Puberende paling wil niet volwassen worden
Palstra, Arjan - \ 2016
eels - eel culture - captive animals - fish culture - reproduction
In gevangenschap planten palingen zich nog niet voort. Wageningen UR kan al wel opgekweekte paling in de puberteit brengen.
An effective rotational mating scheme for inbreeding reduction in captive populations illustrated by the rare sheep breed
Windig, J.J. ; Lansbergen, L.M.T.E. - \ 2008
Animal 2 (2008)12. - ISSN 1751-7311 - p. 1733 - 1741.
dierveredeling - schapen - zeldzame rassen - populaties - inteelt - genetische diversiteit - fokkerijmethoden - agrobiodiversiteit - dieren in gevangenschap - kempisch heideschaap - animal breeding - sheep - rare breeds - populations - inbreeding - genetic diversity - animal breeding methods - agro-biodiversity - captive animals - kempen heath sheep - genetic contributions - selection - systems - strategies - programs - rates
Within breeds and other captive populations, the risk of high inbreeding rates and loss of diversity can be high within (small) herds or subpopulations. When exchange of animals between different subpopulations is organised according to a rotational mating scheme, inbreeding rates can be restricted. Two such schemes, a breeding circle and a maximum avoidance of inbreeding scheme, are compared. In a breeding circle, flocks are organised in a circle where each flock serves as a donor flock for another flock, and the same donor–recipient combination is used in each breeding season. In the maximum inbreeding avoidance scheme, donor¿recipient combinations change each year so that the use of the same combination is postponed as long as possible. Data from the Kempisch Heideschaap were used with computer simulations to determine the long-term effects of different breeding schemes. Without exchanging rams between flocks, high inbreeding rates (>1.5% per year) occurred. Both rotational mating schemes reduced inbreeding rates to on average 0.16% per year and variation across flocks in inbreeding rates, caused by differences in flock size, almost disappeared. Inbreeding rates with maximum inbreeding avoidance were more variable than with a breeding circle. Moreover, a breeding circle is easier to implement and operate. Breeding circles are thus efficient and flexible and can also be efficient for other captive populations, such as zoo populations of endangered wild species
Nutritional analysis and intervention in the captive woolly monkey (Lagothric lagotricha)
Ange-van Heugten, K.D. - \ 2008
Wageningen University. Promotor(en): Martin Verstegen, co-promotor(en): P. Ferket. - [S.l.] : S.n. - ISBN 9789085049012 - 191
apen - diervoeding - diergezondheid - dierziekten - diëten - voedingsstoffen - levensverwachting - bloedserum - bloedchemie - diabetes mellitus - hydrocortison - voedselsupplementen - dierentuinen - dieren in gevangenschap - voeding en gezondheid - monkeys - animal nutrition - animal health - animal diseases - diets - nutrients - life expectancy - blood serum - blood chemistry - diabetes mellitus - hydrocortisone - food supplements - zoological gardens - captive animals - nutrition and health
Woolly monkeys (Lagothrix ssp.) are a threatened species in the wild and are extremely difficult to breed and successfully maintain in captivity. The majority of health complications in woolly monkeys (WM) may be of nutritional origin. The objectives of this thesis were to: 1) determine the current status of the captive WM, 2) isolate potential nutritional causes for primary disorders in captive WM, and 3) investigate the effects that diet nutrients have on WM serum chemistry and cortisol concentrations. Our studies showed that the number of captive WM have decreased by 11% in the past 16 years. The number of institutions holding WM decreased and the birth to death ratio is 0.65 compared to 1.26 for their close relative the spider monkey (SM) (Ateles spp.). Lack of genetic diversity in captive WM also may negatively influence their success. Serum chemistry from 30 WM housed at two zoos were similar to previously reported concentrations for howler (Aloutta sp.) and SM; however, serum glucose was above the baseline range compared to humans and SM. Fasting concentrations of glucose, insulin, fructosamine, glycated hemoglobin, circulating lipids and urinary glucose were within normal ranges in six WM with known hypertension problems compared to other monkeys and humans. Potential stressors, such as unnatural diet, can contribute to the low success of endangered primates via noted health abnormalities. Fecal and salivary cortisol concentrations in WM and SM, at multiple zoological institutions showed that zoos with the highest dietary total carbohydrates, total sugars, glucose and fruit content had the highest cortisol. Supplementation of WM and SM diets with inulin-type fructans numerically decreased fecal cortisol after 4 weeks of supplementation, primarily in SM. The lifespan and reproductive success of captive primates will improve if stressors and negative effects of nutrition on the health status can be reduced and dietary nutrients can be optimized.