Dietary electrolyte balance for broiler chickens exposed to thermoneutral or heat-stress environments

Abstract

Ross male broiler chicks (n = 480) on new litter were used in a randomized block design with two blocks (environmental rooms) and four treatments having four replicate pens (1.0 x 2.5 m; 15 chicks) each to evaluate dietary electrolyte balance (DEB; P < 0.05). Two rooms were 1) thermoneutral (Weeks 1 through 6, with decreasing maximum from 32 to 25 degrees C and minimum from 28 to 19 degrees C; relative humidity 49 to 58%) and 2) cyclic daily heat stress (Weeks 1 and 2, thermoneutral; Weeks 2 through 6, maximum temperatures 35, 35, 33, and 33 degrees C, respectively; and minimum temperatures 23, 20, 19, and 19 degrees C, respectively; relative humidity 51 to 54%). The DEB treatments (0, 140, 240, or 340 mEq Na + K - Cl/kg) had NaHCO3 plus NH4Cl, or KHCO3, or both added to corn-soybean meal mash basal diets with 0.30% salt (NaCl). In the thermoneutral room, DEB 240 increased 42-d weight gain and 44-d lymphocyte percentage and decreased heterophil percentage and heterophil to lymphocyte ratio compared to the DEB 40 treatment. The DEB 240 diets had 0.35 and 0.35% Na and 0.37% and 0.29% Cl in starter (0.75% K) and grower (0.67% K) diets, respectively. No DEB treatment differences were found in the heat stress room. For combined rooms, 42-d feed intake was higher for DEB 240 than for DEB 40. The 21-d weight gain was higher for DEB 240 than for DEB 40 or 140; and 21-d feed/gain was lower for DEB 40 than for DEB 340. The predicted maximum point of inflection for 21- and 42-d weight gains were DEB 250 and 201, with highest 42-d feed intake at 220.

Electrolyte balance in diets with reduced protein for semi-weighted laying hens in the second production cycle

“…Imbalances in the electrolyte supplementation in the diet cause reduced appetite with weight gain and death when the compensatory mechanisms are not sufficient to maintain acid-base homeostasis (Borges, 2003b). When imbalances are not compensated, they increase mortality (Mongin, 1981).…”

Aplicação estratégica do balanço eletrolítico em dietas para matrizes pesadas

“…Segundo MONGIN (1981), quando o balanço ácido-base é desviado da homeostase para o estado de alcalose ou acidose, vias metabólicas podem ser alteradas, ficando mais envolvidas na regulação da homeostasia do que no crescimento ou produção do animal. Esses desbalanços na suplementação eletrolítica podem causar morte quando mecanismos compensatórios não são suficientes para manter a homeostase ácido-base (BORGES et al, 2003). Esta variação pode ocorrer tanto pelo excesso de prótons, como pelo excesso de sódio, descrito no trabalho de JUNQUEIRA et al (1980), como pelo excesso de ânions.…”

Balanço eletrolítico para suínos machos castrados em crescimento mantidos em ambiente de alta temperatura

“…Conforme Borges et al (2003), animais submetidos a continuado estresse por calor, têm aumento da frequência respiratória, resultando em perdas excessivas de dióxido de carbono, que conduz a diminuição da pressão de CO 2 , levando a queda na concentração de ácido carbônico e hidrogênio. Isso caracteriza a ocorrência de alcalose respiratória, em razão da excessiva eliminação de dióxido de carbono.…”