Dietary Electrolyte Balance Influences Endogenous Amino Acid Losses in Broilers25 April 2014
Losses of essential amino acids in the ileum of broiler chickens were significantly affected by dietary electrolyte balance (DEB) but not by the ratio of corn starch to dextrose in the experimental diets in a new study at Purdue University.
The objective of a Purdue University study reported in the current issue of Poultry Science was to determine the effect of nitrogen-free diets formulated with two ratios of corn starch and dextrose and two levels of dietary electrolyte balance (DEB; calculated as Na+K–Cl−, in mEq per kg of diet) on ileal endogenous amino acid (EAA) losses in 48-day-old broiler chickens.
Adedokun and Applegate explain that, on day 43, 240 broiler chickens were allotted to four dietary treatments with six replicate cages per diet in a completely randomised design.
Each experimental diet was fed for five days (days 43 to 48). All diets were free of nitrogen with two ratios of corn starch-to-dextrose (0.31 and 1.04) and two levels of DEB (108 and 219mEq per kg of diet).
Final bodyweight and bodyweight loss between birds fed the two corn starch-to-dextrose ratios and between birds fed two levels of DEB were not different (P>0.05).
Birds fed the diet containing a high level of DEB consumed less (P<0.05) feed than birds on the low-DEB diet. Birds on the high-corn starch-to-dextrose (1.04) diet showed a tendency for higher (P=0.08) feed intake.
High dietary dextrose level (corn starch-to-dextrose ratio of 0.31) resulted in higher (P<0.05) ileal dry matter and energy digestibility.
A high level of DEB resulted in higher (P<0.05) ileal endogenous nitrogen loss. Arginine, isoleucine, leucine, phenylalanine, valine, alanine, glutamine, glycine, proline and tyrosine secretion into the gut increased (P≤0.05) with an increasing level of DEB.
Endogenous histidine, lysine, threonine, aspartamine, cystine and serine showed a tendency for increased (P≤0.1) losses with a high level of DEB.
Mean ileal EAA losses for the indispensable and dispensable amino acids for the low-DEB diet were 81 and 82 per cent, respectively, that of the birds fed the high-DEB diet.
The four amino acids with the lowest endogenous flow were methionine, histamine, tyrosine and cystine, whereas the highest endogenous flow was found in glutamine, aspartamine, valine and leucine.
Adedokun and Applegate concluded data from their study showed that EAA losses in the ileum of broiler chickens are significantly affected by DEB but not by the ratio of corn starch to dextrose.
Adedokun S.A. and T.J. Applegate. 2014. Dietary electrolyte balance influences ileal endogenous amino acid losses in broiler chickens. Poultry Science. 93(4):935-942. doi: 10.3382/ps.2013-03661
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