232 Effects of Yarrowia Lipolytica Supplementation on Growth Performance and Apparent Ileal Digestibility of Diets Fed to Nursery Pigs

The objective was to evaluate Yarrowia lipolytica (YL) as a lipid supplement fed to nursery pigs for the growth performance and apparent ileal digestibility (AID). Twenty-four pigs weaned at 21 d of age (12 barrows and 12 gilts with initial BW at 7.2 ± 0.6 kg) were allotted to 3 dietary treatments (n = 8) based on the randomized complete block design with sex and BW as blocks. The main effect was the dietary supplementation of YL (0, 1.5, and 3.0%, replacing poultry fat) with nutrients meeting or exceeding the requirements by NRC (2012) and fed to pigs for 21 d based on 2 phases. Feed intake and BW were recorded at d 0, 10, and 21 to calculate ADG, ADFI, and G:F. Fecal scores were recorded at every odd day from d 3 to 19. Pigs were euthanized on d 21 to collect ileal digesta for AID of nutrients in diets. Data were analyzed using Proc Mixed of SAS. There were no differences in growth performance among treatments. Whereas, pigs fed 0 and 1.5% YL had higher (P < 0.05) AID of DM (55.0 and 52.2% to 40.2%, respectively) and GE (62.1 and 60.6% to 49.8%, respectively) than pigs fed 3% YL. There were no differences in AID of DM and GE between the pigs fed 0% and 1.5% YL. In conclusion, 1.5% Yarrowia lipolytica could be supplemented in nursery pig diets reducing 0.8% of poultry fat without affecting growth performance and AID of DM and GE.

The effects of rapeseed cake intake during the finishing period on the fatty-acid composition of the longissimus muscle of Limousin steers and changes in meat colour and lipid oxidation during storage

Context Cold-pressed rapeseed cake is a by-product of biodiesel manufacturing that can be obtained on-farm after simple mechanical extraction of the oil. It has a high crude fat content and contains significant amounts of linoleic acid, which make it a promising lipid supplement to modulate meat fatty acid profile. However, previous studies have indicated that using unsaturated fats in beef cattle diets could promote lipid oxidation and reduce meat redness. Aims The present study aimed to evaluate the effects of supplementation of intensively fattened beef steers with cold-pressed rapeseed cake on the fatty acid composition of beef fat and changes in measures of meat colour and lipid oxidation during 6 days of aerobic storage. Methods Sixteen Limousin steers were divided into two homogeneous groups and were fed ad libitum with barley straw and a concentrate mixture supplemented with either PROGRAS (PROGRAS at 2.7% of the diet, high in palmitic acid C16:0 from palm oil; CTR, experimental control; n = 8) or cold-pressed rapeseed cake (CPRC at 14.8% of the diet; CPRC treatment; n = 8) for a period of 9 months. The growth performance and carcass traits were assessed. The intramuscular fatty acids were analysed and the colour stability and lipid oxidation were measured in meat stored aerobically at 4°C for 0, 3 or 6 days. Key results Slaughter bodyweight and average daily gain were not affected by the inclusion of CPRC in the diet. Nor were there any changes in carcass weight, conformation or fatness. The longissimus thoracis from CPRC-fed animals depicted a higher UFA–SFA ratio and a lower atherogenic index than did that from animals fed CTR. Feeding CPRC increased the oleic acid , the vaccenic acid and the rumenic acid proportions in the muscle fat without affecting the ratio of C18:1 trans-10 to C18:1 trans-11. The extents of lipid oxidation and colour deterioration during aging were not affected by the dietary treatments. Conclusions The use of cold-pressed rapeseed cake as a lipid supplement in beef-steer diet improved the fatty acid profile of muscle fat without compromising meat oxidative stability, animal growth performance and carcass characteristics. Implications The supplementation of beef-steer diet with cold-pressed rapeseed cake could be an advantageous economical strategy allowing exploitation of an important by-product of small-scale biodiesel manufacturing to provide consumers with healthier meat.

Incorporation of two levels of black soldier fly (Hermetia illucens L.) larvae fat or extruded linseed in diets of growing rabbits: effects on growth performance and diet digestibility

The use of black soldier fly (BSF) (Hermetia illucens L.) larvae fat as a lipid supplement in growing rabbit’s diet was evaluated at two levels of supplementation in comparison to two levels of extruded linseed. Forty-eight weaned rabbits aged 35 days were individually housed in digestibility cages and randomly allocated to one of the four diets: Linseed-Low (30 g/kg of fat from linseed), Linseed-High (60 g/kg of fat from linseed), BSF-Low (30 g/kg of BSF fat), BSF-High (60 g/kg of BSF fat). Animals had ad libitum access to water and feed during 5 weeks, and were slaughtered at 70 days of age. In the fourth week of the trial, faeces were collected to allow the evaluation of total tract apparent digestibility (TTAD) of the diets. Mortality, dry matter (DM) intake, average daily gain, slaughter live weight, and carcass, liver, perirenal fat, scapular fat, and digestive tract weights were not affected (P > 0.05) either by fat source or fat level. The TTAD of DM, organic matter, ether extract, and gross energy were lower (P < 0.05) in the diet containing BSF fat than in linseed diets, and the decrease observed ranged between 2.3 to 3.1 percent points. With increasing the fat inclusion level, ether extract TTAD increased (P < 0.001) but the cellulose TTAD decreased (P < 0.01). Overall, diets containing BSF fat resulted in a slightly lower TTAD than linseed diets, but this seemed not to have affected growth performance and carcass yield. In conclusion, BSF fat could be considered an alternative lipid source for growing rabbit diets highlighting similar productive results to linseed.