Arginina para matrizes suínas primíparas em lactação

With the emergence of new genetic lines due to intense breeding improvement on swine production in recent years, there is the need to adapt more accurately diets for the current sows, which have higher nutritional demands. The use of functional amino acids aimsto optimize the sows production and among these amino acids arginine has excelled. Arginine is involved in several important metabolic pathways, for example, it serves as a substrate forsynthesis of protein, creatine, nitric oxide, polyamines, citrulline, agmatine, ornithine, proline, and glutamate. It also helps to stimulate the secretion of some hormones such as insulin, prolactin, and growth hormone.As arginine plays such important roles, its supplementation has been suggested in lactation feed once it may enhance the development of the mammary gland and milk nutritional profile, thus, providing a better piglet development.Thus, the objective was to evaluate the effect of lactation feed supplementation with L-Arginine on the productive performance of primiparoussows and their respective litter.One hundred forty sows from the same genetic lineage on a commercial farm, located in the city of Oliveira, MG were used in this study, in a completely randomized design with five treatments: control diet without amino acid supplementation and four diets with increasing levels of L-Arginine supplementation (containing 98.5% purity) - 0.5, 1.0, 1.5, and 2.0%. Each treatment hadtwenty-eight swine sows, and the experimental unit was the sowand its litter.It was used ‘on top’ amino acid supplementation.All data was submitted to variance analysis using the SAEG Software: version 9.1 (SAEG, 2005).The data relating to days of lactation were compared by Tukey test (5%). L-Arginine supplementation levels in lactation feed did not influence (P>0.05) average daily feed intake, body condition variables, and blood parameters of the sows (urea, creatinine, and non-esterified fatty acids) as well as it did not affect the dry matter, crude protein, and amino acid profile of milk and the litter performance. There was effect (P<0.05) of days of lactation on the percentage of crude protein and amino acids in milk, which reduced througout the days of lactation. The L-Arginine supplementation on the lactation diet at levels of 0.5, 1.0, 1.5, and 2.0% did not influence the sow and its respective litter performance.

Estabilidade da fitase e sua utilização na alimentação de frangos de corte

This work was designed to evaluate the effect of storage forms and conditions upon the enzyme activity of phytase and bioavaibility of calcium and phosphorus in broiler diets. The work was accomplished in two steps. The first step, made in the laboratory measured the activity of the phytase enzyme along the storage period. In this step, two experiments were performed: Experiment 1, constituted of 5 treatments (pure phytase stored at 0 °C, 4 °C and environmental temperature and mixed to vitamin and mineral supplement, stored at environmental temperature) in CRD and split plot scheme. The activities were evaluated every 14 days for 112 days of storage, being verified that the phytase storage in the pure form at 0o C was superior to the other treatments. Experiment 2, made up of 4 treatments (phytase mixed to the ration directly, directly and afterwards pelleted, via mineral supplement and via vitamin supplement),all the treatments being stored at environmental temperature, in CRD and split plot scheme. The activities were evaluated every 7 days for 56 days' storage, being verified that the storage of the phytase mixed to the ration via vitamin supplement and directly with the ration pelleted later, provoked a fall in phytase activity when compared with the other treatments. In the second step, the effect of phytase on the bioavaibility of calcium and phytic phosphorus was evaluated, 2 experiments being accomplished (3 and 4); in both experiments were utilized 576 broiler line chicks, housed in an array of heated batteries, receiving practical diets on the basis of corn and soybean meal (basal) for 21days. At the end of 27 days of age,96 birds were slaughtered for evaluation of the mineral contents (Ca and P) in the tíbias and plasma phosphorus. The excretae were collected from 22 to 27 days of age of the birds. Experiment 3: A CRD with the treatments in 2 x 3 x 2 +4 factorial arrangement was utilized, namely, two levels of total phosphorus (0.35 and 0.45% of total phosphorus), three leveis of phytase (500, 750 and 1,000 FTU) and four additional treatments with levels of 0.35 and 0.45 % of available phosphorus for each sex, with three replicates per treatment. There was significant interaction among levels of phosphorus and phytase (P< 0.05) for weight gain, ration consumption and feed conversion. Phytase did not indicate significant differences when the level 0.45% was utilized, nevertheless, at the level 0.35% as phytase was supplemented, weight gain, ration consumption and feed conversion were improved, chiefly with 1,000 FTU/Kg, in both sexes. The males presented greater weight gain. The ration consumption and feed conversion were equal to those of females. The contrast 0.45% did not affect the performance of males and females, the same not occurring with the level 0.35%,at which the available phosphorus was superior in both the sexes. The highest contents of ashes, phosphorus and calcium in the tíbias and plasma phosphorus were obtained with the levels of 750 and 1,000 FTU/Kg of phytase and 0.45% of total phosphorus. The males presented higher contents of ashes in the tibias. The level 0.45% of available phosphorus presented the greatest contents of ashes, calcium and phosphorus in the tibias, and phosphorus in the plasma. The lowest excretions of phosphorus occurred at the levels 0.35% of total phosphorus and 1,000FTU/kg of phytase. The lowest contents of ashes and calcium in the excretae were obtained with 0.35% and 1,000FTU/Kg of phytase. The females excreted smallest amounts of ashes, calcium and phosphorus than the males. Experiment 4: a CRD with the treatments in 3 x 4 x 2 factorial arrangement, namely, three levels of phytase (0, 500 and 1,000 FTU), four levels of calcium (0.7, 0.8, 0.9 and 1.0%) with four replicates per treatment. The performance was not affected by the treatments utilized, the males being superior to the females in weight gain, feed consumption and conversion. The contents of ashes in the tibias were not affected by the levels of phytase but as calcium levels raised, the ash contents increased. The contents of calcium and phosphorus in the tibias increased with the supplementation of 500 and 1,000 FTU/kg of phytase and with calcium levels. The utilization of phytase did not decrease the excretion of ashes, calcium and phosphorus.