mark s. edwards, rongping wei, janet hawEs, meg sutherland-smith, chunxiang tang, desheng li, daming hu, guiquan zhang introduction
Among eutherians, ursids have a significant disparity between maternal weight and neonatal weight (Leitch et al, 1959). The giant panda also produces a smaller litter mass relative to maternal body mass than, for example, the American black bear (Oftedal & Gittleman, 1989; Ramsay & Dunbrack, 1996; Zhu et al., 2001). The giant panda neonate is particularly altricial (i.e. highly dependent on parental care), requiring 24-hour care during the first weeks of life. This chapter deals with the issues and intricacies associated with the newborn giant panda cub, including hand-rearing and medical management.
neonatal care and hand-rearing: methods, results and recommendations
Although maternal care is always preferred for the giant panda cub, there are situations when human care-giving is mandatory. The most obvious is maternal abandonment, which usually becomes apparent
Giant Pandas: Biology, Veterinary Medicine and Management, ed. David E. Wildt, Anju Zhang, Hemin Zhang, Donald L. Janssen and Susie Ellis. Published by Cambridge University Press. # Cambridge University Press 2006.
within the first five to ten minutes of birth. A female that abandons her cub will typically leave it on the ground and move away, showing little or no interest. Intervention is also required when the dam holds the cub improperly (malpositioning). Such a cub can neither nurse nor rest, often moves about excessively (in an attempt to achieve proper positioning on its own) and then can fall to the ground. A third complication is the common production of two or more cubs (mean litter size is 1.7; range 1-3) (Schaller et al, 1985). Despite the frequency of multiple births, a female giant panda rarely cares for more than one offspring, probably because of the intensity of maternal attention required. One mitigating strategy has been hand-rearing one of the twins or, more recently, implementing 'twin swapping' (see below). Some females also produce inadequate amounts of milk, thereby requiring human assistance. In this case, the neonate often shows excessive activity searching for the female's nipple. Finally, dam or cub illness or injury may require separating the female from neonate to provide treatment.
Criteria indicating the need for hand-rearing are most obvious during the first three days postpartum and include neonate vocalisation, activity levels and skin colouration. The significance of these criteria declines with the cub's increasing age. Of the three, vocalisation is perhaps most important. Loud calls, emitted a few times each hour, indicate a healthy cub. However, increased frequency of loud vocalisations suggests that the neonate is uncomfortable, e.g. being held in an awkward position or consuming too little milk. A decline in call intensity and frequency can mean reduced vitality. If vocalisations are not heard for more than one hour, the cub should be examined. It may be useful to awaken the female, prompting her to reposition the cub so that caregivers can more easily monitor its movements and calls. It is also important to see skin with a healthy pink colour. The skin of a sickly cub will increase in pallor, suggesting the need for hands-on evaluation.
A cub transferred from the dam's enclosure to a nursery should be examined and treated as needed (see 'Medical management of neonates', p. 330). Once completed, the neonate should be placed in a pre-warmed incubator (Fig. 13.1; Plate XI) or a similar controlled environment. Most healthy cubs will be moving actively within two to three hours, seeking a nipple. Animals showing this behaviour should be fed
(see 'Feeding and nutrition', p. 320 below) and stimulated to urinate and defecate (see 'Feeding regimes and concerns', p. 325). Each of these activities should be conducted within the confines of the incubator to avoid sudden shifts in environmental temperature. If'nipple seeking' is not observed within five hours, the neonate should be encouraged to take its first bottle. Those that are weak or unable to suck may require enteral feeding via a stomach tube (see 'Feeding and nutrition').
Personnel, housing and environmental conditions
The number of personnel working with a hand-reared cub should be limited during the first month - fewer caregivers increase the chance to detect early problems in appetite, behaviour and overall vitality. A schedule of 12-hour shifts around the clock may be necessary during this critical time.
Due to its altricial nature, the supporting microclimate for a giant panda cub is critical, especially for the first 50 days of life. A summary of required housing and environmental conditions on the basis of early age is provided in Table 13.1.
Table 13.1 Housing equipment, environmental temperature and humidity suggested for hand-rearing the giant panda cub from day of birth (Day 0) to Day 50
Day Housing Temperature Humidity (%)
40 Begin weaning from incubator 22.0°C (71.6°F) 70
50 Incubator discontinued 19-20°C (66.2-68.0°F) 77
The incubator environment (either human infant incubator or animal intensive care unit) should be kept sanitary with any soiled bedding changed immediately. The incubator should provide warmth, softness and security. The neonate needs supplemental heat to maintain its body temperature in the early weeks of life. Since heat lowers humidity, both should be monitored inside the incubator using a thermometer and hygrometer, respectively. Low humidity causes dry skin (most notable on the feet and at the tail base) and may lead to dehydration. The incubator should be adjusted to achieve a desired humidity (see Table 13.1) and, if necessary, a small sponge or cloth soaked with clean water may be placed in the rear of the incubator. A warm or cool mist humidifier should also be added to the nursery room to increase overall humidity. Humidifiers and incubators should be cleaned routinely to prevent mould and mildew growth.
While in the incubator, the giant panda cub should be provided with a 'surrogate' for the maternal body. Unlike other bears, the mother panda does not place the infant on the ground, floor or substrate unless she leaves the den. Instead, she continually holds the cub ventrally (similar to many primates) while using a paw to steady and support the infant. Surrogates developed at the San Diego Zoo include a human infant car seat lined with fur as well as a 30-cm round bean-bag covered with fur, and long flat pillows to simulate the mother's paws (Fig. 13.2;
Plate XII). Simulated fur hairs should be about 2.5 cm long (similar to that found on an adult female's chest) and should be high quality to avoid shedding and accidental ingestion. Because rough edges can catch on bedding (especially in the case of towels with loops), the animal's claws should be clipped and filed. Ripped or frayed bedding should be discarded to avoid entanglement. Cage furnishings should not block the air circulation openings in the incubator unit.
At about six weeks of age, the cub can begin a transition over about a seven-day interval from the incubator to a draft-free room environment (at room temperature). Based on observations of mother-reared giant pandas, dams may leave cubs on the ground for long periods by Day 30; thus, some surrogate weaning should be attempted at this age. Durability and safety are important in designing transition housing for young pandas. The interim enclosure should be safe while providing adequate space for stimulation, investigation, climbing and enrichment. Favourite comfort items from the previous incubator environment should be incorporated into the new enclosure to provide continuity and security. Any toys should be durable and disinfected, as a young giant panda can easily destroy and ingest fragile materials.
Visits to adult enclosures or larger exercise areas are important to develop locomotor skills and desensitise the hand-reared animal to noise, commotion and the larger world. Visits should begin as soon as the panda is able to self-ambulate. However, these exercise areas require frequent inspection for hazards and for the animal's time to be supervised by a familiar care-giver. A young panda will gradually become comfortable in such surroundings, which will allow increased exercise time.
When preparing formula, all equipment must be kept sanitary, and personnel must wash their hands properly and frequently. Measuring cups, mixing utensils and containers used for the storage or preparation of milk formula should be washed in hot water with mild detergent and a 2% bleach solution. All equipment should be soaked, scrubbed and then thoroughly rinsed and air-dried. Bottles, nipple rings and formula containers should be steam-sterilised over boiling water for three minutes before refilling. Latex nipples should never be heat-sterilised as this can cause premature hardening or cracking. Formula ingredients must be accurately weighed and kept only for the length of time indicated by the manufacturer. Containers of prepared formula should be dated, and no formula fed after the recommended expiration date.
Concentrations and relative transfer of maternal immunoglobulins (Ig) and active phagocytic cells via first milk produced during lactation (colostrum) have not been quantified in the giant panda. However, practical experience and information from other carnivores (i.e. cat, dog and mink) suggest that this secretion is important for establishing the neonate's passive immunity. How long the gastrointestinal tract remains permeable to IgG is unknown, but this interval ranges from eight days in mink to 170 to 200 days in altricial marsupials (Hanson & Johansson, 1970; Yadav, 1971). The potential importance of other Ig, such as IgA, in protecting against infection at the level of the gastrointestinal tract, even after the period of intact protein absorption, should not be overlooked.
Four strategies have been considered for providing colostrum, or its physiological equivalent, to a giant panda cub needing supportive care. The first - colostrum collection from a donor - requires extensive pre-partum conditioning and a strong relationship between the panda and its human care-giver. In the absence of quantified concentrations of Ig in early stage milk, samples collected two to three days postpartum may be used in feeding the neonate. The mammary gland and nipple are massaged four to five times per day for the first three days postpartum, with each collection typically providing 1 to 3 ml of colostrum-rich milk. Colostrum has a light green colour for six or seven days, sometimes longer (G. Zhang, pers. comm.); however, it is important to recognise that the association of this colour with secretions of higher Ig content has not been quantified. Harvested colostrum is poured through a coarse filter to remove particulate (hair, dirt) contamination, then placed in a hot water bath at no less than 63°C for 30 minutes to kill bacteria (low temperature, long-time treatment pasteurisation). It can be used immediately for feeding, be refrigerated until needed or frozen for future use.
The remaining strategies are all theoretical. One could rely on using Ig from serum that has been aseptically collected from a healthy donor. Handling, processing and administration of such serum has been outlined for other mammals (Levy et al, 2001). Harvested serum should be administered on the day of birth (Day 0) and the day after (Day 1) based on 1 ml per 20 g of body weight or 3650 mg IgG per kg body weight. Another strategy could include using a commercial colostrum substitute, such as those available for the dog and cat. These products may provide Ig for passive transfer, as well some protection at the gut mucosa. Finally, there is the potential of using concentrated giant panda Ig, a procedure described by Loeffler et al. (see Chapter 16).
Samples of opportunistically collected maternal milk may be available in quantities sufficient for feeding a neonate. If used for feeding, these samples would be handled in a sanitary fashion similar to colostrum (as described above).
In the absence of maternal milk, formula may be offered as the primary nutrient and energy source. A formula that has supported giant panda cubs as part or all of the diet from birth to weaning is provided in Table 13.2. The principal components of this formula are a human milk
Table 13.2 Ingredients and selected nutrient composition of a formula for feeding giant panda cubs
Ingredient Amount (g)
Esbilac® powder 12.5
Enfamil® (low irona/with ironb) powder 12.5
Composition As-fed basis Dry-matter basis
Esbilac® powder 12.5
Enfamil® (low irona/with ironb) powder 12.5
Composition As-fed basis Dry-matter basis
Total solids (%)
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