Rams express differences in sexual performance during the breeding season. Breeding rams with high sexual performance scores as measured during a sexual performance test can improve flock fertility. Whether selecting rams for high sexual performance score will indirectly improve ewe reproductive performance is not known. The objective of this study was to estimate the genetic correlation betwee...

BACKGROUND Housing sheep in insulated, warm buildings, which is common in Norway, involves high buildings costs, but has not been reported to improve health and performance. Few studies have dealt with the association between housing and management and reproductive performance.Data on housing and management during the indoor period from a questionnaire were merged with herd level data from the ...

The objective of the current study was to determine the effects of maternal MP intake in isocaloric diets during late gestation on female offspring growth from birth to breeding and measure reproductive performance of those offspring in their first breeding season. In yr 1, maternal dietary treatments were applied at d 100 of gestation, were similar in total energy, and contained 60MP1, 60% of ...

The present study was carried out to estimate (co)variance components and genetic parameters for some productivity traits of Baluchi ewes. The data were collected during a 31 year period (1984-2014) at the experimental breeding station of Baluchi sheep, which is located in north-east of Mashhad, Iran. The analysis was based on 14030 records of lambs and 4371 records of ewes. Investigated traits...

Objectives were to estimate effects of sire breed (Dorset, Finnsheep, Romanov, Texel, and Montadale), dam breed (Composite III and northwestern whiteface), mating season (August, October, and December), ewe age (1, 2, and 3 yr), and their interactions on reproductive traits of F1 ewes. A total of 1,799 F1 ewes produced 3,849 litters from 4,804 exposures to Suffolk rams during 35-d mating season...

Records from 2,525 adult Targhee ewes and 10,099 lambs were used to estimate genetic parameters in an animal model for ewe stayability (STAY), productive life (PL), adult BW (AW) and BCS, fleece characteristics, and number of lambs born (NLB) and for lamb BW at birth and approximately 45 d, 120 d (120W; weaning), 12 mo, and 18 mo of age. Stayabilities were analyzed as overall stayability (STAYn...

Reproduction traits are important but difficult to improve in sheep because they are lowly heritable and are recorded later in life. Genomic information can be used for genomic prediction of breeding values to increase the accuracy of selection. Alternatively, genomic information can be used to identify recessive lethal mutations, which cause embryonic losses. We investigated both uses of genom...