Considering dairy cattle reproduction, profitability is maximized when every cow gets pregnant at her optimal time after calving (at a low cost). This optimal time of conception has consequences for economically optimal breeding decisions and the value of a pregnancy, both a new pregnancy and a loss of pregnancy (abortion). Some cows are more important to get pregnant than others. This paper di...

The concept of superfetation, a second conception during pregnancy, has been controversial for a long time. In this paper we use an experimental approach to demonstrate that female European brown hares (Lepus europaeus) frequently develop a second pregnancy while already pregnant and thereby increase their reproductive success. After a new, successful copulation, we confirmed additional ovulati...

Previously, the concept of a gestation period of sheep shorter than 121 days was unheard of in the field of sheep biology. Our findings during a farmers’ survey in the Lotkho area of Chitral, Pakistan, revealed that the sheep native to the region, locally called “Kari”, gestates for a period of only three months. This duration is 25-40% short of the usual gestation length and is shorter than ev...

This manuscript is aimed at reviewing the performance responses of dairy cattle against thermal stress resulting from climate change. Climate change major factor that largely affects industry. Thermal (TS) perceived discomfort and physiological strains associated with exposure to excessive ambient temperature. Temperature Humidity Index (THI) have been adopted describe conditions drive in cattl...

Gregarious mammals generally synchronize birthing by adjusting the time of estrus. Berger (Ecology 73: 323-329, 1992) proposed that American bison (Bison bison) females in good condition are capable of adjusting gestation length, as well. He hypothesized that females in good condition that breed late in the season can shorten their gestation length so as to give birth during the birthing peak. ...