INTRODUCTION
N. Maniatis and G. E. Pollott write about maternal environmental, cytoplasmic and maternal additive genetic effects. In this article were included studies of fat and muscle traits in sheep. Maniatis and Pollott conducted the environmental and genetic text by using ultrasound to measure the muscle and the fat depth. The two groups of maternal genetic and maternal environmental effects exist but according to these studies they do not find cytoplasmic effects.
The maternal effects are an important source of variation in fat and muscle traits but are often expelled from the research; this research seeks to address the omission. The hypothesis was that part of the indirect maternal effect is not quite implicit therefore the genes inherited by cytoplasm are unidentified.
MATERIAL AND METHODS
The experiments used in this study was six different models including maternal additive genetic, direct additive genetic, and maternal environmental. Also was included the lineage of animals. Then they used the information from past studies conducted by U.K. Suffolk sire reference scheme. The scientists also used the lumber vertebral to get the fat measures. In addition some of the records were obtained by using the vetscan B-mode scanners or by using ultrasonic technology. Therefore some of the studies were adjusted to fit the criteria from birth to weighing. Ultrasonic measure characteristics prove to be the best fit for the information. Also this studies show that Muscle and fat depth the maternal variation is inherited rather than environmental.
RESULTS
The result is the effects in some of the model decreased direct additive genetic variance.
On the other hand, the two resource traits in eight week weigh and scanning weight model six

was the best fit from all models tested. However between the models that were studied have demonstrated an example of irregularity that led the maternal variances has development to advance the negative correlation, "This indicates that some cross-h2 direct replacement with direct covariance mother may have taken place, which often occurs when the parameters are strongly correlated"(Mianiatis & Pollot 2012). According to the study of Tosh and Wilton were demonstrated that the prediction error variance was minimized when existing group centered on less than five animals were excluded from the analyses. This demonstrates the importance of the studies that errors found in groups with a limit of records. Therefore the groups of subclass that are smaller dismissed from examination, also information regarding animals that were raised with artificial mothers or with missing age or type of birth were excluded from the genetic examines for better results.
DISCUSSION
In conclusion the maternal genetic and environmental effects are substantial. However not conducting an in depth studies of this important concept can lead to further misunderstandings. On the contrary, maternal genetic and environmental effects go hand and hand; the study shows that cannot study one without the other because the environment in which the mother was raised affects the maternal genetics. The Scientists emphasize that the studies should be based on estimates from model that additive direct and maternal effects without much of the maternal ancestry. Also when the sheep are young the maternal effects are significant, but lessen with age. Beside that previous resource that has been done maternal environmental effect explain eighth percentage on the whole variation, which decreased six percentages from scanning weight. The importance of maternal effects both genetic and environmental on early weight and body compile characteristics, were overestimated and ignored. Therefore the studies

conclusion was more incomplete because they need more information about additive direct and maternal effects.

Work sited
N. Maniatis and G. E. Pollott. “Nuclear, cytoplasmic, and environmental effects on growth, fat, and muscle traits in Suffolk lacbs from a sire referencing scheme”. Journal of Animal
Science 2002, 80:57-67 may 24,2012 web.