Juliana Beatriz Toledo

Reduction of the crude protein content of diets supplemented with essential amino acids for piglets weighing 15 to 30 kilograms

Two experiments were carried out to evaluate the reduction of crude protein (CP) in diets supplemented with synthetic amino acids for piglets of 15 to 30 kg. In the performance assay (Exp I), 60 piglets with initial weight of 15.34±0.87 kg and final weight of 30.08±1.59 kg were distributed in a randomized block design with six replicates, five treatments and two animals per experimental unit. The treatments consisted of five diets in which the CP was reduced by 1.5 percentage points, resulting in low-protein diets (19.24, 17.74, 16.24, 14.74 and 13.24%), meeting the requirements of amino acids with inclusion of L-lysine, DL-methionine, L-threonine, L-tryptophan, L-valine and L-isoleucine. The average daily gain and feed conversion according to the Linear Response Plateau model (LRP) were estimated at 14.23 and 14.79% of CP, respectively. As the CP levels were reduced, there was an increase in the essential:non-essential amino acids ratio. The plasma urea concentration decreased linearly, indicating that there was a better use for amino acids with the CP reduction. In the nitrogen balance (Exp II), 30 crossbred barrow piglets with average weight of 21.69±4.46 kg were housed in metabolic cages, distributed in a completely randomized design with five treatments and six replicates, and the experimental unit consisted of a piglet. The biological protein value in the diets remained above the ideal (70%), in which the level of 13.24% CP corresponded to the highest value. There was no difference in levels of urea in blood and urine. Reduction of protein levels is efficient in decreasing the pollution effect in the excreta, with lower nitrogen excretion in feces and urine.

Glicerinas semipurificadas na alimentação de suínos nas fases de crescimento e terminação (30-90 kg)

Dois experimentos foram conduzidos com o objetivo de determinar o valor nutricional e avaliar o desempenho e caracteristicas de carcaca de suinos na fase de crescimento-terminacao, alimentados com racoes contendo dois tipos de glicerinas semipurificadas, uma de oleo vegetal (GSPV) e uma mista de oleo de soja + gordura animal (GSPM). No ensaio de digestibilidade (experimento I) foram utilizados 32 suinos mesticos, machos castrados, com 45,08 ± 4,11kg. Foram utilizados tres niveis de inclusao (6; 12 e 18%) de glicerina semipurificada (GSPV e GSPM) na dieta referencia. A energia metabolizavel (EM) das glicerinas foi estimada pela analise de regressao do consumo de EM (Kcal/kg) associada a glicerina vs. o consumo de glicerina (kg). Os valores de EM (Kcal/kg) obtidos foram: 2.731 para GSPV e 2.210 para GSPM. No Experimento II, 72 suinos (30,08 ± 1,65kg a 60,58 ± 3,57kg) na fase de crescimento e (60,83 ± 2,63kg a 93,79 ± 5,72kg) na fase de terminacao, foram distribuidos em delineamento inteiramente ao acaso, em esquema fatorial 2 x 4 + 1, sendo dois tipos de glicerina semipurificada (GSPV e GSPM), quatro niveis de inclusao (4; 8; 12 e 16%), oito unidades experimentais e uma racao testemunha, nao contendo glicerina (0%). Todos os suinos foram abatidos para determinacao das caracteristicas da carcaca. Os resultados de desempenho sugerem que e viavel a utilizacao em ate 16% de ambas as glicerinas na alimentacao de suinos em crescimento e terminacao, sem prejuizos no desempenho e caracteristicas de carcaca.

Levedura de cana-de-açúcar spray dry na alimentação de suínos na fase de crescimento e terminação

ABSTRACT The nutritional value of two spray dry yeast (sugar cane – SCYSD and brewer+sugar cane – BYSD) and their inclusion effects on growing and finishing pigs feeding was studied. The DE (kcal/kg) values for SCYSD and BYSD were 3.496 and 3.901 and for ME (kcal/kg) they were 3.475 and 3.862. The values of digestible lysine, methionine+cistine and threonine for SCYSD and BYSD were: 2.66 and 2.64%; 1.11 and 1.03%: 1.95 and 1.92%. 40 pigs with initial weight of 34.39±7.57kg (growing) and 62.45±5.68kg (finishing), allotted in a completely randomized design with five levels of SCYSD inclusion were used in the performance assay. In the growing phase, there was an impairing on DWG and F:G, however, in the finishing phase, DFI presented a quadratic effect, being 3.32% the best level and linear reduction of DWG, F:G, slaughter weight, hot carcass weight, cold carcass yield and ham weight. The results suggest that increasing levels of SCYSD may impair the performance of growing and finishing pigs. Keywords: Brewer yeast, by-product, digestible amino acids, ileal canula, nutritional value

Digestible tryptophan requirements of meat quails in the growth phase

The objective of this experiment was to estimate the digestible tryptophan (DTrp) requirements for growing meat quails. In the first experiment (1-14 days of age), 1,950 quails were distributed in a completely randomized design, with six levels of DTrp (0.27; 0.30; 0.33; 0.36; 0.39 and 0.42% of diet), five replications and 65 quails per experimental unit. There was a linear increase of feed intake, tryptophan intake, weight gain and body weight with the DTrp levels increase. In the second experiment (15-35 days of age), 1,350 quails were distributed in a completely randomized design, with six levels of DTrp (0.22; 0.25; 0.28; 0.31; 0.34 and 0.37% of diet), five replications and 45 quails per experimental unit. There was a linear increase for tryptophan intake, carcass yield, ash levels and protein deposition rate with the DTrp levels increase. In the third experiment (28-35 days of age), conducted to determine the nitrogen balance, 150 males were housed in galvanized wire cages featuring drinker, feeder and individual metal tray lined with plastic to collect the excreta. The design was completely randomized, with six levels of DTrp (0.22; 0.25; 0.28; 0.31; 0.34 and 0.37% of diet), five replicates and five quails per experimental unit. Linear decrease was observed on the nitrogen balance and metabolization coefficient with the DTrp levels increase. The nutritional requirement of digestible tryptophan for maximum growing of meat quail, in the period from 1 to 14 days of age, is higher or equal to 0.42%; in the period from 15 to 35 days, it is 0.22%.

Suplementação de aminoácidos essenciais em dietas de baixo nível proteico para leitões: Revisão

In swine, the development of animal nutrition and a better understanding of protein metabolism makes it possible to optimize diets that meet nutritional requirements in protein and amino acids with a lower environmental impact. Proteins are essential nutrients that exhibit a variety of biological functions, participating primarily in muscle deposition, aiding in hormonal regulation and obtaining energy, and overeating or deficiencies of these can be reflected in plasma concentrations of variables such as urea, total proteins And creatinine which are considered good indicators to analyze the process of degradation of amino acids in the body. At present, the formulation of rations with an ideal profile of amino acids in addition to decreasing the nitrogen excretion allows to reduce the percentage of crude protein without affecting the performance variables of zootechnical importance. The objective of this review is to contribute to a better knowledge and understanding of the importance of essential amino acids in pig feed.

Aminoácidos de cadeia ramificada na alimentação de suínos: Revisão

Protein is the component that most interferes with animal growth, influencing parameters such as weight gain, daily feed intake and feed conversion ratio. This organic component consists of polymerized units of amino acids, which are classified as essential and non-essential amino acids. The branched-chain amino acids (leucine, valine and isoleucine) are part of the group of essential amino acids characterized by their branched chain structure, they are oxidized as fuel mainly by the muscular, adipose, renal and encephalic tissues, having the ability to directly influence the synthesis of protein, in addition to having a synergistic effect with insulin to stimulate the uptake of glucose by the cells. These characteristics are of interest to nutritionists who aim to optimize diets for pigs that meet the nutritional requirements of animals, improving production parameters and avoiding excess ingredients in diets to reduce environmental pollution. The objective of this review is to facilitate the knowledge and importance of branched chain amino acids in nutrition pigs.

Method of using increasing levels of substitution of the basal diet by test feedstuffs in pig digestibility trials

Two experiments were carried out to study the methodology of using increasing levels of substitution of the basal diet with fibrous test feedstuffs (sticky coffee hull - SCH) in digestibility trials with pigs. In Experiment 1, a digestibility trial was conducted using 30 crossbred barrows, allotted in a randomized block design. In Experiment 2, 42 growing and 42 finishing pigs were used, allotted in a completely randomized design, with six diets and seven replicates, with one animal per experimental unit. The six diets consisted of: a control diet, four diets using SCH ME values as obtained in Experiment 1 plus a diet using SCH ME value estimated by linear regression equation for 15% substitution. The digestibility study indicated that the use of increasing levels of substitution (7, 14, 21 and 28%) reduced SCH digestibility. ME values, as-fed basis, were 2,456, 2,377, 2,247 and 1,945kcal/kg. The overall results indicate that higher levels of substitution overestimate the energy value and that the method of increasing levels of substitution of the basal diet with feedstuffs test can be used to more accurately estimate the energy values of fibrous feedstuffs for pigs. For growing and finishing pigs respectively, up to 28% and 15% of sticky coffee hull can be used without impairing pig performance and economic feasibility.

Avaliação nutricional de soja integral desativada e desempenho de leitões na fase de creche

Two experiments were carried out to determine the nutritional value and to verify the piglets performance from 6 to 15kg, fed diets with two types of disabled whole soybeans characterized by shell presence (CS) or not (SS). In the digestibility assay 15 castrated male piglets were used, with average weight of 7.36±1.71kg, housed in metabolism cages. Except for gross energy (EB), no differences between treatments were observed for the dry matter digestibility, crude protein, ether extract and organic matter, and for the coefficient of metabolism of EB between the two soybeans evaluated. The values of digestible energy (DE), as well the metabolizable energy (ME) on fed basis for SC and SS were: 3,979 and 4,300kcal/kg, 3,768 and 4,111kcal/kg, respectively. In the performance experiment 56 weaned piglets were used, at 21 days of age with initial body weight of 6.19±0.67kg. No differences were observed in the performance variables with the inclusion of SS and SC disabled soybeans in the diets, concluding that the studied soybeans can be used for piglet diets.