Total weaning weight is a function of pig quantity and quality. Pig quality can be associated with individual pig weights and survivability. As litter size increases, total weaning weight increases at a decreasing rate. As shown in Figure 1., larger litter sizes not only wean more weight, but also have higher preweaning mortality. Increased litter size has been associated with smaller, more fra...

Progesterone and oestrone alone or in combination were administered to sows during early gestation. A dose of 25 mg progesterone and 12-5 mug oestrone injected together for 10,5 or 2 consecutive days during the implantation interval caused increased litter size at term.

in this study, we investigated the relationship between the genetic polymorphism of growth differentiation factor 9 (gdf9) genes and the litter size in 384 individuals of five breeds of black goats. four pairs of primers were designed to detect single nucleotide polymorphism of gdf9 gene in goats by pcr-sscp. the least square was used to analyze the relation between different genotypes and the ...

the objective of this study was to evaluate genetic and phenotypic parameters for some reproductive traits of black bengal does. genetic parameters were estimated by residual maximum likelihood procedure, fitting an animal model ignoring maternal genetic or permanent environmental effects. the least-squares means of litter size at birth (lsb), litter size at weaning (lsw), litter weight at birt...

UANTITATIVE geneticists have long been aware that correlated responses Q are common in populations under different types of selection. The primary implication of a correlated response is that the character under selection is genetically correlated with another character, though other parameters affect the magnitude of the correlated response. In the course of selection for a single trait, other...

Despite increasing professionalism in dog breeding, the physiological range of birth weight in this species remains unclear. Low birth weight can predispose to neonatal mortality and growth deficiencies in humans. To date, the influence of the morphotype on birth weight has never been studied in dogs. For this purpose, an Italian census of birth weight was collected from 3293 purebred pups base...

Mink skin size in Finland, as well as in other countries, has increased considerably during last decade. However, there are signs that selection for large body size has a negative impact on litter size (LS) and also for survival of kits. Therefore, it is important to study the genetic relationships among fertility traits and animal size (AS). The variance components for age at first mating (AFM...

Previous analysis of the rules regarding how much more a female should invest in a litter of size C rather than producing a litter with one more offspring revealed an invariance relationship between litter size and the range of resources per offspring in any litter size. The rule is that the range of resources per offspring should be inversely proportional to litter size. Here we present a modi...

Divergent selection in mice was renewed in 3 independent replicates for high (MH) and low (ML) heat loss. An unselected control (MC) was maintained in all replicates. Heat loss was measured for individual male mice for 15 h, overnight in direct calorimeters. After 16 initial generations of selection followed by 26 generations of relaxed selection, divergent selection resumed for 9 generations. ...

Background RFamide-related peptide-3 (RFRP-3) inhibits gonadotropin releasing hormone (GnRH) and luteinizing hormone (LH) secretion in rats. This study evaluates the effects of litter size and suckling intensity on RFRP mRNA expression in the dorsomedial hypothalamic nucleus (DMH) of rats. MaterialsAndMethods A total of 32 pregnant and 4 non-lactating ovariectomized (control group) Sprague-Dawl...