Welfare issues associated with moulting of laying hens
P. C. Glatz
A C and A. J. Tilbrook B
+ Author Affiliations
- Author Affiliations
A 29 Russell Avenue, Hazelwood Park, SA 5066, Australia.
B Centre For Animal Science, Queensland Alliance for Agriculture and Food Innovation, The University of Queensland, 306 Carmody Road, St Lucia, Qld 4072, Australia.
C Corresponding author. Email: philglatz@internode.on.net
Animal Production Science 61(10) 1006-1012 https://doi.org/10.1071/AN19700
Submitted: 3 December 2019 Accepted: 27 April 2020 Published: 21 July 2020
Abstract
A practice that is used to extend the period of lay of hens is induced moulting. It involves restriction of nutrients, and sometimes manipulation of lighting, with the consequent loss of bodyweight and feathers, regression of the reproductive tract and cessation of egg lay. When the period of moulting is completed, the reproductive tract will regenerate and egg production will resume, thereby extending the overall period of lay. Towards the end of the laying cycle of hens, the production and quality of eggs decline. At this point, some egg farmers will induce a moult in the flocks to reduce bird-replacement costs and improve profitability. In the Australian egg industry, less than 10% of layers are moulted. There are implications for the welfare of hens that are induced to moult, particularly due to loss of bodyweight and feathers. Histopathological studies have shown the extent to which loss of feathers may affect welfare from a physical perspective, and it terms of pain. It is apparent that induced moulting can lead to an increase in aggression and injurious pecking, and birds with poor feather cover are vulnerable to damage from this pecking. Induced moulting can increase stress, although the implications of this for the welfare of hens is not well understood. The endocrine events associated with induced moulting are reasonably well known and it is possible to manipulate the endocrine system to extend the lay of hens without the need to moult. Nevertheless, these approaches are unlikely to be adopted into practice. More importantly, hens should always have feed and water available and are in good condition before undergoing a moult. This is essential from the perspective of ensuring adequate standards of welfare of birds.
Additional keywords: animal behaviour, animal stress, animal welfare, poultry.
References
Abougabal MSh, Taboosha MF (2017) Productive performance, economic efficiency and egg quality of laying hens as affected by different molting methods. Middle East Journal of Applied Sciences 7, 349–360.Adams JL (1955) Progesterone-induced unseasonable molt in Single Comb White Leghorn pullets. Poultry Science 34, 702–707.
| Progesterone-induced unseasonable molt in Single Comb White Leghorn pullets.Crossref | GoogleScholarGoogle Scholar |
Adams JL (1956) A comparison of different methods of protraction to the fowl in affecting egg production and molt. Poultry Science 35, 323–326.
| A comparison of different methods of protraction to the fowl in affecting egg production and molt.Crossref | GoogleScholarGoogle Scholar |
Akbari Moghaddam Kakhki R, Mousav Z, Anderson KE (2018) An appraisal of moulting on post-moult egg production and egg weight distribution in white layer hens; meta-analysis. British Poultry Science 59, 278–285.
| An appraisal of moulting on post-moult egg production and egg weight distribution in white layer hens; meta-analysis.Crossref | GoogleScholarGoogle Scholar | 29376738PubMed |
Almond A, Cransberg P, Peacock R, Goldsmith J (1997) ‘Evaluation of performance of hens fed high nutrient density diets post moult. Project No VCA-4A.’ (Rural Industries Research and Development Corporation: Canberra, ACT, Australia)
Alodan MA, Mashaly MM (1999) Effect of induced molting in laying hens on production and immune parameters. Poultry Science 78, 171–177.
| Effect of induced molting in laying hens on production and immune parameters.Crossref | GoogleScholarGoogle Scholar | 10051027PubMed |
Anderson K, Havenstein G (2007) Effects of alternative molting programs and population on layer performance: results of the thirty-fifth North Carolina layer performance and management test. Journal of Applied Poultry Research 16, 365–380.
| Effects of alternative molting programs and population on layer performance: results of the thirty-fifth North Carolina layer performance and management test.Crossref | GoogleScholarGoogle Scholar |
Anderson KE, Davis GS, Jenkins PK, Carroll AS (2004) Effects of bird age, density, and molt on behavioral profiles of two commercial layer strains in cages. Poultry Science 83, 15–23.
| Effects of bird age, density, and molt on behavioral profiles of two commercial layer strains in cages.Crossref | GoogleScholarGoogle Scholar | 14761079PubMed |
Andrews DK, Berry WD, Brake J (1987) Effect of lighting programme and nutrition on reproductive performance of molted single comb white leghorn hens. Poultry Science 66, 1298–1305.
| Effect of lighting programme and nutrition on reproductive performance of molted single comb white leghorn hens.Crossref | GoogleScholarGoogle Scholar | 3684852PubMed |
Australian Egg Corporation Knowledge Guide (2014) Coordinate and monitor production performance and environments for growing stock and egg production. Certificate III in Agriculture. Australian Egg Corporation Limited, Sydney, NSW, Australia.
Bar A, Razaphkovsky V, Wax E, Malka Y (2001) Effect of age at molting on postmolting performance. Poultry Science 80, 874–878.
| Effect of age at molting on postmolting performance.Crossref | GoogleScholarGoogle Scholar | 11469648PubMed |
Barnett JL, Glatz PC, Almond A, Hemsworth PH, Cransberg PH, Parkinson GB, Jongman EC (2001) ‘A welfare audit for the chicken meat industry.’ (Rural Industries Research and Development Corporation: Canberra, ACT, Australia)
Bass PD, Hooge DM, Koutsos EA (2007) Dietary thyroxine induces molt in chickens (Gallus gallus domesticus). Comparative Biochemistry and Physiology Part A: Molecular and Integrative Physiology 146, 335–341.
Bell DD (2003) Historical and current molting practices in the US table egg industry. Poultry Science 82, 965–970.
| Historical and current molting practices in the US table egg industry.Crossref | GoogleScholarGoogle Scholar | 12817452PubMed |
Bell DD, Kuney DR (2004) Farm evaluation of alternative molting procedures. Journal of Applied Poultry Research 13, 673–679.
| Farm evaluation of alternative molting procedures.Crossref | GoogleScholarGoogle Scholar |
Bentley GE, Ubuka T, McGuire NL, Chowdhury VS, Morita Y, Yano T, Tsutsui K (2008) Gonadotropin-inhibitory hormone and its receptor in the avian reproductive system. General and Comparative Endocrinology 156, 34–43.
| Gonadotropin-inhibitory hormone and its receptor in the avian reproductive system.Crossref | GoogleScholarGoogle Scholar | 18031743PubMed |
Berry WD (2003) The physiology of induced molting. Poultry Science 82, 971–980.
| The physiology of induced molting.Crossref | GoogleScholarGoogle Scholar | 12817453PubMed |
Biggs PE, Douglas MW, Koelkebeck KW, Parsons CM (2003) Evaluation of nonfeed removal methods for molting programs. Poultry Science 82, 749–753.
| Evaluation of nonfeed removal methods for molting programs.Crossref | GoogleScholarGoogle Scholar | 12762396PubMed |
Brake J, Thaxton P (1979) Physiological changes in caged layers during a molt. 2. Gross changes in organs. Poultry Science 58, 707–716.
| Physiological changes in caged layers during a molt. 2. Gross changes in organs.Crossref | GoogleScholarGoogle Scholar | 514955PubMed |
Campo JL, Prieto MT, Davila SG (2008) Effects of housing system and cold stress on heterophil-to-lymphocyte ratio, fluctuating asymmetry, and tonic immobility duration of chickens. Poultry Science 87, 621–626.
| Effects of housing system and cold stress on heterophil-to-lymphocyte ratio, fluctuating asymmetry, and tonic immobility duration of chickens.Crossref | GoogleScholarGoogle Scholar | 18339981PubMed |
Cransberg P, Parkinson G (2005) ‘Strategies to improve moulting practice and reduce reliance on beak trimming. Project no. VAG-1A.’ (Australian Egg Corporation: Sydney, NSW, Australia)
Cunningham D, Mauldin J (1996) Cage housing, beak trimming, and induced molting of layers: a review of welfare and production issues. Journal of Applied Poultry Research 5, 63–69.
| Cage housing, beak trimming, and induced molting of layers: a review of welfare and production issues.Crossref | GoogleScholarGoogle Scholar |
Davis GS, Anderson KE, Carroll AS (2000) The effects of long-term caging and molt of single comb White Leghorn hens on heterophil to lymphocyte ratios, corticosterone and thyroid hormones. Poultry Science 79, 514–518.
| The effects of long-term caging and molt of single comb White Leghorn hens on heterophil to lymphocyte ratios, corticosterone and thyroid hormones.Crossref | GoogleScholarGoogle Scholar | 10780646PubMed |
Davison TF, Rowell JG, Rea T (1983) Effects of dietary corticosterone on peripheral blood lymphocyte and granu-opulations in immature domestic fowl. Research in Veterinary Science 34, 236–239.
| Effects of dietary corticosterone on peripheral blood lymphocyte and granu-opulations in immature domestic fowl.Crossref | GoogleScholarGoogle Scholar | 6856997PubMed |
Dickerman RW, Bahr JM (1989) Molt induced by gonadotropin-releasing hormone agonist as a model for studying endocrine mechanisms of molting in laying hens. Poultry Science 68, 1402–1408.
| Molt induced by gonadotropin-releasing hormone agonist as a model for studying endocrine mechanisms of molting in laying hens.Crossref | GoogleScholarGoogle Scholar | 2685798PubMed |
Dickey ER, Bregendahl K, Stalder K, Fitzgerald R, Johnson AK (2010) Effects of a premolt calcium and lowenergy molt program on laying hen behavior and heterophil-to-lymphocyte ratios. Poultry Science 89, 2317–2325.
| Effects of a premolt calcium and lowenergy molt program on laying hen behavior and heterophil-to-lymphocyte ratios.Crossref | GoogleScholarGoogle Scholar | 20952693PubMed |
Dunkley CS, Friend TH, McReynolds JL, Woodward CL, Kim WK, Dunkley KD, Kubena LF, Nisbet DJ, Ricke SC (2008) Behavioral responses of laying hens to different alfalfa-layer ration combinations fed during molting. Poultry Science 87, 1005–1011.
Etches RJ, Williams JB, Rzasa J (1984) Effects of corticosterone and dietary changes in the hen on ovarian function, plasma LH and steroids and the response to exogenous LHRH. Journal of Reproduction and Fertility 70, 121–130.
| Effects of corticosterone and dietary changes in the hen on ovarian function, plasma LH and steroids and the response to exogenous LHRH.Crossref | GoogleScholarGoogle Scholar | 6363688PubMed |
Fraser HM (1982) Antifertility effects of GnRH. Journal of Reproduction and Fertility 64, 503–515.
| Antifertility effects of GnRH.Crossref | GoogleScholarGoogle Scholar | 7040651PubMed |
Gildersleeve RP, Satterlee DG, Johnson WA, Scott TR (1982) The effect of forced molt treatment on selected steroids in hens. Poultry Science 6, 2362–2369.
Glatz PC (2002) Claw abrasives in layer cages: review. International Journal of Poultry Science 1, 1–5.
| Claw abrasives in layer cages: review.Crossref | GoogleScholarGoogle Scholar |
Glatz PC (2004) Effect of claw abrasives in cages on claw condition, feather cover and mortality of hens. Asian-Australasian Journal of Animal Sciences 17, 1465–1471.
| Effect of claw abrasives in cages on claw condition, feather cover and mortality of hens.Crossref | GoogleScholarGoogle Scholar |
Glatz P, Runge G (2017) ‘Managing fowl behaviour. A best practice guide to help egg producers and poultry breeders manage feather pecking and cannibalism in their flocks.’ (Australian Egg Corporation: Sydney, NSW, Australia)
Glatz PC, Polkinghorne RW, Howard B (1987) Physiological relationships with production measures in White Leghorns subjected to restricted feeding from 18 weeks of age. Australian Journal of Agricultural Research 38, 445–453.
| Physiological relationships with production measures in White Leghorns subjected to restricted feeding from 18 weeks of age.Crossref | GoogleScholarGoogle Scholar |
Gross WB, Siegel HS (1983) Evaluation of the heterophil/lymphocyte ratio as a measure of stress in chickens. Avian Diseases 27, 972–979.
| Evaluation of the heterophil/lymphocyte ratio as a measure of stress in chickens.Crossref | GoogleScholarGoogle Scholar | 6360120PubMed |
Hurwitz S, Wax E, Nisenbaum Y, Ben-Moshe M, Plavink M (1998) The response of laying hens to induced moult as affected by strain and age. Poultry Science 77, 22–31.
| The response of laying hens to induced moult as affected by strain and age.Crossref | GoogleScholarGoogle Scholar | 9469747PubMed |
Johnson AL, van Tienhoven A (1981) Hypothalamo-hypophyseal sensitivity to hormones in the hen. II. Plasma concentrations of LH, progesterone and testosterone in response to peripheral and central injections of LHRH testosterone. Biology of Reproduction 25, 153–161.
| Hypothalamo-hypophyseal sensitivity to hormones in the hen. II. Plasma concentrations of LH, progesterone and testosterone in response to peripheral and central injections of LHRH testosterone.Crossref | GoogleScholarGoogle Scholar | 7025926PubMed |
Kang SY, Ko YH, Moon YS, Sohn SH, Jang IS (2011) Effects of the combined stress induced by stocking density and feed restriction on hematological and cytokine parameters as stress indicators in laying hens. Asian-Australasian Journal of Animal Sciences 24, 414–420.
| Effects of the combined stress induced by stocking density and feed restriction on hematological and cytokine parameters as stress indicators in laying hens.Crossref | GoogleScholarGoogle Scholar |
Keshavarz K, Quimby FW (2002) An investigation of different molting techniques with an emphasis on animal welfare. Journal of Applied Poultry Research 11, 54–67.
| An investigation of different molting techniques with an emphasis on animal welfare.Crossref | GoogleScholarGoogle Scholar |
King JA, Davidson JS, Miller RP (1986) Desensitisation to gonadotropin-releasing hormone in perifused chicken anterior pituitary cells. Endocrinology 119, 1510–1518.
| Desensitisation to gonadotropin-releasing hormone in perifused chicken anterior pituitary cells.Crossref | GoogleScholarGoogle Scholar | 3093193PubMed |
Koch JM, Lay DC, McMunn KA, Moritz JS, Wilson ME (2007) Motivation of hens to obtain feed during a molt induced by feed withdrawal, wheat middlings, or melengestrol acetate. Poultry Science 86, 614–620.
| Motivation of hens to obtain feed during a molt induced by feed withdrawal, wheat middlings, or melengestrol acetate.Crossref | GoogleScholarGoogle Scholar | 17369530PubMed |
Koelkebeck KW, Anderson KE (2007) Molting layers: alternative methods and their effectiveness. Poultry Science 86, 1260–1264.
| Molting layers: alternative methods and their effectiveness.Crossref | GoogleScholarGoogle Scholar | 17495103PubMed |
Kuenzel WJ, Wideman RF, Chapman M, Golden C, Hooge DM (2005) A practical method for induced moulting of caged layers that combines full access to feed and water, dietary thyroactive protein, and short-day length. World’s Poultry Science Journal 61, 599–624.
| A practical method for induced moulting of caged layers that combines full access to feed and water, dietary thyroactive protein, and short-day length.Crossref | GoogleScholarGoogle Scholar |
Lunam CA, Glatz PC (1997) ‘Effects of foot lesions and feather loss on the welfare of caged layers using anatomical and behavioural approaches. Project no. UF 4E’. (Egg Industry Research and Development Council: Sydney, NSW, Australia)
Mazzuco H, Hester PY (2005) The effect of an induced molt using a nonfasting program on bone mineralization of White Leghorns. Poultry Science 84, 1483–1490.
Mazzuco H, Avila VS, Coldebella A, Mores R, Jaenisch FRF, Lopes LS (2011) Comparison of the effect of different methods of molt: production and welfare evaluation. Poultry Science 90, 2913–2920.
| Comparison of the effect of different methods of molt: production and welfare evaluation.Crossref | GoogleScholarGoogle Scholar | 22080033PubMed |
Millar RP, King JA (1984) Structure-activity relations of LHRH in birds. The Journal of Experimental Zoology 232, 425–430.
| Structure-activity relations of LHRH in birds.Crossref | GoogleScholarGoogle Scholar | 6097627PubMed |
Nicol CJ, Bouwsema J, Caplen G, Davies AC, Hockenhull J, Lambton SL, Lines JA, Mullan S, Weeks CA (2017) ‘Farmed bird welfare science review.’ (Department of Economic Development, Jobs, Transport and Resources: Melbourne, Vic., Australia)
Primary Industries Standing Committee (2002) ‘Model code of practice for the welfare of animals: domestic poultry.’ 4th edn. SCARM report 83. (CSIRO Publishing: Melbourne, Vic., Australia)
Rault JL, Scott P, Tilbrook A, Hemsworth P (2015) The effect of time off water on the welfare of spent laying hens. In ‘Proceedings of the 26th Australian Poultry Science Association conference’. (Ed. P Selle) pp. 245–247. (The University of Sydney: Sydney, NSW, Australia)
Reddy K, Malathi V, Venkatarami T, Reddy BS (2008) Effect of induced molting in male and female line broiler breeder hens by zinc oxide and feed withdrawal methods on post molt performance parameters. International Journal of Poultry Science 7, 586–593.
| Effect of induced molting in male and female line broiler breeder hens by zinc oxide and feed withdrawal methods on post molt performance parameters.Crossref | GoogleScholarGoogle Scholar |
Roberts JR (2004) ‘Optimising infectious bronchitis vaccination of laying hens for maximum eggshell quality. Project no. UNE-76A.’ (Australian Egg Corporation: Sydney, NSW, Australia)
Sekimoto K, Suzuki IM, Takikawa H, Hoshino N (1987) Thyroxine-induced molting and gonadal function of laying hens. Poultry Science 66, 752–756.
| Thyroxine-induced molting and gonadal function of laying hens.Crossref | GoogleScholarGoogle Scholar | 3615336PubMed |
Shaffner CS (1955) Progesterone induced molt. Poultry Science 34, 840–842.
| Progesterone induced molt.Crossref | GoogleScholarGoogle Scholar |
Sharp PJ, Sterling RJ, Milton RC de L, Miller RP (1986) Effect of luteinising hormone releasing hormone and its analogues on plasma luteinising hormone concentrations in incubating Bantam hens. British Poultry Science 27, 129–135.
| Effect of luteinising hormone releasing hormone and its analogues on plasma luteinising hormone concentrations in incubating Bantam hens.Crossref | GoogleScholarGoogle Scholar | 3518873PubMed |
Shippee RL, Stake PE, Koehn UK, Lambert JL, Simmons RW (1979) High dietary zinc or magnesium as forced-forced-resting agents for laying hens. Poultry Science 58, 949–954.
| High dietary zinc or magnesium as forced-forced-resting agents for laying hens.Crossref | GoogleScholarGoogle Scholar |
Soomro H, Rajput N, Soomro NM, Kalhoro NH (2018) Alternative use of turmeric in induced molting on performance of layers. International Journal of Scientific and Engineering Research 9, 1150–1172.
Tanabe Y, Ogawa T, Nakamura T (1981) The effect of short-term starvation on pituitary and plasma LH, plasma estradiol and progesterone, and on pituitary response to LH-RH in the laying hen (Gallus domesticus). General and Comparative Endocrinology 43, 392–398.
| The effect of short-term starvation on pituitary and plasma LH, plasma estradiol and progesterone, and on pituitary response to LH-RH in the laying hen (Gallus domesticus).Crossref | GoogleScholarGoogle Scholar | 7011898PubMed |
Tanabe H, Nakamura T, Tanabe Y (1982) Endocrine mechanism of ovarian follicular atresia caused by fasting of the hen. In ‘Aspects of avian endocrinology: practical and theoretical implications’. Graduate Studies (Texas Tech University), no. 26. pp. 191–199. (Texas Technical Press: Lubbock, TX, USA)
Tilbrook AJ, Fisher A (2020) Stress, health and the welfare of laying hens. Animal Production Science.
| Stress, health and the welfare of laying hens.Crossref | GoogleScholarGoogle Scholar |
Tilbrook AJ, Johnson RJ, Eason PJ, Walsh JD, Trigg TE, Clarke IJ (1992) Short-term reduction in egg production in laying hens treated with an agonist of GnRH. British Poultry Science 33, 621–638.
| Short-term reduction in egg production in laying hens treated with an agonist of GnRH.Crossref | GoogleScholarGoogle Scholar | 1643525PubMed |
Tsutsui K, Bentley GE, Ubuka T, Saigoh E, Yin H, Osugi T, Wingfield JC (2007) The general and comparative biology of gonadotropin-inhibitory hormone (GnIH). General and Comparative Endocrinology 153, 365–370.
| The general and comparative biology of gonadotropin-inhibitory hormone (GnIH).Crossref | GoogleScholarGoogle Scholar | 17141777PubMed |
Tsutsui K, Bentley GE, Bedecarrats G, Osugi T, Ubuka T, Kriegsfeld LJ (2010) Gonadotropin-inhibitory hormone (GnIH) and its control of central and peripheral reproductive function. Frontiers in Neuroendocrinology 31, 284–295.
| Gonadotropin-inhibitory hormone (GnIH) and its control of central and peripheral reproductive function.Crossref | GoogleScholarGoogle Scholar | 20211640PubMed |
Tsutsui K, Ubuka T, Bentley GE, Kriegsfeld LJ (2012) Gonadotropin-inhibitory hormone (GnIH): discovery, progress and prospect. General and Comparative Endocrinology 177, 305–314.
| Gonadotropin-inhibitory hormone (GnIH): discovery, progress and prospect.Crossref | GoogleScholarGoogle Scholar | 22391238PubMed |
Webster AB (2003) Physiology and behavior of the hen during induced molt. Poultry Science 82, 992–1002.
| Physiology and behavior of the hen during induced molt.Crossref | GoogleScholarGoogle Scholar | 12817455PubMed |
Williams JB, Etches RJ, Rzasa J (1985) Induction of a pause in laying by corticosterone infusion or dietary alterations: effects on the reproductive system, food consumption and body weight. British Poultry Science 26, 25–34.
| Induction of a pause in laying by corticosterone infusion or dietary alterations: effects on the reproductive system, food consumption and body weight.Crossref | GoogleScholarGoogle Scholar | 3971194PubMed |
Willis WL, Goktepe I, Isikhuemhen OS, Reed M, King K, Murray C (2008) The effect of mushroom and pokeweed extract on Salmonella, egg production, and weight loss in molting hens. Poultry Science 87, 2451–2457.
| The effect of mushroom and pokeweed extract on Salmonella, egg production, and weight loss in molting hens.Crossref | GoogleScholarGoogle Scholar | 19038799PubMed |
Wilson HR, Fry JL, Harms RH, Arrington LR (1967) Performance of hens molted by various methods. Poultry Science 46, 1406–1412.
| Performance of hens molted by various methods.Crossref | GoogleScholarGoogle Scholar | 6081735PubMed |
