The effects of increased hay‐to‐grain ratio on behavior, metabolic health measures, and fecal bacterial communities in four Masai giraffe (Giraffa camelopardalis tippelskirchi) at Cleveland Metroparks Zoo

Abstract

We evaluated whether increasing the hay-to-grain ratio offered to Masai giraffe (Giraffa camelopardalis tippelskirchi) at Cleveland Metroparks Zoo would reduce oral stereotypies and alter feeding behaviors, maintain or increase serum calcium-to-phosphorus ratio, decrease serum insulin-to-glucose ratio and salivary insulin, and alter fecal bacterial community structure. Giraffe transitioned to a ∼90:10 hay-to-grain ratio in even increments over 8 weeks. A ration balancer was added during the seventh week of transition to ensure proper mineral and nutrient balance. We collected (1) behavioral data collected approximately daily using instantaneous focal sampling; (2) serum collections every other week for insulin-to-glucose and calcium-to-phosphorus ratio analysis and saliva weekly for insulin analysis; and (3) weekly fecal sample collections to examine changes in bacterial community structure during the 8 weeks preceding and following the diet change. After the diet change, giraffe spent significantly more time feeding and less time performing tongue and mouth stereotypies, people-directed and alert behaviors. Salivary and serum insulin and serum insulin-to-glucose ratio decreased, and fecal bacterial community structure changed significantly. However, serum calcium-to-phosphorus ratio remained >1:1 throughout the study. While further studies are needed to elucidate the nature and implications of the change in fecal bacterial community structure and metabolic hormones, the results of this study show promise for incremental improvements in health and welfare from feeding a higher proportion of forage in the diet.

The influence of feeding opportunities of six zoohoused Giraffa camelopardalis rothschild

“…The type of branches given to the giraffes may influence browsing activity. Shorter browsing periods have been found to decrease oral stimulation, and thus increase oral stereotypy (Monson et al, 2018). Different branches in the browsing feed for giraffes may prolong browsing periods.…”

“…Different branches in the browsing feed for giraffes may prolong browsing periods. Hawthorne has been found to increase the browsing time when compared to willow and cherry branches, which in turn led to a reduced expression of oral stereotypy (Monson et al, 2018;Okabe et al 2019). Branches without leaves will be more dominated by fibres (Ngaha et al, 2016;Gussek et al, 2017b).…”

“…The feed composition was changed from a 1:1 ratio between hay and grain (Mazuri® Wild Herbivore Diet Hi-Fiber) to a 9:1 ratio, along with added supplemental browsing material. This resulted in a reduction in the expression of oral stereotypy along with a decrease in salivary production (Monson et al, 2018). Hummel et al (2006b) found, that during fermentation, browse material has the lowest gas production when compared to grass, herbs and legumes.…”

“…A less energy-rich diet led to a higher level of foraging along with a decrease in oral stereotypy (Gussek et al, 2017a). This was further investigated by Monson et al (2018) in which an experimental feed was given to six giraffes in Cleveland Metropark Zoo. The feed composition was changed from a 1:1 ratio between hay and grain (Mazuri® Wild Herbivore Diet Hi-Fiber) to a 9:1 ratio, along with added supplemental browsing material.…”

Effect of amount of high‐fibre pellet in the diet and bedding type on feed intake, nutrient digestibility, eating behaviour and rumination in bongo (Tragelaphus eurycerus)

“…Requirements for those activities in captivity are covered mostly by feeding roughages that are willingly consumed by animals, that is, pelleted feed does not meet those needs. Too little time performing eating in captivity may lead to oral stereotypies and other behavioural disorders (Monson et al, 2018; Schaub et al, 2004). In consequence, the high‐fibre supplementary feed can be used to increase DM intake by bongo, but excessive amounts fed (e.g., >1.5−2 kg/day) have negative impacts on feeding behaviour and rumination.…”