OORMATIGE TEMPERATURE KAN LAE SKAAPKUDDES VEROORSAAK
Hoë temperature gedurende kritieke tydperke van die voortplantingsiklus van skape lei daartoe dat 2,1 miljoen minder lammers elke jaar in Australië geproduseer word. Dit kos skaapboere jaarliks na raming $97 miljoen.
Die werk, befonds deur Meat and Livestock Australia en uitgevoer deur ‘n transdissiplinêre span navorsers van die Universiteit van Adelaide en die Suid-Australiese Navorsingsontwikkelingsinstituut (SARDI), het bevind dat die dae wanneer temperature bo 32°C behaal word gedurende die week van paring, tot ‘n aansienlike verlies in produksiepotensiaal gelei het.
Die studie, wat in Nature Food gepubliseer is, het bevind dat jaarlikse verliese aan potensiële lammers tot 2,5 miljoen sal toeneem as gemiddelde aardverwarming met 1°C toeneem, en 3,3 miljoen as dit met 3°C toeneem.
“Hierdie modellering is belangrik aangesien dit aantoon dat hittegebeurtenisse die volhoubaarheid van skaapproduksie bedreig, beide in Australië en wêreldwyd,” sê die Universiteit van Adelaide se medeprofessor William van Wettere, wat die studie gelei het.
Hittestres verminder nie net die aantal lammers wat gebore word nie, maar dit kan ook die lam se geboortegewig met tussen 0,6 en 1,4 kg verminder.
“As die uitwerking van geboortegewig verreken word, kan ekonomiese verliese toeneem tot $168 miljoen onder ons huidige klimaat, en $203 miljoen en $278 miljoen in onderskeidelik die 1°C en 3°C temperatuur scenario’s,” sê medeprofessor van Wettere.
Die navorsing het getoon baie skape is nie in staat om hul hitte te reguleer tydens periodes van erge hitte nie, wat ‘n uitwerking op die dier se vrugbaarheid het.
Die navorsers ondersoek nou of die selektiewe teling van diere wat hul hitte meer doeltreffend reguleer die klimaatveerkragtigheid van skaaptroppe kan verbeter, en hoe skape se hitteregulering en gedrag vrugbaarheid tydens hitteperiodes beïnvloed.
Bron :https://www.sciencedaily.com/releases/2024/03/240321001148.htm
EXCESS TEMPERATURES CAUSE LOW FLOCKING CONCERNS IN SHEEP
High temperatures during critical periods of the reproductive cycle of sheep result in 2.1 million fewer lambs produced in Australia each year, costing sheep farmers an estimated $97 million annually.
The work, funded by Meat and Livestock Australia and conducted by a transdisciplinary team of researchers from the University of Adelaide and South Australian Research Development Institute (SARDI), found that days above 32°C during the week of mating caused the significant loss of potential lambs.
Published in Nature Food, the study found annual losses of potential lambs would increase to 2.5 million if median global warming increased by 1°C, and 3.3 million if it increased by 3°C.
“This modelling is important as it demonstrates that heat events threaten the sustainability of sheep production, both within Australia and globally,” says the University of Adelaide’s associate professor William van Wettere, who led the study.
Not only does heat stress decrease the number of lambs born, but it can also reduce lamb birthweight by between 0.6-1.4kg.
“If the effects of birthweight are accounted for, economic losses could increase to $168 million under our current climate, and $203 million and $278 million for the 1°C and 3°C temperature scenarios, respectively,” associate professor van Wettere says.
The research showed many sheep are not able to thermoregulate during periods of heat, leading to effects on the animal’s fertility.
The researchers are now investigating whether selectively breeding animals which thermoregulate more effectively can improve the climate resilience of sheep flocks, and how sheep thermoregulation and behaviour affect fertility during periods of heat.
Source : https://www.sciencedaily.com/releases/2024/03/240321001148.htm