted. The amylose:amylopectin ratio in the starch of the diet did not affect growth, carcass and body composition of fish. This demonstrates that the jundia has the potential to use starchy sources consisting of up to 26% amylose without altering the digestibility of nutrients and fat deposition.