Effect of selection for growth rate and inheritance on posthatch muscle development in turkeys

Abstract

The inheritance of, and effect of selection for increased BW on, measurements of muscle fibers and extracellular space in turkeys were studied using a randombred control line (RBC2), a subline (F) of RBC2 selected long-term only for increased 16 wk BW, a commercial sire line (B), and reciprocal crosses of the F and B lines. Measures of additive genetic variation were obtained by comparing all of the pure lines or just the large-bodied F and B lines. Estimates of nonadditive genetic variation were obtained by contrasting the average of the reciprocal crosses with the average of the parental lines. A contrast of the reciprocal crosses provided estimates of sex linkage or maternal effects. Samples of pectoralis major muscle were obtained from three males and three females of each genetic group at 1, 4, 8, and 16 wk of age in a manner to avoid muscle contraction. After fixing and cross sectioning, the muscle samples were stained with hematoxylin and eosin to view muscle morphology. The stained sections were analyzed for muscle fiber width, muscle fiber bundle width (except at 16 wk of age), number of fibers within a 136-microm2 area, and extracellular matrix perimysial (PW) and endomysial (EW) width. Additive genetic variation, as measured by line differences, of measures of muscle fibers and extracellular matrix was a more important source of variation when the RBC2 line was included in the comparison. When all of the pure lines were compared, line differences were significant for fiber bundle width at 4 wk of age; individual fiber width and number of fibers in a given area at 4, 8, and 16 wk of age; PW at all ages; and EW at 1, 8, and 16 wk of age. With the possible exception of PW, nonadditive genetic variation was not an important source of variation for muscle measurements. For PW, the estimates of heterosis were -14.6, 26.4, 14.5, and 17.3% at 1, 4, 8, and 16 wk of age, respectively, but none of the values was significant (P > 0.05). Genetic increases in BW were associated with an increase in muscle fiber width, a smaller number of fibers in a given area, and less extracellular space at older ages. Apparent differences in growth patterns among the genetic groups may have been responsible for the different patterns of change in muscle measurements in the various genetic groups over ages.

The effect of early posthatch local feed in pectoralis muscle of Jawa Super chicks (Gallus gallus domesticus)

“…Paraffin blocks then were cut by rotary microtome in 5 mm and then fixing was done using preparation glass. The next step is deparaffination and rehydration with xylene and alcohol [16].…”

The metabolic rate of cultured muscle cells from hybrid Coturnix quail is intermediate to that of muscle cells from fast-growing and slow-growing Coturnix quail

“…Cells were suspended in media and left in an incubator at 37 °C, and in an atmosphere of 5 % CO 2 and O 2 , for 1 h before being transferred to a culture flask for growth. This technique helped to reduce contamination by other cell types, namely fibroblasts, because these cells tend to adhere to a culture plate before myoblasts (Velleman et al 2003). We also visually assessed the morphology of the cells and discarded cultures that appeared to contain fibroblasts.…”

“…Fibroblast growth factor is a potent stimulator of muscle cell proliferation, and prevents the differentiation of these cells (Velleman et al 2003). At 60 % confluence, we suspended cells by placing them in 0.05 % trypsin and froze them in liquid nitrogen.…”

The ontogeny of delta-like protein 1 messenger ribonucleic acid expression during muscle development and regeneration: Comparison of broiler and Leghorn chickens

“…The skin was immediately removed from the breast region after euthanizing the birds, and a sample of the pectoralis major muscle, approximately 0.5 × 3.0 cm, was obtained by carefully dissecting muscle fibers following the orientation in a manner to prevent contraction (Velleman et al, 2003). Injury samples were taken from the area (right side of pectoralis major) of muscle injury of the chicken breast muscle, whereas control samples were taken from the uninjured left side of pectoralis major muscle.…”

“…Injury samples were taken from the area (right side of pectoralis major) of muscle injury of the chicken breast muscle, whereas control samples were taken from the uninjured left side of pectoralis major muscle. The tissue samples were dehydrated, cleared, embedded in paraffin, sectioned at 5 μm, and mounted on slides as previously reported (Velleman et al, 2003). Before staining with hematoxylin and eosin, the tissue sections were incubated and rehydrated (Velleman et al, 2002).…”