Predicting Ewe Body Condition Score Using Lifetime Liveweight and Liveweight Change, and Previous Body Condition Score Record
The body condition score (BCS) in sheep (<i>Ovis aries</i>) is a widely used subjective measure of body condition. Body condition score and liveweight have been reported to be statistically and often linearly related in ewes. Therefore, it was hypothesized that current BCS could be accur...
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| Format: | Article |
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MDPI AG
2020-07-01
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| Series: | Animals |
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| Online Access: | https://www.mdpi.com/2076-2615/10/7/1182 |
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| author | Jimmy Semakula Rene Anne Corner-Thomas Stephen Todd Morris Hugh Thomas Blair Paul Richard Kenyon |
| author_facet | Jimmy Semakula Rene Anne Corner-Thomas Stephen Todd Morris Hugh Thomas Blair Paul Richard Kenyon |
| author_sort | Jimmy Semakula |
| collection | DOAJ |
| description | The body condition score (BCS) in sheep (<i>Ovis aries</i>) is a widely used subjective measure of body condition. Body condition score and liveweight have been reported to be statistically and often linearly related in ewes. Therefore, it was hypothesized that current BCS could be accurately and indirectly predicted using a ewe’s lifetime liveweight, liveweight change, and previous BCS record. Ewes born between 2011 and 2012 (<i>n</i> = 11,798) were followed from 8 months to approximately 67 months of age in New Zealand. Individual ewe data was collected on liveweight and body condition scores at each stage of the annual cycle (pre-breeding, pregnancy diagnosis, pre-lambing, and weaning). Linear regression models were fitted to predict BCS at a given ewe age and stage of the annual cycle using a ewe’s lifetime liveweight records (liveweight alone models). Further, linear models were then fitted using previous BCS and changes in liveweight, in addition to the lifetime liveweight records (combined models). Using the combined models improved (<i>p</i> < 0.01) the R<sup>2</sup> value by 39.8% (from 0.32 to 0.45) and lowered the average prediction error by 10% to 12% (from 0.29 to 0.26 body condition scores). However, a significant portion of the variability in BCS remained unaccounted for (39% to 89%) even in the combined models. The procedures found in this study, therefore, may overestimate or underestimate measures by 0.23 to 0.32 BCS, which could substantially change the status of the ewe, leading to incorrect management decisions. However, the findings do still suggest that there is potential for predicting ewe BCS from liveweight using linear regression if the key variables affecting the relationship between BCS and liveweight are accounted for. |
| first_indexed | 2024-03-10T18:30:44Z |
| format | Article |
| id | doaj.art-8c2a59ee04604e4986f249b6ac853a3a |
| institution | Directory Open Access Journal |
| issn | 2076-2615 |
| language | English |
| last_indexed | 2024-03-10T18:30:44Z |
| publishDate | 2020-07-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Animals |
| spelling | doaj.art-8c2a59ee04604e4986f249b6ac853a3a2023-11-20T06:38:36ZengMDPI AGAnimals2076-26152020-07-01107118210.3390/ani10071182Predicting Ewe Body Condition Score Using Lifetime Liveweight and Liveweight Change, and Previous Body Condition Score RecordJimmy Semakula0Rene Anne Corner-Thomas1Stephen Todd Morris2Hugh Thomas Blair3Paul Richard Kenyon4School of Agriculture and Environment, Massey University, Private Bag 11222, Palmerston North 4410, New ZealandSchool of Agriculture and Environment, Massey University, Private Bag 11222, Palmerston North 4410, New ZealandSchool of Agriculture and Environment, Massey University, Private Bag 11222, Palmerston North 4410, New ZealandSchool of Agriculture and Environment, Massey University, Private Bag 11222, Palmerston North 4410, New ZealandSchool of Agriculture and Environment, Massey University, Private Bag 11222, Palmerston North 4410, New ZealandThe body condition score (BCS) in sheep (<i>Ovis aries</i>) is a widely used subjective measure of body condition. Body condition score and liveweight have been reported to be statistically and often linearly related in ewes. Therefore, it was hypothesized that current BCS could be accurately and indirectly predicted using a ewe’s lifetime liveweight, liveweight change, and previous BCS record. Ewes born between 2011 and 2012 (<i>n</i> = 11,798) were followed from 8 months to approximately 67 months of age in New Zealand. Individual ewe data was collected on liveweight and body condition scores at each stage of the annual cycle (pre-breeding, pregnancy diagnosis, pre-lambing, and weaning). Linear regression models were fitted to predict BCS at a given ewe age and stage of the annual cycle using a ewe’s lifetime liveweight records (liveweight alone models). Further, linear models were then fitted using previous BCS and changes in liveweight, in addition to the lifetime liveweight records (combined models). Using the combined models improved (<i>p</i> < 0.01) the R<sup>2</sup> value by 39.8% (from 0.32 to 0.45) and lowered the average prediction error by 10% to 12% (from 0.29 to 0.26 body condition scores). However, a significant portion of the variability in BCS remained unaccounted for (39% to 89%) even in the combined models. The procedures found in this study, therefore, may overestimate or underestimate measures by 0.23 to 0.32 BCS, which could substantially change the status of the ewe, leading to incorrect management decisions. However, the findings do still suggest that there is potential for predicting ewe BCS from liveweight using linear regression if the key variables affecting the relationship between BCS and liveweight are accounted for.https://www.mdpi.com/2076-2615/10/7/1182accuracymultivariatevariableprediction errorrecord |
| spellingShingle | Jimmy Semakula Rene Anne Corner-Thomas Stephen Todd Morris Hugh Thomas Blair Paul Richard Kenyon Predicting Ewe Body Condition Score Using Lifetime Liveweight and Liveweight Change, and Previous Body Condition Score Record Animals accuracy multivariate variable prediction error record |
| title | Predicting Ewe Body Condition Score Using Lifetime Liveweight and Liveweight Change, and Previous Body Condition Score Record |
| title_full | Predicting Ewe Body Condition Score Using Lifetime Liveweight and Liveweight Change, and Previous Body Condition Score Record |
| title_fullStr | Predicting Ewe Body Condition Score Using Lifetime Liveweight and Liveweight Change, and Previous Body Condition Score Record |
| title_full_unstemmed | Predicting Ewe Body Condition Score Using Lifetime Liveweight and Liveweight Change, and Previous Body Condition Score Record |
| title_short | Predicting Ewe Body Condition Score Using Lifetime Liveweight and Liveweight Change, and Previous Body Condition Score Record |
| title_sort | predicting ewe body condition score using lifetime liveweight and liveweight change and previous body condition score record |
| topic | accuracy multivariate variable prediction error record |
| url | https://www.mdpi.com/2076-2615/10/7/1182 |
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