Plasma Concentrations Of Linoleic Acid Research Articles

Effects of fat source in calf starter on growth performance, blood fatty acid profiles, and inflammatory markers during cold season

This study was conducted to investigate the effects of supplementation of different fat sources in calf starters on growth performance, health, blood fatty acid profiles, and inflammatory markers during the cold season in dairy calves. A total of 48 Holstein calves (24 males and 24 females) were randomly assigned to 1 of 4 starter diets throughout the experiment (d 3 to 65): (1) no supplemented fat (CON), (2) 3% calcium-salts of soybean oil (Ca-SBO), (3) 3% calcium-salts of fish oil (Ca–FO), and (4) 3% mixture of Ca-SBO and Ca–FO (1.5% each, DM basis; MIX). Calves were given free access to starter feed and water and were raised individually in pens from 3 to 65 d of age. Calves fed Ca-SBO consumed a greater proportion of n-6 FA, while calves fed Ca–FO consumed a greater level of n-3 FA compared to the other dietary treatments. Fat supplementation increased the intake of linoleic acid, the major n-6 FA, with the greater intake observed in the Ca-SBO group compared to the other dietary treatments. Calves fed the Ca–FO and MIX diets consumed more long-chain n-3 FA than the other diets. In addition, calves fed Ca-SBO and Ca–FO diets consumed more starter feed and total dry matter than calves fed MIX and CON throughout the experiment (d 3 to 65). Calves fed Ca–FO had higher average daily gain throughout the trial (d 3 to 65) than the other treatment groups. Of all treatment groups, calves fed Ca–FO achieved the highest final body weight and showed the greatest feed efficiency. Random forest analysis revealed that eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA), and arachidonic acid were the serum levels of FA most affected by the diets. The principal component analysis of blood FA profile, blood parameters, and inflammatory markers showed distinct differences between dietary treatments. Calves fed Ca-SBO had higher plasma concentrations of linoleic acid, while calves fed Ca–FO had higher plasma concentrations of long-chain n-3 polyunsaturated fatty acids (PUFA), such as EPA, docosapentaenoic acid (DPA), and DHA than the other treatment groups. Plasma inflammatory markers were lower in calves fed Ca–FO and higher in calves fed CON than in the other treatment groups. The Ca–FO group had lower levels of inflammatory markers, including serum amyloid A, tumor necrosis factor-alpha, Interferon-γ, haptoglobin, and interleukin-6 compared to the other experimental treatments. Also, the blood malondialdehyde levels, an indicator of oxidative stress, were lower in calves fed Ca–FO compared with calves fed the other treatment diets. In conclusion, the performance of preweaned dairy calves can be improved by adding fat to their starter feed under cold conditions. Overall, the type of fat in milk may affect growth and inflammation of dairy calves before weaning under cold conditions, with n-3 FA (Ca–FO) promoting growth and reducing inflammation more effectively than n-6 FA (Ca-SBO).

Plasma Lipidomic n-6 Polyunsaturated Fatty Acids and Type 2 Diabetes Risk in the EPIC-Potsdam Prospective Cohort Study.

Evidence on plasma n-6 polyunsaturated fatty acids (PUFAs) and type 2 diabetes risk is inconsistent. We examined the associations of lipid class-specific PUFA concentrations with type 2 diabetes risk. In the prospective European Prospective Investigation into Cancer and Nutrition (EPIC)-Potsdam cohort (nested case-cohort study: subcohort 1,084 participants, 536 participants with type 2 diabetes, median follow-up 6.5 years), we measured plasma 18:2, 20:3, and 20:4 concentrations in 12 lipid (sub)classes, likely reflecting the plasma concentrations of linoleic acid (18:2n-6), dihomo-γ-linolenic acid (20:3n-6), and arachidonic acid (20:4n-6). The Δ-5 desaturase (D5D) activity was estimated as the 20:4/20:3 ratio. Associations with diabetes were estimated with Cox proportional hazards models. Higher concentrations of 18:2 were inversely associated with type 2 diabetes risk, particularly in lysophosphatidylcholines (hazard ratio [HR] per 1 SD 0.53; 95% CI 0.23-1.26) and monoacylglycerols (HR 0.59; 0.38-0.92). Higher concentrations of 20:3 in phospholipid classes phosphatidylcholines (HR 1.63; 1.23-2.14), phosphatidylethanolamines (HR 1.87; 1.32-2.65), and phosphatidylinositol (HR 1.40; 1.05-1.87); free fatty acids (HR 1.44; 1.10-1.90); and cholesteryl esters (HR 1.47; 1.09-1.98) were linked to higher type 2 diabetes incidence, and these associations remained statistically significant after correction for multiple testing. Higher 20:4 concentrations were not associated with risk. The estimated D5D activity in phospholipids and cholesteryl esters was associated with lower type 2 diabetes risk. Single nucleotide polymorphisms in the D5D-encoding FADS genes explained relatively high proportions of variation of estimated D5D activity in those lipid classes. Plasma n-6 PUFAs were associated differently with type 2 diabetes, depending on fatty acid and the lipid class.

Supplementing Ca salts of soybean oil to late-gestating beef cows: impacts on performance and physiological responses of the offspring.

This experiment compared the performance and physiological responses of the offspring from cows supplemented with Ca salts of soybean oil (CSSO) or prilled saturated fat (CON) during late gestation. Nonlactating, pregnant, multiparous Angus × Hereford cows (n = 104) that conceived during the same fixed-time artificial insemination protocol were assigned to this experiment. Cows were ranked by pregnancy sire (one of two sires), body weight (BW), and body condition score (BCS) on day -15 of the experiment (day 180 of gestation). Cows were then assigned to receive (dry matter basis) 415 g of soybean meal per cow daily in addition to: 1) 195 g/cow daily of CSSO (n = 52) or 2) 170 g/cow daily of CON (n = 52). Cows were maintained in two pastures (26 cows/treatment per pasture) and received daily 12.7 kg/cow (dry matter basis) of grass-alfalfa hay from day -15 to calving. Cows were segregated into 1 of 24 feeding pens three times weekly and received treatments individually from day 0 to calving. Calves were weaned on day 290 of the experiment, preconditioned for 35 d (day 291 to 325), and transferred to a feedyard, where they remained until slaughter (day 514). Cows receiving CSSO and their calves had greater (P < 0.01) plasma concentrations of linoleic acid and total ω-6 PUFA compared with CON after calving. Concentrations of immunoglobulin G in the colostrum and in calf plasma 24 h after birth were greater (P ≤ 0.02) in CSSO vs. CON cattle. Calves from CSSO cows had greater (P ≤ 0.05) expression of adipogenic (adipocyte fatty acid-binding protein and stearoyl-CoA desaturase) and myogenic (myogenic differentiation 1 and myogenin) genes in the longissimus muscle (LM) compared with CON. No treatment differences in birth BW, weaning BW, and final preconditioning BW were noted (P ≥ 0.36). Average daily gain and final BW in the feedyard were greater (P ≤ 0.05) in steers from CSSO cows compared with CON. The incidence of calves diagnosed with BRD that required a second antimicrobial treatment was less (P = 0.03) in calves from CSSO cows, resulting in reduced (P = 0.05) need of treatments to regain health compared with CON. Upon slaughter, LM area was greater (P = 0.03) in calves from CSSO cows compared with CON. Collectively, these results are indicative of programming effects on postnatal offspring growth and health resultant from CSSO supplementation to late-gestating cows. Hence, supplementing CSSO to beef cows during pregnancy might be a feasible alternative to optimize offspring productivity and welfare.

PSVII-23 Using low-moisture molasses-based blocks to supplement Ca salts of soybean oil to forage-fed beef cows

Abstract This experiment compared plasma fatty acid (FA) profile of forage-fed beef cows receiving a molasses-based supplement enriched with Ca salts of soybean oil [(CSSO); 24.7% of dry matter (DM)] via a self-fed low-moisture block (LMB) or hand-fed granular concentrate daily (CONC). Thirty-six cows were allocated to 1 of 9 drylot pens, which were enrolled in a replicated 3 x 2 Latin square design with 2 periods of 42 d. Pens were randomly assigned to receive 1 of the 3 treatments, in a manner that pens did not receive the same treatment in both periods. Cows received hay for ad libitum consumption during the study. Hay intake was recorded daily from d 0 to 42, and LMB intake was recorded from d 14 to 42. The CONC was offered at 0.420 kg/cow daily (DM basis) from d 0 to 13, and then adjusted (d 14 to 42) to match LMB intake. Average LMB intake during the initial 13 d was 0.846 ± 0.107 kg/cow daily (DM basis). Supplement DM intake did not differ (P = 0.39) between LMB and CONC cows from d 14 to 42. No treatments effects were noted (P ≥ 0.40) for hay intake, BCS, and BW. Plasma FA profile did not differ (P ≥ 0.20) between treatments on d 0. From d 14 to 42, plasma concentrations of linoleic acid, ω-6 polyunsaturated FA, and total FA were greater (P &amp;lt; 0.01) in CONC and LMB vs. NOSUPP cows. Plasma concentrations of these FA were also greater (P ≤ 0.03) in LMB vs. CONC cows on d 14, but did not differ (P ≥ 0.35) on d 28 and 42. Inclusion of CSSO into LMB resulted in similar incorporation of ω-6 polyunsaturated and total FA in the circulation compared with CONC offered at the same daily rate.

267 Supplementing Ca salts of soybean oil to late-gestating beef cows: Impacts on performance and physiological responses of the offspring

Abstract This experiment compared performance and physiological responses of the offspring from cows supplemented with Ca salts of soybean oil (CSSO) or prilled saturated fat (CON) during late gestation. Non-lactating, pregnant Angus × Hereford cows (n = 104) that conceived during the same fixed-time artificial insemination protocol, using semen from 2 sires, were used in this experiment. Cows were ranked by pregnancy sire, body weight (BW), and body condition score (BCS). On d 180 of gestation (d -15), cows were randomly assigned to receive (dry matter basis) 415 g of soybean meal per cow daily in addition to 1) 195 g/cow daily of CSSO (n = 52) or 2) 170 g/cow daily of CON (n = 52). Cows were maintained in 2 pastures (26 cows/treatment per pasture), and received daily 12.7 kg/cow (dry matter basis) of grass-alfalfa hay. From d 0 until calving, cows were segregated into 1 of 24 feeding pens thrice weekly and received treatments individually. Cow BW and BCS were recorded, and blood samples were collected on d -15 of the experiment and within 12 h after calving. Calf BW was also recorded and blood sample collected within 12 h of calving. Calves were weaned on d 290 of the experiment, preconditioned for 35 d (d 291 to 325), and transferred to a feedyard where they remained until slaughter. Upon calving, CSSO cows and calves had greater (P &amp;lt; 0.01) plasma concentrations of linoleic acid and total ω - 6 FA compared with CON cohorts. No differences in calf birth BW, weaning BW, and final preconditioning BW were noted (P ≥ 0.36) between treatments. Average daily gain and final BW in the feedlot were greater (P ≤ 0.05) in steers from CSSO cows compared with CON. The incidence of calves diagnosed with BRD that required a second antimicrobial treatment was less (P = 0.03) in calves from CSSO cows, resulting in reduced (P = 0.05) need of treatments to regain health compared with CON (Table 5). Upon slaughter, longissimus muscle area was greater (P = 0.03) in calves from CSSO cows compared with CON. Collectively, these results suggest that supplementing CSSO to late-gestating beef cows stimulated programming effects on postnatal offspring growth and Page 2 of 15 For Peer Review health. Therefore, supplementing late-gestating beef cows with CSSO appears to optimize offspring welfare and productivity in beef production systems.

Using low-moisture molasses-based blocks to supplement Ca salts of soybean oil to forage-fed beef cows.

This experiment compared plasma fatty acid (FA) profile of forage-fed beef cows receiving a molasses-based supplement enriched with Ca salts of soybean oil [CSSO; 24.7% of dry matter (DM)] via a self-fed low-moisture block (LMB) or hand-fed granular concentrate daily (CONC). Thirty-six nonlactating, nonpregnant, multiparous beef cows were blocked by age (three blocks), ranked within blocks by body weight (BW) and body condition score (BCS), and allocated to 1 of three drylot pens (27 × 10 m) per block. Nine pens with four cows each were enrolled in a replicated 3 × 2 Latin square design with two periods of 42 d, and a 21-d washout interval. On day 0, pens within each block were randomly assigned to receive one of the three treatments, in a manner that pens did not receive the same treatment in both periods (total n = 6 pens per treatment). Cows received hay (Cynodon dactylon), water, and a mineral–vitamin mix for ad libitum consumption during the study. Hay intake was recorded daily from days 0 to 42, and LMB intake was recorded from days 14 to 42 to allow cows to adapt to supplement with minimal interference from days 0 to 13. The CONC was offered at 0.420 kg/cow daily (DM basis) from days 0 to 13 and then adjusted (days 14 to 42) to match LMB intake. Cow BW and BCS were recorded, and blood samples were collected on days 0, 14, 28, and 42. Average LMB intake during the initial 13 d was 0.846 ± 0.107 kg/cow daily (DM basis). Supplement DM intake did not differ (P = 0.39) between LMB and CONC cows from days 14 to 42 as designed (0.570 vs. 0.583 kg/d, respectively; SEM = 0.011), despite a greater variation in daily intake of LMB vs. CONC (treatment × day interaction; P < 0.01). No treatments effects were noted (P ≥ 0.40) for hay intake, BCS, and BW. Treatment × day interactions were detected (P ≤ 0.01) for plasma concentrations of ω-6 polyunsaturated FA and total FA. On day 0, plasma FA profile did not differ (P ≥ 0.20) between treatments. From days 14 to 42, plasma concentrations of linoleic acid, ω-6 polyunsaturated FA, and total FA were greater (P < 0.01) in CONC and LMB vs. NOSUPP cows. Plasma concentrations of these FA were also greater (P ≤ 0.03) in LMB vs. CONC cows on day 14, but did not differ (P ≥ 0.35) on days 28 and 42. These results indicate that CSSO inclusion into LMB resulted in similar incorporation of ω-6 polyunsaturated and total FA in the circulation compared with CONC offered at the same daily rate. Hence, the use of self-fed LMB appears to be a valid strategy to provide CSSO to forage-fed beef cattle with reduced labor needs.

Supplementing Ca salts of soybean oil after artificial insemination increases pregnancy success in Bos taurus beef cows.

Two experiments investigated the effects of supplementing Ca salts of soybean oil (CSSO) during early gestation on reproductive function and pregnancy rates to AI in Bos taurus beef cows. In Exp. 1, 771 suckled, lactating, multiparous Angus cows were divided into 22 groups of approximately 35 cows per group and timed inseminated on day 0. After AI, groups were assigned randomly to receive (as-fed basis) 100 g of ground corn + 100 g of soybean meal per cow/d, in addition to 1) 100 g/cow daily of CSSO (n = 11) or 2) 87 g of prilled saturated fat + 13 g of limestone per cow/d (CON; n = 11). Groups were maintained in individual tall fescue-dominated pastures and offered treatments from day 0 to 21. Pregnancy status was determined between days 45 and 55 via transrectal ultrasonography. Cows receiving CSSO had greater (P = 0.01) pregnancy rates to timed AI compared with CON (60.2 vs. 51.7%; SEM = 4.2). In Exp. 2, 90 suckled, lactating, multiparous Angus × Hereford cows housed in 18 drylot pens (5 cows per pen) were assigned to the same timed AI program and treatments from Exp. 1 (9 pens per treatment) and received 20 kg/d (DM basis) of grass-alfalfa hay. Transrectal ultrasonography was performed to verify ovulation and corpus luteum (CL) volume before AI (day 0), on days 7 and 15. After ultrasonography on day 15, cows diagnosed without a CL on day 0, but with a CL greater than 0.38 cm3 in volume on days 7 and 15 (2 or 3 cows per pen; CSSO, n = 20; CON, n = 24), were assigned to conceptus collection via transcervical flushing and endometrial biopsy in the uterine horn ipsilateral to the CL. Blood samples were collected for FA analysis on days 0, 7, and 15. Blood was collected from cows not assigned to conceptus collection for whole-blood RNA extraction on day 20 and for pregnancy diagnosis on day 30 by measuring concentrations of pregnancy-associated glycoproteins. Cows receiving CSSO had greater (P ≤ 0.04) mean plasma concentrations of linoleic acid and ω-6 FA compared with CON on days 7 and 15. Moreover, CSSO supplementation increased (P = 0.05) mRNA expression of interferon-tau by the conceptus and blood mRNA expression of interferon-stimulated gene 15 and 20,50-oligoadenylate synthetase on day 20 in gestating cows. Hence, post-AI CSSO supplementation to B. taurus beef cows improved pregnancy rates to timed AI, which can be associated with increased mRNA expression of interferon-tau by the conceptus when CSSO is supplemented during early gestation.

Feeding distillers dried grains in replacement of forage in limit-fed dairy heifer rations: Effects on metabolic profile and onset of puberty

The objective of this study was to determine the effect of increasing the inclusion rate of distillers dried grains (DDGS) in replacement of forage in limit-fed diets on the metabolic profile and onset of puberty in dairy heifers. A 16-wk randomized complete block design study was conducted using 48 Holstein heifers (199 ± 2 d of age) with 3 treatments. Treatments were (1) 30% DDGS (30DG), (2) 40% DDGS (40DG), and (3) 50% DDGS (50DG), with the remainder of the diet consisting of grass hay and 1.5% mineral mix. Heifers were housed in groups of 6 and individually limit-fed using Calan gates at 2.65, 2.50, and 2.35% of body weight (BW) on a dry matter (DM) basis for 30DG, 40DG, and 50DG, respectively. Jugular blood samples were collected during wk 0, 4, 8, 12, and 16 for metabolite and metabolic hormone analysis. Additional samples were taken during wk 16 for plasma fatty acid analysis. When heifers weighed 200 kg, coccygeal vein blood samples were taken twice per week for progesterone analysis to estimate onset of puberty. Blood samples continued until cycling was confirmed via ultrasound for the presence of a corpus luteum. A quadratic response and a linear tendency in the proportion of total fatty acids as linoleic acid were observed. Linear and quadratic responses for plasma concentrations of linoleic acid and arachidonic acid occurred. Overall results for fatty acid analysis demonstrated that total fatty acid and polyunsaturated fatty acids concentration in the blood were linearly increased, with a quadratic response for polyunsaturated fatty acids with 30DG and 50DG having the greatest concentrations. No interactions of treatment by week were observed for any of the metabolites and metabolic hormones measured. Glucose, insulin, insulin-like growth factor-1, leptin, and triglycerides were similar across treatments. A linear response of plasma urea nitrogen and a quadratic response tendency for cholesterol concentration were observed. Age and BW at puberty were similar across treatments. Limit-feeding heifers with greater inclusion rates of DDGS maintained energy status without the accumulation of excess adipose tissue as indicated by leptin. Treatments had no detrimental effects on age or BW at puberty.

Post–artificial insemination supplementation with calcium salts of soybean oil influences pregnancy establishment factors in Bos indicus beef cows1

The objective of this experiment was to compare hormonal, uterine, and conceptus factors associated with pregnancy establishment in beef cows supplemented or not with Ca salts of soybean oil (CSSO) for 21 d beginning after timed AI. One hundred lactating multiparous Nelore cows were allocated to 20 groups of 5 cows/group and timed inseminated on d 0 of the experiment. After AI, groups were randomly assigned to receive (as-fed basis) 100 g of protein-mineral mix + 100 g of ground corn per cow per day, in addition to 1) 100 g/cow daily of CSSO ( = 10) or 2) 100 g/cow daily of kaolin (CON; rumen-inert indigestible substance; = 10). Groups were maintained in 4 pastures (5 groups from the same treatment within each pasture) with ad libitum access to forage. Groups were segregated daily and individually offered treatments from d 0 to 21. Blood samples were collected and transrectal ultrasonography was performed to verify ovulation and corpus luteum (CL) volume immediately before AI (d 0) and on d 7 and 15. After ultrasonography on d 15, 60 cows (30 cows/treatment and 3 cows/group) diagnosed without the presence of a CL on d 0 but with a CL greater than 0.38 cm3 in volume on d 7 and 15 were assigned to conceptus collection via transcervical flushing with PBS followed by endometrial biopsy in the uterine horn ipsilateral to the CL. Additional blood samples were collected for whole-blood RNA extraction (d 20), and pregnancy status was verified by transrectal ultrasonography (d 30) in cows not assigned to conceptus collection. Cows receiving CSSO had greater ( ≤ 0.04) mean plasma linoleic acid concentration, plasma linoleic:linolenic acid ratio, plasma progesterone (P4) concentration, and CL volume during the experiment compared with CON cows. Moreover, CSSO supplementation increased ( ≤ 0.04) length and mRNA expression of and by the conceptus as well as blood mRNA expression of interferon-stimulated genes on d 20 in gestating cows. No treatment differences were detected ( ≥ 0.30) for endometrial mRNA expression of and . In summary, post-AI CSSO supplementation to B. indicus beef cows increased plasma concentration of linoleic acid and enhanced pregnancy establishment factors, which included CL development and plasma P4 concentration, conceptus growth, and mRNA expression of as well as blood mRNA expression of interferon-stimulated genes.

Effect of dietary enrichment with either n-3 or n-6 fatty acids on systemic metabolite and hormone concentration and ovarian function in heifers

The objective of this experiment was to examine the effects of dietary n-3 or n-6 fatty acid (FA) supplementation on blood FA, metabolite and hormone concentrations, follicle size and dynamics and corpus luteum (CL) size. Reproductively normal heifers (n = 24) were individually fed diets of chopped straw and concentrate containing either (i) no added lipid (CON; n = 8); (ii) 2% added fat as whole raw soya beans (WSB, n-6; n = 8); or (iii) 2% added fat as fish oil (FO, n-3; n = 8). Following oestrous cycle synchronisation, blood samples were collected at appropriate times and intervals for the measurement of hormones, FAs and metabolites. On days 15 and 16 of the cycle, animals were subjected to an intravenous oxytocin challenge and prostaglandin F2α (PGF2α) response, measured as venous concentrations of 13,14-dihydro-15-keto PGF2α (PGFM). Dry matter intake and average daily gain were similar among treatments (P > 0.05). Plasma concentration of linoleic acid was highest on WSB (P < 0.05), while eicosapentaenoic (EPA, n-3; P < 0.0001) and docosahexaenoic acid (DHA, n-3; P < 0.0001) were greatest in the FO group. Plasma concentrations of arachidonic acid were higher on FO (P < 0.05) compared with CON and WSB. Plasma triglyceride concentrations increased, while β-hydroxybutyrate (BHBA) decreased with time on all diets (P < 0.05). There was a diet × time interaction (P < 0.01) for non-esterified fatty acid (NEFA) concentrations. Plasma cholesterol was higher on WSB and FO (P < 0.01) compared with CON. Progesterone (P4) and oestradiol (E2) concentrations, as well as follicle growth rate and CL diameter were similar across diets (P > 0.05). There was a diet × day interaction for PGFM (P < 0.01). When corrected for systemic E2 : P4 ratio, day 15 concentrations of PGFM were higher in the WSB group at 15 and 30 min (P < 0.01) post oxytocin administration compared with CON and FO, which were similar (P > 0.05). Concentrations of PGFM on day 16 were similar for WSB and FO and were greater than CON at 15 (P < 0.01) and 45 min (P < 0.05) post oxytocin administration, and at 30 min for FO (P < 0.05). With the exception of PGFM, dietary lipid source did not affect the reproductive variables measured.

Influence of Prepartum Fat Supplementation on Subsequent Beef Cow Reproduction and Calf Performance

High fat range supplement (HFRS) and HFRS with lipid from soybean soapstock (HFRS-SPH; Consolidated Nutrition, Omaha, NE) were compared with a corn-soybean meal supplement (control). In Exp. 1, primiparous cows were individually fed the control supplement (n = 12), HFRS (n = 12), or HFRS-SPH (n = 10) for 62 ± 2 d prepartum. Heifer body condition score pre- and postpartum did not differ (P=0.78) among groups. Milk production was not influenced (P=0.15) by source of supplement. Somatic cell counts, however, tended to be less (P=0.07) in HFRS-supplemented heifers than in heifers fed the control supplement. At birth, calf body temperature (P=0.8), vigor (P=0.7), and BW (P=0.6), as well as BW gain through 90 d postpartum (P=0.6), did not differ among prepartum supplementation treatments. Plasma concentrations of linoleic acid were greater (P=0.02) in fat-supplemented heifers at 30 d prepartum and at calving compared with heifers on the control treatment; however, concentrations of plasma linoleic acid returned to levels comparable with those in control heifers by 30 d postpartum. Neither number of cows cycling by 90 d postpartum (P=0.15) nor length of the postpartum interval (P=0.25) differed among treatment groups. In Exp. 2, multiparous cows were pen-fed the control supplement (n = 49), HFRS (n = 47), or HFRS-SPH (n = 49) for 59 ± 2 d prepartum. Prior to parturition, cows fed the control supplement had better body condition scores (5.8 ± 0.1; P=0.004) than cows fed either commercial supplement (5.4 ± 0.1). Calf performance (P=0.7) and conception rates (P= 0.5) did not differ among treatments. Productivity of cows and calves was not improved with provision of supplemental fat prepartum.

Effect of different fat sources on in vitro degradation of nutrients and certain blood parameters in sheep.

This study was designed to determine the effects of calcium salt of palm oil fatty acids (CS), hydroxyethylsoyamide (HESA), butylsoyamide (BSA) and soybean oil (SO) on degradation of crude protein and fibre in vitro, and on the blood plasma lipid parameters in vivo. Five mature wethers (body weight 75 kg) were fed five diets in a 5 x 5 Latin square experiment. The control diet consisted of 50% meadow hay and 50% concentrate with no added fat. The control diet was supplemented with CS, HESA, BSA, or SO. Fat was added at 3.5% of dietary dry matter (DM). The final ether extract content of the ration was near 6%. Each period lasted 20 days. Fat supplements, except HESA, consistently decreased the in vitro DM disappearance of soybean meal as compared to control. In contrast to the effect of other treatments, crude protein degradation was greatest in the test tubes with inocula obtained from sheep fed diet with HESA. Fat supplements equally inhibited the DM and fibre breakdown of alfalfa pellet. CS and HESA seemed to be less detrimental to in vitro fermentation of neutral detergent fibre (NDF) than BSA and SO. All fat supplements increased blood plasma triglyceride, cholesterol and total lipid content. Plasma concentration of cholesterol and total lipid was highest with SO. The inclusion of CS in the diet increased 16:0, while all fat supplements increased plasma 18:0 and decreased 16:1 and 18:1 fatty acid content. Plasma 18:2n-6 was not changed by feeding CS and SO. However, compared to the control diet, 18:2n-6 increased with 12 and 41% in plasma fatty acids when sheep were fed HESA and BSA, respectively. The results showed that plasma concentration of linoleic acid was enhanced more when the amide was synthesised from butylamine than when from ethanolamine.

Effects of Early Nutrition on Free Radical Formation in VLBW Infants with Respiratory Distress

Objective: We studied the development of essential fatty acid deficiency (EFAD) and its effects together with those of vitamin E deficiency on the free radical formation of very low birth weight (VLBW) infants with respiratory distress.Methods: Infants were divided into three groups based on the way each was supplied with daily total energy intake: (1) by fat free parenteral nutrition only or by nutrition composed of (2) less than or (3) higher than 25% of total daily energy intake given in oral feeding. We measured plasma lipid parameters and autoxidative susceptibility (AOS) of red blood cells (RBCs).Results: Plasma concentrations of linoleic acid were low in all the groups. After at least 14 days of feeding, eicosatrienoic acid (EA) was not detected. One week after the introduction of oral feeding, the abnormal triene/tetraene ratio of the groups had decreased, but was not normalized. Vitamin E deficiency was associated with significantly increased AOS, but EFAD was not. The two factors together caused an increase of AOS, that was additive.Conclusions: Our data confirm that EFAD increases AOS of RBCs in VLBW infants. We assume that prevention of EFAD in VLBW infants could decrease the prevalence of complications associated with free radical formation.

Plasma fatty acids, prostaglandin F2alpha metabolite, and reproductive response in postpartum heifers fed rumen bypass fat.

An experiment was conducted to determine whether feeding rumen-protected fatty acids (FA) to postpartum heifers would increase plasma concentrations of linoleic acid and PGF2, metabolite (PGFM), shorten the interval from calving to first increase in plasma concentrations of progesterone (P4), and increase pregnancy rate relative to controls. Hereford x Angus heifers (346 kg) were assigned randomly to treatments containing either lipid or barley supplemented diets for the first 30 d postpartum. Lipid was .23 kg.heifer(-1).d(-1) of calcium salts of FA (CSFA; n = 20), and an isocaloric amount of barley served as the control (n = 19). Supplements, with .23 kg of barley as a vehicle, and a basal diet of meadow and alfalfa hays were pen fed to heifers (5/pen). Heifers were bled on alternate days (d1 to 30) and twice weekly (d 30 to 2 wk after first estrus) for RIA of plasma PGFM and P4, respectively. Weight percentage of major FA in plasma on d1 and 7 was determined with gas chromatography. First behavioral estrus was detected by use of intact bulls and confirmed by an increase in plasma P4. On d 7, but not d 1, plasma from heifers fed CSFA had altered proportions of major FA (P < .01), including an increase in linoleic acid compared with those of controls (29.1 vs 25.6% of total FA; SE = .75; P < .01). Analysis of variance of contrast variables revealed an effect of treatment on direction of change in PGFM from d 3 to 5 (P < .01). By d 7 and on d 9, plasma concentrations of PGFM were greater in heifers fed CSFA than in controls (P = .02 and P = .06, respectively). There was no difference in plasma concentration of PGFM between treatments on d 1, 3, 5, 11, 13, and 15 postpartum (P = .80, .17, .52, .82, .46, and .77, respectively). Days to first estrus with ovulation, pregnancy rate, and calving interval were not affected by treatments (P = .58, .52, and .24, respectively). Although supplemental lipid fed to primiparous beef heifers increased plasma levels of linoleic acid and production of PGFM in the early postpartum period, it did not improve the fertility of these heifers in the subsequent breeding season.

Prostaglandin f(2alpha) concentrations, fatty acid profiles, and fertility in lipid-infused postpartum beef heifers.

Effects of lipid infusion into postpartum (PP) beef heifers on plasma concentrations of linoleic acid and prostaglandin (PG) F(2alpha) metabolite (PGFM), days to first estrus, and subsequent pregnancy rate were examined. Treatments (n = 5 per group) of 1 L intralipid (20% soybean oil; IL), 1 L 50% dextrose (DEXT; isocaloric to IL), 0.5 L intralipid (0.5 IL), and 1 L physiological saline (SAL) were infused i.v. over 4 h on each of Days 7 through 11 PP. Capacity of the uterus to produce PG was evaluated after i.v. injection of 150 IU of oxytocin (OT) to IL- and DEXT-treated heifers Day 12 PP. Change in plasma concentrations of PGFM from 0 to 4 h was greater for IL-treated heifers than for heifers given other treatments on Day 7 (P = 0.04) and on Day 11 (P = 0.01), but not on Day 9 (P>0.10). Plasma linoleic acid on Day 11 and OT-induced release of PGFM on Day 12 were greater in IL-treated heifers compared with DEXT-treated heifers (P<0.06 and P = 0.01, respectively). There were no significant differences among treatments for mean days to first estrus or pregnancy rate. Infusion of lipid increased systemic concentrations of linoleic acid and increased the capacity of PP heifers to produce uterine PGF(2alpha) as indicated by plasma PGFM concentration after OT injection.

Bile diversion in rats leads to a decreased plasma concentration of linoleic acid which is not due to decreased net intestinal absorption of dietary linoleic acid

Decreased bile secretion into the intestine has been associated with low plasma concentrations of essential fatty acids (EFA) in humans. We studied the mechanism behind this relationship by determining the status and absorption of the major dietary EFA, linoleic acid (LA), in control and 1-week bile-diverted rats. The absorption of LA was quantified by a balance method and by measuring plasma concentrations of [ 13C]LA after its intraduodenal administration. Absolute and relative concentrations of LA in plasma were decreased in bile-diverted rats ( P<0.01 and P<0.001, respectively). Fecal excretion of LA was increased at least 20-fold in bile-diverted rats (0.72±0.11 vs. 0.03±0.00 mmol/day; P<0.0001). Due to increased chow ingestion by bile-diverted rats, net intestinal absorption of LA was similar between bile-diverted and control rats (1.96±0.14 vs. 1.91±0.07 mmol/day, respectively; P>0.05). After intraduodenal administration of [ 13C]LA, plasma concentrations were approximately 3–4-fold lower in bile-diverted rats for at least 6 h ( P<0.001). Plasma concentrations of both [ 12C]arachidonic acid and [ 13C]arachidonic acid were increased in bile-diverted rats ( P<0.05). We conclude that decreased plasma concentrations of LA in 1-week bile-diverted rats are not due to decreased net intestinal absorption of LA, but may be related to increased metabolism of LA.

Central metabolic messengers and the effects of nutrition on gonadotrophin secretion in sheep.

Nutrition influences the reproductive axis via alteration of gonadotrophin secretion. However, a link between nutrition and the secretion of GnRH, which drives the axis, has yet to be established. The aim of the present study was to measure the change in the concentrations of metabolic substances in the cerebrospinal fluid of adult male sheep offered a diet designed to maintain constant gonadotrophin secretion (Group M; n = 6), or a diet known to increase gonadotrophin secretion (Group M + L; n = 6). On days 1, 3 and 10 of the dietary treatments, cerebrospinal fluid and jugular blood were sampled and analysed for metabolic fuels (glucose, amino acids and free fatty acids) and metabolic hormones (insulin, insulin-like growth factor I, GH, prolactin, cortisol and the thyroid hormones). On day 11 of the dietary treatment, LH pulse frequency and mean FSH concentrations in Group M + L had increased relative to Group M and to day 0. Plasma concentrations of prolactin and insulin on days 3 and 10, and glucose and insulin-like growth factor I on day 10, were higher in Group M + L than in Group M, but only cerebrospinal fluid concentrations of insulin, glucose and certain amino acids were affected by the dietary treatments on days 3 and 10. Cerebrospinal fluid, but not plasma, concentrations of aspartate, tyrosine, cystine, phenylalanine and arginine on day 3, and glutamine, gamma-aminobutyric acid, threonine, alanine on days 3 and 10, were higher in Group M + L relative to Group M. On day 10, plasma and cerebrospinal fluid concentrations of arginine, phenylalaine, proline, tyrosine, methionine and phosphoserine, but only the plasma concentrations of linoleic acid, aspartate and serine, were higher in Group M + L than in Group M. Concentrations of triiodothyronine, thyroxine, and cortisol in plasma and cerebrospinal fluid were not affected. These results show that the nutritional stimulation of gonadotrophin secretion is accompanied primarily by fluctuations in plasma and cerebrospinal fluid concentrations of insulin and certain amino acids, which suggests that, when nutritional status is improved, insulin, amino acids and possibly glucose interact to modulate GnRH secretion.

Renal effects of dietary supplementation with fish oil in cyclosporine-treated liver transplant recipients

Nephrotoxicity is the main untoward effect of cyclosporine (CsA) treatment. Experimental and clinical data suggest that dietary supplementation with fish oil may lessen cyclosporine nephrotoxicity, possibly by lowering renal thromboxane (Tx) production. We have studied the renal effects of a daily supplementation for 2 months of 12 g fish oil (18% C20:5 n-3 eicosapentaenoic acid [EPA] and 12% C22:6 n-3 docosahexanoic acid [DHA]) in a placebo-controlled (12 g corn oil), prospective, randomized, double-blind study of stable CsA-treated liver transplant recipients. Thirteen patients ingested corn oil capsules and 13 fish oil. Compliance with dietary regimen was confirmed by fatty acid chromatography that showed increased plasma concentrations of EPA (from 0.4 +/- 0.02% to 4.6 +/- 0.5%, P < .0001) and DHA (from 1.8 +/- 0.2% to 3.9 +/- 0.1%, P < .0001) in the fish oil group and increased plasma concentration of linoleic acid (C18:2 n-6) in the corn oil group (from 25 +/- 2% to 28.4 +/- 2%, P < .001). At the end of the 2 months of the study, in the fish oil group the effective renal plasma flow increased by 22% (P = .012), the glomerular filtration rate increased by 33% (P = .057), the renal blood flow increased by 17% (P = .024), and the calculated total renal vascular resistances decreased by 20% (P = .034). In contrast, none of these parameters changed in the corn oil group. The renal functional reserve determined during L-arginine infusion, plasma renin activity (PRA), and plasma aldosterone (PA) remained unchanged during the study in either group.(ABSTRACT TRUNCATED AT 250 WORDS)

Renal effects of dietary supplementation with fish oil in cyclosporine-treated liver transplant recipients

Nephrotoxicity is the main untoward effect of cyclosporine (CsA) treatment. Experimental and clinical data suggest that dietary supplementation with fish oil may lessen cyclosporine nephrotoxicity, possibly by lowering renal thromboxane (Tx) production. We have studied the renal effects of a daily supplementation for 2 months of 12 g fish oil (18% C20:5 n-3 eicosapentaenoic acid [Epa]and 12% C22:6 n-3 docosahexanoic acid [Dha]) in a placebo-controlled (12 g corn oil), prospective, randomized, double-blind study of stable CsAtreated liver transplant recipients. Thirteen patients ingested corn oil capsules and 13 fish oil. Compliance with dietary regimen was confirmed by fatty acid chromatography that showed increased plasma concentrations of EPA (from 0.4 ± 0.02% to 4.6 ± 0.5%, P < .0001) and DHA (from 1.8 ± 0.2% to 3.9 ± 0.1%, P < .0001) in the fish oil group and increased plasma concentration of linoleic acid (C18:2 n-6) in the corn oil group (from 25 ± 2% to 28.4 ± 2%, P < .001). At the end of the 2 months of the study, in the fish oil group the effective renal plasma flow increased by 22% ( P = .012), the glomerular filtration rate increased by 33% ( P = .057), the renal blood flow increased by 17% ( P = .024), and the calculated total renal vascular resistances decreased by 20% ( P = .034). In contrast, none of these parameters changed in the corn oil group. The renal functional reserve determined during l-arginine infusion, plasma renin activity (PRA), and plasma aldosterone (PA) remained unchanged during the study in either group. The urine excretion of Tx B 2 decreased from 707 ± 192 to 276 ± 76 pg/hr ( P = .013) in fish oil group, whereas it increased from 428 ± 195 to 870 ± 310 pg/hr ( P = .016) in corn oil group. In conclusion, 2 months of diet supplementation with fish oil in stable CsA-treated liver transplant recipients was associated with significant improvement of renal hemodynamics and with significant reduction of the renal production of TxB 2.