No document available.
Keywords :
Verrat, anomalies morphologique, analyse de sperme, zinc
Abstract :
[en] The semen of three 18- (A), 15- (B) and 9- (C) month-old Piétrain boars kept in an educational herd presented the same morphological abnormality. Sampled once a week since mid-September, boars A and B showed an increasing rate of flagellar abnormalities: tails bent between the mid- and the main piece or even coiled tails. Boar C, which was first trained for semen production at the end of November, immediately presented abnormal semen. The normal spermatozoa rate of boar A fell from 84% to 16% between 30/09/2024 and 3/12/2024. At that moment, the normal spermatozoa rate, semen mobility and motility were respectively 16%, 30% and 2 (boar A), 0%, 10% and 1 (boar B) and 0%, 5% - 2 (C). On 3/12/2024, boar C's ejaculate was hemorrhagic, suggesting urolithiasis. On that day, the boars' feed was modified, and blood samples were taken to measure zinc levels (boars A-B). A feed analysis was also carried out. The blood zinc concentration of boars A and B was 148 and 194 µg/dL (normal range: 65-131 µg/dL). The feed analysis has shown that zinc, manganese, copper, iodine, cobalt and selenium concentrations were respectively 4,201; 226; 670; 1,400; 55 and 1,788 mg/kg of dry matter. So, the toxicity threshold was exceeded for zinc (>2000 mg/kg), copper (>250 mg/kg), selenium (>5 mg/kg) and iodine (>800 mg/kg). In boar, an excess of zinc in the seminal fluid is known to cause folded tails. In pig farms, an abnormal sperm motility/morphology is primarily associated to iatrogenic (hyperthermia consecutive to vaccination), infectious, environmental (heat stress), traumatic or genetic causes. Nutritional imbalances should also be included in the differential diagnosis as zinc excess in feed is associated to a high percentage of folded tails.
