Alginate increases water stability whilst maintaining diet digestibility in farmed saltwater crocodiles ().

Saltwater crocodile () farming in Papua New Guinea is an emerging industry that supplies high-quality skins to the fashion industry. Crocodiles are semiaquatic and fed high-quality feed made from extrudated animal byproducts (i.e., forced through a die at low pressure but not heat treated); however, it disintegrates on contact with water, and this leads to low utilization. Alginate is used extensively in food and pharmaceutical processes because it quickly forms a gel at room temperature; however, its effects on nutrient availability are equivocal, and its utility in crocodile diets is unknown. Extrudated chicken byproduct-based crocodile diets were formulated (as-fed) with and without 1.7 and 3.3% Na alginate with either CaCl or CaCO to cross-link. After immersion in water at 30°C for 24 h, feed retained on a 0.5-mm screen was measured to determine DM retention (DMR). Regardless of inclusion level, alginate addition resulted in a 13-fold increase in DMR ( < 0.05) when CaCO was used as a Ca source; however, CaCl use resulted in a much lower DMR. In a digestibility trial, 10 juvenile crocodiles (2.2 to 2.4 yr of age; 1.2 to 1.9 kg BW) were chosen from farm-raised stocks and fed extrudated chicken byproduct-based diets with and without 1.5% Na alginate and 1.9% CaCO. Animals fed 2% BW for 12 d and with excreta collected the last 5 d were slaughtered and had digesta sampled from the ileum. There were no differences in apparent ileal digestibilities of any AA, N (65.0 vs. 55.8%, SE = 12.2%), and OM (46.8 vs. 39.6%, SE = 12.8%) between diets with and without alginate, respectively. Total-tract digestibilities of OM (69.8 vs. 39.2%, SE = 9.1%) and energy (72.2 vs. 44.4%, SE = 8.3%), however, were greater in alginate-containing diets ( < 0.05). Our study showed that alginate addition to crocodile feed improved its stability in water and did not impair nutrient digestion. Application of these findings should greatly decrease feed wastage, which ultimately will benefit Papua New Guinea by simultaneously increasing economic returns and decreasing environmental impacts.

Effect of lipid type on growth performance, meat quality and the content of long chain n-3 fatty acids in pork meat.

The aim of the present study was to produce pork with enhanced nutritive value for humans, both in terms of fatty acid profile (mainly long chain n-3 fatty acids by feeding fish oil) and selenium. Forty-eight female pigs were allocated to one of six treatment groups: animal by-products and plant feedstuffs with tallow, plant feedstuffs with a blend of soybean oil and linseed oil with or without a supplement (CLA, selenium, vitamin E and vitamin C), plant feedstuffs with tallow and supplement, plant feedstuffs with fish oil and supplement. The diets containing the fish oil were fed up to either 49 days or 28 days before slaughter. The dietary treatments had no significant effects on growth performance, carcass characteristics and meat quality. When fish oil was included in the diet, higher levels of EPA, DPA and DHA were measured in the subcutaneous fat (up to 3.74%).

Effects of dietary components including garlic on concentrations of skatole and indole in subcutaneous fat of female pigs.

The results reported here showed that threshold concentrations of skatole and indole in rice-bran oil for Singaporean consumers were 0.028 µg/g and 0.051 µg/g, respectively, and that skatole and indole levels in subcutaneous fat of pigs can be affected by diet. In Experiment A, 31 female pigs were fed with diets based on plant products only (P) or plant plus animal by-products (AP), with added levels of garlic essential oil from zero to 2.15 g/kg feed. Concentrations of skatole and indole increased with increasing garlic concentration (P < 0.001). In Experiment B, P and AP diets were fed to 47 female pigs with different dietary lipid sources (fish oil, tallow, and a mix of linseed oil and soya oil). Skatole and indole concentrations were higher in backfat of pigs fed with the AP diet (P < 0.05), but were unaffected by the type of lipid.

The production of pork with garlic flavour notes using garlic essential oil.

Garlic essential oil (GEO) added directly to pork mince or to the diet of pigs was evaluated for its effectiveness in masking undesirable mutton flavour. Pork was from 31 female pigs (Duroc x (Large White x Landrace)) grown on diets containing either animal-plus-plant products (AP diet) or plant products only (P diet) with four levels of GEO: 0, 0.55, 1.44 and 1.84 g/kg feed and 0, 0.55, 1.44 and 2.15 g/kg feed in the AP and P diet, respectively. Garlic flavour increased and mutton flavour decreased in pork from pigs that consumed more than about 150 g and 220 g of GEO in P and AP diets, respectively over the 57-day feeding period. The garlic flavour was stronger and the mutton flavour less intense for pork from pigs on the P diet. When GEO was added to pork mince at 125 ppm, it significantly reduced mutton flavour.