title: Effects of dietary electrolyte balance and addition of electrolyte-betaine supplements in feed or water on performance, acid-base balance and water retention in heat-stressed broilers.
abstract: The effects of dietary electrolyte balance (DEB) and electrolyte-betaine (El-Be) supplements on heat-stressed broiler performance, acid-base balance and water retention were evaluated during the period 31-40 d of age in a 2 × 3 factorial arrangement of treatments. A total of 240 broilers were assigned to 6 treatment groups each with 8 replicates of 5 birds per cage and were exposed to cyclic high temperature (32 - 24 ± 1°C). Birds were provided with diets having DEB of either 180 or 220 mEq/kg. El-Be supplements were either added to the diet, water or not added to either of them to complete the array of 6 treatment groups. An additional 80 birds were kept at thermoneutral temperature (20 ± 1°C) and were provided with tap water and diets with DEB of either 180 or 220 mEq/kg to serve as negative controls. Exposure to high temperature depressed growth performance, increased rectal temperature and decreased potassium (K(+)) retention. In high-temperature room, birds fed on diets with DEB of 220 mEq/kg tended to increase BW from 35-40 d of age. However, at thermoneutral temperature, broilers fed on diets with DEB of 220 mEq/kg increased K(+) retention. Adding El-Be supplements in feed or water improved feed conversion ratio (FCR), enhanced water consumption and increased K(+) and sodium (Na(+)) retention. Interactions between DEB and El-Be supplements tended to affect body weight gain and FCR during the periods 35-40 and 31-40 d of age, respectively. It is suggested that when using a diet with DEB of 180 mEq/kg, adding the El-Be supplements in drinking water was more beneficial than in feed. Adding the supplements in feed or water was equally useful when using DEB of 220 mEq/kg.
authors.affiliation: a Faculty of Agriculture , Assiut University , Assiut , Egypt.
authors.forename: M A M
authors.initials: MA
authors.lastname: Sayed
authors.forename: J
authors.initials: J
authors.lastname: Downing
mesh_terms: D000136:Acid-Base Equilibrium; D000821:Animal Feed / Q000032:analysis; D000824:Animal Nutritional Physiological Phenomena; D000818:Animals; D001622:Betaine / Q000008:administration & dosage / Q000378:metabolism*; D001831:Body Temperature; D002645:Chickens / Q000254:growth & development / Q000502:physiology*; D004032:Diet / Q000662:veterinary; D019587:Dietary Supplements; D004305:Dose-Response Relationship, Drug; D004573:Electrolytes / Q000008:administration & dosage / Q000378:metabolism*; D018869:Heat-Shock Response; D008297:Male; D008460:Meat / Q000032:analysis; D014867:Water / Q000378:metabolism
chemical_list: D004573:Electrolytes; D014867:Water; D001622:Betaine