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Wayne L Bacon - One of the best experts on this subject based on the ideXlab platform.
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2001a. Preovulatory luteinizing hormone surge interval in old and young laying Turkey Hens early in the egg production period. Poult. Sci
2016Co-Authors: -k. H. Liu, David W Long, Wayne L BaconAbstract:ABSTRACT Egg production rate normally declines with duration of the reproductive period, but hen age and duration of the reproductive period are usually con-founded. Initiation of egg production can be delayed in Turkey Hens with short-day lighting, allowing hen age to be separated from duration of the reproductive period. The objective of the present report is to determine if the interval between luteinizing hormone (LH) surges is dif-ferent between old and young laying Turkey Hens during the peak of egg production. Turkey Hens were given short-day lighting [6 h light (L):18 h darkness (D)] at 16 wk of age, and were photostimulated with 24L:0
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Frequency of luteinizing hormone surges and egg production rate in Turkey Hens
2016Co-Authors: -k. H. Liu, David W Long, K. E. Nestor, Wayne L BaconAbstract:Whether the interval between preovulatory surges of LH was different between lines of Turkey Hens with either poor (RBC3 line, peak at 55%) or excellent rate of egg production (Egg line, peak at 85%) was examined. Laying Hens were cannulated and bled hourly for 10 days at peak of production. A constant light photoschedule was used to avoid diurnal masking of innate cir-cadian rhythms. The mean interval between LH surges in the RBC3 line was longer than in the Egg line and had a higher coefficient of variation. A few longer LH surge intervals (.72 h) were found in some RBC3 line Hens (2 of 7 Hens), but none were found in Egg line Hens (0 of 11 Hens). All progesterone (P4) surges were coupled with LH surges, but not all LH-P4 surges were coupled with ovipositions (blind LH-P4 surges). The per-centage of blind LH-P4 surges was not different between lines. The baseline concentration of LH was higher in Egg line than RBC3 line Hens, but LH surge amplitude, and surge duration were not different. The baseline and surge amplitude concen-trations of P4 were not different between lines, nor was the con-centration of estradiol-17b. The longer interval between LH surges was the major factor tested that was associated with the poorer egg production rate in RBC3 line Hens in comparison to Egg line Hens. A higher incidence of blind LH surges further contributed to lower egg production in RBC3 line Turkey Hens. estradiol, luteinizing hormone, ovulation, ovulatory cycle, pro-gesteron
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Progesterone Injection and Egg Production in Turkey Hens
Biology of reproduction, 2004Co-Authors: Wayne L Bacon, Han-ken LiuAbstract:Abstract An arrest in laying associated with either a polyovarian follicle (POF) or a polycystic ovarian follicle (PCOF) syndrome has been reported in Turkey Hens photostimulated at an early age with a constant-light photoperiod. Hens expressing the POF or PCOF syndrome had stopped laying for several weeks, but the ovary contained an increased number of mature-size and larger follicles (POF Hens), which were cystic (PCOF) in some of the Hens. Hens with the POF or PCOF syndrome had plasma progesterone (P4) concentrations that were relatively high and without surges. We hypothesized that high plasma P4 concentrations may block ovulatory surges of LH but not the growth or maintenance of hierarchical follicles leading to development of the POF or PCOF syndrome in Turkey Hens. In the first six studies, Hens were photostimulated with either a 14L:10D or a 24L:0D photoperiod and, after laying for 1–38 wk, were then injected daily for up to 14 days with P4 (up to 1.50 mg kg−1 day−1) and necropsied. At all ages, t...
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Interval between preovulatory surges of luteinizing hormone increases late in the reproductive period in Turkey Hens.
Biology of reproduction, 2002Co-Authors: Han-ken Liu, David W Long, Wayne L BaconAbstract:In Turkey Hens, the egg production rate is relatively high early during a reproductive period, but declines as the period progresses. Among lines with different egg production potential, the interval between preovulatory surges of LH is the primary determinant of the egg production rate. The main objective of this study was to determine whether the decline in egg production rate late during an egg production period is also associated with a difference in the interval between LH preovulatory surges. A group of photosensitive Turkey Hens (Early) were photostimulated with continuous light (24L:0D) at 40 wk of age to induce egg laying, and serial blood samples were collected after about 3 wk of egg production. A second group of Hens (Late) were housed in floor pens and photostimulated with 14L:10D at 40 wk of age for a normal 36-wk reproduction period and were then switched to 24L:0D lighting for 2 wk before collection of serial blood samples. Continuous light photostimulation was used for at least 2 wk before and during serial blood sampling to avoid potential masking effects of diurnal lighting on the interval between LH surges. The Early (n = 12) and Late (n = 16) Hens were cannulated 3 days before being serially bled hourly for 10 days. The mean interval between preovulatory surges of LH was shorter in the Early Hens than in the Late Hens (26.1 ± 2.5 h and 34.7 ± 3.9 h, respectively). The intra-hen LH surge interval coefficient of variation was lower in the Early Hens than in the Late Hens (7.2% and 18.6%, respectively). The inter-hen LH surge interval coefficient of variation was similar in the Early and Late Hens (9.5% and 11.2%, respectively). The incidence of blind surges of LH (those not retrospectively associated with ovipositions) was not different between Early and Late laying Hens (8.4% ± 15.2% and 7.3% ± 14.6%, respectively). In conclusion, in Turkey Hens, longer intervals and greater intra-hen variation between LH surges were associated with a poorer rate of egg production late in the reproductive period relative to early in the reproductive period.
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preovulatory luteinizing hormone surge interval in old and young laying Turkey Hens early in the egg production period
Poultry Science, 2001Co-Authors: H K Liu, David W Long, Wayne L BaconAbstract:Egg production rate normally declines with duration of the reproductive period, but hen age and duration of the reproductive period are usually confounded. Initiation of egg production can be delayed in Turkey Hens with short-day lighting, allowing hen age to be separated from duration of the reproductive period. The objective of the present report is to determine if the interval between luteinizing hormone (LH) surges is different between old and young laying Turkey Hens during the peak of egg production. Turkey Hens were given short-day lighting [6 h light (L):18 h darkness (D)] at 16 wk of age, and were photostimulated with 24L:OD (constant light) at 30 (young Hens) or at 70 (old Hens) wk of age. Egg production in the young Hens started about 2 wk after they were photostimulated, but some of the old Hens had started laying at 64 wk of age while under short-day lighting, and all old Hens were laying after 1 wk of photostimulation. To monitor the interval between plasma LH surges at peak of production, Hens were serially bled hourly for 240 h, starting about 6 wk after photostimulation. The interval of LH surges was not different between young (n = 5) and old (n = 10) laying Hens. Not all LH surges were coincident with oviposition of eggs 1 to 2 d later (blind LH surges), and the percentage of young Hens with at least one blind LH surge was higher than for old Hens (60% of young Hens and 10% of old Hens). The baseline concentration of LH was not different between the young and old laying Hens. In conclusion, the interval between LH surges, baseline concentration of LH, and amplitude of LH surges were not related to age of the Hens during the peak rate of lay.
Katarzyna Ognik - One of the best experts on this subject based on the ideXlab platform.
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Modification of the lipid profile and antioxidant status of the blood plasma of Turkey Hens fed mixtures with raw or extruded linseed.
Journal of animal physiology and animal nutrition, 2017Co-Authors: Anna Czech, Katarzyna Ognik, Monika Laszewska, Ewelina Cholewińska, Anna StępniowskaAbstract:The aim of the study was to determine the most beneficial proportion of raw linseed in complete feed mixtures for Turkey Hens on the basis of lipid and redox indicators in the blood. In experiment 1, the Turkey Hens received the complete mixture with 2%, 4% or 6% linseed. On the basis of the results obtained in experiment 1, we selected the most effective proportion of linseed, which was given to the birds in the group receiving a 4% linseed additive. In experiment 2, the birds were fed mixtures with a 4% addition of raw or extruded linseed. The use of 4% raw linseed was found to improve production effects (improvement of weight gain, and lower feed conversion ratios), while extruded linseed in the diet of Turkey Hens did not affect growth performance. The use of linseed (4% and 6%) as a feed component for Turkey Hens led to an increase in indicators of antioxidant potential, that is the total antioxidant potential of the plasma, vitamins E and C, bilirubin and creatinine. A benefit resulting from the use of linseed, particularly in the amounts of 2% and 4% was a marked improvement in lipid indicators in the blood. The reduced percentage of unsaturated fatty acids (n-3) following the use of extruded linseed resulted in a decrease in lipid peroxidation (lower content of malondialdehyde, superoxide and vitamins C and E in the blood). The most effective dose and form of linseed in the diet of Turkey Hens is 4% raw linseed.
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The Effect of Adding Hesperidin, Diosmin, Quercetin and Resveratrol Extracts to Feed for Turkey Hens on Selected Immunological and Biochemical Blood Indices
Annals of Animal Science, 2016Co-Authors: Katarzyna Ognik, Ewelina Cholewińska, Anna CzechAbstract:Abstract It was postulated that naturally occurring phenolic compounds obtained from various plant species may have potential use as feed additives for poultry. Therefore the aim of the study was to compare extracts of hesperidin, diosmin, quercetin and resveratrol in terms of their health-promoting (particularly immunostimulatory) effect on Turkeys at different ages. The experiment was conducted on 720 Big 6 Turkey Hens assigned to 6 experimental groups of 120 individuals (6 repetitions with 20 birds each). The Turkey Hens in group G-C were the control, receiving a basal compound feed with no experimental additives. The Turkey Hens in the remaining groups, from the first to the 16th week of life, received a basal diet containing hesperidin (group G-H), diosmin (group G-D), quercetin (group G-Q) or resveratrol (group G-R) in the amount of 200 g per tonne of feed. Ht, Hb, RBC, WBC, lysozyme activity, %PC, IgA, IL-6, GLU, TP and minerals were determined in blood samples. The addition of quercetin or resveratrol in the amount of 200 g per tonne of feed was found to have a beneficial effect on haemoglobin synthesis and phosphorus availability, and may also modulate immunity in Turkey Hens.
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Effect of aloe preparation and 5-oxo-1,2,4-triazine on mineral composition of tissues of Turkey Hens subjected to stress
Journal of Applied Animal Research, 2016Co-Authors: Katarzyna Ognik, Anna Czech, Anna Stępniowska, Iwona Sembratowicz, Ewelina CholewińskaAbstract:ABSTRACTThe aim of this study was to determine the influence of aloe preparation and 5-oxo-1,2,4-triazine on mineral composition of muscles and liver of Turkey Hens under conditions of stress. Groups C and C (+)stress were control that did not receive any additive. Birds from groups A and A (+)stress were administered aloe preparation in a dose of 0.70 ml/kg (BW)/day. Turkey Hens from groups T and T (+)stress received 5-oxo-1,2,4-triazine in a dose of 30 μg/kg BW/day. The applied stress factors did not affect the mineral composition of the analysed tissues of Turkey Hens. Administration of 5-oxo-1,2,4-triazine caused a significant decrease in iron concentration and an increase in zinc concentration in thigh muscles and liver. In turn, aloe preparation contributed to an increase in tissue levels of calcium (except for shank muscles), zinc (in leg muscles and liver) and copper (in thigh muscles). A decrease in iron concentration in leg muscles and liver in birds supplemented with aloe preparation was also d...
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The effect of aloe preparation and 5-oxo-1,2,4-triazine on immunological and haematological indices of blood of Turkey Hens subjected to stress
Acta Veterinaria Brno, 2015Co-Authors: Katarzyna Ognik, Iwona Sembratowicz, Anna CzechAbstract:The aim of this study was to determine the effect of aloe extract or 5-oxo-1,2,4-triazine on immunological and haematological indices during artificially induced stress in Turkey Hens. The experiment was carried out on 360 Turkey Hens (6 groups). The groups C and C+stress were the control groups and did not receive any additive. Birds from the groups A and A+stress were administered aloe extract at the amount of 0.70 ml/kg body weight (bw)/day. The Turkey Hens from the groups T and T+stress received 5-oxo-1,2,4-triazine at the amount of 30 μg/kg bw/day. The additives were administered in the birds’ drinking water twice for 28 days (days 36–63 and 78–105) of the birds’ life. On days 61–63 and 103–105 a stress factor (simultaneous crowding and a change in temperature and lighting) was introduced in the groups C+stress, A+stress and T+stress for 1 hour a day. The results showed that the applied stress factors caused a significant (P ≤ 0.05) decrease in the lysozyme level and % phagocytic cells, as well as a non-significant reduction in the metabolic activity of heterophils. Under the influence of stress an increase (P ≤ 0.05) in the percentage of monocytes and basophils was observed. The use of aloe preparation improved some indicators of immunity (increased, P ≤ 0.05, lysozyme and % phagocytic cells) in the Turkey Hens. To alleviate the negative effect of stress on immune reactions, supplementation of diets with aloe extract supplemented with resveratrol and vitamin C may be considered. Poultry, stressors, supplements, immunity The response of the immune system to stress may vary depending on the type and intensity of stress factors and the time of exposure. Stress conditions may inhibit or stimulate the immune response, change its type, and modulate autoimmune phenomena (Zimecki and Artym 2004). Stress factors can also modify the morphology of blood – both white blood cell and red blood cell indices (Qureshi et al. 2002). To counteract the adverse effects of stress on the defensive reactions and morphology of the blood of birds, it is advisable to use immunostimulating and biostimulating preparations, both synthetic and natural. Among natural immunostimulants, herbal preparations prepared from the coneflower, garlic, aloe and other plants have an important role in animal feeding (Ognik et al. 2013). The immunostimulatory properties of aloe extracts have been confirmed in studies on Turkeys (Ognik and Sembratowicz 2012a). Improvements in haematological and immunological indices in Turkeys have also been demonstrated for the newly-synthesized amidrazone derivative 5-oxo-1,2,4-triazine (Ognik and Sembratowicz 2009). This compound exhibits anti-inflammatory, antibacterial, antiviral, and antifungal (in vitro analysis) properties (Modzelewska-Banachiewicz and Kaminska 2000). Taking into account the biological properties of aloe extracts and the newly synthesized amidrazone derivative 5-oxo-1,2,4-triazine, the aim of this study was to determine their effect on immunological and haematological indices during artificially induced stress in Turkey Hens. ACTA VET. BRNO 2015, 84: 365-371; doi:10.2754/avb201584040365 Address for correspondence: Katarzyna Ognik Department of Biochemistry and Toxicology Faculty of Animal and Breeding University of Life Sciences Ul Akademicka 13, 20-950 Lublin, Poland Phone: +48 81 445 69 31 E-mail: kasiaognik@poczta.fm http://actavet.vfu.cz/
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The effect of yeast Yarrowia lipolytica on the antioxidant indices and macro-and microelements in blood plasma of Turkey Hens.
Polish journal of veterinary sciences, 2015Co-Authors: Malwina Merska, Anna Czech, Katarzyna OgnikAbstract:The aim of the study was to assess the effect of different amounts of Yarrowia lipolytica yeast on the redox response and content of macro- and microelements in the blood plasma of Turkey Hens. The experiment was carried out on 240 Turkey Hens aged from 1 to 16 weeks. The birds were randomly assigned to 3 experimental groups of 80 birds each. Group I served as a control (K) and did not receive any experimental compounds. The Turkey Hens from the experimental groups (YL3 and YL6) were administered dried Yarrowia lipolytica yeast in their feed mixtures in the amount of 3% (YL3) or 6% (YL6). Yarrowia lipolytica yeast in the feed mixtures for the Turkey Hens did not induce oxidation reactions in the organism of the birds. However, an increase in catalase activity and a reduction in the level of LOOH, MDA and vitamin C were observed in the blood plasma of the Turkey Hens whose diet was supplemented with YL yeast. In the case of other indices, such as superoxide dismutase activity and total antioxidant potential (FRAP), the additive caused no significant changes. Administering Yarrowia lipolytica yeast to Turkey Hens may stimulate the enzymatic response of the antioxidant system (e.g. increasing catalase activity), mainly by increasing the concentration of iron in the plasma.
Anna Czech - One of the best experts on this subject based on the ideXlab platform.
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Modification of the lipid profile and antioxidant status of the blood plasma of Turkey Hens fed mixtures with raw or extruded linseed.
Journal of animal physiology and animal nutrition, 2017Co-Authors: Anna Czech, Katarzyna Ognik, Monika Laszewska, Ewelina Cholewińska, Anna StępniowskaAbstract:The aim of the study was to determine the most beneficial proportion of raw linseed in complete feed mixtures for Turkey Hens on the basis of lipid and redox indicators in the blood. In experiment 1, the Turkey Hens received the complete mixture with 2%, 4% or 6% linseed. On the basis of the results obtained in experiment 1, we selected the most effective proportion of linseed, which was given to the birds in the group receiving a 4% linseed additive. In experiment 2, the birds were fed mixtures with a 4% addition of raw or extruded linseed. The use of 4% raw linseed was found to improve production effects (improvement of weight gain, and lower feed conversion ratios), while extruded linseed in the diet of Turkey Hens did not affect growth performance. The use of linseed (4% and 6%) as a feed component for Turkey Hens led to an increase in indicators of antioxidant potential, that is the total antioxidant potential of the plasma, vitamins E and C, bilirubin and creatinine. A benefit resulting from the use of linseed, particularly in the amounts of 2% and 4% was a marked improvement in lipid indicators in the blood. The reduced percentage of unsaturated fatty acids (n-3) following the use of extruded linseed resulted in a decrease in lipid peroxidation (lower content of malondialdehyde, superoxide and vitamins C and E in the blood). The most effective dose and form of linseed in the diet of Turkey Hens is 4% raw linseed.
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The Effect of Adding Hesperidin, Diosmin, Quercetin and Resveratrol Extracts to Feed for Turkey Hens on Selected Immunological and Biochemical Blood Indices
Annals of Animal Science, 2016Co-Authors: Katarzyna Ognik, Ewelina Cholewińska, Anna CzechAbstract:Abstract It was postulated that naturally occurring phenolic compounds obtained from various plant species may have potential use as feed additives for poultry. Therefore the aim of the study was to compare extracts of hesperidin, diosmin, quercetin and resveratrol in terms of their health-promoting (particularly immunostimulatory) effect on Turkeys at different ages. The experiment was conducted on 720 Big 6 Turkey Hens assigned to 6 experimental groups of 120 individuals (6 repetitions with 20 birds each). The Turkey Hens in group G-C were the control, receiving a basal compound feed with no experimental additives. The Turkey Hens in the remaining groups, from the first to the 16th week of life, received a basal diet containing hesperidin (group G-H), diosmin (group G-D), quercetin (group G-Q) or resveratrol (group G-R) in the amount of 200 g per tonne of feed. Ht, Hb, RBC, WBC, lysozyme activity, %PC, IgA, IL-6, GLU, TP and minerals were determined in blood samples. The addition of quercetin or resveratrol in the amount of 200 g per tonne of feed was found to have a beneficial effect on haemoglobin synthesis and phosphorus availability, and may also modulate immunity in Turkey Hens.
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Effect of aloe preparation and 5-oxo-1,2,4-triazine on mineral composition of tissues of Turkey Hens subjected to stress
Journal of Applied Animal Research, 2016Co-Authors: Katarzyna Ognik, Anna Czech, Anna Stępniowska, Iwona Sembratowicz, Ewelina CholewińskaAbstract:ABSTRACTThe aim of this study was to determine the influence of aloe preparation and 5-oxo-1,2,4-triazine on mineral composition of muscles and liver of Turkey Hens under conditions of stress. Groups C and C (+)stress were control that did not receive any additive. Birds from groups A and A (+)stress were administered aloe preparation in a dose of 0.70 ml/kg (BW)/day. Turkey Hens from groups T and T (+)stress received 5-oxo-1,2,4-triazine in a dose of 30 μg/kg BW/day. The applied stress factors did not affect the mineral composition of the analysed tissues of Turkey Hens. Administration of 5-oxo-1,2,4-triazine caused a significant decrease in iron concentration and an increase in zinc concentration in thigh muscles and liver. In turn, aloe preparation contributed to an increase in tissue levels of calcium (except for shank muscles), zinc (in leg muscles and liver) and copper (in thigh muscles). A decrease in iron concentration in leg muscles and liver in birds supplemented with aloe preparation was also d...
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The effect of aloe preparation and 5-oxo-1,2,4-triazine on immunological and haematological indices of blood of Turkey Hens subjected to stress
Acta Veterinaria Brno, 2015Co-Authors: Katarzyna Ognik, Iwona Sembratowicz, Anna CzechAbstract:The aim of this study was to determine the effect of aloe extract or 5-oxo-1,2,4-triazine on immunological and haematological indices during artificially induced stress in Turkey Hens. The experiment was carried out on 360 Turkey Hens (6 groups). The groups C and C+stress were the control groups and did not receive any additive. Birds from the groups A and A+stress were administered aloe extract at the amount of 0.70 ml/kg body weight (bw)/day. The Turkey Hens from the groups T and T+stress received 5-oxo-1,2,4-triazine at the amount of 30 μg/kg bw/day. The additives were administered in the birds’ drinking water twice for 28 days (days 36–63 and 78–105) of the birds’ life. On days 61–63 and 103–105 a stress factor (simultaneous crowding and a change in temperature and lighting) was introduced in the groups C+stress, A+stress and T+stress for 1 hour a day. The results showed that the applied stress factors caused a significant (P ≤ 0.05) decrease in the lysozyme level and % phagocytic cells, as well as a non-significant reduction in the metabolic activity of heterophils. Under the influence of stress an increase (P ≤ 0.05) in the percentage of monocytes and basophils was observed. The use of aloe preparation improved some indicators of immunity (increased, P ≤ 0.05, lysozyme and % phagocytic cells) in the Turkey Hens. To alleviate the negative effect of stress on immune reactions, supplementation of diets with aloe extract supplemented with resveratrol and vitamin C may be considered. Poultry, stressors, supplements, immunity The response of the immune system to stress may vary depending on the type and intensity of stress factors and the time of exposure. Stress conditions may inhibit or stimulate the immune response, change its type, and modulate autoimmune phenomena (Zimecki and Artym 2004). Stress factors can also modify the morphology of blood – both white blood cell and red blood cell indices (Qureshi et al. 2002). To counteract the adverse effects of stress on the defensive reactions and morphology of the blood of birds, it is advisable to use immunostimulating and biostimulating preparations, both synthetic and natural. Among natural immunostimulants, herbal preparations prepared from the coneflower, garlic, aloe and other plants have an important role in animal feeding (Ognik et al. 2013). The immunostimulatory properties of aloe extracts have been confirmed in studies on Turkeys (Ognik and Sembratowicz 2012a). Improvements in haematological and immunological indices in Turkeys have also been demonstrated for the newly-synthesized amidrazone derivative 5-oxo-1,2,4-triazine (Ognik and Sembratowicz 2009). This compound exhibits anti-inflammatory, antibacterial, antiviral, and antifungal (in vitro analysis) properties (Modzelewska-Banachiewicz and Kaminska 2000). Taking into account the biological properties of aloe extracts and the newly synthesized amidrazone derivative 5-oxo-1,2,4-triazine, the aim of this study was to determine their effect on immunological and haematological indices during artificially induced stress in Turkey Hens. ACTA VET. BRNO 2015, 84: 365-371; doi:10.2754/avb201584040365 Address for correspondence: Katarzyna Ognik Department of Biochemistry and Toxicology Faculty of Animal and Breeding University of Life Sciences Ul Akademicka 13, 20-950 Lublin, Poland Phone: +48 81 445 69 31 E-mail: kasiaognik@poczta.fm http://actavet.vfu.cz/
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The effect of yeast Yarrowia lipolytica on the antioxidant indices and macro-and microelements in blood plasma of Turkey Hens.
Polish journal of veterinary sciences, 2015Co-Authors: Malwina Merska, Anna Czech, Katarzyna OgnikAbstract:The aim of the study was to assess the effect of different amounts of Yarrowia lipolytica yeast on the redox response and content of macro- and microelements in the blood plasma of Turkey Hens. The experiment was carried out on 240 Turkey Hens aged from 1 to 16 weeks. The birds were randomly assigned to 3 experimental groups of 80 birds each. Group I served as a control (K) and did not receive any experimental compounds. The Turkey Hens from the experimental groups (YL3 and YL6) were administered dried Yarrowia lipolytica yeast in their feed mixtures in the amount of 3% (YL3) or 6% (YL6). Yarrowia lipolytica yeast in the feed mixtures for the Turkey Hens did not induce oxidation reactions in the organism of the birds. However, an increase in catalase activity and a reduction in the level of LOOH, MDA and vitamin C were observed in the blood plasma of the Turkey Hens whose diet was supplemented with YL yeast. In the case of other indices, such as superoxide dismutase activity and total antioxidant potential (FRAP), the additive caused no significant changes. Administering Yarrowia lipolytica yeast to Turkey Hens may stimulate the enzymatic response of the antioxidant system (e.g. increasing catalase activity), mainly by increasing the concentration of iron in the plasma.
David W Long - One of the best experts on this subject based on the ideXlab platform.
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2001a. Preovulatory luteinizing hormone surge interval in old and young laying Turkey Hens early in the egg production period. Poult. Sci
2016Co-Authors: -k. H. Liu, David W Long, Wayne L BaconAbstract:ABSTRACT Egg production rate normally declines with duration of the reproductive period, but hen age and duration of the reproductive period are usually con-founded. Initiation of egg production can be delayed in Turkey Hens with short-day lighting, allowing hen age to be separated from duration of the reproductive period. The objective of the present report is to determine if the interval between luteinizing hormone (LH) surges is dif-ferent between old and young laying Turkey Hens during the peak of egg production. Turkey Hens were given short-day lighting [6 h light (L):18 h darkness (D)] at 16 wk of age, and were photostimulated with 24L:0
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Frequency of luteinizing hormone surges and egg production rate in Turkey Hens
2016Co-Authors: -k. H. Liu, David W Long, K. E. Nestor, Wayne L BaconAbstract:Whether the interval between preovulatory surges of LH was different between lines of Turkey Hens with either poor (RBC3 line, peak at 55%) or excellent rate of egg production (Egg line, peak at 85%) was examined. Laying Hens were cannulated and bled hourly for 10 days at peak of production. A constant light photoschedule was used to avoid diurnal masking of innate cir-cadian rhythms. The mean interval between LH surges in the RBC3 line was longer than in the Egg line and had a higher coefficient of variation. A few longer LH surge intervals (.72 h) were found in some RBC3 line Hens (2 of 7 Hens), but none were found in Egg line Hens (0 of 11 Hens). All progesterone (P4) surges were coupled with LH surges, but not all LH-P4 surges were coupled with ovipositions (blind LH-P4 surges). The per-centage of blind LH-P4 surges was not different between lines. The baseline concentration of LH was higher in Egg line than RBC3 line Hens, but LH surge amplitude, and surge duration were not different. The baseline and surge amplitude concen-trations of P4 were not different between lines, nor was the con-centration of estradiol-17b. The longer interval between LH surges was the major factor tested that was associated with the poorer egg production rate in RBC3 line Hens in comparison to Egg line Hens. A higher incidence of blind LH surges further contributed to lower egg production in RBC3 line Turkey Hens. estradiol, luteinizing hormone, ovulation, ovulatory cycle, pro-gesteron
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Interval between preovulatory surges of luteinizing hormone increases late in the reproductive period in Turkey Hens.
Biology of reproduction, 2002Co-Authors: Han-ken Liu, David W Long, Wayne L BaconAbstract:In Turkey Hens, the egg production rate is relatively high early during a reproductive period, but declines as the period progresses. Among lines with different egg production potential, the interval between preovulatory surges of LH is the primary determinant of the egg production rate. The main objective of this study was to determine whether the decline in egg production rate late during an egg production period is also associated with a difference in the interval between LH preovulatory surges. A group of photosensitive Turkey Hens (Early) were photostimulated with continuous light (24L:0D) at 40 wk of age to induce egg laying, and serial blood samples were collected after about 3 wk of egg production. A second group of Hens (Late) were housed in floor pens and photostimulated with 14L:10D at 40 wk of age for a normal 36-wk reproduction period and were then switched to 24L:0D lighting for 2 wk before collection of serial blood samples. Continuous light photostimulation was used for at least 2 wk before and during serial blood sampling to avoid potential masking effects of diurnal lighting on the interval between LH surges. The Early (n = 12) and Late (n = 16) Hens were cannulated 3 days before being serially bled hourly for 10 days. The mean interval between preovulatory surges of LH was shorter in the Early Hens than in the Late Hens (26.1 ± 2.5 h and 34.7 ± 3.9 h, respectively). The intra-hen LH surge interval coefficient of variation was lower in the Early Hens than in the Late Hens (7.2% and 18.6%, respectively). The inter-hen LH surge interval coefficient of variation was similar in the Early and Late Hens (9.5% and 11.2%, respectively). The incidence of blind surges of LH (those not retrospectively associated with ovipositions) was not different between Early and Late laying Hens (8.4% ± 15.2% and 7.3% ± 14.6%, respectively). In conclusion, in Turkey Hens, longer intervals and greater intra-hen variation between LH surges were associated with a poorer rate of egg production late in the reproductive period relative to early in the reproductive period.
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preovulatory luteinizing hormone surge interval in old and young laying Turkey Hens early in the egg production period
Poultry Science, 2001Co-Authors: H K Liu, David W Long, Wayne L BaconAbstract:Egg production rate normally declines with duration of the reproductive period, but hen age and duration of the reproductive period are usually confounded. Initiation of egg production can be delayed in Turkey Hens with short-day lighting, allowing hen age to be separated from duration of the reproductive period. The objective of the present report is to determine if the interval between luteinizing hormone (LH) surges is different between old and young laying Turkey Hens during the peak of egg production. Turkey Hens were given short-day lighting [6 h light (L):18 h darkness (D)] at 16 wk of age, and were photostimulated with 24L:OD (constant light) at 30 (young Hens) or at 70 (old Hens) wk of age. Egg production in the young Hens started about 2 wk after they were photostimulated, but some of the old Hens had started laying at 64 wk of age while under short-day lighting, and all old Hens were laying after 1 wk of photostimulation. To monitor the interval between plasma LH surges at peak of production, Hens were serially bled hourly for 240 h, starting about 6 wk after photostimulation. The interval of LH surges was not different between young (n = 5) and old (n = 10) laying Hens. Not all LH surges were coincident with oviposition of eggs 1 to 2 d later (blind LH surges), and the percentage of young Hens with at least one blind LH surge was higher than for old Hens (60% of young Hens and 10% of old Hens). The baseline concentration of LH was not different between the young and old laying Hens. In conclusion, the interval between LH surges, baseline concentration of LH, and amplitude of LH surges were not related to age of the Hens during the peak rate of lay.
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frequency of luteinizing hormone surges and egg production rate in Turkey Hens
Biology of Reproduction, 2001Co-Authors: Han-ken Liu, David W Long, K. E. Nestor, Wayne L BaconAbstract:Abstract Whether the interval between preovulatory surges of LH was different between lines of Turkey Hens with either poor (RBC3 line, peak at 55%) or excellent rate of egg production (Egg line, peak at 85%) was examined. Laying Hens were cannulated and bled hourly for 10 days at peak of production. A constant light photoschedule was used to avoid diurnal masking of innate circadian rhythms. The mean interval between LH surges in the RBC3 line was longer than in the Egg line and had a higher coefficient of variation. A few longer LH surge intervals (>72 h) were found in some RBC3 line Hens (2 of 7 Hens), but none were found in Egg line Hens (0 of 11 Hens). All progesterone (P4) surges were coupled with LH surges, but not all LH-P4 surges were coupled with ovipositions (blind LH-P4 surges). The percentage of blind LH-P4 surges was not different between lines. The baseline concentration of LH was higher in Egg line than RBC3 line Hens, but LH surge amplitude, and surge duration were not different. The base...
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Active immunization with vasoactive intestinal peptide in Turkey Hens.
Poultry science, 2000Co-Authors: M. E. El Halawani, J.l. Silsby, S. E. Whiting, G. R. Pitts, Yupaporn ChaisehaAbstract:Abstract Active immunization of Turkey Hens against vasoactive intestinal peptide (VIP) has been shown to inhibit incubation behavior and to increase egg production in second-cycle Hens. The objective of this study was to compare the effect of VIP immunization on first- and second-cycle Turkey Hens during a 27-wk production period. First- (25-wk-old) and second- (54-wk-old) cycle Hens were intermixed, distributed among 16 pens, and subjected to a photoperiod of 6 h of light and 18 h of darkness for 10 wk. The first-cycle Hens were divided into two groups: keyhole limpet hemocyanin (KLH)-immunized controls (n = 16) and VIP-immunized (n = 18). Second-cycle Hens were divided into four groups: 1) unimmunized controls (n = 19), 2) KLH-immunized controls (n = 18), 3) VIP-immunized (n = 19), and 4) VIP-preimmunized (immunized during first cycle; n = 16). Each hen received four antigen injections beginning the day of photostimulation (4-wk intervals), except for the preimmunized Hens, which received three injections beginning 4 wk after photostimulation. The maximum titer of VIP antibodies in first-cycle, second-cycle, and preimmunized Hens was 17.2±2.2, 20.9±2.9, and 21.7±3.2%, respectively. After photostimulation, plasma prolactin of first- and second-cycle control Hens peaked between 484 ±105 and 630±118 ng/mL. In contrast, prolactin changed very little in VIP-immunized Turkeys. The average number of daily nest visits was less in first- and second-cycle VIP-immunized Hens (1.68±0.23 and 1.09±0.15 visits per hen per day, respectively) than in their respective KLH-immunized controls (2.47±0.36 and 2.65±0.45 visits per hen per day). Expression of incubation behavior was 50.0 and 52.6% in first- and second-cycle control Hens, respectively, upon termination of the study. In contrast, only 11.1% first-cycle and 5.2% second-cycle VIP-immunized Turkeys exhibited the hormonal and behavioral characteristics of incubating Hens. Average weekly egg production of first- and second-cycle VIP-immunized Turkeys was similar (3.58±0.19 vs. 3.63±0.14 eggs per hen per wk). First- and second-cycle control Hens laid 2.63±0.25 and 2.41±0.20 eggs per hen per wk, respectively. The present results show that comparable egg production was attained in first- and second-cycle Hens by active immunization with VIP.
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Characterization of vasoactive intestinal peptide pituitary membrane receptors in Turkey Hens during different stages of reproduction.
Biology of reproduction, 1993Co-Authors: Israel Rozenboim, M. E. El HalawaniAbstract:Vasoactive intestinal peptide (VIP) is a prolactin-releasing factor in Turkey Hens. Membranes from anterior pituitaries of Turkey Hens were used to characterize VIP receptors. Using HPLC-purified monoiodinated VIP, we found specific VIP receptors in the anterior pituitary glands. Binding was saturable and was time- and temperature-dependent. Scatchard analysis of competitive binding studies indicated two binding sites, a high-affinity binding site (Kd1) of 6.6 +/- 1.8 pM and maximum binding (Bmax1) of 1.52 +/- 0.2 pM, and a low-affinity binding site (Kd2) of 542 +/- 200 pM and Bmax2 of 15.8 +/- 8.0 pM. Binding of VIp to pituitary membranes was specific, as compared to other peptides of the glucagon family. The rank order of potency of the peptides tested was chicken VIP > porcine VIP > peptide histidine isoleucine > secretin > glucagon > growth hormone-releasing factor. Two binding sites were found in all the examined reproductive stages. The lowest binding site levels were found in nonphotostimulated and photorefractory birds, followed by photostimulated birds and layers; highest levels were found in incubating birds. Nest deprivation significantly reduced Bmax1 levels without changing hypothalamic VIP content. These results suggest the involvement of the anterior pituitary VIP receptors in the regulation of prolactin secretion from the pituitary gland.
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Intracranial prolactin perfusion induces incubation behavior in Turkey Hens.
Biology of reproduction, 1991Co-Authors: Orlan M. Youngren, M. E. El Halawani, J.l. Silsby, Richard E. PhillipsAbstract:Intracranial perfusion of ovine prolactin (oPrl) via osmotic pump in laying Turkey Hens caused a sudden onset in incubation behavior, defined as an increase in nest visits. The Hens also displayed a gradual decrease in egg laying during the time they were receiving oPrl, another indicator of the onset of incubation. Circulating immunoreactive Turkey Prl levels fell during the perfusion period, even though the Hens were displaying persistent nesting activity and reduced egg laying. No effects on serum LH were noted. Perfusion of oPrl during the first 14 days of photostimulation delayed the onset of egg laying by several days. No effects on serum Prl or serum LH were noted. It is suggested that incubation behavior is facilitated by central levels of Prl.
