Diet and diet‐related disorders in captive ruminants at the national zoological gardens of South Africa

Abstract

Although diet-related disorders have received much attention in the zoo literature, evidence-based results on relationships between diet and disease are still rare, often due to a lack of quantitative dietary information that can be linked to clinical or necropsy reports. We investigated 24 species of captive ruminants from one facility for which quantitative feeding instructions and necropsy reports between 1991 and 2012 were available. Species were classified as grazer (GR), intermediate feeder (IM), or browser (BR). Feeding type and body mass were significantly correlated to the diet fed, with smaller and BR species receiving higher proportions of non-roughage diet items. There were no significant differences between feeding types in the occurrence of parakeratosis/ruminitis/acidosis (PRA) at necropsy, but in body condition score, with BR more often in poor and less often in excellent body condition at necropsy. While there was no direct correlation between the proportion of non-roughage diet items and PRA across species, there was a significant effect of the proportion of non-roughage diet items on PRA when body mass was also taken into account: larger species, and those that received more non-roughage diet items, had higher prevalence of PRA. The results underline that diet and lack of structured feed items can be associated with the disease complex of acidosis in ruminants, but also suggest that this is modified by factors related to animal size. These latter may include susceptibility to acidosis, or husbandry-related opportunities to monopolize non-roughage feeds and ingest higher proportions than intended by feeding instructions.

Effect of pelleted cereal-based feed for addax antelope (<i>Addax nasomaculatus</i>) on feed intake and nutrient digestibility

“…An even higher proportion of unstructured feed in the diet (61% of DM) for addax was reported in other studies (Schilcher et al, 2013). Thus, current feeding practices of addax in the captivity do not follow widely propagated recommendations for zoo ruminants (Clauss and Dierenfeld, 2008;Schilcher et al, 2013;Gattiker et al, 2014).…”

“…This leads to low structured feed intake and high proportion of unstructured feeds in the consumed diet (Schilcher et al, 2013;Taylor et al, 2013;Górka et al, 2016); however, energy-rich, unstructured feeds have an unfavourable influence on the fermentation pattern in the rumen (Gussek et al, 2016). Such a situation is considered as the main cause of diarrhoea, laminitis, poor body condition, short life span and post mortal signs of rumenitis, often reported in captive ruminants (Clauss and Dierenfeld, 2008;Taylor et al, 2013;Gattiker et al, 2014). The above mentioned problems can further ABSTRACT.…”

Effect of pelleted cereal-based feed used in the diet on feed intake, eating behaviour, rumination and nutrient digestibility in antelope sitatunga (<i>Tragelaphus spekii</i>)

“…The proportion of those components in the diet, their sources (e.g., lucerne hay or meadow hay) and chemical composition of offered feed (e.g., fibre or protein content) are widely accepted factors determining health of this animals (Schilcher et al, 2013;Taylor et al, 2013;Gattiker et al, 2014). It is especially accepted that the diet offered in captivity should promote the intake of structured feed (browse and roughages) and limit the intake of unstructured feed easily fermentable in the rumen (cereal-based products, vegetables and fruits), in order to stimulate the normal eating and rumination behaviour and prevent disturbances of rumen function (Hummel et al, 2006;Taylor et al, 2013; ABSTRACT.…”

“…Pelleted cereal-based supplement used in the diet affects feeding behaviour and thus may affect health and welfare of sitatunga in zoological gardens. Gattiker et al, 2014). However, unstructured feed intake, namely cereal-based products, often exceeds 50% of dry matter (DM) ingested by captive ruminants, especially browsers (Clauss et al, 2003;Clauss and Dierenfeld, 2008;Schilcher et al, 2013;Taylor et al, 2013).…”

“…Nevertheless, pelleted cereal-based supplements are widely used in diets for wild captive ruminants (Schilcher et al, 2013;Taylor et al, 2013;Gattiker et al, 2014). However, it was shown that pelleted feed increases feeding rate and decreases rumination time as well as decreases digesta retention time in the rumen and ruminal and total tract digestibility of fibre in livestock ruminants (Waghorn and Reid, 1983;Abouheif et al, 2012).…”