Ubushakashatsi bushya bwerekana ko ubuziranenge bw’intanga ngabo buba buri hejuru mu mpeshyi, mu gihe bumanuka mu gihe cy’itumba. Abashakashatsi bo mu Bwongereza, Canada na Denmark basuzumye ingero 15,581 z’uturemangingo tw’abagabo bafite hagati y’imyaka 18 na 45 mu bihugu bitandukanye, birimo Denmark na Florida muri Amerika.
Ibyavuye mu bushakashatsi byerekanye ko ubushobozi bw’uturemangingo bwo kugenda neza (motility) bwari hejuru cyane mu mezi ya Kamena na Nyakanga.
Ibi bisobanura ko igihe cy’umwaka kigira ingaruka ku bushobozi bw’intanga z’abagabo, bityo bigafasha mu kunoza uburyo bwo kuvura uburumbuke.
Uyu mwitwarariko w’ibihe by’umwaka ushobora gutuma haboneka inama nziza ku bashakanye bashaka kubyara, cyane cyane mu gihe cy’amasuzumabuzima.
Umugabo ufite intanga ngabo zifite ubushobozi bwo kwihuta, abasha gufasha umugore we kugira amahirwe menshi yo gutwita.
Mu bushakashatsi bwashyizwe ahagaragara mu kinyamakuru Reproductive Biology and Endocrinology, abashakashatsi babonye ko ubushobozi bw’intanga ngabo bwo kwihuta butahinduka bitewe n’ikirere, ahubwo bushingiye gusa ku bihe by’umwaka.
Ibi byerekana ko ubushobozi budahinduka mu buryo buzwi, ahubwo butekerezwaho hakurikijwe imiterere y’ibihe.
Kugeza ubu, ubushobozi bw’intanga z’abagabo bwaragaragaye ko bumanuka mu kwezi kwa 12 no mu kwa mbere, hatitawe ku bushyuhe buriho muri Florida.
Ariko, umubare w’intanga mu masohoro (total sperm concentration) na bwinshi bw’amasohoro asohoka (ejaculate volume) ntibyigeze bihinduka, bagaragaza neza ko ibihe by’umwaka bigira ingaruka ku bushobozi bwo kubyara, ariko umubare w’intanga ntuhinduka.
Iri tandukaniro rigaragaza ko ubushyuhe bwihariye bw’intanga ngabo bugomba kuba ku gipimo kiri hagati ya dogere 2 na 4 ugereranyije n’Ubushyuhe bw’umubiri busanzwe bwa dogere 37. Ibi bisobanuye ko kwitondera ibi bipimo bishobora kugira ingaruka ku bushobozi bw’intanga ngabo bwo kwihuta, bigahitamo kubyara neza.
Profeseri Allan Pacey wo muri University of Manchester yagize ati: “Ubushakashatsi bwacu bwerekana akamaro ko kwitondera ibihe by’umwaka mu gihe cyo gusuzuma ubuziranenge bw’amasohoro.”
Ibi bisubizo bitanga icyizere ko dushobora kuzamura amahirwe yo kubyara, binyuze mu gutegura neza igihe cyo gusuzuma no kuvura, duharanira ubuzima bwiza bw’imyororokere y’abagabo.
