Increasing dietary inclusions of camelina cake fed to pigs from weaning to slaughter: Safety, growth performance, carcass traits, and n-3 enrichment of pork1

Abstract

Feeding cake with remaining oil content not only provides additional dietary energy but may also enrich pork with -3 fatty acids. Limited information is available on feeding camelina cake to pigs relating to feeding safety (toxicity), growth performance, and efficacy of -3 enrichment of pork. Therefore, we evaluated the effects of feeding increasing camelina cake (12.2% crude fat) inclusions in diets for nursery and grower-finisher pigs. In total, 128 pigs (9.2 kg BW) were randomly allocated by sex to 32 nursery pens for 4 wk and were then moved and combined into 16 mixed-sex grower-finisher pens. Pigs were fed 1 of 4 wheat/barley-based diets including camelina variety 'Celine' cake (0%, 6%, 12%, or 18% in the nursery phase and 0%, 5%, 10%, or 15% in the grower-finisher phase) replacing soybean meal over 5 feeding phases (d 0 to 7, d 7 to 28, d 28 to 56, d 56 to 84, and d 84 to slaughter). Individual pigs and pen feed added were weighed. On d 106, a blood sample was collected from the pig with the lowest BW per pen, which was then euthanized. A pathologist conducted a gross clinical examination, and organs were weighed. Liver, back fat, and belly and jowl fat were sampled for fatty acid analysis. Pigs were slaughtered at approximately 125 kg BW. Increasing dietary camelina cake inclusion linearly decreased ( < 0.010) ADFI, ADG, BW, and G:F over the 105-d trial. Increasing dietary camelina cake inclusion linearly increased days to slaughter ( < 0.001) and carcass lean yield ( < 0.010) and linearly decreased farm ship weight ( < 0.010), carcass weight ( < 0.001), dressing percentage ( < 0.050), and back fat thickness ( < 0.010) but did not affect loin depth and index. Increasing camelina cake inclusion linearly increased liver and pancreas weight ( < 0.050) relative to BW but did not affect heart, thyroid, or kidney weights. Increasing camelina cake inclusion did not result in gross clinical or serological findings that would indicate toxicity. Increasing dietary camelina cake inclusion linearly increased ( < 0.050) -3 fatty acids, including docosahexaenoic acid, in back fat and belly and jowl fat. In conclusion, feeding camelina cake to pigs at up to 18% in the nursery phase and 15% in the grower, developer, and finisher phases did not result in clinical signs of toxicity and enriched carcass fat depots with -3 fatty acids. The observed decrease in ADFI and, consequently, ADG as camelina cake inclusion increased resulted in pigs fed 15% reaching slaughter weight 27 d later than controls.