Physiological and production response of dairy goats bred in a tropical climate.
The aim of this work was to determine the adaptability of Saanen and ½Saanen × ½Anglo-Nubian (½S½AN) goats bred in tropical climates. The study included 30 goats, 15 Saanen and 15 ½S½AN. The data was collected during the rainy and dry seasons. During the whole experimental period, the environment variables were recorded, as well as rectal temperature (RT), superficial temperature (ST), respiratory rate (RR) and heart rate (HR) and milk production (MP). The adaptability coefficient (AC) was calculated for both genotypes. The averages were evaluated by ANOVA at 5% probability. There was a genotype and period of year effect, as well as the interaction genotype × period of year. Pearson's simple correlation analysis was then carried out between milk production and physiological and environment variables. There was a statistical difference (p < 0.05) between the seasons for RT, ST and RR. RT, RR and HR were lower for ½S½AN than Saanen goats, regardless of the season. MP was greater in the dry season (p < 0.05) (2.52 ± 0.50 kg/day for ½S½AN and 2.41 ± 0.38 kg/day for Saanen) than the rainy season (2.17 ± 0.27 kg/day for ½S½AN and 2.28 ± 0.53 kg/day for Saanen). The MP correlations were very significant (p < 0.05), however low and negative, where it was higher when correlated with RR in Saanen goats. Under the conditions of the present study, it is concluded that the goats were influenced by climatic factors, where the rainy period was more likely to cause thermal stress in the animals.
Faculdade de Veterinária, Universidade Estadual do Ceará - UECE, Avenida Paranjana, 1700. Campus do Itaperi, CEP 60714-903, Fortaleza, CE, Brazil, priscilatsvet@yahoo.com.br.
Priscila Teixeira
PT
de Souza
Maria Gorete Flores
MG
Salles
Antônio Nélson Lima
AN
da Costa
Hilton Alexandre Vidal
HA
Carneiro
Leonardo Peres
LP
de Souza
Davide
D
Rondina
Airton Alencar
AA
de Araújo
D000222:Adaptation, Physiological; D000818:Animals; D001831:Body Temperature; D001938:Brazil; D005260:Female; D006041:Goats / Q000502:physiology*; D006339:Heart Rate; D006813:Humidity; D007774:Lactation; D011891:Rain; D056152:Respiratory Rate; D013696:Temperature; D014329:Tropical Climate