Efeito da temperatura e umidade do ar sobre as características seminais de galos alojados em galpões semiclimatizados

Abstract

The Effect of temperature and air humidity on the seminal characteristics of Cobb 500 strain roosters 45 to 65 weeks old housed in a semi air-conditioned shed was assessed. The roosters were kept separately in a 90 x 90 x 90 cm cage and semen collections were made fortnightly, totaling 267 samples. In relation to the statistical analysis, the Kruskal-Wallis non-parametric test was applied, followed by the Dunn test, both at 0.05 level of significance. In order to evaluate the influence of the environmental conditions on the seminal characteristics the Pearson linear correlation coefficient was used. It was verified that the semen volume at the 1st collection (45 weeks old) did not differ from the others, except for the 8th collection (59 weeks). The mean motility value at the 2nd collection (47 weeks) differed from the 6th, 7th, 8th collections, which correspond to 55, 57 and 59 weeks, respectively. The mean vigor and spermatic pathology values were not different between collections. Among the characteristics studied in this work, the spermatic pathologies presented higher VC (85.91%) and the motility presented the lowest (11.33%). There was a low positive and significant correlation between maximum temperature at the collection day and motility; and six days before collection, the correlation was negative and significant. Low negative and significant correlation was found between maximum temperature 2, 3 and 4 days prior to collection and seminal volume. However, thirteen days before collection, the correlation was positive and significant. Positive and significant correlation was found between maximum temperature six days before collection and vigor. There was a low positive and significant correlation between maximum temperature 8 days before collection and total spermatic pathology. In relation to the maximum humidity, the correlation between maximum humidity and volume at the collection day and 1, 3, 17, 18 and 19 days before semen collection was positive and significant, but of low magnitude. There was a positive and significant correlation between maximum humidity and vigor at 8, 15 and 18 days before collection. Correlations between maximum humidity and total spermatic pathology were not found. In the experimental conditions, it was concluded that the environmental factors represented by temperature and air humidity presented low association with the roosters seminal characteristics, once no intense oscillations in the environmental conditions were observed.