Maternal obesity upregulates fatty acid and glucose transporters and increases expression of enzymes mediating fatty acid biosynthesis in fetal adipose tissue depots

Maternal nutrient restriction leads to alteration in fetal adipose tissue, and offspring from obese mothers have an increased risk of developing obesity. We hypothesized that maternal obesity increases fetal adipogenesis. Multiparous ewes (Columbia/Rambouillet cross 3 to 5 yr of age) carrying twins were assigned to a diet of 100% (Control; CON; n = 4) or 150% (Obese; OB, n = 7) of NRC maintenance requirements from 60 d before conception until necropsy on d 135 of gestation. Maternal and fetal plasma were collected and stored at -80°C for glucose and hormone analyses. Fetal measurements were made at necropsy, and perirenal, pericardial, and subcutaneous adipose tissues were collected from 7 male twin fetuses per group and snap frozen at -80°C. Protein and mRNA expression of fatty acid translocase [cluster of differentiation (CD) 36], fatty acid transport proteins (FATP) 1 and 4, insulin-sensitive glucose transporter (GLUT-4), fatty acid synthase (FASN), and acetyl-coA carboxylase (ACC) was evaluated. Fetal weight was similar, but fetal carcass weight (FCW) was reduced (P < 0.05) in OB versus CON fetuses. Pericardial and perirenal adipose tissue weights were increased (P < 0.05) as a percentage of FCW in OB versus CON fetuses, as was subcutaneous fat thickness (P < 0.001). Average adipocyte diameter was greater (P < 0.01) in the perirenal fat and the pericardial fat (P = 0.06) in OB fetuses compared with CON fetuses. Maternal plasma showed no difference (P > 0.05) in glucose or other hormones, fetal plasma glucose was similar (P = 0.42), and cortisol, IGF-1, and thyroxine were reduced (P ≤ 0.05) in OB fetuses compared with CON fetuses. Protein and mRNA expression of CD 36, FATP 1 and 4, and GLUT-4 were increased (P ≤ 0.05) in all fetal adipose depots in OB versus CON fetuses. The mRNA expression of FASN and ACC was increased (P < 0.05) in OB vs. CON fetuses in all 3 fetal adipose tissue depots. Fatty acid concentrations were increased (P = 0.01) in the perirenal depot of OB versus CON fetuses, and specific fatty acid concentrations were altered (P < 0.05) in subcutaneous and pericardial adipose tissue because of maternal obesity. In conclusion, maternal obesity was associated with increased fetal adiposity, increased fatty acid and glucose transporters, and increased expression of enzymes mediating fatty acid biosynthesis in adipose depots. These alterations, if maintained into the postnatal period, could predispose the offspring to later obesity and metabolic disease.

Fatty acid compositions of mixed ruminal microbes isolated from sheep supplemented with soybean oil

Two experiments were conducted to examine the changes in the fatty acid (FA) composition of mixed ruminal microbes (MRM) from sheep fed various levels of dietary forage and soybean oil (SBO). In Experiment 1, diets included five ratios of forage to concentrate. Increased dietary forage did not change MRM concentrations of 18:1(trans-11) and 18:2 (P>0.10), but increased 18:3 (P<0.01) and cis-9, trans-11 conjugated linoleic acid (CLA) (P<0.01). In Experiment 2, SBO was added to the diets at 0%, 3.2%, 6.3%, or 9.4% of dietary DM. Increasing dietary SBO resulted in linear increases (P<0.01) in 18:1(trans-11)and 18:1(cis-9), but linear decreases (P<0.01) in 18:2 of MRM. It was concluded that FA composition of MRM was affected by diet. Additionally, MRM of sheep fed the diet containing 18.4% forage and 9.4% SBO contained the greatest individual and total FA concentrations.

Quantitative trait loci with additive effects on palatability and fatty acid composition of meat in a Wagyu-Limousin F2 population

A whole-genome scan was conducted on 328 F(2) progeny in a Wagyu x Limousin cross to identify quantitative trait loci (QTL) affecting palatability and fatty acid composition of beef at an age-constant endpoint. We have identified seven QTL on five chromosomes involved in lipid metabolism and tenderness. None of the genes encoding major enzymes involved in fatty acid metabolism, such as fatty acid synthase (FASN), acetyl-CoA carboxylase alpha (ACACA), solute carrier family 2 (facilitated glucose transporter) member 4 (SLC2A4), stearoyl-CoA desaturase (SCD) and genes encoding the subunits of fatty acid elongase, was located in these QTL regions. The present study may lead to a better-tasting and healthier product for consumers through improved selection for palatability and lipid content of beef.

Fatty acid composition of plasma, medial basal hypothalamus, and uterine tissue in primiparous beef cows fed high-linoleate safflower seeds

The experimental objectives were to evaluate the influence of supplemental high-linoleate safflower seeds on fatty acid concentrations in plasma, medial basal hypothalamus, uterine tissues, and serum 13,14-dihydro-15-keto PGF(2)alpha metabolite (PGFM) in primiparous beef cows during early lactation. Beginning 1 d postpartum, 18 primiparous, crossbred beef cows (411 +/- 24.3 kg of BW) were fed foxtail millet hay at 1.68% of BW (DM basis) and either a low-fat supplement (control: 63.7% cracked corn; 33.4% safflower seed meal; and 2.9% liquid molasses; DM basis) at 0.35% of BW (n = 9) or a supplement (linoleate) containing 95.3% cracked high-linoleate (79% 18:2n-6) safflower seeds and 4.7% liquid molasses (DM basis) at 0.23% of BW (n = 9). Diets were formulated to be isonitrogenous and isocaloric. The linoleate diet contained 5.4% of DMI as fat vs. 1.2% for control. Beginning 1 d postpartum, cattle were bled every 3 d for collection of serum and plasma. Cattle were slaughtered at 37 +/- 3 d postpartum for collection of the medial basal hypothalamus, myometrium, endometrium, caruncular tissue, intercaruncular tissue, and oviduct. Feeding linoleate increased (P = 0.001) plasma concentrations of 18:2n-6, 18:2cis-9 trans-11 and total unsaturated fatty acids; however, 18:1trans-11 did not differ (P = 0.19) between treatments. Concentrations of 20:5n-3 in the medial basal hypothalamus tended (P = 0.10) to be greater for cattle fed linoleate. Concentrations of fatty acids in the oviduct were greater (P < 0.05) than in other uterine tissues. Cows fed linoleate had greater (P = 0.05) concentrations of 18:3n-3 in the endometrium and less (P = 0.06) 18:2cis-9 trans-11 in the myometrium than cows fed the control. Supplemental fat increased (dietary treatment x day postpartum, P = 0.01) concentrations of PGFM in serum more in linoleate than control cows from d 3 to 9 postpartum. Lipid supplementation early in the postpartum period altered the fatty acid composition of medial basal hypothalamus, uterine tissue, and serum concentrations of PGFM. The most novel observation was that the oviduct appeared to be the most sensitive tissue to additional dietary linoleic acid, which could potentially influence fertility.

Effects of adding poultry fat in the finishing diet of steers on performance, carcass characteristics, sensory traits, and fatty acid profiles

Use of poultry fat in the finishing diets of steers has not been studied as a potential source of added energy. Therefore, 60 Angus crossbred steers were fed 1 of 3 dietary treatments consisting of 1) a corn-soybean meal control diet devoid of added fat; 2) the control diet formulated with 4% tallow; or 3) the control diet formulated with 4% poultry fat. Addition of fat did not (P = 0.17) affect ADG for the 112-d study. The inclusion of tallow in the diet reduced (P < 0.05) ADFI of steers compared with those on the control diet; however, ADFI of steers fed poultry fat did not differ from those fed the control (P = 0.06) or the tallow (P = 0.36) diets. At d 55, steers consuming either fat source had improved (P < 0.05) G:F compared with steers fed the control diet. For the entire 112 d, steers consuming the poultry fat diet gained more efficiently (P < 0.05) than the control steers, and the tallow-fed steers were intermediate and not different from the other groups (P > or = 0.14). The inclusion of fat in the diet did not (P > or = 0.15) affect carcass characteristics. Steaks from the steers consuming diets with added fat were darker (lower L* value; P < 0.05) than the controls; however, dietary treatments did not (P > or = 0.10) affect any other objective color measurements or discoloration scores during retail display. Thiobarbituric acid reactive substances for LM steaks did not differ (P = 0.21) by dietary treatment. The cooked LM steaks from steers fed poultry fat did not (P > or = 0.80) differ in juiciness or flavor intensity from steaks of steers fed the control or tallow diets. There were also no differences (P = 0.18) in off flavors as a result of added dietary fat. In the LM and adipose tissue, percentages of total SFA were increased (P = 0.05) by adding supplemental fat to the diet, regardless of source. In the LM, total MUFA were decreased (P = 0.02) by adding supplemental fat. Conversely, diet did not (P > or = 0.14) affect the proportions of total PUFA in either tissue or total MUFA in the adipose tissue. Results indicated that replacing beef tallow in finishing diets with poultry fat, a more economical energy source, had no detrimental effects on growth performance, carcass characteristics, retail display life, fatty acid profiles, or palatability.

Evaluation of milk somatic cells as a source of mRNA for study of lipogenesis in the mammary gland of lactating beef cows supplemented with dietary high-linoleate safflower seeds

Our objectives were 2-fold: to determine the effect of dietary linoleate on milk fat composition and on transcript abundance of acetyl-CoA carboxylase (ACC), fatty acid synthase (FAS), lipoprotein lipase (LPL), and stearoyl-CoA desaturase (SCD) mRNA in mammary tissue, and to evaluate milk somatic cell mRNA as a source of mammary tissue mRNA for these enzymes. Eighteen primiparous, crossbred beef cows (BW = 411 +/- 24 kg; BCS = 5.25) were offered Foxtail millet hay at 1.68% of BW daily and either a low-fat control (n = 9) or a high-linoleate (79% 18:2n-6), cracked safflower seed supplement (n = 9). Diets were isonitrogenous and isocaloric, and the linoleate diet contained 5.4% of DMI as fat. At slaughter (37 +/- 3 d postpartum), mammary tissue was sampled and immediately frozen in liquid N2 before being stored at -80 degrees C. Milk samples were obtained from the same mammary glands and immediately centrifuged at 1,200 x g to pellet somatic cells. A ribonuclease protection assay was used to quantify the mRNA in the mammary gland and milk somatic cells. Effects of diet, tissue, or their interaction were not observed for ACC (P = 0.28, 0.89, and 0.35, respectively), FAS (P = 0.38, 0.66, and 0.20, respectively), LPL (P = 0.09, 0.15, and 0.43, respectively), or SCD (P = 0.45, 0.19, and 0.29, respectively). Dietary effects on fatty acid profile of the milk fat suggested that linoleate supplementation might have decreased de novo lipogenesis while increasing uptake of dietary fatty acids; this effect was consistent with a trend toward greater LPL mRNA for linoleate-fed cows (P = 0.09). Correlations (r values) between mammary tissue and milk somatic cell data for each mRNA for the low-fat control diet were: ACC, 0.76 (P = 0.02); FAS, 0.69 (P = 0.04); LPL, 0.68 (P = 0.04); and SCD, 0.73 (P = 0.05), and for the linoleate diet were: ACC, 0.85 (P = 0.003); FAS, 0.75 (P = 0.02); LPL, 0.90 (P = 0.001); and SCD, 0.73 (P = 0.03). We conclude that milk somatic cells obtained from lactating beef cows can be used as a source of RNA to study nutritional regulation of mammary gland lipogenesis in cows fed dietary fat supplements.

Effects of postpartum dietary fat and body condition score at parturition on plasma, adipose tissue, and milk fatty acid composition of lactating beef cows

Two experiments were conducted with lactating Angus x Gelbvieh beef cows to determine the effects of postpartum lipid supplementation, BCS at parturition, and day of lactation on fatty acid profiles in plasma, adipose tissue, and milk. In Exp. 1, 36 pri-miparous cows (488 +/- 10 kg of initial BW; 5.5 +/- 0.02 initial BCS) were given ad libitum access to hay and assigned randomly to a low-fat (control) supplement or supplements with cracked, high-linoleate safflower seeds (linoleate) or cracked, high-oleate safflower seeds (oleate) from d 3 to 90 of lactation. Diets were formulated to be isonitrogenous and isocaloric; safflower seed diets provided 5% of DMI as fat. Plasma and milk samples were collected on d 30, 60, and 90 of lactation. Adipose tissue biopsies were collected near the tail-head region of cows on d 45 and 90 of lactation. In Exp. 2, 3-yr-old cows achieving a BCS of 4 +/- 0.07 (479 +/- 36 kg of BW) or 6 +/- 0.07 (580 +/- 53 kg of BW) at parturition were used in a 2-yr experiment (n = 36/yr). Beginning 3 d postpartum through d 61 of lactation, cows were fed diets similar to those of Exp. 1. Adipose tissue and milk samples were collected on d 30 and 60, and plasma was collected on d 31 and 61 of lactation. Responses to postpartum dietary treatment were comparable in both experiments. Cows fed linoleate and oleate had greater (P < 0.001) total fatty acid concentrations in plasma than cows fed control. Except for 15:1, milk fatty acids with <18 carbons were greatest (P < or = 0.01) for cows fed control, whereas milk from cows fed linoleate had the greatest (P < or = 0.02) 18:1trans-11, 18:2n-6, and cis-9, trans-11 CLA. Milk from cows fed oleate had the greatest (P < 0.001) 18:1cis-9. In Exp. 1, total fatty acid concentrations in adipose tissue samples decreased at d 90 compared with d 45 of lactation, but the fatty acid profile of cow adipose tissue was not affected (P = 0.14 to 0.80) by dietary treatment. In Exp. 2, the percentage of cis-9, trans-11 CLA in adipose tissue of cows with a BCS of 6 decreased (P = 0.001) from d 30 to 60 of lactation. Plasma and milk fatty acid composition reflected alterations in postpartum diet. Less medium-chain fatty acids and more 18-carbon fatty acids in milk were indicative of reduced de novo fatty acid synthesis in the mammary gland of beef cows fed lipid supplements; however, the metabolic demands of lactation prevented the deposition of exogenously derived fatty acids in adipose tissue through d 90 of lactation.

Immune response and serum immunoglobulin G concentrations in beef calves suckling cows of differing body condition score at parturition and supplemented with high-linoleate or high-oleate safflower seeds

Two experiments were conducted to determine the effect of maternal lipid supplementation on the immune response to antigenic challenge in suckling calves. In Exp. 1, beginning 1 d postpartum, 18 primiparous crossbred beef cows were fed Foxtail millet hay and a low-fat (control) supplement or a supplement containing cracked, high-linoleate safflower seed in individual feeding stanchions until d 40 of lactation. The diets were formulated to provide similar quantities of N and TDN, and the linoleate diet was formulated to contain 5% of DMI as fat. Calves were injected s.c. with 15 mg of antigen (ovalbumin) at d 21 and again at d 35 of age. To measure the total serum antibody production in response to the antigen, blood samples were collected from the calves every 7 d via jugular venipuncture from d 14 to 42. Calves from linoleate-supplemented cows had a decrease (P = 0.04) in total antibody production in response to ovalbumin and appeared to have a delayed response to antigen challenge. Total antibody production increased (P < 0.001) after secondary exposure to ovalbumin. In Exp. 2, 36 Angus x Gelbvieh beef cows that were nutritionally managed to achieve a BCS of 4 or 6 at parturition were used to determine the effects of prepartum energy balance and postpartum lipid supplementation on the passive transfer of immunoglobulins and the immune response to antigenic challenge in their calves. Beginning at 3 d postpartum and continuing until d 60 of lactation, cows were fed hay and a low-fat control supplement or supplements consisting of either cracked, high-linoleate or high-oleate safflower seeds. Safflower seed supplements were formulated to provide 5% of DMI as fat. Calves were injected s.c. with 15 mg of ovalbumin at 21 d of age and again at 48 d of age. The antibody responses were determined in serum; cell-mediated immunity was assessed by intradermal antigen injection at 60 d of age. A trend was noted (P = 0.10) for calves suckling control-supplemented cows to have a greater response to antigen compared with calves from linoleate- and oleate-supplemented cows; however, no difference was observed among treatments (P = 0.86) in cell-mediated immune response. Postpartum oilseed supplementation in beef cows appears to decrease antibody production in response to antigenic challenge in suckling calves. However, BCS at parturition did not influence passive transfer of immunoglobulins in neonatal calves.

Postpartum supplemental fat, but not maternal body condition score at parturition, affects plasma and adipose tissue fatty acid profiles of suckling beef calves1

Three-year-old Angus x Gelbvieh beef cows, which were nutritionally managed to achieve a BCS of 4 +/- 0.07 (479 +/- 36 kg of BW) or 6 +/- 0.07 (580 +/- 53 kg of BW) at parturition, were used in a 2-yr experiment (n = 36/yr) to determine the effects of maternal BCS at parturition and postpartum lipid supplementation on fatty acid profile of suckling calf plasma and adipose tissue. Beginning 3 d postpartum, cows within each BCS were assigned randomly to 1 of 3 treatments in which cows were all fed hay and either a low-fat (control) supplement or supplements with either high-linoleate cracked safflower seeds (linoleate) or high-oleate cracked safflower seeds (oleate) until d 61 of lactation. Diets were formulated to be isonitrogenous and isocaloric, and safflower seed supplements were provided to achieve 5% of DMI as fat. Total concentration of fatty acids in plasma did not differ (P = 0.48) due to maternal BCS at parturition. Percentage of 20:5n-3 in plasma tended (P = 0.06) to be greater for calves suckling cows with a BCS of 6 at parturition. No other differences (P = 0.12 to 0.99) were noted in calf plasma fatty acid profile due to maternal BCS at parturition. Likewise, no differences were detected for total fatty acid concentration (P = 0.88) in calf adipose tissue due to maternal BCS at parturition. Weight percentage of 14:1 (P = 0.001) was greatest in adipose tissue of calves suckling cows fed control and oleate; however, the percentages of 14:0, 15:0, 16:0, 16:1, 17:0, and 18:3n-3 were greater (P < 0.001) in adipose tissue from calves suckling cows fed control compared with calves suckling cows fed linoleate or oleate. Percentages of 18:0, 18:1trans-11, 18:2n-6, and cis-9, trans-11 CLA were greater (P < 0.001) in adipose tissue from calves suckling cows fed linoleate compared with calves suckling cows fed control and oleate. Calves suckling cows fed oleate had greater (P < 0.001) percentages of 18:1trans-9, 18:1trans-10, and 18:1cis-9 in adipose tissue than calves suckling cows fed control or linoleate. Calf plasma and adipose tissue fatty acid profiles were reflective of milk fatty acids. Because fatty acids play an important role in metabolic regulatory functions, changes in milk fatty acid profile should be considered when beef cows are fed lipid supplements.

Effects of body condition score at parturition and postpartum supplemental fat on metabolite and hormone concentrations of beef cows and their suckling calves1

To determine the effects of BCS at parturition and postpartum lipid supplementation on blood metabolite and hormone concentrations, 3-yr-old Angus x Gelbvieh beef cows, which were nutritionally managed to achieve a BCS of 4 +/- 0.07 (479.3 +/- 36.3 kg of BW) or 6 +/- 0.07 (579.6 +/- 53.1 kg of BW) at parturition, were used in a 2-yr experiment (n = 36/yr). Beginning at 3 d postpartum, cows within each BCS were assigned randomly to be fed hay and a low-fat control supplement or lipid supplements with either cracked high-linoleate or high-oleate safflower seeds until d 61 of lactation. The diets were formulated to be isonitrogenous and isocaloric, and the safflower seed supplements were formulated to achieve 5% DMI as fat. On d 31 and 61 of lactation, blood samples were collected preprandially and then hourly postprandially (at 0, 1, 2, 3, and 4 h). Serum insulin (P = 0.27) and glucose (P = 0.64) were not affected by BCS at parturition. The mean concentrations of plasma NEFA (P = 0.08) and beta-hydroxybutyrate (P = 0.08) tended to be greater, and serum IGF-I was greater (P < 0.001) in BCS 6 than BCS 4 cows. Conversely, serum GH was greater (P = 0.003) for BCS 4 cows, indicating that regulation of IGF by GH may have been uncoupled in BCS 4 cows. The postpartum diet did not affect NEFA (P = 0.94), glucose (P = 0.15), IGF-I (P = 0.33), or GH (P = 0.62) concentrations. Oleate-supplemented cows had greater (P = 0.03) serum insulin concentrations, whereas control cows had greater (P = 0.01) plasma beta-hydroxybutyrate concentrations. Concentrations of NEFA (P = 0.05) and glucose (P < 0.001) were greater, and beta-hydroxybutyrate tended (P = 0.07), to be greater at d 3, whereas serum IGF-I was greater (P = 0.003) at d 6 of lactation. Similar concentrations of NEFA, glucose, GH, and IGF-I indicate that the nutritional status of beef cows during early lactation was not influenced by lipid supplementation. However, perturbations of the somatotropic axis in BCS 4 cows indicate that the influence of energy balance and BCS of the cow at parturition on postpartum performance should be considered when making managerial decisions.

Site and extent of digestion, duodenal flow, and intestinal disappearance of total and esterified fatty acids in sheep fed a high-concentrate diet supplemented with high-linoleate safflower oil

Our objective was to determine duodenal and ileal flows of total and esterified fatty acids and to determine ruminal fermentation characteristics and site and extent of nutrient digestion in sheep fed an 80% concentrate diet supplemented with high-linoleate (77%) safflower oil at 0, 3, 6, and 9% of DM. Oil was infused intraruminally along with an isonitrogenous basal diet (fed at 2% of BW) that contained bromegrass hay, cracked corn, corn gluten meal, urea, and limestone. Four crossbred wethers (BW = 44.3 +/- 15.7 kg) fitted with ruminal, duodenal, and ileal cannulas were used in a 4 x 4 Latin square experiment, in which 14 d of dietary adaptation were followed by 4 d of duodenal, ileal, and ruminal sampling. Fatty acid intake increased (linear, P = 0.004 to 0.001) with increased dietary safflower oil. Digestibilities of OM, NDF, and N were not affected (P = 0.09 to 0.65) by increased dietary safflower oil. For total fatty acids (free plus esterified) and esterified fatty acids, duodenal flow of most fatty acids, including 18:2c-9,c-12, increased (P = 0.006 to 0.05) with increased dietary oil. Within each treatment, duodenal flow of total and esterified 18:2c-9,c-12 was similar (P = 0.32), indicating that duodenal flow of this fatty acid occurred because most of it remained esterified. Duodenal flow of esterified 18:1t-11 increased (P = 0.08) with increased dietary safflower oil, indicating that reesterification of ruminal fatty acids occurred. Apparent small intestinal disappearance of most fatty acids was not affected (P = 0.19 to 0.98) by increased dietary safflower oil, but increased (P = 0.05) for 18:2c-9,c-12, which ranged from 87.0 to 97.4%, and for 18:2c-9,t-11 (P = 0.03), which ranged from 37.9% with no added oil to 99.2% with supplemental oil. For esterified fatty acids, apparent small intestinal disappearance was from 80% for 18:3c-9,c-12,c-15 at the greatest level of dietary oil up to 100% for 18:1t-11 and 18:1c-12 with 0% oil. We concluded that duodenal flow of 18:2c-9,c-12 was predominately associated with the esterified fraction, suggesting that the extent of ruminal lipolysis was decreased with increased dietary high-linoleate safflower oil. Furthermore, biohydrogenation intermediates observed in the esterified fatty acids indicated that some reesterification occurred, and the high level of apparent absorption of esterified fatty acids indicated that intestinal lipolysis did not limit overall digestion of the fatty acids fed to the sheep.

Effects of body condition score at parturition and postpartum supplemental fat on adipose tissue lipogenic activity of lactating beef cows1

Three-year-old Angus x Gelbvieh beef cows nutritionally managed to achieve a BCS of 4 +/- 0.07 (479.3 +/- 36.3 kg of initial BW) or 6 +/- 0.07 (579.6 +/- 53.1 kg of initial BW) at parturition were used in a 2-yr experiment (n = 36/yr) to determine the effects of BCS at parturition and postpartum lipid supplementation on cow adipose tissue lipogenesis. Beginning 3 d postpartum, cows within each BCS were randomly assigned to be fed hay and a low-fat control supplement or supplements with either cracked high-linoleate safflower seeds or cracked high-oleate safflower seeds until d 60 of lactation. Diets were formulated to be isonitrogenous and isocaloric, and safflower seed diets provided 5% DMI as fat. Adipose tissue biopsies were collected near the tail-head region of cows on d 30 and 60 of lactation. Dietary treatment did not affect (P > or = 0.43) adipose tissue lipogenesis. Body condition score at parturition did not affect acetate incorporation into lipid (P = 0.53) or activity of acetyl CoA carboxylase (P = 0.77) or fatty acid synthase (P = 0.18). Lipoprotein lipase activity and palmitate incorporation into triacyl-glycerol tended to be greater (P = 0.06), and palmitate esterification into total acylglycerols was greater (P = 0.01) in cows with a BCS of 4 at parturition. Mean activity of acetyl-CoA carboxylase (P < 0.001), lipoprotein lipase (P = 0.01), and rate of palmitate incorporation into monoacylglycerol (P = 0.02), diacylglycerol (P = 0.001), triacylglycerol (P = 0.003), and total acylglycerols (P = 0.002) were greater at d 30 than d 60, suggesting a greater proclivity for fatty acid biosynthesis and esterification by adipose tissue at d 30 of lactation. Although dietary lipid supplementation did not affect adipose tissue lipogenesis, results suggest that cows with a BCS of 4 at parturition have a greater propensity to deliver exogenously derived fatty acids to the adipocyte surface and incorporate preformed fatty acids into acylglycerols as stored adipocyte lipid. Additionally, cows in early lactation seemed to be able to synthesize and incorporate more fatty acids into stored lipid than cows during peak lactation.

Body condition score at parturition and postpartum supplemental fat effects on cow and calf performance1

Three-year-old Angus x Gelbvieh beef cows nutritionally managed to achieve a BCS of 4 +/- 0.07 (479.3 +/- 36.3 kg of BW) or 6 +/- 0.07 (579.6 +/- 53.1 kg of BW) at parturition were used in a 2-yr experiment (n = 36/yr) to determine the effects of prepartum energy balance and postpartum lipid supplementation on cow and calf performance. Beginning 3 d postpartum, cows within each BCS were assigned randomly to be fed hay and a low-fat control supplement or supplements with either high-linoleate cracked safflower seeds or high-oleate cracked safflower seeds until d 60 of lactation. Diets were formulated to be isonitrogenous and isocaloric, and safflower seed supplements were provided to achieve 5% of DMI as fat. Ultrasonic 12th rib fat and LM area were lower (P < 0.001) for cows in BCS 4 compared with BCS 6 cows throughout the study. Cows in BCS 4 at parturition maintained (P = 0.02) condition over the course of the study, whereas cows in BCS 6 lost condition. No differences (P = 0.44 to 0.71) were detected for milk yield, milk energy, milk fat percentage, or milk lactose percentage because of BCS; however, milk protein percentage was less (P = 0.03) for BCS 4 cows. First-service conception rates did not differ (P = 0.22) because of BCS at parturition, but overall pregnancy rate was greater (P = 0.02) in BCS 6 cows. No differences (P = 0.48 to 0.83) were detected in calf birth weight or ADG because of BCS at parturition. Dietary lipid supplementation did not influence (P = 0.23 to 0.96) cow BW change, BCS change, 12th rib fat, LM area, milk yield, milk energy, milk fat percentage, milk lactose percentage, first service conception, overall pregnancy rates, or calf performance. Although cows in BCS of 4 at parturition seemed capable of maintaining BCS during lactation, the overall decrease in pregnancy rate indicates cows should be managed to achieve a BCS >4 before parturition to improve reproductive success.

Soybean oil supplementation of a high-concentrate diet does not affect site and extent of organic matter, starch, neutral detergent fiber, or nitrogen digestion, but influences both ruminal metabolism and intestinal flow of fatty acids in limit-fed lambs

Our objective was to measure ruminal fermentation characteristics and site and extent of nutrient digestion in sheep limit-fed an 81.6% (DM basis) concentrate diet supplemented with increasing levels of soybean oil. Eight white-faced wether lambs (39.9+/-3.0 kg BW) fitted with ruminal, duodenal, and ileal cannulas were used in a replicated 4 x 4 Latin square experiment. Diets were formulated to contain 15.0% CP (DM basis) and included bromegrass hay (18.4%), cracked corn, soybean oil, corn gluten meal, urea, and limestone. Soybean oil was added to diets at 0, 3.2, 6.3, and 9.4% of dietary DM. The diet was limit-fed at 1.4% of BW. After 14 d of dietary adaptation, Cr2O3 (2.5 g) was dosed at each feeding for 7 d followed by ruminal, duodenal, ileal, and fecal sample collections for 3 d. Digestibilities of OM, starch, NDF, and N were not affected (P = 0.13 to 0.95) by increasing dietary soybean oil level. Means for true ruminal (percentage of intake), lower-tract (percentage entering the duodenum), and total-tract (percentage of intake) digestibility for each nutrient were (mean+/-SEM): OM = 50.7+/-4.66%, 71.6+/-2.58%, and 82.7+/-0.93%; starch = 92.0+/-1.94%, 96.1+/-0.70%, and 99.8+/-0.05%; NDF = 36.7+/-6.75%, 50.9+/-7.58%, and 71.7+/-1.93%; and N = 31.6+/-9.93%, 84.1+/-1.50%, and 81.0+/-1.10%, respectively. Total VFA concentration was greatest in sheep fed 6.3% soybean oil and least in sheep fed 9.4% soybean oil (cubic, P = 0.01). Duodenal flow of fatty acids from the diet and those metabolized within the rumen increased (linear, P < 0.001) with increasing dietary soybean oil level. Ileal flow of 16:0, 17:0, 18:0, 18:1trans, and 18:1cis-9 fatty acids increased (P < or = 0.04) with increasing dietary soybean oil level. Apparent small intestinal disappearance of 18:0 decreased (linear, P = 0.004) as dietary soybean oil increased, and with 9.4% dietary soybean oil, nearly half the duodenal 18:0 was observed at the ileum; thus, the true energy value of the soybean oil decreased with increasing oil supplementation. We conclude that supplementation of a high-concentrate diet with increasing amounts of soybean oil in limit-fed sheep resulted in a trade off between loss of potential dietary energy from the fat and gain of important PUFA and biohydrogenation intermediates, but without a marked influence on digestibility of other important macronutrients.

Influence of supplemental cracked high-linoleate or high-oleate safflower seeds on site and extent of digestion in beef cattle1

Our objectives were to evaluate ruminal fermentation patterns, apparent ruminal biohydrogenation, and site and extent of nutrient disappearance in cattle fed supplemental cracked safflower seeds differing in 18 C fatty acid profile. Nine Angus x Gelbvieh heifers (641 +/- 9.6 kg) fitted with ruminal and duodenal cannulas were used in a triplicated 3 x 3 Latin square. Cattle were fed (OM basis) 9.1 kg of bromegrass hay and either 1) 1.8 kg of corn and 0.20 kg of soybean meal (Control); 2) 0.13 kg of soybean meal and 1.5 kg of cracked high-linoleate (67.2% 18:2) safflower seeds (Linoleate); or 3) 1.5 kg of cracked high-oleate (72.7% 18:1) safflower seeds (Oleate). Safflower seed supplements were formulated to provide similar quantities of N and TDN and 5% dietary fat. Single degree of freedom orthogonal contrasts (Control vs. Linoleate and Oleate; Linoleate vs. Oleate) were used to evaluate treatment effects. True ruminal OM and ruminal NDF disappearances (percentage of intake) were greater (P < or =0.02) for Control than Linoleate and Oleate. True ruminal N degradability (% of intake) was not different (P = 0.38) among treatments. Apparent ruminal biohydrogenation of dietary 18:2 was greatest (Linoleate vs. Oleate, P < 0.001) for Linoleate, whereas biohydrogenation of dietary 18:1 was greatest (Linoleate vs. Oleate, P = 0.02) for Oleate. Duodenal flow of 18:0 was least (P < 0.001) for Control but did not differ (P = 0.92) between Oleate and Linoleate. Total flow of unsaturated fatty acid to the duodenum was greatest (P < 0.001) in cattle fed safflower seeds, and was greater with Linoleate (P < 0.001) than with Oleate. Duodenal flow of 18:1 and 18:2 increased (P < 0.001) in Oleate and Linoleate, respectively. Duodenal flow of 18:1trans-11 was greater (P < 0.001) in cattle fed safflower seeds and in Linoleate than in Oleate. Postruminal disappearance of saturated fatty acids was greatest (P < 0.001) for Control; however, postruminal disappearance of total unsaturated fatty acids was greater (P = 0.002) for Linoleate vs. Oleate. Supplemental high-linoleate or high-oleate safflower seeds to cattle fed forage-based diets may negatively affect ruminal OM and fiber disappearance but not N disappearance. Provision of supplemental fat in the form of safflower seeds that are high in linoleic acid increased intestinal supply and postruminal disappearance of unsaturated fatty acids, indicating that the fatty acids apparently available for metabolism are affected by dietary fat source.

Comparison of muscle fatty acid profiles and cholesterol concentrations of bison, beef cattle, elk, and chicken

The objective of this study was to compare fatty acid weight percentages and cholesterol concentrations of longissimus dorsi (LD), semitendinosus (ST), and supraspinatus (SS) muscles (n = 10 for each) of range bison (31 mo of age), feedlot-finished bison (18 mo of age), range beef cows (4 to 7 yr of age), feedlot steers (18 mo of age), free-ranging cow elk (3 to 5 yr of age), and chicken breast. Lipids were analyzed by capillary GLC. Total saturated fatty acids (SFA) were greater (P < 0.01) in range bison than in feedlot bison and were greater (P < 0.01) in SS of range beef cattle than in feedlot steers. Muscles of elk and range bison were similar (P > 0.05) in SAT. In LD, polyunsaturated fatty acids (PUFA) were highest (P < 0.01) for elk and range bison and lowest (P < 0.01) for feedlot steers within each muscle. Range bison and range beef cows had greater (P < 0.01) PUFA in LD and ST than feedlot bison or steers, respectively. Range-fed animals had higher (P < 0.01) n-3 fatty acids than feedlot-fed animals or chicken breast. Chicken breast n-6 fatty acids were greater (P < 0.01) than for muscles from bison, beef, or elk. Elk had higher (P < 0.01) n-6 fatty acids than bison or beef cattle; however, range-fed animals had higher (P < 0.01) n-6 fatty acids than feedlot-fed animals in ST. Conjugated linoleic acid (CLA, 18:2cis-9, trans-11) in LD was greatest (P < 0.01) for range beef cows (0.4%), and lowest for chicken breast and elk (mean = 0.1%). In ST, CLA was greatest (P < 0.01) for range and feedlot bison and range beef cows (mean = 0.4%) and lowest for elk and chicken breast (mean = 0.1%). Also, SS CLA was greatest (P < 0.01) for range beef cows (0.5%) and lowest for chicken breast (0.1%). Mean total fatty acid concentration (g/100 g tissue) for all muscles was highest (P < 0.01) for feedlot bison and feedlot cattle and lowest (P < 0.01) for range bison, range beef cows, elk, and chicken. Chicken breast cholesterol (mg/100 g tissue) was higher (P < 0.01) than LD and ST cholesterol, which were lowest (P < 0.01; 43.8) for range bison and intermediate for the other species. Cholesterol in SS was highest (P < 0.01) for feedlot bison and steers, which were similar to chicken breast (mean = 61.2 vs 52.8 for the mean of the other species). We conclude that lipid composition of bison muscle varies with feeding regimen, and range-fed bison had muscle lipid composition similar to that of forage-fed beef cows and wild elk.

Feeding lambs high-oleate or high-linoleate safflower seeds differentially influences carcass fatty acid composition

Our objective was to determine effects of dietary high-oleate (Oleate; 76% 18:1) or high-linoleate (Linoleate; 78% 18:2) safflower seeds on fatty acids in muscle and adipose tissue of feedlot lambs. White-faced ewe lambs (n = 36) were fed a beet pulp, oat hay, and soybean meal basal diet (Control), blocked by BW, and allotted randomly to dietary treatments. Cracked safflower seeds were used in isocaloric and isonitrogenous replacement of beet pulp, oat hay, and soybean meal so that Oleate and Linoleate diets contained 5.0% additional fat. Fatty acids were determined in semitendinosus, longissimus dorsi (longissimus), and adipose tissue from the tail head (tailhead adipose tissue), adjacent to the 12th rib (s.c. adipose tissue), and kidney and pelvic fat (KPH adipose tissue) depots. Fatty acid data were analyzed within muscle and adipose tissue as a split-block design. Single degree of freedom orthogonal contrasts were used to compare treatment effects. Average daily gain, feed efficiency, and carcass characteristics did not differ (P = 0.15 to 0.96) across dietary treatments. Adipose tissue saturated fatty acids were greater (P = 0.04) for Controls but were not different (P = 0.36) in muscle. Trans-vaccenic acid (18:1(trans-11)) increased (P < 0.0001) with safflower supplementation and was greater (P < 0.0001) in Linoleate than in Oleate for both tissue types. Linoleate lamb had greater (P < 0.0001) PUFA than Oleate lamb in muscle and adipose tissue. Conjugated linoleic acids (CLA; cis-9, trans-11 and trans-10, cis-12) were greater (P < 0.0001) in muscle and adipose tissue of lambs fed safflower seeds. Lambs fed Linoleate had greater (P < 0.0001) CLA in adipose tissue and muscle than lambs fed Oleate. Saturated fatty acids were greater (P < 0.0001) in s.c. adipose tissue than in tailhead adipose tissue. Mono- and polyunsaturated fatty acids were greater (P < 0.0001) in tailhead adipose tissue than in s.c. adipose tissue. Weight percentages of 18:1(trans-11) ranked tailhead adipose tissue = KPH adipose tissue > s.c. adipose tissue and semitendinosus > longissimus, whereas CLA ranked tailhead adipose tissue > s.c. adipose tissue > KPH adipose tissue and semitendinosus > longissimus. Feeding mono- and polyunsaturated fatty acids increased tissue 18:1(trans-11) and CLA, which is a favorable change in regard to current human dietary guidelines.

Supplemental soybean oil or corn for beef heifers grazing summer pasture: effects on forage intake, ruminal fermentation, and site and extent of digestion

Nine Angus x Gelbvieh heifers (average BW = 347 +/- 2.8 kg) with ruminal and duodenal cannulas were used in a split-plot designed experiment to determine the effects of soybean oil or corn supplementation on intake, OM, NDF, and N digestibility. Beginning June 8, 1998, heifers continually grazed a 6.5-ha predominantly bromegrass pasture and received one of three treatments: no supplementation (Control); daily supplementation of cracked corn (Corn) at 0.345% of BW; or daily supplementation (0.3% of BW) of a supplement containing cracked corn, corn gluten meal, and soybean oil (12.5% of supplemental DM; Oil). Soybean oil replaced corn on a TDN basis and corn gluten meal was included to provide equal quantities of supplemental TDN and N. Three 23-d periods consisted of 14 d of adaptation followed by 9 d of sample collections. Treatment and sampling period effects were evaluated using orthogonal contrasts. Other than crude fat being greater (P = 0.01) for supplemented heifers, chemical and nutrient composition of masticate samples collected via ruminal evacuation did not differ (P = 0.23 to 0.56) among treatments. Masticate NDF and ADF increased quadratically (P < or = 0.003) and N decreased linearly (P = 0.0001) as the grazing season progressed. Supplementation did not influence (P = 0.37 to 0.83) forage OM intake, total and lower tract OM digestibility, ruminal and total tract NDF digestibility, or total ruminal VFA; however, supplemented heifers had lower ruminal molar proportions of acetate (P = 0.01), higher ruminal molar proportions of butyrate (P = 0.007), and greater quantities of OM digested in the rumen (P = 0.10) and total tract (P = 0.02). As the grazing season progressed, total tract OM and N and ruminal NH3 concentrations and NDF digestibility decreased quadratically (P < or = 0.04). Microbial N flow (P = 0.09) and efficiency (P = 0.04) and postruminal N disappearance (P = 0.02) were greater for Control heifers and declined linearly (P < or = 0.02) as the grazing season advanced. Depressed microbial N flow seemed to be more pronounced for Oil than for the Corn treatment. Although total digestible OM intake increased with supplementation, metabolizable protein supply was reduced in supplemented heifers. Therefore, feeding low levels of supplemental grain with or without soybean oil is an effective strategy to increase dietary energy for cattle grazing high-quality forages, but consideration should be given to reduced supply of metabolizable protein.

Perceptions of vocational trainees on gender and racial disadvantage within the Thames vocational training programme

BACKGROUND

A recent report has suggested that vocational trainees within London experienced racial or gender disadvantage during their selection. This exploratory study did not investigate the extent or the nature of this disadvantage.

AIM

To undertake a survey using a pre-tested questionnaire with dental vocational trainees on the Thames Scheme. The questionnaire explored perceived and experienced aspects of gender and racial disadvantage during their vocational training programme.

RESULTS

127 trainees completed the questionnaire (response rate 92%). Minority ethnic respondents were more than twice as likely to feel their selection was influenced by gender (odds ratio [OR] 2.25, 95% Confidence Interval [CI] 1.02, 5.10) and more than three times likely to feel selection was influenced by their race when compared with their white colleagues (OR 3.05, 95%; CI 1.01,11.45). The majority of trainees did not perceive any disadvantage whilst on the vocational training course. For example, only five respondents (4%) felt that minority ethnic individuals were treated less favourably during the vocational training course.

CONCLUSION

In conclusion, this preliminary study has attempted to explore inter-ethnic differences within the profession on perceived racial disadvantage and possible strategies for change. It is clear that the perception of disadvantage is greater than the reality within the experience of most trainees.

Effect of forage:concentrate ratio on ruminal digestion and duodenal flow of fatty acids in ewes

The objective of this study was to determine the forage:concentrate ratio that would provide the greatest duodenal flow of unsaturated fatty acids in ewes supplemented with soybean oil and to determine how diets differing in forage content affect flow of conjugated linoleic acid (CLA) and trans-vaccenic acid (18:1(trans-11)). Five mature ewes (66.5 +/- 12.8 kg) fitted with ruminal and duodenal cannulas were used in a 5 x 5 Latin square experiment. Diets were isonitrogenous and included bromegrass hay, cracked corn, corn gluten meal, urea, and limestone. Dietary fat was adjusted to 6% with soybean oil. Five ratios of forage:concentrate (18.4:81.6, 32.2:67.8, 45.8:54.2, 59.4:40.6, and 72.9:27.1) were fed at 1.3% of BW daily in equal allotments at 0630 and 1830. After 14 d, Cr2O3 (2.5 g) was dosed at each feeding for 7 d and ruminal, duodenal, and fecal collections were taken for the next 3 d. Duodenal flow of 18:0 increased linearly (P < 0.01) with dietary forage. Duodenal flow of 18:1(cis-9) and 18:2(cis-9,12) decreased (P < 0.001) but duodenal flow of 18:3(cis-9,12,15) increased (P < 0.01) with increased dietary forage. Biohydrogenation of dietary unsaturated fatty acids increased (P < 0.001) as dietary forage increased, which was concomitant with increased ruminal pH. Duodenal flow of 18:2(cis-9,trans-11) increased linearly (P < 0.01) with increased dietary forage but increased abruptly when forage was fed at 45.8%. Duodenal flow of the trans-10, cis-12 and cis-10, cis-12 CLA isomers decreased as dietary forage increased, but flow tended to increase on the highest-forage diet, resulting in both linear (P < 0.01) and quadratic (P < 0.01) effects. Duodenal flow of 18:1(trans-11) decreased from 8.28 g/d on the 18.4% forage diet to 5.47 g/d on the 59.4% forage diet then increased to 7.29 g/d on the highest-forage diet (quadratic, P < 0.1). Duodenal flow of 18:1(trans-11) was 27- to 69-fold greater than flow of CLA. We conclude that when ewes were fed a 6% crude fat diet duodenal flows of dietary fatty acids changed incrementally as dietary forage was increased, whereas changes in flows of CLA isomers seemed to be more abrupt. Biohydrogenation changes were gradual with diet, suggesting a gradual shift in ruminal microbial populations with increasing forage. Finally, the highest-concentrate diet supported the greatest duodenal flows of dietary unsaturated fatty acids, as well as the highest flow of 18:1(trans-11).

A retrospective study of unerupted maxillary incisors associated with supernumerary teeth

We retrospectively reviewed the clinical records and radiographs of 100 patients who had had supernumerary teeth removed. Their mean (SD) age was 9 years 3 months (2). The 100 patients had a total of 127 unerupted maxillary incisors associated with supernumerary teeth. The supernumerary tooth was removed without exposure of the permanent tooth more often among the 79 younger children (aged 10 years or less) (SND=3.52, P<0.01), and when the incisors were less mature (Cvek classification 1, 2, and 3) (SND=5.27, P<0.01). Of these incisors with immature roots that were treated conservatively, 60 (72%) erupted and 24 (28%) required further operation. Of the mature incisors treated conservatively, 10 (63%) required further operation. In this study, almost three-quarters of immature incisors erupted spontaneously after removal of the associated supernumerary teeth. Over half of the mature teeth required further operation. Mature teeth should be exposed with or without bonding at the time of removal of the supernumerary teeth.

Direct transesterification of lipids from feedstuffs and ruminal bacteria

Direct transesterification of feedstuffs, browse plants, and ruminal bacteria was compared to transesterification of solvent extracted lipids. Weight percentages were of similar magnitude between procedures. Direct transesterification often produced higher concentrations of fatty acids. Results indicate that direct transesterification is an acceptable method for analysis of total fatty acids. Key words: Transesterification, lipids, feedstuffs, bacteria

Fatty acid composition and cholesterol concentration in tissues of white-tailed deer (Odocoileus virginianus) as influenced by lactation, age, and season of the year

The purpose of this study was to determine effects of lactation, season, and age on fatty acid compositions of adipose tissue (subcutaneous and perirenal), liver, and muscle (m. longissimus dorsi), and on cholesterol concentration of liver and muscle, of female white-tailed deer (Odocoileus virginianus). Lactation did not affect fatty acid composition in adipose tissue or muscle, but in liver, weight percentages of 18:2 were lower, and of 20:4 higher in non-lactating does. Increased age (fawns, yearlings, 2 and 3+(-)years old) decreased 14:0, 15:0, and 16:0 in subcutaneous adipose tissue; decreased 14:0, 15:0, 16:1, 18:2, and increased 18:0 in perirenal adipose tissue; increased 18:1 and decreased 18:2 in liver; and increased 18:1, 18:3, and 20:4, and decreased 18:2 in muscle. Season of the year had little effect on adipose tissue and muscle fatty acids. Liver of fall season does had greater concentrations of most fatty acids than winter does, and cholesterol concentration was greatest in liver of winter does. It was concluded that season and lactation minimally affect fatty acid composition in adipose and muscle, whereas changes in saturated and unsaturated fatty acids occur with increased age. Also, liver fatty acids are influenced by each parameter studied, but cholesterol varies only with season.

Influence of sire growth potential, time on feed, and growing-finishing strategy on cholesterol and fatty acids of the ground carcass and longissimus muscle of beef steers

The purpose of this study was to determine how diverse beef cattle production systems affect fatty acids and cholesterol of meat. Crossbred cows were bred by AI to high (H) or moderate (M) growth rate potential bulls to produce spring- or fall-born calves. Steer calves from these matings were placed on finishing diets at three ages. Spring-born steers were started at 6 or 18 mo of age (A6 and A18), and fall-born calves were started at 12 mo of age (A12). Slaughter times were 0, 90, 180, and 270 d for A6; 68, 136, and 204 d for A12; and 0, 45, 90, and 135 d for A18. Four steers of each type were slaughtered in each of 2 yr for each sire type x time on feed x slaughter group. Fatty acids and cholesterol of ground carcass and longissimus muscle (LM) were determined by GLC. Carcass fat increased faster in M than in H steers (P < .01). Ground carcass cholesterol was greater for M steers (P = .06) than for H steers because of the greater fat content in the M ground carcass. No differences in LM cholesterol were observed for sire growth potential or time on feed. Fatty acid differences in ground carcass with time on feed were due primarily to decreases in 18:0 and increases in 18:1. The LM saturated and monounsaturated fatty acids changed little with time on feed, but total saturates were greater for M steers (44.5%) than for H steers (42.8%) (P = .02). A18 steers of H sires had the greatest (P = .04) ratio of 18:0 plus unsaturates to 14:0 plus 16:0 (most hypocholesterolemic). We conclude that cholesterol in lean muscle is not altered by the sire growth potential x time on feed x growing-finishing strategy imposed, and that lean beef from steers sired by H bulls and backgrounded before finishing may produce meat with the healthiest lipid composition.

Adenomatoid odontogenic tumour in a 12-year-old boy

We present a rare finding of adenomatoid odontogenic tumour (AOT) in a 12-year-old boy who was referred to the Department of Paediatric Dentistry at the Eastman Dental Hospital for the extraction of a carious maxillary permanent molar. First presentation revealed that the maxillary right permanent lateral incisor and canine were unerupted. Radiological examination revealed a circumscribed radiolucent area associated with the distal aspect of the maxillary right permanent lateral incisor. The patient was admitted to our Day Care Unit where the carious maxillary molar was extracted and the radiolucent area associated with the maxillary right permanent incisor was explored. Pathological examination confirmed the lesion as adenomatoid odontogenic tumour. We present a brief review of the literature and consider how differential diagnosis of this tumour from more common odontogenic lesions can be established.

Multiple supernumeraries: the importance of clinical and radiographic follow-up

The occurrence of multiple supernumerary teeth is a rare phenomenon. Three cases of multiple supernumeraries are presented which illustrate problems which may arise during long-term follow-up: resorption of adjacent teeth, enlargement of the follicles, movement of the unerupted teeth and development of further supernumeraries. These cases highlight the importance of adequate initial surveillance, anticipation of potential problems, assessing the risk-benefits of surgery and long-term monitoring, in some cases following the surgical removal of supernumeraries.

The changing pattern of day-care treatment for children in a London dental teaching hospital

Day-stay general anaesthesia facilities may be employed to provide comprehensive dental care for children who are unable to accept treatment using alternative methods of patient management. This approach to delivery of care has been shown to be cost-effective, acceptable and efficaceous. This study was set up to investigate changes in the pattern of care provided in day-care facilities at a London dental teaching hospital over a 20-year period--1972 to 1992. The results show that the use of the facilities at this centre has increased with time, with a greater increase amongst older children in recent years. Although the main use is still for the treatment of caries, oral surgery procedures, especially those related to orthodontic treatment, have increased by 200% between 1982 and 1992. This correlates with the increase in older age groups being treated. Details of mean numbers of teeth restored and extracted for each age group are presented for 1992. They indicate, for the younger age groups, not only the high treatment needs of patients referred to the hospital, but also suggest a trend for more radical treatment planning in order to avoid further general anaesthesia. Readers are reminded that, despite its advantages, general anaesthesia should be avoided if possible.

Midline supernumeraries: a family affair

Supernumerary teeth are relatively common in the general population and appear to be more likely to occur in patients with a family history of such teeth. It is important that these teeth are identified and in some cases removed before undertaking orthodontic treatment. This article describes two patients who presented with supernumeraries, and their treatment.

Effect of dietary canola on fatty acid composition of bovine adipose tissue, muscle, kidney, and liver

The purpose of this study was to determine effects of feeding canola and soybean products as protein supplements on fatty acid composition of adipose tissue and muscle of slaughter bulls and steers and on fatty acid composition of kidney and liver total lipids of bulls. Products included canola meal (CM), extruded canola (EC, full-fat), ground canola (GC, full-fat), soybean meal (SBM), and extruded soybeans (ES, full-fat). Tissues were obtained at slaughter from 75 crossbred beef bulls and 50 crossbred beef steers fed corn silage (17.2 to 29.7% of DM), ground corn (56.5 to 75.0% of DM), and protein supplements (6.8 to 21.6% of DM). The DMI was not influenced by dietary fat in either trial. Gain: feed was greater (P < .05) for bulls fed CM than for bulls fed ES, EC, or GC. Carcasses were not influenced appreciably by dietary fat. Adipose tissue of EC-fed cattle had the lowest percentage of 16:0 (P < .05, vs SBM, CM, and GC), whereas both EC- and GC-fed cattle had the highest 18:0 (P < .05). In muscle (pectoral), EC-fed bulls had a higher percentage of 18:1 than SBM-fed bulls (P < .05), and EC-fed steers had the lowest 16:0 and 16:1 and highest 18:0, 18:3, and 20:1 (P < .05). Kidney total lipids of EC- and GC-fed bulls had the lowest percentage of 16:0 and highest 18:1 and 18:3 (P < .05); bulls fed ES had the highest percentage of 18:2. Liver-lipid 16:0 was highest in ES-fed bulls and lowest in EC-fed bulls, which also had the highest 18:0 (P < .05). Bulls fed EC and GC had the highest 18:3 and 20:5 (P < .05). In conclusion, dietary full-fat canola and in some cases full-fat soybeans altered the fatty acid composition of lipids of adipose tissue, muscle, kidney, and liver of beef cattle.

The influence on partial denture design of a teaching video for general dental practitioners

This evaluation was based on replies from a random sample of general dental practitioners who were asked to complete questionnaires before and after being sent a video and accompanying booklet on partial denture design. Forty per cent (257) of the original sample (636) completed and returned both questionnaires. A total of 212 respondents (82%) felt the video had been of value and 175 (68%) said they would be more likely to provide metal partial dentures after having watched it. The positive effects of the video were greatest amongst the most recently qualified. Despite some improvement after watching the video, there remained 105 (40%) who indicated that they would leave all partial denture design decisions to the technician on at least some occasions. Comparison of data from first and second questionnaires showed little evidence of substantial shifts in choice of denture design for a series of specific situations. It was concluded that whilst the programme had been well received and had produced changes in intention, there was less objective evidence of change.

Effects of a tristearate-containing lipid and canola oil on plasma and tissue lipids in rats

Male Sprague-Dawley rats were fed semipurified diets containing 12% fat and 0.4% cholesterol for 4 wk. The fats were palm oil, a high-stearate fat and canola oil; each of the latter two fat sources was substituted for palm oil in 4% (w/w) increments (i.e, 4, 8 and 12%) thus yielding 3 stearate-containing, 3 canola-containing, and a 12% palm oil diet. Stearate-fed animals exhibited significantly decreased food efficiency ratios, plasma total cholesterol, and liver cholesterol whereas the substitution of canola for palm oil did not consistently alter these parameters. Liver fatty acids generally reflected the composition of the dietary fat sources with the exception of significantly higher arachidonate observed in the stearate-fed rats.

Effects of dietary fatty acid composition on glycerophosphate acyltransferase activity in rat adipose tissue and liver

1. How source of dietary fat influences glycerophosphate acyltransferase (GPAT) activity in homogenates of adipose tissue and liver was determined using 5 rats per diet that contained 12% fat from either corn- (CO), high-oleate-safflower (HOSO), palm- or high-stearate-oils. 2. Activity was greatest in adipose tissue homogenates of rats fed HOSO and CO whereas no treatment effects were observed in liver homogenates. 3. No differences in fat pad weights were observed; thus HOSO- and CO-diets likely depressed other lipid synthetic rates. 4. Data indicate that mono- and diunsaturated fatty acid diets supported greater adipose tissue GPAT activity than did saturated fat diets when fed to rats.

Palmitate esterification and glycerophosphate acyltransferase activity in adipose tissue of growing lambs

The purposes of this study were to determine the effects of BW in growing lambs on rates of palmitate esterification (PE) and activity of glycerophosphate acyltransferase (GPAT) in subcutaneous and intermuscular adipose tissue in vitro and to determine the relationship between these in vitro measurements and carcass lipid accretion. At 37, 49, 60, and 71 kg of live weight, nine, nine, eight, and seven Columbia-Rambouillet-cross ewe lambs, respectively, were slaughtered and adipose tissue was dissected for glycerolipid biosynthesis assays. One-half of each carcass was boned, and carcass soft tissue lipid was measured. In both adipose tissues, PE and GPAT activity were highest at 37 kg (P = .0001); the greatest accumulation of carcass fat occurred between 37 and 49 kg (P = .0001). Differences in PE and GPAT were less well marked between 49-, 60-, and 71-kg lambs, but both were generally decreased with increased BW. Significant R2 from regressions of mass and percentage of carcass fat on either PE, GPAT, or steady-state glycerolipid synthesis (GLS) were from .39 to .44 (PE), .40 to .58 (GPAT), .50 to .75 (GLS), and .60 to .77 (PE, GPAT, and GLS combined). Changes in PE, GPAT, and GLS with BW were consistent with changes in rates of carcass fat accretion, which indicated a close relationship between glycerolipid biosynthesis in vitro and lipid deposition in vivo in growing-finishing lambs.

Effect of fluoride on the ATP requirement for glycerolipid biosynthesis in adipose tissue of four mammalian species

1. Maximal glycerolipid biosynthesis activity was determined with 700 g homogenates of human, ovine, rat and bovine adipose tissue, and in the presence of varied concentrations of ATP and fluoride (as KF). 2. Minimal responses to either ATP or KF were observed with human homogenates. 3. Increasing ATP, from 4 to 20 mM, markedly increased glycerolipid biosynthesis in ovine and rat homogenates, but not in those of the bovine; similar responses were observed with 4 mM ATP plus 12.5 mM KF for rat and ovine. 4. Results indicated that KF inhibited ATP degradation in adipose tissue homogenates and that the severity of ATP degradation differed with species.

The use of general anaesthesia for tooth extraction in children in London: a multi-centre study

Following publication of the Poswillo report, the continued use of general anaesthesia in dentistry became the subject of a major debate. In particular, the provision of general anaesthetic services by general dental practitioners in order to carry out simple extractions for child patients has been called into question. Other authors have strongly supported the continued need for general anaesthesia and insist that for some patients it remains the technique of choice. There is, however, little evidence of current patterns of attendance from which argument may be advanced to support or refute the differing views. In this study data was drawn from three London dental teaching hospitals providing out-patient general anaesthesia for extractions. During the 12-month period investigated 7852 general anaesthetics had been administered for child patients. There was evidence of an increase in numbers at one centre when results were compared to those of a previous study and some evidence of a change in pattern of referral with time at the same centre, with an increase in the numbers of patients referred by general dental practitioners. Eighty-three per cent of the anaesthetics had been given for the extraction of carious primary teeth, with an average of 3.3 being extracted per child. Nearly one-third of the anaesthetics were for children under the age of 5 years.

Comparison of glycerolipid biosynthesis in homogenates from human, ovine, bovine and rat adipose tissue in vitro

1. Assay conditions were compared for glycerolipid biosynthesis in homogenates prepared from human abdominal, ovine and bovine subcutaneous, and rat epididymal adipose tissues. 2. In contrast to other species, longer incubation time and greater homogenate concentration resulted in decreased glycerolipid biosynthesis with rat adipose tissue homogenates. 3. Species differences were observed in concentration-dependency for ATP and fatty acids (palmitate, oleate and palmitoleate). 4. Results indicated that glycerolipid biosynthesis transpired at different rates in the four species, and that ovine and human adipose tissue homogenates had similar properties.

Glycerolipid biosynthesis in adipose tissue of the bovine during growth

1. Rates of palmitate esterification in tissue slices and glycerophosphate acyltransferase activity in homogenates were determined in bovine subcutaneous and intermuscular adipose tissue at 340, 418 or 498 kg of live weight. 2. Lower rib section fat accretion rates were observed from 340 to 418 kg than from 418 to 498 kg. 3. Changes in palmitate esterification rates at different body weights were consistent with reduced rib section fat accretion as well as with reported differences in fat accretion in subcutaneous and intermuscular fat depots. 4. Glycerophosphate acyltransferase activity was increased at 418 kg and remained elevated whereas palmitate esterification was decreased at 418 and then increased at 498 kg. 5. Differences between palmitate esterification and glycerophosphate acyltransferase in vitro may have been related to differences in substrate supply.

Effect of adipose tissue site, animal size, and fasting on lipolysis in bovine adipose tissue in vitro

1. Lipolytic rates expressed as mumol glycerol released per mg protein increased with body weight in Holstein steers. 2. Lipolytic rates were greatest in both inner and outer back fat and lowest in omental, perirenal, and intermuscular fat depots. 3. Epinephrine stimulated overall glycerol release 3-5-fold. 4. Fasting resulted in greater basal lipolytic rates but epinephrine-stimulated rates tended to be greater for nonfasted steer adipose tissue. 5. Lipolytic activity in adipose tissue seems to increase with growth and fattening, and differences in lipolytic rates between various depots diminish with growth.

Dental treatment for children under general anaesthesia in day care facilities at a London dental hospital

Day-stay facilities are gaining in popularity in general surgery, especially in surgery for children. In dentistry, day-stay care has been shown to be of great value for the treatment of specific groups of child patients, including handicapped and those too young to tolerate treatment with local anaesthetic alone. The present study considered the characteristics of 103 patients attending for treatment in the day-care facilities of the Eastman Dental Hospital, the morbidity of the technique and the acceptability of the service to those using it. Of the 103 patients, 46 were seen in the unit because they required minor oral surgery and 22 because of particular problems with management. Ninety-four patients had one or more symptoms following treatment. In at least 53 cases this related to the treatment and not to the anaesthetic. Despite a cost to the families in terms of money and time, the service proved acceptable to almost all of those who used it.

Growth, carcass characteristics, and lipid composition of adipose tissue and muscle of pigs fed canola

Sixty-one finishing pigs (53.4 kg) were fed a control diet (containing soybean meal) or diets containing 20% intact canola (IC) or 20% ground canola (GC) for 8 wk. Diets were not isocaloric. Daily gain and feed efficiency were not affected by dietary treatment, but pigs fed GC ate less than pigs fed either IC or the control diet. Carcass measurements, obtained on 43 of the pigs, were not affected by diet. For 27 pigs, fatty acid composition of perirenal adipose tissue (PRF), subcutaneous adipose tissue (SCF), and longissimus muscle (LDM) was analyzed. Nine pigs (three per treatment) were randomly selected for fatty acid composition analysis of intramuscular adipose tissue (IMF) and for cholesterol analysis of several tissues. Pigs fed canola had greater (P less than .05) proportions of mono- and polyunsaturated fatty acids and less (P less than .05) saturated fatty acids in PRF and SCF. The differences were more pronounced for PRF than for SCF. In the LDM, pigs fed canola tended to have elevated levels of unsaturated fatty acids at the expense of the saturated fatty acids, but this effect was significant for linolenic acid only. The fatty acid composition of IMF was not affected by diet (P greater than .05). Diet did not alter the cholesterol content of the tissues, but cholesterol in IMF was higher (P less than .05) than in PRF, SCF, and LDM. In conclusion, 20% IC or GC did not alter growth performance or carcass characteristics of pigs. Feeding of canola increased the degree of unsaturation of PRF and SCF, but it had less effect on IMF and LDM.

Effect of indomethacin, epinephrine, prostaglandin E2 and insulin on lipolysis in bovine adipose tissue in vitro

1. Fasting of ad libitum- or maintenance-fed steers for 4 to 9 days did not alter basal lipolytic rates in vitro. 2. Epinephrine stimulation of adipose tissue of fasted steers resulted in greater (P less than 0.05) lipolysis than in tissue from fed steers. 3. Prostaglandin E2 (PGE2) did not alter epinephrine-stimulated lipolysis in ad libitum- or maintenance-fed cattle. 4. Indomethacin did not influence basal lipolysis, even in the presence of PGE2. 5. Insulin neither affected basal lipolysis nor inhibited dibutyl cAMP-stimulated lipolysis.

An evaluation of bitewing radiographs in 5-year-old children

Bitewing radiographs remain the most universally accepted aid in the detection of approximal caries in posterior teeth. The aim of this study was to evaluate their use in 5-year-old children. A total of 435 selected sets of films were read and the numbers of readable and unreadable surfaces were recorded. Of the total, 57 per cent of the sets of films were wholly readable; out of a maximum of 8700, 7490 readable surfaces were seen. Of the 248 wholly readable sets of films, 172 (69 per cent) had no evidence of caries, fillings or extracted teeth. The most common reason for loss of information was that surfaces were absent from the film (accounting for 7 per cent of all surfaces). Blurring of the surface affected 4 per cent of surfaces and overlaps a further 3 per cent. Despite the deficiencies seen, caries was diagnosed from more than one-third of all sets of films.

Lipoprotein lipase gene expression in rat adipocytes is regulated by isoproterenol and insulin through different mechanisms

Lipoprotein lipase (LPL) is highly regulated by catecholamines and insulin in adipocytes. Isoproterenol, a beta-adrenergic agonist, decreases LPL enzyme activity, whereas insulin increases LPL activity. We have isolated an 868-basepair rat LPL cDNA clone to assess hormone-mediated changes in LPL steady state mRNA levels and LPL gene transcription rates in adipocytes. Northern blot analysis of isoproterenol-treated (10(-6) M) adipocytes showed that LPL steady state mRNA decreased by 15 min. Nuclear run-on transcription assays in isoproterenol-treated cells indicated that LPL gene transcription was also decreased at 15 min compared to that in control cells. Conversely, insulin (6.7 x 10(-8) M) mediated an increase in LPL steady state mRNA in treated adipocytes, yet LPL gene transcription was not different from that in control cells. Thus, the isoproterenol-mediated decrease in LPL enzyme activity and steady state mRNA levels in adipocytes is associated with decreases in LPL gene transcription. Insulin, which does not affect LPL gene transcription, increases LPL enzyme activity and steady state mRNA levels. The effect of insulin on LPL mRNA is probably due to insulin-induced changes in mRNA stability.

Glycerolipid biosynthesis in porcine adipose tissue in vitro: effect of adiposity and depot site

To compare genetic differences in glycerolipid biosynthesis, rates were determined in s.c. adipose tissue of lean and obese pigs at 28, 60 and 110 d of age. To compare depot-specific differences, glycerolipid biosynthetic rates were determined in outer s.c., middle s.c., perirenal and omental adipose tissues obtained from 105-kg contemporary pigs. Rates were determined with a 700 x g infranatant fraction of an adipose tissue homogenate by measuring glycerophosphate incorporation into total lipids (mostly phosphatidic acid) during 4 min. This assay represents entrance of substrates into the glycerolipid synthesis pathway or glycerophosphate acyltransferase (GPAT) activity. Rates measured for 60 min represent maximal synthesis of glycerolipid (more triacylglycerol than phosphatidic acid) or lipid synthesis capacity (LSC). Adipocyte diameter and volume were greater for adipose tissue of obese than of lean pigs both at 60 and 110 d. When expressed per cell, activity of GPAT and LSC were similar for lean and obese pigs at 28 d. At 60 d and 110 d, LSC was greater for obese than for lean pigs; GPAT activity was greater at 60 but not at 110 d in obese than in lean pigs. Expressed on a cell basis, GPAT activity was highest in omental and outer s.c., intermediate in perirenal and lowest in middle s.c. adipose tissue depots. Lipid synthesis capacity was highest in perirenal and lowest in outer and middle s.c. depots. Our results indicate that the LSC assay was more closely related to the accretion of fat in vivo than to GPAT activity.

Glycerolipid biosynthesis in porcine adipose tissue in vitro. II. Synthesis by various types of cellular preparations

Glycerolipid biosynthesis by porcine adipose tissue homogenates did not yield the 90+% triacylglycerol observed in situ. Consequently, we compared intact tissue slices and various subcellular fractions to characterize the usefulness of such systems to assess glycerolipid biosynthesis in vitro. Glycerolipid biosynthesis by porcine adipose tissue homogenates was measured in vitro using either [14C]-fatty acid or [14C]-glycerol-3-phosphate (G3P) as a radiolabelled substrate. Removal of residual 14C-labelled fatty acid from lipid extracts was difficult. Because G3P is soluble in water, residual [14C]-G3P separated easily from the glycerolipid-containing organic phase and, thus, was the preferred radiolabelled substrate. With tissue slices, glycerol and G3P were minimally incorporated into lipid so that [14C]-fatty acid was the preferred radiolabelled tracer. A washing procedure followed by thin layer chromatography was devised to separate residual [14C]-fatty acid from glycerolipids, including phospholipids. Fatty acid esterification into glycerolipids in tissue slices yielded about 4% phospholipids, whereas with homogenates, esterification yielded up to 50% phospholipids. Comparison of several subcellular fractions indicated that microsomes contained most of the glycerolipid biosynthetic activity when activity was expressed on a protein basis. However, when activities were expressed on a tissue wet weight basis, the 700 x g infranate and the 10,000 x g supernate had about equal activity that was far greater than the microsomes. The 700 x g infranate was the preferred enzyme preparation for assay of the entrance of G3P into the pathway as well as the capacity to synthesize triacylglycerol. Several methods of freezing and storing tissue or 700 x g infranates were not acceptable. Freezing of the 700 x g infranate in liquid N2 with storage at -80 degrees C may be an acceptable procedure.