Increasing the amount of n-3 fatty acid in meat from young Holstein bulls through nutrition1

Abstract

Fifty-four Holstein bulls were blocked by initial BW (301 +/- 7.4 kg) and randomly assigned to 6 treatments following a 3 x 2 factorial arrangement, with 3 concentrate lipid levels (5, 8, and 11% of DM) and 2 lipid sources (whole canola seed and whole linseed), with the objective of evaluating the possibility of increasing the content of n-3 fatty acids in meat. Concentrates (mostly corn meal) were isonitrogenous and isocaloric. Concentrate and straw were both fed ad libitum. Animal BW was recorded every 2 wk, and feed consumption was recorded weekly. Ruminal pH and VFA concentrations were determined monthly. Bulls were transported to the slaughterhouse when they achieved the target slaughter weight of 443 kg (after 105 +/- 4 d of fattening). After slaughter, a sample of LM from the sixth to the eighth ribs was dissected and analyzed for intramuscular fat content and fatty acid profile. Dietary lipid source did not affect overall animal performance, rumen fermentation, or carcass quality. Rumen pH was >6.0 despite consumption by the bulls of large amounts of concentrate. In bulls fed linseed, the percentage of n-3 fatty acids in LM increased linearly with lipid level, whereas in bulls fed canola seed it remained constant. The ratio of n-6:n-3 fatty acids was lower (P < 0.01) in the LM of bulls fed linseed (10.0) than in those fed canola seed (26.0). The content of cis-9, trans-11-CLA in the LM tended (P = 0.06) to be greater in the bulls fed linseed than in those fed canola seed (62.9 vs. 49.2 mg/kg of LM, respectively). Concentration of n-3 fatty acids in meat of bulls fed high-concentrate diets can be enhanced by whole linseed supplementation without affecting animal performance, ruminal fermentation, or carcass quality.

Performance, behaviour and meat quality of beef heifers fed concentrate and straw offered as total mixed ration or free-choice

“…The low roughage intake registered in heifers fed FCH is in agreement with data reported by Iraira et al (2012), who recorded an average proportion of 96% and 4% of concentrate and barley straw respectively, when they used this feeding method in Simmental heifers fed a concentrate diet from 115 to 185 kg of BW. This contrasts, however, with data obtained by other authors (Mach et al, 2006;Robles et al, 2007;González et al, 2008) who also worked in the finishing period and fed animals with concentrate and barley straw, both offered separately and ad libitum. These latter studies reported proportions of concentrate in the diet ranging from 86 to 88%, and proportions of barley straw ranging from 14 to 12%.…”

“…Carcasses classified according to the EU classification system were close to values recorded by FEDNA (2008) for Simmental heifers. The final pH (5.6 on average) was in the interval considered to be normal (between 5.4 to 5.8) for beef (Mach et al, 2006). These values suggest that there was no increased stress before slaughter, because the acidification of the muscle occurred as expected.…”

“…These latter studies reported proportions of concentrate in the diet ranging from 86 to 88%, and proportions of barley straw ranging from 14 to 12%. However, whereas the breed used in these experiments was Holstein, bulls in Mach et al (2006), and heifers in Robles et al (2007) and González et al (2008), Simmental heifers were used in the present experiment.…”

Functional and association studies on the pig HMGCR gene, a cholesterol-synthesis limiting enzyme

“…Samples of 200 g gluteus medius muscle were collected immediately after slaughter for meat analyses carried out at the Centre of Meat Technology (CTC-IRTA). Analyses of gluteus medius lipid components included the determination of percentage of IMF, cholesterol content and fatty acid composition (in the C12 to C22 interval) were performed as follows: IMF content was determined by Near Infrared Transmittance (NIT; Infratec R 1625, Tecator AB, Hoganas, Sweden) , Pinhu et al, 2008 fatty acid composition was analysed by gas chromatography of methyl esters as described in (Mach et al, 2006), and cholesterol content was measured following (Cayuela et al, 2003). The most relevant phenotypic traits analysed in this study, along with their abbreviations and statistics in the studied Duroc population, are shown in Table 1 (complete data set was finally obtained from 338 animals).…”

Linseed: a valuable feedstuff for ruminants

“…Due to ruminal biohydrogenation, the proportion of 18:3 n-3 in percentage of total FA remains low. For example in Longissimus thoracis, it increases from 0.5 to 0.9-1.6% (Normand et al, 2005, 5 trials), from 0.4 to 1.9% (Mach et al, 2006), from 0.4 to 0.8% (Barton et al, 2007), from 0.6 to 2.0% (Herdmann et al, 2010), from 1.2 to 1.6% (Corazzin et al, 2012), from 0.4 to 0.6% (Habeanu et al, 2014), from 0.9 to 1.4% (Mialon et al, 2015). Differences in the extent of the increase depend more on the amount of added fat and their processing than on the duration of distribution before slaughter.…”