Coat traits, skin evaporation, and milk production of Majorera and Palmera goats in a temperate region.

Abstract

The present study aimed to (i) characterize the seasonal dynamics of coat morphology and skin evaporation (SE) as adaptive indicators, (ii) evaluate milk production and composition throughout the lactation period, and (iii) investigate the relationships between these adaptative traits and milk production in Majorera and Palmera goats raised on Tenerife Island (28°N). Morphological data, skin evaporation and milk production (MP) and composition of 30 Majorera and 20 Palmera lactating and non-pregnant goats of similar reproductive age were collected over 18 months period. Except for coat diameter, all variables showed an interaction effect (p < 0.001) between season and breed. Coat thickness was greater (p < 0.001) in the Palmera breed than in Majorera goats in all seasons. Hair length was greater (p < 0.001) by more than 200% in Palmera goats than in Majorera goats in all seasons. Except for summer, skin evaporation (SE) was higher (p < 0.001) for the Palmera than Majorera. Majorera goats showed higher MP (p < 0.001) throughout all months of the lactation period compared to Palmera goats. The average total MP over the 210-day lactation period was 338.46 for Majorera and 207.3 L for Palmera. Regarding milk composition, Palmera goats had higher fat (p = 0.007) content than Majorera goats, whereas protein content was similar (p = 0.358) between breeds. Canonical correlation analysis indicated that the climate of Tenerife Island exerts a greater influence on coat morphological traits and SE in Palmera goats (r_c²= 0.38; p < 0.001). These climate effects on adaptive traits showed a stronger tendency to be associated with MP (r_c²= 0.29; p = 0.058). In contrast, although the climatic influence on morphological traits and SE was lower in Majorera goats (r_c²=0.22; p < 0.001), these adaptive variables were not significantly related to MP (r_c²=0.25; p = 0.160). Majorera and Palmera goats exhibited distinct seasonal responses in coat traits and SE under the climate of Tenerife. Palmera goats, with longer and denser coats, showed greater susceptibility to heat stress and a stronger tendency for adaptive traits to influence MP. In contrast, Majorera goats, whose coats favored heat dissipation, had higher MP and greater productive stability under environmental fluctuations. These findings highlight the importance of including coat traits in genetic improvement programs for dairy goats in temperate regions.