We now show that loss of Magel2 in mice causes reduced fertility in both males and females through extended breeding intervals and early reproductive decline and termination.
In addition, the time from calving to breeding, the time COD diagnoses to breeding, as well as between breeding intervals within the same lactation were calculated.
Furthermore, for both male and female Magel2-null mice that were eventually successful in breeding, the interval between pairing and birth was significantly extended at all ages.
Data on parity, previous calving interval, breeding values, calf birth weight and calf 200-d weights were obtained from the NBCRS database.
Original versus predicted breeding values for interval between first and last insemination for the two methods (GBLUP and BSSVS) using the three types of data (BovineHD, ImputedHD, and imputed sequence) for the 2087 validation animals.
Temporal progesterone patterns were classified as: 1) Normal cyclicity; 2) Cessation of luteal activity; 3) Prolonged luteal activity; 4) Erratic phase: failure to conform to 1, 2 or 3. Data concerning parity, previous calving interval, breeding values, calf birth and 200-d weight were obtained from the Norwegian Beef Cattle Recording System database.
A log-scale 95% prediction interval for mid-parent variance breeding values, i.e. the interval for which 95% of future families is expected to fall in absence of selection, can then be defined as μ − 1.96 1 2 σ a 2, μ + 1.96 1 2 σ a 2 = − 0.98, − 0.18, which corresponds to within-family variances of body weight in the range [ e− 0.98, e− 0.18] = [0.38, 1.18].
It allows breeders to select traits more precisely and thus speeds up breeding by reducing generational intervals: if you know which genetic traits an animal has, there is no need to wait several generations to see how things turn out.This will not happen everywhere.
The female kakapo lays 1-2 eggs (rarely 3) per breeding cycle, with long intervals between laying of first and second eggs.
Genomic selection would strongly enhance breeding efficiency by decreasing generation interval and increasing the accuracy of breeding value estimates and selection intensity.
