Influence of breed on adult doe attrition rates in a central Tennessee meat goat herd
Straightbred Boer (n=132), Kiko (n=92) and Spanish (n=79) does were evaluated to determine if meat goat breed influences survival rates and cumulative productivity. The herd was semi-intensively managed on humid subtropical pasture in central Tennessee. Annual herd records across 6 production yrs (2003–04 to 2008–09) were used to assess doe stayability, cumulative production and to determine the reasons for doe exits. Does entered the herd in each year except Year 6. Regardless of entry year, records for all does remaining in the herd at the conclusion of Year 6 were considered censored (n=102) and all does that exited the herd were considered failures (n=201). All does that entered the herd had the opportunity to complete at least 2 yr of production. Does were bred to kid once each year. Culling from the breeding herd was involuntary. Two culling criteria were used for survival analysis: 1) Actual: failure to wean a kid for any 2 yr on the study 2) Imposed: first failure to wean a kid. Survival analysis to compare breeds within the herd was done by the product-limit method. Production traits analyzed were cumulative number of kids weaned and cumulative weight weaned. Production data were analyzed using least-square method. Significant differences were found between the Boer and Kiko (P < 0.05) and between the Boer and Spanish ( P < 0.05) for stayability rate, cumulative weaning weights and cumulative number of kids weaned to 2, 3 and 5 production yr. Overall stayability, stayability up to 2 yr in the herd and cumulative production were lower for Boer does than for Kiko and Spanish does. Stayability results were similar for both culling analysis. Health-related failures constituted largest proportion of whole-herd exits (82.09%) under the actual culling criteria. Sold/culled does had the highest proportion (51.17%) under the imposed culling criteria. These proportions were similar within each breed population. Breed of doe significantly influenced stayability rates and cumulative production. Boer does demonstrated a lower level of fitness than the Kiko and Spanish does as evidence by relatively higher exit rates and lower productivity under the management conditions of the study.
Ashley Nicole Pellerin,
"Influence of breed on adult doe attrition rates in a central Tennessee meat goat herd"
ETD Collection for Tennessee State University.