The next study (Matos et al., 1997) on the use of different statistical models (linear, threshold, Poisson and negative binomial sire models, as well as linear, threshold, Poisson and negative binomial animal models) for reproductive traits prediction (fertility, litter size
and ovulation rate) in Rambouillet and Finnsheep sheep revealed their moderate predictive performance.
The observed differences do not indicate a systematic relationship between the size of the oviducts and litter size
. They also did not show significant differences concerning the weight and volume of the ovaries in the compared groups of gilts.
The dependent variable was teat functionality, while litter size
, litter birth weight, litter sex and parturition number were independent variables.
Correlation between capacitation status before and after capacitation, difference (A) in capacitation status before and after capacitation, and litter size
and latitude in a large mammal: the wild boar Sus scrofa.
The probability of producing at least one male calf increased with age ([beta] = 1.8, Odds Ratio = 6.0, AUC = 0.89, P = 0.03, n = 21 dams), but not weight ([beta] = -0.02, P = 0.35) or litter size
([beta] = -0.49, P = 0.68; Table 3).
For example, a review comprising 29 studies on wild boar litter size
in Europe did not include any site in Fennoscandia or Russia, i.e.
Most litters appear in early June and the average litter size
is very small (3.2 young).
Sow age and weight were positively correlated with fetal litter size
in this population.
The significant interaction between the litter size
at birth and the dam's age demonstrates that the cannibalistic behavior of the dam may be affected by age and the number of pups born.
Considerable development in farm animal breeding has been made in the last few decades, but doing greater understanding in the development of litter size
was very slow before molecular markers became an accessible technology with wide applications in breeding methods.