Suckling, weaning, and growth in captive woodland caribou

Abstract

LAVIGUEUR, L., and BARRETTE, C. 1992. Suckling, weaning, and growth in captive woodland caribou. Can. J. Zool. 70:1753 -1766. To delimit the different stages of the weaning process and to understand the relationship between suckling and growth, the evolution of suckling performance and mother -young interactions associated with milk transfer was closely monitored in a group of woodland caribou (Rangifer tarandus caribou) from birth up to 160 days. Suckling rate and total suckling time dropped rapidly during the first 20 days and slowly thereafter, while suckle duration remained stable during the first 20 days and decreased gradually thereafter. In the first 20 days of life, suckling success declined from 90 to 50%, the proportion of suckles terminated by the mother increased from 30 to 90%, and the proportion of suckles with bunting increased from 40 to almost 100%. The mother licked the calf in 70% of the suckles from birth to 20 days, 40% from 20 to 40 days, and less than 20% subsequently. Suckles with licking were longer than suckles without licking during the first 30 days of life. Suckling was initiated by the calf in more than 80% of the suckles, even in the first days of life. No sex differences were found at any age for any of the behavioral variables measured. Birth weights and growth rates of males from 0 to 45 days, however, were higher than those of females. Growth rates from birth to 45 days were positively correlated with suckling rate during the first 35 days. From 46 to 100 days, growth rates were positively correlated with time spent feeding on pelleted ration and on hay. We suggest that metabolic weaning could begin at around 15 -20 days, when suckling success and the mother's contribution to establishing and maintaining suckling interactions decreased most steeply. The end of metabolic weaning could occur at 40-45 days, when suckling rate, suckling success, and the mother's contribution to suckling reached low values from which they declined very slowly to the end of behavioral weaning. Behavioral weaning was not yet completed at the age of 160 days. LAVIGUEUR, L., et BARRETTE, C. 1992. Suckling, weaning, and growth in captive woodland caribou. Can. J. Zool. 70 : 1753 -1766. Pour tenter de delimiter les differentes phases du processus de sevrage et pour comprendre la relation entre l'allaitement et la croissance, des mesures fines de la performance d'allaitement ont etC effectuees chez un groupe de Caribous des bois (Rangifer tarandus caribou), de la naissance a 160 jours. La frequence et la duree totale des allaitements ont baisse rapidement au cours des 20 premiers jours, et trks lentement par la suite, alors que la durte moyenne des allaitements est deme;rte relativement constante pendant cette periode et a ensuite diminue graduellement. De la naissance a 20 jours, le succks de I'allaitement a baisse de 90 a 50% et la proportion des allaitements terminks par la mkre a augment6 de 30 a 90%. Le lechage du faon par la mkre, qui etait observe dans 70% des allaitements de 0 a 20 jours, se produis...

Mother-calf relationships and maternal investment in European bisonBison bonasus

“…In ungulate females the greater part of reproduction costs is connected with lactation (Oftedal 1985), and nursing behaviour was reported to be a reliable indicator of milk intake in some species (Wettemann et al 1978, Lavigueur andBarrette 1992). According to this, the highest maternal investment in European bison took place in week 1, as the level of suckling rates suggest.…”

“…According to Lavigueur and Barrette (1992), sex differences in investment ought to be revealed in suckling performance or the growth of calves. Birth weight of European bison male and female calves does not differ (Krasiñska and Krasiñski 2002) which precludes biased prenatal investment of mothers.…”

Growth of European roe deer: patterns and rates

“…In mammals where juvenile mortality is often high compared with adult mortality, post-natal growth rates tend to be high (Case 1978). Roe deer Capreolus capreolus (Linnaeus, 1758) are known to have high growth rates in the immediate postnatal period (Gaillard et al 1993), a time when growth is almost entirely dependent on the mother's investment in the form of milk (Lavigueur and Barrette 1992), and which has been termed the strict lactation period (Pontier et al 1989). The data available show that there are no differences between males and females in the rates of growth during the first few days of life (Gaillard et al 1993), but there are no published longitudinal data on the patterns of growth beyond one month of age, and differences could exist at later stages.…”

Land management strategies for the long-term persistence of boreal woodland caribou in central Saskatchewan

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