The Influence of Early Nutrition on Muscle Development in the Poult

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Date

2005-02-14

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Abstract

The focus of the dissertation is on myonuclear accretion of the early post-hatch poult because an increase in myofiber size is limited to the number of myonuclei present and the ability of the myofiber to acquire new nuclei is not consistent from hatch to market. The objective of the first experiment was to develop a technique to manipulate the turkey fetus three days prior to hatch. In order to understand satellite cell mitotic activity, an injection of 5-Bromo-2'-deoxyuridine (BrdU), a thymidine analog, can be given and detected via immunohistochemistry. The post-hatch bird can be given an intra-peritoneal injection of BrdU; however, the hard shell surrounding the avian fetus makes it difficult to administer BrdU to a precise location in the fetus during late development in the turkey. A successful method was accomplished and employed in experiment two. The objectives of the second experiment were to study the injection of nutrients before hatch to the turkey fetus and to determine the influence of myogenic satellite cell mitotic activity and muscle development before hatch and immediately post-hatch. The nutrient injection did not improve muscle development following hatch when compared to a saline injected control. However, satellite cell mitotic activity was highest at day of hatch and one day of age when compared to one week of age indicating the importance of the first week post-hatch in muscle development. The objective of the third experiment was to determine the influence of beta-hydroxy beta-methylbutyrate (HMB) and fasting during the first week period on satellite cell mitotic activity, and muscle development. This experiment also employed BrdU injection for satellite cell mitotic activity determination. The detection of the protein Pax7, found in quiescent myogenic satellite cells and recently activated satellite cells, was employed in this experiment. Immediately fed poults given a diet containing HMB had higher body weights at 48 hours and one week of age, and had higher satellite cell mitotic activity at 48 hours of age compared to the immediately fed poults on a standard industry based starter diet and fasted poults. However, the fasted poults had the lowest amount of satellite cell mitotic activity at 48 hours post-hatch than the other two groups. Therefore, HMB may play an anabolic role in early post-hatch muscle development. The objectives of the fourth experiment were to examine the influence of fasting on skeletal muscle dynamics of the immediately post-hatch poult and to understand the skeletal muscle dynamics involving the satellite cell population. The experiment used BrdU, Pax7, Bcl-2, a cell marker found underneath the basal lamina of the myofiber. Fed poults had higher body weights throughout the experiment and had higher muscle weights at ten days of age than the fasted poults. Fed poults had higher satellite cell mitotic activity at 72 hours and four days of age compared to the fasted poults. However, Pax7 labeling index was higher in the fasted poults at 72 hours and four days post-hatch than the fed group. The results indicate that a level of fasting and nutrition during the first week post-hatch may influence the overall dynamics of muscle development involving satellite cell mitotic activity and the overall satellite cell population.

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Keywords

myogenic satellite cells, turkey

Citation

Degree

PhD

Discipline

Nutrition

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