title: A correlation of fecal volatiles and steroid hormone profiles with behavioral expression during estrous cycle of goat, Capra hircus.
abstract: Chemical signals (both volatile and non-volatile) form the major communication channels in animals. These signals are transferred mainly through excretory sources to facilitate inter-individual communication. In particular, the reproductive cycle of female mammals, including goats, exhibits significant changes in the constituents of their excretory products, and female mammals also express different behavioral patterns. We propose that feces is one of the important sources of chemo-signals in goats. However, the behavioral patterns and analysis of excretory sources based on chemical communication have not yet been studied in the Indian goat, Capra hircus. To validate our hypothesis, we analyzed the behavioral patterns and the volatiles and steroid hormone profiles in the feces samples of female goats during the estrous cycle. Here, we synchronized the estrous cycle in six female goats and obtained feces samples. The samples were extracted with dichloromethane and analyzed using gas chromatography-mass spectrometry. A portion of the sample was used for hormone assay to confirm the phases in the estrous cycle. Induction of she-goats into estrus was detected from the vaginal swelling, mucus discharge, restlessness, reduced milk secretion, bellowing, bleating, frequent urination, standing heat, allowing the male to mount, mounting on other females and teasing of males. The repeated male behaviors viz., flehmen, mounting, penile protrusion, body rubbing, dominance over other males and finally coitus with estrus female by male goats were observed. Analysis of volatiles revealed a total of twenty-four compounds combining all the phases in the estrous cycle. Among those, some of the volatile compounds and two antioxidants (ascorbic acid and vitamin E) were estrus-specific. Based on the fecal steroid analysis, higher level of estradiol during estrus and higher level of progesterone during post-estrus were observed. The behavioral patterns of female and male goats combined with qualitative differences in the volatile compounds and the two antioxidants rendered the estrus identifiable. Furthermore, the fecal steroid analysis also supported the detection of hormonal status during the estrous cycle. To the best of our knowledge, this is the first report correlating the behavior with volatiles and hormones in the feces samples from female Indian goats. It is concluded that the volatile pattern and hormone profile in feces, supported by specific behavioral patterns, should be considered a better modality of non-invasive estrus detection in goats.
authors.affiliation: Department of Environmental Biotechnology, Bharathidasan University, Tiruchirappalli 620 024, Tamilnadu, India.
authors.forename: Devaraj
authors.initials: D
authors.lastname: SankarGanesh
authors.affiliation: Department of Environmental Biotechnology, Bharathidasan University, Tiruchirappalli 620 024, Tamilnadu, India.
authors.forename: Rajamanickam
authors.initials: R
authors.lastname: Ramachandran
authors.affiliation: Center for Pheromone Technology, Department of Animal Science, Bharathidasan University, Tiruchirappalli 620 024, Tamilnadu, India.
authors.forename: Samuthirapandi
authors.initials: S
authors.lastname: Muniasamy
authors.affiliation: Department of Livestock Production and Management, Veterinary College and Research Institute, Namakkal 637 002, Tamilnadu, India.
authors.forename: Veluchamy Ramesh
authors.initials: VR
authors.lastname: Saravanakumar
authors.affiliation: Department of Environmental Biotechnology, Bharathidasan University, Tiruchirappalli 620 024, Tamilnadu, India.
authors.forename: Udhayaraj
authors.initials: U
authors.lastname: Suriyakalaa
authors.affiliation: Department of Zoology, Periyar University, Salem 636 001, Tamilnadu, India.
authors.forename: Soundarapandian
authors.initials: S
authors.lastname: Kannan
authors.affiliation: Center for Pheromone Technology, Department of Animal Science, Bharathidasan University, Tiruchirappalli 620 024, Tamilnadu, India.
authors.forename: Govindaraju
authors.initials: G
authors.lastname: Archunan
authors.affiliation: Department of Environmental Biotechnology, Bharathidasan University, Tiruchirappalli 620 024, Tamilnadu, India; Center for Pheromone Technology, Department of Animal Science, Bharathidasan University, Tiruchirappalli 620 024, Tamilnadu, India. Electronic address: achiramans@gmail.com.
authors.forename: Shanmugam
authors.initials: S
authors.lastname: Achiraman
mesh_terms: D000818:Animals; D001522:Behavior, Animal; D004958:Estradiol / Q000032:analysis* / Q000378:metabolism; D030762:Estrous Cycle / Q000502:physiology*; D005243:Feces / Q000737:chemistry*; D005260:Female; D008401:Gas Chromatography-Mass Spectrometry; D006041:Goats; D008297:Male; D011374:Progesterone / Q000032:analysis* / Q000378:metabolism; D012098:Reproduction / Q000502:physiology*
chemical_list: D011374:Progesterone; D004958:Estradiol
keywords: Behaviors; Estrus detection; Feces; Goat; Hormone assay; Volatiles