The effect of varying dietary nutrient densities on the relative growth of ostrich body components

The influence of varying dietary protein and energy levels on the relative growth of body components of ostriches was evaluated over a 244-day growth period. One hundred twenty 1-day-old ostrich chicks were randomly assigned to 15 pens. Three varying energy regimes (high, medium and low) and five protein levels (1-5) were supplied ad libitum to each pen. A randomly selected bird from each pen was slaughtered at 1, 35, 63, 103, 159, 168 and 244 days of age. Each bird was weighed, stunned, exsanguinated, defeathered and eviscerated. Individual body components were dissected and weighed at every slaughter age. Proximate analysis was performed on these components, which were ground with the remainder of the carcass, excluding gut content, but including blood and feathers. Based on the analysis of ostrich feathers and the known mass of the feathers, the protein mass contribution of the feathers was deducted from the protein accretion of the bird. All the data were transformed to natural logarithms and regressed against the featherless body protein growth. Intercepts and slopes were compared to determine differences in growth rate ascribed to nutrient densities. Neither dietary energy nor dietary protein level had a significant effect on the relative growth of the measured components in this study. Allometric coefficients were established, which could be helpful to improve the accuracy of simulation modelling attempts for ostrich nutrition

The effect of dietary energy content on quality characteristics of Boer goat meat

The palatability and chemical composition of Longissimus lumborum muscles from 24 Boer goat castrates (eight goats per treatment), finished on diets varying in energy content (9.7, 10.2 and 10.6 MJ ME/kg feed), were evaluated by a trained sensory panel on a line scale ranging from low to high intensity for aroma, flavour and texture attributes. Physical measurements as well as proximate analysis were performed for each sample. No differences (P > 0.05) were found between the dietary treatments for any of the attributes analysed. Lamb flavour and aroma were the most prominent attributes, while only low levels of goat-like flavours were detected. Juiciness and tenderness had a strong correlation (r = 0.864) and were rated to be moderate. The findings suggest that energy density of feedlot diets can be varied to still produce chevon with uniform meat quality characteristics

Feather and skin development of ostriches Struthio camelus

Information on feather and skin growth is important for the development of mathematical optimisation nutritional models for ostriches. Ostriches (n = 65) were subjected to a four-stage formulated growth diet programme (pre-starter, starter, grower and finisher), with declining protein and energy content. Nine birds were weighed, stunned, exsanguinated, defeathered, skinned and eviscerated at 1, 54, 84, 104, 115, 132 and 287 days of age. Feathers from four pre-selected locations on the body were harvested and weighed. The wet skin weight, wet unstretched skin size and wet unstretched crown size were measured at each slaughter stage. The live weight, feather and skin yields of the birds increased with age at slaughter, as did feather shaft diameter. Prediction models were developed to estimate the yield of the skin in terms of live weight and of empty body protein weight to aid in diet formulation. The allometry of feather growth was determined from total feather weight, as the maturation rates of the feathers differ from that of the ostrich body. Results from this study will aid in setting up a mathematical optimisation nutritional model for ostriches