Effects of Light Environment and Pinealectomy on Growth and Thyroid Function in the Broiler Cockerel

Osol, J. G.; Foss, D. C.; Carew, L. B.

doi:10.3382/ps.0590647

Cited by 14 publications

(12 citation statements)

References 28 publications

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“…This observation does not support a previous study on cockerels (Osol et al 1980) in which pinealectomy was found not to affect levels of plasma thyroid hormones. However, the depressive action of the pineal gland on levels of plasma T4 is consistent with an inhibi¬ tory action of the pineal gland on the neuroendocrinethyroid axis as has been demonstrated in the rat and hamster (Vaughan et al 1982;Vriend, 1983).…”

Section: Discussioncontrasting

confidence: 99%

“…In birds, the role of the pineal gland in the control of thyroid function is uncertain. Pinealectomy in the quail causes an increase in the weight of the thyroid glands (Oishi & Lauber, 1974) but it was found not to affect levels of plasma thyroid hormones in cockerels exposed to 14h light: 10h darkness (14L: 10D) or to constant darkness (Osol, Ross & Carew, 1980) or to different ambient temperatures (Cogburn & Harrison, 1980). The present study was carried out in the chicken to determine whether the pineal gland plays a role in regulating levels of plasma T4 and T3, taking into account the daily rhythms in plasma levels of these hormones (Klandorf, Sharp & Duncan, 1978a;Klandorf, Sharp & MacCleod, 1981a;Klandorf, Sharp & Newcomer, 198le;Sharp & Klandorf, 1984).…”

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confidence: 97%

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Influence of lighting cycles on daily rhythms in concentrations of plasma tri-iodothyronine and thyroxine in intact and pinealectomized immature broiler hens (Gallus domesticus)

Sharp¹,

Klandorf²,

Lea³

1984

Journal of Endocrinology

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The effects of pinealectomy on the daily rhythms of concentrations of tri-iodothyronine (T3) and thyroxine (T4) were investigated in sexually immature female chickens exposed to 21-, 24- and 27-h cycles of light and darkness, or to extended periods of light or darkness for more than 24 h. In pinealectomized and control birds, rhythms in levels of plasma T3 and T4 were entrained by all lighting cycles and decreased in amplitude or disappeared in continuous light or darkness. In pinealectomized and control birds held on 21-h (11 h light:10 h darkness; 11L:10D) and 24-h (14L:10D) lighting cycles, the peak of the T4 rhythm coincided with, or lagged, the trough in the rhythm of T3 while in birds held on a 27-h (14L:13D) lighting cycle, the peak of the T4 rhythm preceded the trough in the rhythm of T3. Pinealectomy resulted in significant effects on the phases or amplitudes of rhythms of T3 or T4 in all lighting schedules except 4L:20D. However, these effects were not consistent in direction between experimental groups and were, therefore, of doubtful physiological significance. Pinealectomy increased the mean level of plasma T4 in birds exposed to continuous light or darkness or to 4L:20D. A corresponding reduction in mean levels of plasma T3 was seen in birds exposed to continuous light or darkness. It is concluded that under the lighting conditions investigated pinealectomy had no clear effect on the phases or amplitude of daily rhythms of levels of T4 or T3. However, after the effects of the feeding pattern on thyroid hormone rhythms imposed by the lighting cycle were removed by placing birds in constant lighting conditions, pinealectomy appeared to exert an inhibitory action on thyroid function.

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Section: Discussioncontrasting

confidence: 99%

mentioning

confidence: 97%

Influence of lighting cycles on daily rhythms in concentrations of plasma tri-iodothyronine and thyroxine in intact and pinealectomized immature broiler hens (Gallus domesticus)

Sharp¹,

Klandorf²,

Lea³

1984

Journal of Endocrinology

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“…These observations suggest improved performance could be obtained by tailoring the light wavelength environment as the bird ages. These observations may be related to the age-pineal-thyroid functions suggested by Oishi and Lauber (1974) and Osol et al (1980).…”

Section: (G)mentioning

confidence: 75%

“…Evaluation of the effect of energy-efficient light sources on laying hens suggests wavelengths being emitted may (Siopes and Wilson, 1980;Pyrzak et al, 1984Pyrzak et al, , 1986 or may not (Fitzsimmons and Cha, 1985;Darre and Spandorf, 1985) affect productivity. Foss et al (1972), Wabeck and Skuglund (1974), and Osol et al (1980) have shown that broiler performance is affected by the wavelength of light. Generally, these studies using monochromatic light suggest blue or green wavelengths enhance growth rate whereas red inhibits growth.…”

Section: Introductionmentioning

confidence: 99%

Broiler Performance When Reared Under Various Light Sources ,

Zimmermann

1988

Poultry Science

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Three trials were conducted to determine if modern energy-efficient light sources, which vary in wavelength emission, affect broiler growth performance. The effect of light source on growth performance was determined by measuring body weight, feed conversion, and livability at intervals throughout rearing and at market age in three flocks of approximately 3,600 broilers each. Illuminance within the light-proof experimental facility was approximately 5 1x and photoregimen was 1 h dark:23 h light. Trial 1 compared incandescent (IN), warm white fluorescent (WWF), and daylight fluorescent (DLF) light sources. The WWF source provided superior body weight compared to IN light but feed conversion ratios were similar. Both IN and WWF light sources resulted in better body weight and feed conversion than that of the DLF light source. Trial 2 used IN, WWF, DLF, PL-5 fluorescent (PLF), design white fluorescent (DWF), and high pressure sodium (HPS) light sources. The PLF source resulted in mean body weight significantly higher than those produced by IN, HPS, and DWF. No other significant differences were observed. Trial 3 used IN, WWF, DLF, PLF, HPS, and low pressure sodium (LPS) light sources. Feed conversion for the HPS treatment was superior to that of PLF and LPS treatments. No other significant differences were observed. Light source did not affect livability in any of the trials. These trials demonstrated that energy-efficient light sources varying in wavelength emission may affect broiler growth performance, but consistent differences were not observed. Generally, IN light sources may be replaced with more energy-efficient light sources without adverse effects on broiler growth performance.

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“…Ballard and Biellier (1975) reported that pinealectomy (PX) did not affect feed intake rhythms in adult chickens. Studies with immature chickens have demonstrated that the pineal gland can influence growth rates and feed efficiency, and this apparently does not involve any persistent change in feed intake, thyroid function, or metabolism (Cogburn and Harrison, 1977;Darre et al, 1980;Osol et al, 1980). Sayler and Wolfson (1968a,b) reported that PX of immature quail did not influence body weight but that blinding of intact or pinealectomized quail depressed body weight in females but not males.…”

Section: Introductionmentioning

confidence: 99%

Pineal Gland and Ocular Influences on Turkey Breeder Hens

Siopes

1987

Poultry Science

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Yearling Large White turkey breeder hens underwent pinealectomy (PX), bilateral ocular enucleation (EX), or both and were then photo-induced into reproductive activity. During the subsequent 20-week reproductive period, data were recorded for body weight, change in body weight, feed intake, egg weight, eggshell thickness, and percent settable eggs. A significant interaction between PX and EX treatments did not occur for any of the parameters of this study. Absolute body weight, feed intake, shell thickness, and percent settable eggs were not significantly affected by PX during the study, but PX significantly increased egg weights. Feed intake was significantly reduced by EX, but other parameters were not affected. Both PX and EX reduced body weight losses typically observed in breeder hens during an in-season egg laying cycle. It was concluded that the pineal gland and the eyes can influence body weight changes, egg size, or feed intake in breeder turkey hens during a reproductive cycle.

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Effects of Light Environment and Pinealectomy on Growth and Thyroid Function in the Broiler Cockerel

Cited by 14 publications

References 28 publications

Influence of lighting cycles on daily rhythms in concentrations of plasma tri-iodothyronine and thyroxine in intact and pinealectomized immature broiler hens (Gallus domesticus)

Influence of lighting cycles on daily rhythms in concentrations of plasma tri-iodothyronine and thyroxine in intact and pinealectomized immature broiler hens (Gallus domesticus)

Broiler Performance When Reared Under Various Light Sources ,

Pineal Gland and Ocular Influences on Turkey Breeder Hens

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