Onderzoek DK Dried Browse Mulch
22-03-2024
Introduction
Giraffes (Giraffa camelopardalis) are browsers, primarily feeding on leaves from trees and shrubs, with a preference for acacias and other leafy plants4, 9. Foraging is their primary activity, essential for maintaining their bodies. Rumination is also crucial to giraffes' natural behavior, aiding in the effective digestion of food, especially breaking down insoluble carbohydrates like fiber found in plant cell walls3. In captivity, fulfilling giraffes' nutritional needs is challenging, particularly during winter when natural food sources diminish. Limited availability of fresh leaves and branches leads to provision of mainly roughage, alfalfa hay, and low-fiber pellets, which may not adequately stimulate natural behaviors, potentially resulting in abnormal behaviors like oral stereotypies1, 2, 7, 8, 9, 10. Increasing fiber content in the diet can promote natural behaviors, including longer rumination periods and reduced abnormal behaviors3,6. The development of "DK Dried Browse Mulch" by Kiezebrink offers a promising nutritional supplement for giraffes, resembling their natural diet and rich in dietary fiber5. This could potentially increase foraging and rumination time while reducing abnormal behaviors in captive giraffes.
Methods & Materials
• The research, carried out at Dierenpark Amersfoort in the Netherlands, spanned from December 11th, 2023, to January 14th, 2024, focusing on the behaviour of four male giraffes.
• Daily rations based on giraffes weighing 900 kg
- Diet 1: 4.4 kg of browser pellets
- Diet 2: 4.4 kg of browser pellets + 2 kg of DK Dried Browse mulch.
Both rations were divided into two feeding sessions.
• For 10 days per diet, instantaneous scan sampling at 30-second intervals during morning feedings monitored foraging behavior.
• For 8 days per diet, continuous focal sampling observed rumination and abnormal behaviors after morning feedings for one hour per giraffe per day.
• Alfalfa hay, browse, and ad libitum water were available throughout the day.
• Linear Mixed Models analyzed the impact of DK Dried Browse mulch on foraging and rumination behavior.
• Due to limited data, oral stereotypies are not statistically tested. A simple descriptive statistics is used to compare oral stereotypies before and after adding DK Dried Browse mulch, specifically focused on 'licking unnatural objects'.
Results & Discussion
• Giraffes spend significantly more time foraging during the morning feeding with Diet 2 compared to Diet 1 (Table 1). The addition of DK Dried Browse mulch to Browser pellets likely increased foraging time (p < 0.05).
• Giraffes spend significantly more time ruminating with Diet 2 compared to Diet 1 (Table 1). The addition of DK Dried Browse mulch to Browser pellets likely increased rumination time (p < 0.05).
• After the addition of DK Dried Browse mulch to Browser pellets, the duration of licking unnatural objects is halved, suggesting a potential alleviation of oral stereotypies (Figure 1). However, this was not statistically tested.
Table 1*: Comparison of Average Duration of Foraging, Rumination, and Oral Stereotypies between Two Diets: Browser Pellets (Diet 1) and Browser Pellets with the Addition of DK Dried Browse Mulch (Diet 2), Highlighting Differences in Foraging and Rumination Times.
Figure 1*: Difference in average duration of foraging, rumination and oral stereotypies between Browser pellets (Diet 1) and Browser pellets with an addition of DK Dried Browse mulch (Diet 2)
*For this study on the impact of DK Dried Browse mulch on the foraging, rumination, and abnormal behaviors of captive giraffes, we used a base diet comprising Kasper Natural Browser (10mm) and Boskos Browser.
• The study provides valuable insights, but factors like limited visibility and sample size could affect interpretation. Changes in mulch quantity and the presence of finely ground acacia fibers in DK Dried Browse mulch could also impact outcomes. Additionally, solely daytime observations may limit comprehensive understanding; nocturnal observations could provide supplementary insights.
Conclusion
• Supplementing Browser pellets with DK Dried Browse mulch positively affects the duration of foraging, rumination, and abnormal behaviors in giraffes.
• Giraffes receiving DK mulch spend significantly more time foraging and rumination while exhibiting reduced abnormal behaviors, particularly in licking unnatural objects.
• Further studies are necessary to evaluate the long-term effects of this dietary adjustment and explore other potential factors influencing behavioral changes.
References
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