[Truncated abstract] Previous studies suggest that the milk of the quokka (Setonix brachyurus) could change composition coincident with critical stages of development of the young, and that the milk energy provided by the mother and its utilisation by the joey would determine the young’s growth rate. To test this general hypothesis, quokkas (n = 19) were bred in captivity and milk was collected during lactation. The samples were analysed using specific biochemical assays and sensitive analytical techniques to determine the composition of the milk of the quokka. The stable isotope, deuterium oxide, was employed to estimate the volume of milk consumed by the joeys. The adult females and their young were weighed and body measurements taken periodically, in order to calculate the body condition of the adults and monitor the growth rate of the offspring. Marsupial lactation can be divided in three phases. Phase 1 of lactation covers the period during pregnancy. Phase 2a of lactation in the quokka (0 to 70 days post partum), is the period when the young is permanently attached to the teat, while Phase 2b (70 to 180 days post partum) is when the joey suckles intermittently but is still confined to the pouch. Phase 3 of lactation extends from the time when the young initially emerges from the pouch to the end of lactation (180 to 300 days post partum) ... The metabolism of fatty acids in quokkas appears to be a combination of the processes in monogastric and ruminant mammals. The growth rate of the young quokkas was dependent on the volume and energy content of the milk consumed. The crude growth efficiency indicates that quokkas are equally efficient as other marsupials reported in the literature, in converting milk energy to body mass. It seems that female quokkas maintained energy balance during lactation, most probably by increasing their food intake rather than mobilising body fat stores. In addition, it appears that quokkas are capable of producing young of similar mass, irrespective of their own body weight or condition, when they have access to an adequate supply of food and water. This was the first study to provide detailed information about milk composition and lactational energetics in the quokka. While the results supported the unifying hypothesis in relation to the major changes associated with the transition through the phases of lactation, wide variations were detected between the quokka and other marsupial species in the changes in the detailed composition of milk and milk production.

[Truncated abstract] Mothers who deliver prematurely often have a delay in lactogenesis II and subsequent milk supply. Furthermore, due to the inability of their babies to breastfeed immediately after birth, these mothers are 'pump dependent' during both initiation and establishment of lactation. Apparently, there are no evidence based guidelines for the expression regime but some data suggesting that expression regimes for both breasts should be at least five times per day and at least 100 minutes expressing time per day. The project was set out to document the self selected current expression regimes of the preterm mothers from day 10 to 60 postpartum. It defined how various aspects of breast expression, such as frequency and interval, impact on the synthesis and production of milk. In addition, it determined the variations in the composition of preterm mother's milk. The collection of 24hr expression data and milk samples at each expression of each breast, each day, of 25 preterm mothers (<32 gestation age) from the neonatal intensive care unit in King Edward Memorial Hospital, Western Australia on day 10, 15-20, 30, 40, 50 and 60 postpartum showed that during the 'pump dependent' period (day 10 20), the frequency of expression for both breasts was 6, 6-7, 3-9 times per day (median, IQR, range) and total duration with the pump was 115, 80-160, 32-320 minute per day (median, IQR, range). Furthermore, during the 'transition from exclusively expressing to exclusively breastfeeding' period (day 30-60), frequency of expression/breastfeed and total duration of milk removal (both expressing and breastfeeding) for both breasts were 6, 5-7, 1-9 and 135, 75-170, 25-320, respectively (median, IQR, range). ... These nutrients make up the energy content of milk, thus the energy content of milk also varied greatly between mothers. Therefore, milk from individual preterm mothers varies greatly for individual values for fat, total protein, lactose and energy and this should be taken into account when calculating the level of fortification required for individual babies. The results suggest that when fortifying mother's milk, weekly measurement of fat and protein in milk would provide good estimates on which to base fortification requirements. The concentration of sIgA plus lactoferrin formed 32% of the total proteins in breastmilk. However there was large variations in the concentration of sIgA and lactoferrin (median, IQR, range: 0.82, 0.59-1.13, 0.05-2.93g/l and 2.41, 1.52-3.52, 0.04-8.82g/l, respectively) between mothers. Therefore the level of protection provided by these two proteins could differ greatly between babies. Further research on the relationship between the concentration of sIgA and lactoferrin in milk and the onset of infection would indicate the minimum amount of these proteins needed for the babies to benefit from the immune protection provided by their mother's milk. The hourly breast expression method and regression analysis of actual milk yield and interval since previous expression provides information that identifies the potential milk synthesis capacity of the breasts of the mothers and the impact of the interval between expressions on the milk production of the mothers. This information can be applied to individualize the interval between expression regimes to optimise milk production and minimize the demand on the mother. In addition, determining the changes in the milk composition of individual mothers would provide a more precise base to fortify their milk for their preterm babies.

Diss. (sammanfattning) Uppsala : Sveriges lantbruksuniv., 2007. / Härtill 4 uppsatser.

Diss. (sammanfattning) Uppsala : Sveriges lantbruksuniv. / Härtill 6 uppsatser.

Diss. (sammanfattning) Uppsala : Sveriges lantbruksuniv., 2004. / Härtill 5 uppsatser.

Diss. (sammanfattning) Uppsala : Sveriges lantbruksuniv., 2003. / Härtill 4 uppsatser.

Diss. (sammanfattning) Uppsala, Sweden : Sveriges lantbruksuniv., 2006. / Härtill 4 uppsatser.

Dissertation (Ph.D.)--The University of North Carolina at Greensboro, 2008. / Directed by Cheryl Lovelady; submitted to the Dept. of Nutrition. Title from PDF t.p. (viewed Aug. 25, 2009). Includes bibliographical references (p. 5-6, p. 36-44, p. 61-63, p.90-93).

Thesis (M.S.)--Brigham Young University. Dept. of Microbiology and Molecular Biology, 2007. / Includes bibliographical references (p. 37-40).

Thesis (Ph. D.)--University of Wyoming, 2007. / Title from PDF title page (viewed on Dec. 15, 2008). Includes bibliographical references (p. 97-113).