Animal-based indicators for on-farm welfare assessment for dairy goats : invited review

This paper reviews animal-based welfare indicators to develop a valid, reliable, and feasible on-farm welfare assessment protocol for dairy goats. The indicators were considered in the light of the 4 accepted principles (good feeding, good housing, good health, appropriate behavior) subdivided into 12 criteria developed by the European Welfare Quality program. We will only examine the practical indicators to be used on-farm, excluding those requiring the use of specific instruments or laboratory analysis and those that are recorded at the slaughterhouse. Body condition score, hair coat condition, and queuing at the feed barrier or at the drinker seem the most promising indicators for the assessment of the \u201cgood feeding\u201d principle. As to \u201cgood housing,\u201d some indicators were considered promising for assessing \u201ccomfort around resting\u201d (e.g., resting in contact with a wall) or \u201cthermal comfort\u201d (e.g., panting score for the detection of heat stress and shivering score for the detection of cold stress). Several indicators related to \u201cgood health,\u201d such as lameness, claw overgrowth, presence of external abscesses, and hair coat condition, were identified. As to the \u201cappropriate behavior\u201d principle, different criteria have been identified: agonistic behavior is largely used as the \u201cexpression of social behavior\u201d criterion, but it is often not feasible for on-farm assessment. Latency to first contact and the avoidance distance test can be used as criteria for assessing the quality of the human\u2013animal relationship. Qualitative behavior assessment seems to be a promising indicator for addressing the \u201cpositive emotional state\u201d criterion. Promising indicators were identified for most of the considered criteria; however, no valid indicator has been identified for \u201cexpression of other behaviors.\u201d Interobserver reliability has rarely been assessed and warrants further attention; in contrast, short-term intraobserver reliability is frequently assessed and some studies consider mid- and long-term reliability. The feasibility of most of the reviewed indicators in commercial farms still needs to be carefully evaluated, as several studies were performed under experimental conditions. Our review highlights some aspects of goat welfare that have been widely studied, but some indicators need to be investigated further and drafted before being included in a valid, reliable, and feasible welfare assessment protocol. The indicators selected and examined may be an invaluable starting point for the development of an on-farm welfare assessment protocol for dairy goats