Pattern of Growth and Plasma Growth Hormone Secretion in Turkeys Selected for Increased Egg Production

Anthony, Nicholas B.; Vasilatos‐Younken, R.; Emmerson, D. A.; Nestor, Karl E.

doi:10.3382/ps.0692057

Cited by 14 publications

(7 citation statements)

References 15 publications

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“…Plasma GH in the E line is higher than in its randombred control line at hatching but higher in the randombred control line from Weeks 7 to 28 of growth (Anthony et al, 1990). Eggs from the E line were smaller and contained less solids than those of the RBC2 line.…”

Section: Discussionmentioning

confidence: 88%

Effect of Maternal Dietary Triiodothyronine on Embryonic Physiology of Turkeys

Christensen

Donaldson

Nestor³

1993

Poultry Science

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The objective of the present experiment was to feed triiodothyronine (T3) to lines of turkey breeders selected for egg production and growth, and an unselected control line. The data were collected to determine a genetic basis for thyroid-mediated maternal effects on embryonic physiology and livability. At 30 wk of age, turkeys of the three lines were photostimulated and half of each line was fed a diet containing .5 ppm T3. Maternal dietary T3 increased egg weight, reduced yolk solids and eggshell conductance constants, and increased albumen solids and water in eggs in all lines compared with control eggs. Hatchability in all lines was not affected by the dietary treatment (Control = 72.2%; T3 treatment = 70.7%), but there was a significant interaction between dietary T3 and line of turkey for the time of embryonic mortality, time of hatching, and carbohydrate metabolism of the embryo. The T3 increased mortality of the Egg line and unselected line during pipping, increased mortality of the Growth line in the plateau stage, but decreased its mortality during internal pipping. Reduced glycogen in liver as well as a reduced gluconeogenesis were evident in embryos of the two selected lines fed T3. It is concluded that genetic lines may have different metabolic patterns based on their genetic constitution in order to compensate for variations in egg solids and eggshell conductance constants. The metabolic patterns are reflected in different levels of embryonic blood plasma glucose, glycogen, and gluconeogenesis.

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Section: Discussionmentioning

confidence: 88%

Effect of Maternal Dietary Triiodothyronine on Embryonic Physiology of Turkeys

Christensen

Donaldson

Nestor³

1993

Poultry Science

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“…Reduced BW resulting from selection for increased 180-day egg production observed in the current study was consistent with this negative correlation. Anthony et al (1990) reported this reduction in growth as a modification of magnitude rather than form. The shape of die growth curve was the same for RBC1 and me E line birds; however, BW at various points on the growth curve were larger for RBC1.…”

Section: Measurementmentioning

confidence: 90%

Genetics of Growth and Reproduction in the Turkey.

1991

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A line of turkeys selected 28 generations for increased 180-day egg production (E) was compared through regression analysis with the randombred control population (RBC1) from which it originated. The only curvilinear trends observed for RBC1 were for egg weight and 8-wk (both sexes) and 16-wk (males) BW. Linear declines in egg production and rate of lay through 84 and 180 days of lay, the number of clutches during the 180-day production period, effective days of egg production, and 16-wk (females) and 20-wk (both sexes) BW were observed for RBC1. The RBC1 turkeys had linear increases in the percentage of broody hens during the first 84 and 180 days of production, the average length of the broody period, and the total number of days lost to broodiness during the 180-day period. When expressed as a deviation from RBC1, positive quadratic curvilinear changes were observed for E turkeys for number of clutches and broody periods, and days lost to broodiness during the first 180 days of production. Percentage hatch of fertile eggs at 8 and 12 wk of production also exhibited a positive quadratic change with generation. Linear increases in egg production, rate of lay, clutch length (average and maximum), number of effective days of production, and percentage hatch of fertile eggs 12 wk into production were observed for E turkeys. There were linear declines in number of days from photostimulation to the production of first egg, number of clutches, and number, average length, and days lost to broodiness for E line turkeys.(ABSTRACT TRUNCATED AT 250 WORDS)

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“…Vasilatos-Younkin et al (1990) found total hepatic GH binding capacity did not differ between the RBC2 and F lines at 2, 4, 8,14, and 24 wk of age. Plasma GH was higher in Line E than in the RBCl line at hatching but higher in the RBCl line than in Line E from Weeks 7 to 28 (Anthony et al, 1990). Bacon et al (1993) measured plasma concentrations of insulin-like growth factor-I (IGF-I) in the RBC2 and F lines from 1 to 28 wk of age.…”

Section: Hormonal Measurements In the Turkey Linesmentioning

confidence: 99%

“…Reported estimates (Cook et al, 1962;Clayton, 1971;Arthur and Abplanalp, 1975) of the genetic correlation between egg production and BW were low (approximately -0.1). Anthony et al (1990) compared the growth curves of the E and RBC1 lines after 28 generations of selection in the E line. The pattern of growth of the two lines, as described by the Gompertz equation, was different in magnitude of growth (BW at point of inflection and asymptote) but not in form (slope and age at point of inflection and age at asymptote).…”

Section: Direct and Correlated Responses To Selectionmentioning

confidence: 99%

Direct and Correlated Responses to Long-Term Selection for Increased Body Weight and Egg Production in Turkeys

et al. 1996

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Lines of turkeys were selected long-term for increased egg production (E line; 34 generations) or increased 16-wk BW (F line; 28 generations). The E and F lines were started from randombred control populations (RBC1 and RBC2, respectively) that were also maintained to remove environmental variation among generations. Realized heritabilities (h2) +/- SE in the E line, based on regressions of response on cumulated actual selection differentials (selection differentials weighted for the number of offspring produced), for 180-d and 250-d egg production were 0.34 +/- 0.02 (17 generations) and 0.26 +/- 0.13 (8 generations), respectively. The realized h2 of 16-wk BW in the F line was 0.26 +/- 0.01. There was no consistent evidence of selection response reaching a plateau in either line. The genetic association of BW and egg production changed with selection in the E and F lines. The genetic correlation varied from near zero to strongly negative and fluctuated between these extremes in both lines even though they started from different base populations and selection criteria differed. Other correlated responses to selection for increased egg production were increased average clutch length (intensity of lay), and decreased broodiness (total days lost), egg weight, shell coloration, and rate of response to stimulatory lighting. Other correlated responses to selection for increased 16-wk BW in the F line included: increased egg weight (due to increased albumen), longer eating bouts, and decreased average clutch length, semen production, walking ability, and resistance to Pasteurella multocida and Newcastle disease virus. Selection within the E and F lines also changed the frequency of MHC haplotypes and the changes appeared to be in opposite directions in the two lines.

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Pattern of Growth and Plasma Growth Hormone Secretion in Turkeys Selected for Increased Egg Production

Cited by 14 publications

References 15 publications

Effect of Maternal Dietary Triiodothyronine on Embryonic Physiology of Turkeys

Effect of Maternal Dietary Triiodothyronine on Embryonic Physiology of Turkeys

Genetics of Growth and Reproduction in the Turkey.

Direct and Correlated Responses to Long-Term Selection for Increased Body Weight and Egg Production in Turkeys

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