Διευρεύνηση των επιπτώσεων από τη χορήγηση αφλατοξίνης β1 στη χημική σύνθεση του γάλακτος και σε αναπαραγωγικές παραμέτρους της εγχώριας ποιμενικής αίγας
Creators: name: Κουρουσέκος, Γεώργιος Δ.
Publisher: name: Aristotle University of Thessaloniki
Year: 2008
Subjects: subject: Αναπαραγωγή
subject: Ορμόνες
subject: Χημική σύνθεση
subject: Reproduction
subject: FOS: Medical biotechnology
subject: Hormones
subject: Chemical composition

description: Σκοπός της διατριβής ήταν η διερεύνηση των επιπτώσεων από τη μακροχόνια χορήγηση αφλατοξίνης β1 στη χημική σύνθεση του γάλακτος και σε αναπαραγωγικές παραμέτρους της εγχώριας ποιμενικής αίγας. Χρησιμοποιήθηκαν 30 αίγες της εγχώριας φυλής που χωρίστηκαν σε 3 ομάδες των 10 ζώων γ καθεμία(ομάδα μαρτυρίων, μ, ομάδα Α50, χορήγηση 50mg αφλατοξίνης β1/ημέρα peros, ομάδα Α100, χορήγηση 100mg αφλατοξίνης β1/ημέρα peros). Κατά τον Α' πειραματισμό λαμβάνονταν δείγματα γάλακτος με σκοπό τον προσδιορισμό των χημικών συστατικών και της συγκέντρωσης της αφλατοξίνης Μ1. Κατά το β' πειραματισμό λαμβάνονταν δείγματα αίματος με σκοπό τον προσδιορισμό της συγκέντρωσης της προγεστερόνης και της οιστροδιόλης -17β, ενώ χορηγήθηκαν 0,5ml προσταγλανδίνης f2α με σκοπό το συγχρονισμό του οίστρου των αιγών. Η αφλατοξίνη Μ1 ανιχνεύθηκε σε όλα τα δείγματα γάλακτος των αιγών που λάμβαναν αφλατοξίνη β1, ενώ η λιποπεριεκτικότητα του γάλακτος στις ίδιες αίγες μειώθηκε σημαντικά. Η συγκέντρωση της προγεστερόνης, στις αίγες που βρίσκονταν σε ωχρινική φάση, πτιν τη χορήγηση προσταγλανδίνης, ήταν σημαντικά υψηλότερες στις ομάδες που λάμβαναν αφλατοξίνη β1 σε σχέση με εκείνη των μαρτύρων. Η συγκέντρωση της οιστραδιόλης -17β ήταν σημαντικά χαμηλότερη στις ομάδες που λάμβαναν αφλατοξίνη, κατά τη διάρκεια των οίστρων πουθ ακολούθησαν τη χορήγηση της προσταγλανδίνης. Συμπερασματικά, η κατανάλωση αφλατοξίνης β1 από την εγχώρια αίγα μπορεί να οδηγήσει σε μείωση της λιποπεριεκτικότητας του γάλακτος, ενώ μπορεί να επηρεάσει τα επίπεδα των ωοθηκικών ορμονών, μειώνοντας τη συγκέντρωση της οιστραδιόλης -17β και αυξάνοντας εκείνη της προγεστερόνης
description: The aim of this study was the investigation of the possible effects of aflatoxin B1 administration on milk composition and reproductive parameters of the Greek indigenous goat. Two reasons, mainly, led to the realisation of this research. Initially, the high number of studies based on the mycotoxins, which attract many researchers nowadays and secondly, the few studies that exist regarding the Greek indigenous goat, which constitutes an important part of the national economy. For the aim of the study 30 Greek indigenous goats were used. The goats were 2-3 years old and their mean body weight was 29.6 ± 3.9 kg. The goats had realised their first childbirth approximately 3 months before the experiment started. The study was divided into two different experimentations. Experimentation A was separated in pre-experimental and experimental stage. The pre-experimental stage lasted for 3 weeks while the experimental stage lasted for 5 weeks. Experimentation B lasted for approximately 2 months. The goats were divided into 3 groups, of 10 animals each. The animals of group M (control group) received daily 1 ml methanol, per os, during the experimental stage of experimentation A and during the experimentation B. The animals of group A50 and group A100, during the experimental stage of experimentation A and during the experimentation B, received respectively 50 μg and 100 μg aflatoxin B1/day, per os, dissolved in 1 ml methanol. During experimentation A the following procedures took place in all goats: 1) milk sampling, 3 times a week, for the determination of the milk components and the aflatoxin M1 concentration, 2) blood sampling, 3 times a week, for the determination of liver biochemical parameters, 3) measurement of body weight, once a week, 4) determination of the indicator of nutrition status, once a week, 5) measurement of the milk quantity, twice a week. During experimentation B the following procedures took place in all goats: 1) blood sampling, 3 times a week for 5 weeks, for the determination of progesterone and oestradiol-17β concentration, 2) administration of 0.5 ml prostaglandin F2α (PGF2α), after week 5 of experimentation B, aiming at the synchronisation of oestrus, 3) blood sampling every 12 hours and for the time interval of 96 hours after PGF2α administration. The determination of aflatoxin M1 in the milk samples was realised with a competitive enzyme immunoassay (EIA), while the determination of progesterone and oestradiol-17β was realised with a radioimmunoassay (RIA). According to the results, aflatoxin M1 was detected in all milk samples of the goats that received aflatoxin B1, while it was not detected in the milk samples of the controls. It seems that aflatoxin M1 concentration was higher in the samples of group A100. Regarding the body weight and the indicator of nutrition status, no significant differences were observed between pre-experimental and experimental stage and among the groups, as well. The milk production decreased considerably in all groups, probably because of the progress of the lactation period of the goats. As for the chemical components of the milk, no significant differences were observed among the groups or between the two stages of experimentation A, regarding proteins, lactose and non-fat solids. Regarding somatic cell count and total microbial count no significant differences were observed among the groups or between the two stages of experimentation A. On the contrary, during the experimental stage of experimentation A, the milk fat content decreased significantly in groups A50 and A100. During the experimental stage, aspartate aminotransferase (AST) of group A100 also differed significantly, presenting higher than that of groups M and A50. As for the reproductive parameters, no significant differences were observed regarding the oestrus presence or the number of oestrus presented by the goats of each group. Contrastingly, during experimentation B and before PGF2α administration, progesterone concentration appeared considerably higher in groups A50 and A100. Regarding oestradiol-17β concentration, it was presented significantly lower in groups A50 and A100 during the oestrus that followed the PGF2α administration. In conclusion, the aflatoxin B1 consumption by the Greek indigenous goat results in the presence of aflatoxin M1 in the milk, while it could lead to reduction of milk fat content. Continuous research is necessary for the mechanism of action of the aflatoxins in the fat synthesis to be determined. It doesn't seem that other milk components are influenced by aflatoxin B1 administration. Finally, aflatoxin B1 could influence the levels of hormones produced by the ovaries, decreasing oestradiol-17β concentration and increasing that of progesterone, without any obvious effects on the oestrus presence. Further research regarding the direct or indirect effect of the aflatoxins on the reproductive system of goat could interestingly be useful