ESTIMATION OF TOTAL BODY WATER IN SHEEP AND GOATS USING ANTIPYRINE FOR DETECTION OF HEAT ADAPTABILITY COEFFICIENT

ABSTRACT
Information on the body water of the live sheep and goats is important
for research either the research involves nutrition, physiology, genetic, disease
or meat production. Body weight alone provides a poor index of the
metabolically active tissue or the mass of tissue available for meat. Live body
weight including total solids and total body water. Water retention is known to
vary considerably between animals during growth due to differences in the rate
of accumulation of the less hydrated, fat, collegen and fibrous tissues in
replacement of the more hydrated functioning protoplasmic mass and to the age
difference in response to nutritional and climatic factors. Chemical analysis of
the whole bodies of animals is a tedious, time-consuming and expensive
operation. The high cost of animal analysis have created an interest in indirect
methods of estimating body water. Indirect methods also can provide repeated
estimates of body composition for the same animal whereas slaughter and
chemical analysis obviously can only be done once. Estimating the total body
water using antipyrine in live sheep and goats and consequently detection of the
heat adaptability coefficient can be done by any one from the 3 techniques as
following:
1 - Total body water (TBW) using Antipyrine dilution technique: The
percentage increase in TBW due to heat stress conditions may be used as index
for heat tolerance coefficient (HTC) as following: HTC =100 - [TBW2 -TBW1 /
TBW1 x 100] where TBW1 and TBW2 are the total body water during
thermoneutral (TN) and hot (HS) climates, respectively. The most heat tolerant
animals are those with the highest values.
2 - Total body solids (TBS) (Live body weight-TBW): Total body solids loss
due to heat stress which includes lean body mass and body fat may be used as
HTI. TBW is determined using Antipyrine before and after heat exposure and
each value subtracted from the corresponding live body weight to obtain TBS at
TN and HS climates as following: HTC = 100 – [TBS at TN –TBS at HS /
TBS at TN x 100]
3 -TBW/ TBS ratio: The heat induced changes in TBW (ml) / TBS (g) as heat tolerance index in
animals. Daily body weight gain (DBWG) had significantly negative correlation with TBW /
TBS as follows:
DBWG = 920.4 – 252.2 x TBW / TBS {r = - 0.8925, P < 0.002}