Effect of Gender on Factors Affecting Excreta Dry Matter Content of Broiler Chickens

Abstract

The purpose of this experiment was to investigate the factors affecting water intake in modern genetic lines of broilers that might contribute to problems of wet litter. A total of 128 Ross 308 one-day-old chicks (equal numbers of males and females) were fed commercial grower and finisher rations ad libitum from 10 to 39 d of age, containing 0.2% Ti2 O3 as an inert marker. Birds were housed in groups of 4 in metabolism cages. Body weight and feed consumption were recorded weekly from d 10, and water intake was recorded daily. Excreta from each cage were collected daily and, at the end of each week, the DM content of a sample of pooled excreta from each cage was measured. The results showed that male broilers consumed more water (P < 0.001) and produced excreta that had a lower mean DM content (P < 0.05) compared with females. Males grew significantly faster (P < 0.05) compared with females. There was a significant correlation between feed intake, and hence the intake of N and the major minerals, and water intake (r = 0.623, P = 0.001). Despite a higher apparent retention of DM, CP, and feed efficiency in favor of males, variation among cages was high, and differences between gender were not statistically significant. Water intake tended to be correlated to mean live weight gain of the cage (r = 0.301, P = 0.06), and when live weight gain was used as a covariate in the analysis, the gender difference in water intake was no longer significant. In conclusion, it appears that the higher water intake and lower excreta DM content for males is related to their higher feed and water intake. Mineral excretion was similar for males and females; however, males retained significantly more P compared with females. Male broilers had greater tibia bone size and strength parameters, which indicate higher bone mineral deposition compared with females.