An investigation into the chemical composition of alternative invertebrate prey

The aim of this study was to determine the chemical composition of eight invertebrate species and evaluate their suitability as alternative prey. The species selected were rusty red cockroaches (Blatta lateralis), six-spotted cockroaches (Eublaberus distanti), Madagascar hissing cockroaches (Gromphadorhina portentosa), fruit flies (Drosophila melanogaster), false katydids (Microcentrum rhombifolium), beetles of the mealworm (Tenebrio molitor), and superworm beetles (Zophobas morio), as well as woodlice (Porcellio scaber). Dry matter (DM), crude protein, crude fat, neutral detergent fiber, acid detergent fiber, ash, macro and trace minerals, vitamins A and E, and carotenoid concentrations were quantified. Significant differences were found between species. Crude protein content ranged from 38 to 76% DM, fat from14 to 54% DM, and ash from 2 to 8% DM. In most species, calcium:phosphorus was low (0.08-0.30:1); however, P. scaber was an exception (12:1) and might prove useful as a dietary source of calcium for insectivores. Vitamin E content was low for most species (6-16¿mg/kg DM), except for D. melanogaster and M. rhombifolium (112 and 110¿mg/kg DM). The retinol content, as a measure of vitamin A activity, was low in all specimens, but varied greatly among samples (0.670-886¿mg/kg DM). The data presented can be used to alter diets to better suit the estimated requirements of insectivores in captivity. Future research on the topic of composition of invertebrate prey species should focus on determination of nutrient differences owing to species, developmental stage, and diet

Development of a standardized body condition score for native cattle in Uganda

A poster prepared for the 5th All Africa Conference on Animal Agriculture and the 18th Annual Meeting of the Ethiopian Society of Animal Production (ESAP), Addis Ababa, October 25-28, 2010

Nutrient composition of pastures in Kayunga District, Uganda: A preliminary investigation with implications for seasonal supplementation in grazing Ruminants

Proximate nutrient composition (crude protein, non-fiber carbohydrates, crude fiber, and ash), fiber fractions (neutral detergent fiber (NDF), acid detergent fiber (ADF), lignin), and both macro (calcium (Ca), phosphorus (P), magnesium (Mg), potassium (K), sodium (Na), and sulfur (S)) and trace (copper (Cu), iron (Fe), manganese (Mn), molybdenum (Mo), and zinc (Zn)) mineral profiles were quantified in mixed pasture samples collected during the wet (n = 8) and dry (n = 15) seasons in north central Uganda. Metabolizable and Net Energy values for dairy production were estimated based on standard calculations, and samples were compared seasonally. Crude fat (p = 0.05) and lignin (p = 0.01) values were lower in the dry compared with the wet season, linked with reduced plant growth. Crude protein (13.0% of dry matter (DM)), fiber fractions, and calculated energy content did not vary seasonally in this data set, and reflected chemical components of a grass-dominated system that appeared energetically limiting for production livestock. Mineral constituents varied more dramatically by season, with Ca, Mg, Cu, and Mn lower (all < 0.05) and K higher in the dry season. Sodium was deficient in these pastures, whereas Ca, P, Mg, S, Cu, and Zn concentrations may have been only marginally sufficient, particularly to meet needs for lactation, dependent on season. These limited data suggest that a high-energy mineral supplement may prove beneficial in meeting nutritional and production needs of multiple grazing ruminant species in this region, particularly during dry seasons

Gaining insights in the nutritional metabolism of amphibians: analysing body nutrient profiles of the African clawed frog, <em>Xenopus</em> <em>laevis</em>

Whole bodies of Xenopus laevis (n = 19) were analysed for chemical composition and morphometrics. The nutrient profile (macronutrients, amino acids, fatty acids and minerals) was evaluated by sex; interactions among variables with body weights and lengths, and comparisons made with different species of marine and fresh water fish. Significant differences were found in morphometric measurements, water content, several minerals and fatty acids between sexes of X. laevis. Amino acid profiles differed in methionine, proline and cysteine, which could underlie different metabolic pathways in frogs when compared to fish. In addition, fatty acid profiles revealed more monounsaturated and n − 6 polyunsaturated fatty acids in frogs than in fish, more similar to values reported for terrestrial than aquatic vertebrates. Important interactions were also found between body measurements and fat, calcium, and phosphorus, as well as between essential and non-essential amino acids. The results indicate that frogs might have particular biochemical pathways for several nutrients, dependent on sex and linked to body weight, which ultimately could reflect specific nutrient need

The relationship between lipid peroxidation, hibernation, and food selection in mammals

A diet that has high levels of polyunsaturated fatty acids enhances mammalian torpor. Polyunsaturated fatty acids are not synthesized by mammals, but are incorporated into both membrane and storage lipids when they occur in the diet. Polyunsaturated fatty acids also undergo autoxidation more readily than other fatty acids, thereby producing highly toxic lipid peroxides. Lipid peroxidation increases during torpor. Natural selection in mammalian hibernators should thus have favored the evolution of dietary preferences that maximize hibernation ability while simultaneously minimizing the degree of lipid peroxidation during torpor. This hypothesis was tested in laboratory experiments and field studies involving golden-mantled ground squirrels (Spermophilus lateralis). We found that the intake of polyunsaturated fatty acids is restricted during the fall and autoxidation in tissues occurs mostly during the later phases of hibernation

Amino acid profile of salivary proteins and plasmatic trace mineral response to dietary condensed tannins in free-ranging zebu cattle (Bos indicus) as a marker of habitat degradation

In the southern hemisphere, foraging areas of cattle are affected by overgrazing and soil erosion resulting in decreased availability of grasses and increased amounts of browse plants high in condensed tannins (CT). This study aimed to identify biomarkers in free-ranging zebu cattle (Bos indicus) for the habitat degradation, based on their salivary and trace mineral response to dietary CT. Saliva and blood samples were collected from 60 randomly involved free-ranging zebu bulls in six study sites, which were further grouped into two regions based on the average CT concentration in the plants regularly consumed by the cattle. Jugular venipunctures for blood sampling and the swabbing technique for saliva collection were used. Plasma samples were analyzed for Cu, Zn and Fe. Saliva samples were analyzed for total amino acid concentrations. Average CT concentrations in the plants ranged between 0 and 166 g CT/kg dry matter (P 0.05). In contrast to Cu, higher Zn concentration was found in the region rich in CT content (P <0.05). The proportion of proline of total amino acids, as main indicator of salivary proline-rich proteins in the saliva, was higher in the tannin-rich region (P <0.01). The ratio of proline to the sum of total amino acids was also higher in this region (P <0.001). Higher ratio of salivary arginine to ornithine was observed in the tannin-rich region (P <0.05), suggesting reduced ruminal protein synthesis due to reduced protein bio-availability. In conclusion, the increase in salivary proline concentration in free-ranging zebu cattle reflects the dietary CT load, which in turn suggests habitat degradation and lower availability of feed sources