Effects of honey locust seed pods on the behavior and nutrient intake of zoo-housed François langurs and prehensile-tailed porcupines

Seed pods represent an under-utilized and valuable dietary resource for zoos because they encourage naturalistic extractive foraging behavior and because seeds pods, like leafy browses, are more fiber-rich than most dietary items typically offered in zoos. The primary goal of this study was to examine the effects of honey locust (Gleditsia triacanthos) seed pods on the behavior and macronutrient intake of zoo-housed François' langurs (Trachypithecus francoisi; n = 3) and prehensile-tailed porcupines (Coendou prehensilis; n = 2) using a pre- versus postdiet implementation design. From December 2019 to April 2020, we recorded behavior using instantaneous interval sampling and daily macronutrient intake via dietary intake records. We found that time spent feeding increased (p < .001) and stereotypic behaviors decreased (p < .001) for the François' langur group during the seed pod phase. The prehensile-tailed porcupines also exhibited increased time spent feeding and decreased inactivity (p < .001 for all comparisons) during the experimental seed pod phase. We found no differences in macronutrient intake for the François' langur group. The female prehensile-tailed porcupine consumed more neutral detergent fiber (NDF) in the seed pod phase (p = .003) and the male consumed more crude protein, NDF, nonstructural carbohydrates, and crude fat (p < .001 for all comparisons). We stress that honey locust seed pods are a fiber-rich (i.e., ~40%-55% NDF by dry weight) dietary option for zoo-housed folivores and promote positive welfare by encouraging naturalistic foraging behavior and may help increase foraging time and decrease stereotypic behaviors.

An investigation of browsing enrichment, especially non-leaf foraging, on giraffes (Giraffa camelopardalis reticulata) at Kyoto City Zoo in Japan

Browsing enrichment may aid in developing species-specific behaviors for giraffes managed in zoos as a means of improving animal welfare. By nature, giraffes are tree-feeding animals, including tree bark, but the extent of food other than leaves as a form of browsing enrichment has not been well investigated. Therefore, to investigate the effectiveness of non-leaf foraging, three giraffes at the Kyoto City Zoo in Japan were observed for 228 h from May 2019 to February 2020. In conjunction with behavioral instantaneous sampling, tree use (landscape tree or enrichment branch) and plant part (leaves, twigs, or barks) were recorded by the 1-0 sampling method. There was no significant change in the foraging behavior on the leaves of enriched branches, nor was there any significant change in the foraging behavior of the giraffes, except for one animal in the deciduous phase. No significant changes were observed in rumination or other behaviors between the two phases. Although vegetation foraging behavior significantly decreased, except for one animal, dry hay foraging behavior significantly increased in all the animals during the deciduous phase. Some individuals also showed a significant increase in the foraging behavior for non-leafy parts of the enrichment branches (twigs and bark) during the deciduous phase. This suggests that in some tree species, giraffes forage on the bark and twigs to compensate for the loss of leaves during the deciduous phase, similar to feeding on hay or hay cubes as a substitute for tree leaves.

Browse from Three Tree Legumes Increases Forage Production for Cattle in a Silvopastoral System in the Southwest Amazon

Simple Summary

Unsustainable cattle ranching in the Amazon leads to land degradation and incentivizes deforestation. Planting trees in pastures (‘silvopasture’ or ‘silvopastoral systems’) is a novel approach that has the potential to increase the sustainability of cattle production in the Amazon. Trees provide additional feed whilst also enhancing biodiversity, capturing carbon and improving soil quality. We measured the potential contribution of tree forage to pasture-fed cattle at a trial farm in Peru. Three leguminous tree species (Erythrina berteroana, Inga edulis and Leucaena leucocephala) were planted with grass, and their productivity was compared to plots containing only grass. We compared destructive and non-destructive methodologies that estimated intake of tree forage by browsing cattle. We found that fresh tree foliage of the three tree species was palatable to cattle and could be directly browsed. Cattle mostly foraged below 1.6 m and consumed 99% of available foliage from E. berteroana, 75% of available forage from I. edulis and 80% of available forage from L. leucocephala. Plots containing trees and grass produced more forage biomass (mean > 2.2 Mg ha⁻¹) than grass only plots (mean = 1.5 Mg ha⁻¹). This research highlights the potential for sustainable intensification of livestock production in the Amazon.

Abstract

Assessing the palatability of forage from locally adapted trees could improve the sustainability of livestock production systems. However, grasses continue to dominate livestock feed across the Amazon. We established a silvopastoral cattle farming system in Peru, comparing three different forage tree species with grass monocultures using a randomised block design. Trees were arranged in alleys of 0.5 × 7.5 m, planted alongside grass, and were directly browsed by cattle. Browse removal was estimated by three methods: destructive sampling, canopy measurements and leaf counts. We found that all three tree species were palatable to cattle. Plots containing trees and grass produced more available forage (mean > 2.2 Mg ha⁻¹) for cattle than the grass monocultures (mean = 1.5 Mg ha⁻¹). Destructive sampling below 1.6 m demonstrated that cattle consumed 99% of the available Erythrina berteroana forage, 75% of the available Inga edulis forage and 80% of the available Leucaena leucocephala forage in 8 days. This research demonstrates methodologies to estimate the intake of locally adapted browse species by cattle and highlights the potential benefits of silvopastoral systems in the Amazon. Planting trees could also benefit animal health and provide ecosystem services such as soil regeneration, enhanced nutrient cycling and carbon capture.

Ensiling of maple leaves and its use in winter nutrition of mantled guereza (Colobus guereza)

Young leaves are favored by mantled guereza (Colobus guereza) and the gastrointestinal tract of this species is well adapted to such a high fiber diet. Fresh maple leaves are often used in the diets for guereza in captivity but their use in winter feeding time is limited. The aim of the study was to evaluate the effect of additives on chemical composition and fermentation parameters of maple leaf silage, as well as inclusion of maple leaf silage in the diet for mantled guereza on feed and nutrient intake. Maple leaves were ensiled without additives (MLS), with a mixture of bacterial inoculants (MLS + BI) and with carrot additives (MLS + C). The chemical composition and fermentation parameters were determined in fresh and ensiled material. A group of seven mantled guerezas were fed a standard diet, and afterwards shifted to a diet with maple leaf silage (contained 20% of MLS; as fed). Each diet was fed for 7 days when the feed and nutrient intake were measured. The ensiling process did not change the concentration of most nutrients compared to the fresh material. The inclusion of leaf silage increased dry matter intake by guereza (125.3 vs. 163.3 g dry matter/day). Therefore, higher nutrient intake (crude protein, NDF, ADF) was observed when maple leaf silage was included in the diet. In conclusion, the ensiling process (even without additives) proved to be a good conservation method for maple leaves. Furthermore, inclusion of maple leaf silage in the winter diets for guereza, and possibly other folivorous primates, may increase dry matter and nutrients (particularly fiber) intake.

Classification of the Use of Online Health Information Channels and Variation in Motivations for Channel Selection: Cross-sectional Survey

BACKGROUND

Existing health education and communication research routinely measures online channel use as a whole by, for example, evaluating how frequently people use the internet to search for health information. This approach fails to capture the complexity and diversity of online channel use in health information seeking. The measurement of generic online channel use may cause too much error, and it lends no support to media planning in public health promotion campaigns or scholarly research involving online channel use.

OBJECTIVE

This study intends to present a thorough picture of patterns of online health information channel use and classify the use of various types of online health information channels, including WeChat, microblogs, web portals, search engines, mobile apps, and online forums. Under the framework of the risk information seeking and processing model, this study also analyzes the differences in individuals' motivations for channel selection to offer further evidence to validate the classification scheme.

METHODS

This study sampled 542 Chinese internet users in Beijing. The average age of the respondents was 33 years, female respondents accounted for 52.0% (282/542) of the sample, and the average monthly income ranged from US $900 to $1200. The study surveyed the use of 13 commonly used online health information channels and various sociopsychological factors associated with online health information seeking.

RESULTS

This study derived 3 categories of online health information channels: searching, browsing, and scanning channels. It was found that the use of online searching channels was affect driven (B=0.11; β=0.10; P=.02) and characterized by a stronger need for health knowledge (B=0.09; β=0.01; P<.001). The use of browsing channels was directly influenced by informational subjective norms (B=0.33; β=0.15; P=.004) and perceived current knowledge (B=0.007; β=0.09; P=.003). The use of scanning channels was mainly influenced by informational subjective norms (B=0.29; β=0.15; P=.007).

CONCLUSIONS

The results of this study suggest that health communication practitioners and scholars may consider measuring the use of internet, new media, or online media more precisely instead of simply asking the public about the frequency of online channel use or internet use in the acquisition of health information. Scholars and practitioners may consider measuring the use of online health information channels by using the 3-category scheme described in this study. Future research is encouraged to further explore how people process health information when using different online channels.

Preference of intake of different tree leaves preserved with drying and ensiling by nyala antelope (Tragelaphus angasii)

It is recommended that browse should be an important part of diets for browsing and intermediate feeding type ruminants. However, provision of browse in winter time is problematic for many zoos located in the temperate climate. Drying or freezing of branches are commonly practiced solutions to this problem, but ensiling of tree leaves could also be an attractive option. The aim of this study was to determine the effect of drying and ensiling of different tree leaves on preference of their intake by nyala antelope (Tragelaphus angasii), an intermediate feeding type ruminant. A study was conducted on five nyala fed a standard diet (meadow hay, dehydrated chopped lucerne and limited concentrates) before and during the study. Preference of intake of five feeds was tested: dried maple (A. platanoides), oak (Q. robur), willow (S. alba), and ensiled maple and lime (T. cordata) leaves. Each day two tested feeds were offered to each animal. After 4 h of presentation, feed refusals were weighed and preference ratio for each tested feed and animal was calculated. Then, preferences were ranked using a pairwise comparison chart. Dried maple and oak leaves were preferred more than other leaves whereas ensiled lime leaves were the least preferred. On the other hand, ensiled and dried maple leaves were equally preferred. Results of this study showed that palatability of ensiled tree leaves should not be a concern when feeding nyala, and likely also other browsing or intermediate feeding type ruminants, but palatability of silage may depend on the species of tree.

Composition of browses consumed by Matschie's tree kangaroo (Dendrolagus matschiei) sampled from home ranges in Papua New Guinea

Twenty-six samples (n = 24 spp.) of foods eaten, including ferns, shrubs, vines, orchids, herbaceous plants, and tree leaves, were collected from the Yopno, Uruwa, and Som Conservation Area at approximately 1,800 m altitude on the Huon Peninsula, Papua New Guinea (PNG). Samples were weighed fresh in the field and transported to the Lae National Herbarium in PNG for drying and confirmed identification, before transporting to the US for analysis of primary nutrient composition and minerals. Water content averaged 76 ± 10% (mean ± standard deviation); on a dry matter (DM) basis, foods averaged moderate protein (11 ± 5%), and soluble carbohydrate (27 ± 8%) content, along with exceptionally low starch (1 ± 1%) and crude fat (3 ± 2%) values, and moderate to high values in fiber fractions (neutral detergent fiber 52 ± 13%, acid detergent fiber 39 ± 10%, lignin 15 ± 6%). Calculated metabolizable energy content of native forages averaged 1.9 ± 0.3 Mcal/kg DM (ruminant model). Macromineral concentrations (DM basis) were not exceptional (calcium 1.1 ± 1.0%, phosphorus 0.2 ± 0.1%, magnesium 0.3 ± 0.2%, potassium 1.8 ± 0.9%, sodium 0.02 ± 0.02%), and select trace minerals were within anticipated ranges for herbivores (copper 12 ± 13 mg/kg, iron 48 ± 26 mg/kg, zinc 34 ± 18 mg/kg) with the exception of manganese (268 ± 225 mg/kg), which could be considered on the high end of dietary adequacy for most herbivores. These data provide useful information that can be used to adjust nutrient targets for dietary development and feeding management of captive populations of tree kangaroos.

Probable Enalapril Hepatotoxicity in a 13-Year-Old Male Western Lowland Gorilla: Pharmacologic Risks and Vigilance

A 13-year-old male Western lowland gorilla presented acutely with a precipitous decline in health status from liver disease. Through diagnostic assessment, including serum chemistries and advanced imaging, it was diagnosed with probable hepatotoxicity resulting from its prescribed medication, enalapril. As one of several angiotensin converting enzyme inhibitors (ACE-I) available to zoo veterinarians, enalapril had been administered for treatment of mild ventricular hypertrophy diagnosed during routine examination 2.5 years prior to the presentation. The gorilla made a complete recovery with discontinuation of this medication, and provision of hepatoprotectants. Hepatotoxicity has been documented in humans receiving this product as an adverse drug reaction and is considered both rare and unpredictable in occurrence. In this event, an association was suspected with indulgent consumption of mulberry browse (Morus sp.) offered as nutritional enrichment immediately prior to clinical presentation and had potential impact on hepatic cytochrome P450 metabolism of the enalapril. Although ACE-I are important medications in this taxon due to its predisposition to cardiac disease, this event underscores the need for vigilance on the part of veterinarians and managers whenever pharmaceuticals are administered. Most drugs are modeled in a limited number of species but utilized in a wide variety, and unintended results are possible.

Within trophic level shifts in collagen-carbonate stable carbon isotope spacing are propagated by diet and digestive physiology in large mammal herbivores

Stable carbon isotope analyses of vertebrate hard tissues such as bones, teeth, and tusks provide information about animal diets in ecological, archeological, and paleontological contexts. There is debate about how carbon isotope compositions of collagen and apatite carbonate differ in terms of their relationship to diet, and to each other. We evaluated relationships between δ¹³C_collagen and δ¹³C_carbonate among free‐ranging southern African mammals to test predictions about the influences of dietary and physiological differences between species. Whereas the slopes of δ¹³C_collagen–δ¹³C_carbonate relationships among carnivores are ≤1, herbivore δ¹³C_collagen increases with increasing dietary δ¹³C at a slower rate than does δ¹³C_carbonate, resulting in regression slopes >1. This outcome is consistent with predictions that herbivore δ¹³C_collagen is biased against low protein diet components (¹³C‐enriched C₄ grasses in these environments), and δ¹³C_carbonate is ¹³C‐enriched due to release of ¹³C‐depleted methane as a by‐product of microbial fermentation in the digestive tract. As methane emission is constrained by plant secondary metabolites in browse, the latter effect becomes more pronounced with higher levels of C₄ grass in the diet. Increases in δ¹³C_carbonate are also larger in ruminants than nonruminants. Accordingly, we show that Δ¹³C_collagen‐_carbonate spacing is not constant within herbivores, but increases by up to 5 ‰ across species with different diets and physiologies. Such large variation, often assumed to be negligible within trophic levels, clearly cannot be ignored in carbon isotope‐based diet reconstructions.

Nutrient and plant secondary compound composition and iron-binding capacity in leaves and green stems of commonly used plant browse (Carolina willow; Salix caroliniana) fed to zoo-managed browsing herbivores

Plant secondary compounds are diverse structurally, and associated biological effects can vary depending on multiple factors including chemical structure and reaction conditions. Phenolic compounds such as tannins can chelate dietary iron, and supplementation of animal species sensitive to iron overload with tannins may prevent/treat iron overload disorder. We assessed the nutrient and phenolic composition and iron-binding capacity of Carolina willow (Salix caroliniana), a plant fed to zoo-managed browsing herbivores. Based on studies in other plant species and the chemical structures of phenolic compounds, we hypothesized that the concentration of condensed tannins in willow would be inversely related to the concentration of phenolic glycosides and directly related to iron-binding capacity. Our results indicated that willow nutrient composition varied by year, season, and plant part, which could be taken into consideration when formulating animal diets. We also found that the predominant plant secondary compounds were condensed tannins with minimal phenolic glycosides. Instead of binding to iron, the willow leaf extracts reduced iron from the ferric to ferrous form, which may have prooxidative effects and increase the bioavailability of iron depending on animal species, gastrointestinal conditions, and whole animal processes. We recommend identifying alternative compounds that effectively chelate iron in vitro and conducting chelation therapy trials in vivo to assess potential effects on iron balance and overall animal health.

Near infrared reflectance spectroscopy (NIRS) analyses of nutrient composition and condensed tannin concentrations in carolina willow (Salix caroliniana)

Iron overload disorder has been described in a number of zoo-managed species, and it has been recommended to increase the tannin composition of the diet as a safe way to minimize iron absorption in these iron-sensitive species. The goal of this study was to examine the potential of near infrared reflectance spectroscopy (NIRS) as a rapid and simple screening tool to assess willow (Salix caroliniana) nutrient composition (crude protein: CP; acid detergent fiber: ADF; neutral detergent fiber: NDF; lignin, gross energy: GE) and condensed tannin (CT) concentrations. Calibration equations were developed by regression of the lab values from 2 years using partial least squares on n = 144 NIRS spectra to predict n = 20 independent validation samples. Using the full 2-year dataset, good prediction statistics were obtained for CP, ADF, NDF, and GE in plant leaves and stems (r(2 ) > 0.75). NIRS did not predict lignin concentrations reliably (leaves r(2)  = 0.52, stems r(2)  = 0.33); however, CTs were predicted moderately well (leaves r(2)  = 0.72, stems r(2)  = 0.67). These data indicate that NIRS can be used to quantify several key nutrients in willow leaves and stems including concentrations of plant secondary compounds which, depending on the bioactivity of the compound, may be targeted to feed iron-sensitive browsing animals.