TY - JOUR
T1 - Body weight estimation of yaks using body measurements from image analysis
AU - Yan, Qi
AU - Ding, Luming
AU - Wei, Haiyan
AU - Wang, Xianju
AU - Jiang, Cuixia
AU - Degen, Allan
N1 - Funding Information:
This work was supported financially by the Qinghai Provincial Science and Technology Major Project ( 2018-NK-A2 ), Qinghai Provincial Key R&D and Transformation Project ( 2018-SF-145 ), Key Lab Project of Qinghai Province ( 2013-Z-Y03 ) and the Fundamental Research Founds for the Central Universities ( lzujbky-2018-kb07 ).
Publisher Copyright:
© 2019 Elsevier Ltd
PY - 2019/7/1
Y1 - 2019/7/1
N2 - Traditionally, yaks graze only natural pasture on the Qinghai-Tibetan Plateau year around without any supplementary feed. Weighing these animals is extremely difficult because of the general wild nature of yaks and the lack of proper weighing equipment on the plateau. The aim of this study was to determine whether body measurements of yaks could be used to estimate their live body weight (LBW). Photographs were taken of 39, 52 and 55 yaks, aged 1 to 8 years, in summer (July), winter (November) and spring (April), respectively. Each yak was weighed and, from its photograph, withers height (WH), body diagonal length (BDL) and body side area (BSA) were calculated. Simple regression analyses between LBW and each of the linear measurements within each season were all highly significant and explained 78.3% to 94.6% of the variance in LBW. Multiple linear regressions between LBW and body measurements improved the predictive power within each season and explained 86.3% to 97.2% of the variance in LBW. We concluded that body measurements could be used to estimate LBW of yaks; to improve the estimate, calibrations of LBW on linear measurements should be done in each season.
AB - Traditionally, yaks graze only natural pasture on the Qinghai-Tibetan Plateau year around without any supplementary feed. Weighing these animals is extremely difficult because of the general wild nature of yaks and the lack of proper weighing equipment on the plateau. The aim of this study was to determine whether body measurements of yaks could be used to estimate their live body weight (LBW). Photographs were taken of 39, 52 and 55 yaks, aged 1 to 8 years, in summer (July), winter (November) and spring (April), respectively. Each yak was weighed and, from its photograph, withers height (WH), body diagonal length (BDL) and body side area (BSA) were calculated. Simple regression analyses between LBW and each of the linear measurements within each season were all highly significant and explained 78.3% to 94.6% of the variance in LBW. Multiple linear regressions between LBW and body measurements improved the predictive power within each season and explained 86.3% to 97.2% of the variance in LBW. We concluded that body measurements could be used to estimate LBW of yaks; to improve the estimate, calibrations of LBW on linear measurements should be done in each season.
KW - Image analysis
KW - Linear measurements
KW - Live body weight
KW - Regression model
KW - Yak
UR - http://www.scopus.com/inward/record.url?scp=85063868635&partnerID=8YFLogxK
U2 - 10.1016/j.measurement.2019.03.021
DO - 10.1016/j.measurement.2019.03.021
M3 - Article
AN - SCOPUS:85063868635
SN - 0263-2241
VL - 140
SP - 76
EP - 80
JO - Measurement: Journal of the International Measurement Confederation
JF - Measurement: Journal of the International Measurement Confederation
ER -