Role Of Maternal Effects Research Articles

Variation in Incubation Periods and Egg Metabolism in Mallards: Intrinsic Mechanisms to Promote Hatch Synchrony

We investigated factors affecting incubation time and metabolic rates of Mallard (Anas platyrhynchos) eggs incubated under constant environmental conditions. Time required to reach the starpipped stage of hatch varied significantly among females, but not with laying sequence or egg size. Metabolic rate of eggs varied positively with position in the laying sequence and tended to vary among females. Metabolic rate did not vary with egg volume or incubation length. Our results indicate metabolic rate may act as one synchronization mechanism for hatch. The role of maternal effects in development time should be considered in subsequent studies of incubation time in ducks.

Inbreeding Depression in Hydrophyllum appendiculatum: Role of Maternal Effects, Crowding, and Parental Mating History

Inbreeding Depression in Hydrophyllum appendiculatum: Role of Maternal Effects, Crowding, and Parental Mating History

The Role of Maternal Effects in Animal Breeding: V. Maternal Effects in Swine

THE importance of maternal influence on the growth of young mammals has been recognized since the earliest attempts to improve livestock production. Varro (66 B.C.) recorded recommendations for feeding sows to enhance milk production (translation by Storr-best, 1912). Studies on milk consumption of suckling pigs were reported in the 1860's. Following the extension of Mendelian genetics to quantitative traits, attempts have been made to elucidate the importance of genetic influences on maternal performance. Beginning in the 1920's and 30's, considerable effort was made to understand the relative roles of genotype and environment in specifying phenotypes. The influence of a dam on her young, through the nutrients provided by the uterus and the mammary gland, was recognized as a special case of the joint action of genotype and environment. Thus, the expression of the dam's genotype was recognized. Traits in mammals influenced by a major maternal component have additional complexity added to the characterization of the genetic variability.

The role of maternal effects in animal breeding. 8. Comparative aspects of maternal effects.

The role of maternal effects in animal breeding. 8. Comparative aspects of maternal effects.

The role of maternal effects in animal breeding. VII. Maternal effects in sheep.

The role of maternal effects in animal breeding. VII. Maternal effects in sheep.

The role of maternal effects in animal breeding. VI. Maternal effects in beef cattle.

The role of maternal effects in animal breeding. VI. Maternal effects in beef cattle.

The role of maternal effects in animal breeding. IV. Maternal effects in laboratory species.

The role of maternal effects in animal breeding. IV. Maternal effects in laboratory species.

The role of maternal effects in animal breeding. 3. Biometrical aspects of maternal effects in animals.

The role of maternal effects in animal breeding. 3. Biometrical aspects of maternal effects in animals.

The role of maternal effects in animal breeding. I. Passive immunity in newborn animals.

The Why of Passive Immunity WHY is it that newborn animals require a supply of gamma globulin passively acquired from their maternal parent? Certainly it is not that they cannot make their own antibodies; indeed, many can. Studies in recent years have shown that developing fetuses can make antibodies to numerous antigens but, in the isolation of their essentially germ-free environment, they rarely come in contact with foreign antigens. The fetal lamb when exposed to various antigens first makes antibodies to bacteriophage φ174, later to ferritin and hemocyanin, and still later to ovalbumin but not at all to diptheria toxoid (Sterzl and Silverstein, 1967). Those studies and comparable studies on embryonating chicks (Brambell, 1970) demonstrate that immunological competence does not arise simultaneously for all antigens. Moreover, competence continues to mature post-term, and it becomes greatly enhanced by multiple contacts with literally hundreds of different antigens. Thus, the logical inference is that passive immunity is required because the