Prediction of heat production in Boer goats using heart rate

TitlePrediction of heat production in Boer goats using heart rate
Publication TypeConference Proceedings
Year of Conference2012
AuthorsPuchala, R, Goetsch, AL, Manley, A, Gipson, TA, Sahlu, T
Conference NameXI International Conference on Goats
Pagination70
Abstract

Measurement of heart rate (HR) is often used to predict heat production (HP) by livestock in settings with unrestricted movement. Because of differences among individual animals in factors such as stroke volume that affect cardiac output, most accurate prediction of HP from HR is achieved by application of HP:HR determined for each individual animal. However, measurement of HP:HR is time consuming and requires considerable equipment. Therefore, it is of interest to determine the decrease in accuracy from predicting HP based on the average HP:HR of a group of animals. In this regard, HR of 163 Boer goat bucks was used to predict HP based on the HP:HR for each animal vs. the average (5.63 ± 0.098 kJ/kg BW0.75 per heart beat). Average body weight and age of bucks were 41.5 ± 0.68 kg and 164 days, respectively. Animals consumed a 50% concentrate pelleted diet ad libitum (1.56 ± 0.426 kg/d) during two buck performance tests, 84 days in length. HP:HR was determined once over a 1 day period while in metabolism cages with a head-box respiration calorimetry system to measure O2 consumption and production of CO2 and CH4. HR was measured at the same time using a Polar RS 400 monitoring system (Polar Electro, Lake Success, NY). HP predicted based on the average HP:HR was moderately correlated with that based on individual HP:HR (r = 0.55; P