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The Significance of Fowls' Bathing in Dust
- D W van Liere
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- Journal:
- Animal Welfare / Volume 1 / Issue 3 / August 1992
- Published online by Cambridge University Press:
- 11 January 2023, pp. 187-202
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Dustbathing in fowls (eg chickens, Gallus gallus) consists of tossing the litter onto and between the fluffed feathers and subsequently enclosing it by flattening the feathers. The proximal contact between litters like sand and peat, and the integument is intensified by rubbing the body. This is not the case in wood-shavings which adhere to the distal plumage after tossing; rubbings in wood-shavings are frequently interrupted by reinitiated tossings. Lipids accumulate on the feathers and become stale during dust deprivation. Only baths in sand and peat are effective in removing excessive lipids from the proximal downy feather parts. Fluffiness of the down is highest in hens on peat, intermediate on sand and lowest on wood-shavings, while the reverse is true for the plumage surface temperature of the back Hens monitor the integumental lipid condition which becomes causally connected with bathing in the course of experiencing litter bathing effects. It is shown from the author's experimental study that hens naive of bathing in litter, and hens experienced with wood-shavings initially shifted bathing litters but finally preferred peat or sand (in that order) when peat, sand and wood-shavings were simultaneously presented Most of the hens experienced with bathing in sand did not shift to another substrate when presented with one. Recommendations are given concerning adequate dustbathing litter. A chronic deprivation of adequate litter leads to an uncontrollable condition of the lipids on the integument and an abnormal development of dustbathing. Such a deprivation therefore reduces animal welfare. Moreover, it is suggested to be costly.
Calm Merino ewes have a higher ovulation rate and more multiple pregnancies than nervous ewes
- E. van Lier, K. W. Hart, C. Viñoles, B. Paganoni, D. Blache
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In 1990, two selection lines of Merino sheep were established for low and high behavioural reactivity (calm and nervous temperament) at the University of Western Australia. Breeding records consistently showed that calm ewes weaned 10% to 19% more lambs than the nervous ewes. We hypothesise that calm ewes could have a higher ovulation rate than nervous ewes and/or calm ewes could have a lower rate of embryo mortality than nervous ewes. We tested these hypotheses by comparing the ovulation rate and the rate of embryo mortality between the calm and nervous lines before and after synchronisation and artificial insemination. Merino ewes from the temperament selection lines (calm, n=100; nervous, n=100) were synchronised (early breeding season) for artificial insemination (day 0) (intravaginal sponges containing fluogestone acetate and eCG immediately after sponge withdrawal). On day-17 and 11 ovarian cyclicity and corpora lutea, and on days 30 and 74 pregnancies and embryos/foetuses were determined by ultrasound. Progesterone, insulin and leptin concentrations were determined in blood plasma samples from days 5, 12 and 17. Ovarian cyclicity before and after oestrus synchronisation did not differ between the lines, but ovulation rate did (day-17: calm 1.63; nervous 1.26; P<0.01; day 11: calm 1.83; nervous 1.57; P<0.05). Ovulation rate on day 11 in nervous ewes was higher than on day-17. Loss of embryos by day 30 was high (calm: 71/150; nervous: 68/130); but nervous ewes had a lower proportion (15/47) of multiple pregnancies compared with calm ewes (30/46; P<0.01). Reproductive loss between days 30 and 74 represented 7.3% of the overall loss. Temperament did not affect concentrations of progesterone, but nervous ewes had higher insulin (32.0 pmol/l±1.17 SEM; P=0.013) and lower leptin (1.18 μg/l±0.04 SEM; P=0.002) concentrations than calm ewes (insulin: 27.8 pmol/l±1.17 SEM; leptin: 1.35 μg/l±0.04 SEM). The differences in reproductive outcomes between the calm and nervous ewes were mainly due to a higher ovulation rate in calm ewes. We suggest that reproduction in nervous ewes is compromised by factors leading up to ovulation and conception, or the uterine environment during early pregnancy, that reflect differences in energy utilisation.