Xanthogranulomatous panniculitis of the head of an aquarium-maintained California moray

An aquarium-maintained male California moray Gymnothorax mordax had a symmetrical enlargement of the soft tissues of the head dorsal to the cranium for 2 years prior to its death. This individual was anesthetized for radiographic and ultrasonographic examination of the lesion, and blood was collected for plasma biochemical analytes and lipid profiles. Radiographs and ultrasound of the lesion demonstrated a symmetrical and homogeneous soft tissue density that was consistent with adipose tissue. Plasma cholesterol and triglyceride values appeared elevated; therefore, the animal's diet was amended to decrease fat consumption. Triglyceride values decreased after dietary changes were made; however, values for cholesterol, high-density lipoproteins, and low-density lipoproteins fluctuated but remained largely unchanged. Histopathological assessment of the lesion revealed localized xanthogranulomatous inflammation of hypodermal adipose tissue. The etiology of the lesion in this animal was never determined. This paper describes the first documented case of localized xanthogranulomatous panniculitis in a California moray and demonstrates the need for additional research on specific dietary requirements, species-specific physiological differences, and lesions involving the adipose tissue of morays in comparison with other teleost species.     

Capsosiphon fulvescens extracts improve obesity‐associated metabolic disorders and hepatic steatosis in high‐fat diet‐induced obese mice

Herbal dietary supplements have attracted more and more attention owing to their relative effectiveness in obesity ‐related metabolic disorders and diseases. This study investigated the therapeutic effects and underlying mechanisms of Capsosiphon fulvescens (CF) extracts on obesity, their associated metabolic disorders and hepatic steatosis in high‐fat diet (HFD)‐induced obese mice. Male C57BL/6 mice were fed with normal, HFD/Vehicle and HFD/CF (orally 300 mg/kg/day for CF). After 12 weeks, CF blocked HFD‐induced body weight, food intake, liver weight, hepatic triglyceride (TG), fat mass (weight of abdominal subcutaneous fat and epididymal adipose tissue) and biochemical parameters (total cohlesterol, glucose, TG, creatinine, high‐density lipoproteins cholesterol and low‐density lipoprotein cholesterol) of serum. CF also had improved serum levels of adiponectin, leptin and insulin‐like growth factor‐1 in HFD/CF mice. Moreover, CF ameliorated the hepatic steatosis‐reducing size of white adipose tissue. These results indicate that CF have anti‐obesity effects and are effective for reducing metabolic risk and hepatic steatosis.     

Plasma biochemistry values of recently wild-caught purple mouth moray eels (Gymnothorax vicinus)

The primary purpose of this study was to establish plasma biochemistry parameters for healthy recently wild-caught purple mouth moray eels (Gymnothorax vicinus) to provide a baseline of data for improved medical care in an aquarium or zoologic setting and for wild health assessments. Thirty-one clinically healthy purple mouth moray eels of unknown age and sex were caught from the wild, and were anesthetized 50 days following capture for blood collection from the ventral coccygeal vein. The median plasma biochemistry values were as follows: hematocrit = 21%, creatinine kinase = 2,100 U/L, lactate dehydrogenase = 97 U/L, aspartate aminotransferase = 88 U/L, alanine aminotransferase = 51 U/L, alkaline phosphatase 3,939 U/L, gamma-glutamyl transpeptidase = 1 U/L, amylase = 40 U/L, blood urea nitrogen = < 11 mg/dl, glucose = 21 mg/dl, calcium = 12.5 mg/dl, triglyceride = 206 mg/dl, creatinine = 0.1 mg/dl, cholesterol = 334 mg/dl, total bilirubin = < 0.1 mg/dl, phosphorus = 6.5 mg/dl, total protein = 4.2 g/dl, albumin = 1.5 g/dl, globulin = 2.7 g/dl, albumin/ globulin ratio = 0.6, sodium = 185 mmol/L, potassium = 3.7 mmol/L, and chloride = 175 mmol/L. Alkaline phosphatase isoenzyme results indicate that the majority of the plasma alkaline phosphatase is the liver isoenzyme. The data acquired in this study also provide baseline values for cholesterol and triglycerides in recently wild-caught moray eels to aid in monitoring elevations to these values in an aquarium setting over time so adjustments to the dietary regime may be utilized to prevent or improve conditions such as lipid keratopathy.     

Proteomics analysis of preadipocytes between fat and lean broilers

ABSTRACT

1. Reducing excessive chicken body fat deposition is a main goal of the poultry industry. Preadipocytes are important in adipose tissue growth and development.

2. To discover proteins related to chicken fat deposition, two-dimensional fluorescence difference gel electrophoresis (2-D DIGE) was used to identify differentially expressed proteins in preadipocytes derived from Northeast Agricultural University broiler lines divergently selected for abdominal fat content (NEAUHLF).

3. A total of 46 differentially expressed protein spots were found in the preadipocytes between fat and lean broilers. Matrix-assisted laser desorption-ionisation time-of-flight mass spectrometry (MALDI-TOF-MS) analysis showed the protein spots corresponded to 33 different proteins. The proteins were mainly related to biological oxidation, cell proliferation, cytoskeleton, lipid metabolism, molecular chaperone, protein synthesis and signal transduction.

4. From the perspective of protein expression, these results lay a foundation for further study of the genetic mechanism of broiler adipose tissue growth and development.     

Effects of degree of fatness in broilers on other carcass characteristics: Relationship between fatness and the stability of meat and adipose tissue1

1. Three trials were carried out to compare the effects of different degrees of fatness in broilers and of dietary a‐tocopherol (AT) concentrations on the stability of meat and adipose tissue at 5 to 9 weeks of age.

2. In spite of higher concentrations of AT in carcass fat, the meat and abdominal fat of lean broilers were less stable than those of obese birds, apparently due to an increase in the unsaturation of their carcass fat.

3. Dietary AT improved significantly the stability of meat and adipose tissue, irrespective of the degree of fatness. However, the difference in the stability of these tissues between obese and lean broilers remained apparent even with 60 mg AT/kg of the diet.

4. A linear relationship was observed between dietary AT and the stability of adipose tissue, whereas the relationship between AT intake and meat stability was logarithmic.     

Fatty Fish and Defatted Fish Products for Male Mink (Mustela vison) in the Growing-Furring Period: II. Effects on Haematological and Clinical-Chemical Parameters,Vitamin E Status and Fatty Acid Composition

The effects of different dietary levels of marine lipids in the diets with a constant distribution of metabolizable energy (ME) on protein, fat and carbohydrate were investigated in male mink kits in the growing-furring period during 2 consecutive years. The physiological investigations included 15 males per experimental group, each consisting of about 75 males. Fat herring and mackerel scrap were used in amounts resulting in levels of marine lipids of 30, 50 and 70% of total dietary lipid, respectively. Defatted herring scrap was used in proportions of 12, 23 and 32% in the diets. Haematocrit value, haemoglobin concentration, number of erythrocytes, leucocytes and platelets, plasma activities of alanine aminotransferase (ALAT), aspartate aminotransferase (ASAT) and creatine kinase (CK), concentrations of tocopherols in plasma, liver and adipose tissue, composition of fatty acids (FA) in liver and adipose tissue, body weight, weight of liver and heart in relation to body weight, and liver fat content were studied. The number of platelets decreased with an increasing proportion of marine lipids of total content of dietary lipids. A high intake of fatty fish products had no influence on the health status of the animals evaluated by haematological and clinical-chemical analyses, vitamin E status and FA composition in growing-furring male mink. No negative effects on the health of the animals were demonstrated when feeding with defatted herring scrap.     

Transfer of dietary sulphamonomethoxine and sulphadimethoxine into various tissues of laying hens

1. Sulphamonomethoxine (SMM) or sulphadimethoxine (SDM) were fed to laying hens at a dietary concentration of 400 mg/kg. Concentrations (mg/kg) of SMM and SDM in the blood, kidney, liver, ovary, muscle and adipose tissue, collected at 4, 8, 16 and 24 h after the start of feeding, were determined by HPLC

2. The relationships between the sulphonamide concentrations (mg/kg) in the tissues and times (h) after the start of the feeding were analysed statistically.

3. Dietary SMM and SDM were transferred throughout the whole body, and concentrations in all tissues became constant 8 h after the start of feeding.

4. Among the 6 tissues examined the constant values (mg/kg) of both SMM and SDM were highest in the kidney and were lowest in adipose tissue.

5. With the exception of adipose tissue, the values of SDM in the tissues were statistically greater than those of SMM.     

Haematological parameters,serum lipid profile,liver function and fatty acid profile of broiler chickens fed on diets supplemented with pomegranate seed oil and linseed oil

1. The objective of the present study was to determine effect of pomegranate seed oil (PSO) and linseed oil (LO) on haematological parameters, serum lipid profile and liver enzymes as well as fatty acids profile of adipose tissue in broilers.

2. Broilers (n = 400) were fed on diets containing graded PSO levels (0.0%, 0.5%, 1.0%, 1.5%) with or without 2% LO. After 6 weeks of feeding, 6 male broilers from each group were slaughtered and abdominal fat, liver and blood samples were collected.

3. Mixtures of pomegranate seed oil (0.5%, 1%) with linseed oil increased white blood cell level in broilers. Total cholesterol was elevated after LO supplementation whereas administration of PSO (1.5%) significantly decreased this parameter. PSO administration caused c9,t11 conjugated linoleic acid (CLA) concentration-dependent deposition in adipose tissue. By LO addition α-linolenic acid (ALA) content was enhanced, decreasing the n-6/n-3 ratio. PSO and ALA also affected oleic acid proportion in adipose tissue. Neither pomegranate seed oil nor linseed oil had any effect on liver parameters.

4. Pomegranate seed oil had no negative effects on broiler health status and can be considered as a functional poultry meat component.

     

Utilization of Dietary β-Carotene and Retinol Acetate by Goslings and Young Geese

One-day-old and 3-month-old geese were fed different concentrations of g -carotene (5, 10, 50 or 150 mg kg -1 feed) or retinol acetate (10 000, 20 000 or 40 000 IU kg -1 feed) for about 3 weeks to assess their ability to convert g -carotene to vitamin A. Blood serum concentrations of g -carotene, retinol, f -tocopherol, triacylglycerides and cholesterol, as well as liver concentrations of g -carotene, retinol, triacylglycerides and cholesterol, were included as response factors. g Carotene was not detectable in serum and liver. Serum and liver retinol concentrations were positively correlated with dietary concentrations of g -carotene and retinol acetate ( R 2 = 0.84 and 0.95, respectively). In goslings 1 mg of g -carotene corresponded to 63 IU retinol and in young geese to 1216 IU, equivalent to 3.8% and 72.9%, respectively, of the theoretical value of 1667 IU retinol. Cholesterol concentrations in blood serum and liver were not affected ( P > 0.05) by the dietary levels of g -carotene and retinol acetate. The concentration of f -tocopherol in blood serum decreased with increasing dietary levels of g -carotene and retinol acetate. In the goslings the concentration of triacylglycerides in serum and liver was significantly ( P < 0.05) influenced by the intake of g -carotene, but not by the intake of retinol acetate. In the young geese the serum concentration of triacylglycerides decreased ( P < 0.05) with increasing dietary levels of g -carotene, but was not affected by the dietary concentrations of retinol acetate. The concentration of triacylglycerides in liver tissue of young geese was not affected by the dietary concentration of either g -carotene or retinol acetate ( P > 0.05).     

Functional microRNA screening for dietary vitamin E regulation of abdominal fat deposition in broilers

ABSTRACT

1. Functional microRNA (miRNA) screening for abdominal fat tissue with different dietary vitamin E (VE) levels was performed to reveal miRNAs, genes and metabolic pathways involved in abdominal fat deposition in broilers.

2. A total of 240, one-day-old healthy female chicks were randomly allocated into five dietary treatments containing either 0, 20, 50, 75 or 100 IU DL-α-tocopherol acetate. The sequencing of miRNAs from abdominal fat tissues was performed. The target genes of miRNAs were predicted and enrichment analysis for these genes was performed. Diets supplemented with 50 IU VE significantly diminished abdominal fat deposition in broilers at day 35 of age.

3. A total of 29 miRNAs were differentially expressed between control and 50 IU VE treatment. Ten of the 23 target genes were enriched in four signalling pathways: tight junction, SNARE interactions in vesicular transport, regulation of autophagy and proteasome.

4. This study identified miRNA, target genes and pathways in dietary VE treatment for broilers, providing new insights into the miRNA regulation of abdominal fat deposition in broilers.     

Channel Catfish with a Rayed Adipose Fin

Abstract

Two channel catfish Ictalurus punctatus with rayed adipose fins were found in an aquaculture population. One specimen was radiographed and then cleared enzymatically and stained to demonstrate cartilaginous and calcified portions of the adipose and anal fins. The adipose fin, which had 33 rays (lepidotrichia) and was supported by pterygiophores, was morphologically similar to the anal fin. The cause of the abnormal adipose fin was not determined.     

Hounsfield Unit dynamics of adipose tissue and non-adipose soft tissues in growing pigs

Changes in the Hounsfield Unit value of adipose tissue and of non-adipose soft tissue during growth are poorly documented. This study examines the HU of these tissues in growing pigs. Computer tomography scans were made in nine growing pigs on three occasions, approximately four weeks apart. Average body weight was 51, 94, and 121 kg for each successive scan. Images from the level of the diaphragm to the hips were analyzed. The mean HU and its standard deviation, for adipose tissue and for non-adipose soft tissues was determined for each pig. The mean adipose tissue HU for all pigs was -90, -98 and -101 on the first, middle and last scans, respectively. Corresponding HU values for non-adipose soft tissues were, 52, 51 and 49. There was a significant difference (p<0.01) between HU at each scan time for each set of tissues.     

The impact of highly concentrated Mo and Cu dietary supplements,fed as a bolus,on the efficacy of chelated versus inorganic Cu in cattle on a low-Cu diet

AIM: To compare the efficacy of chelated versus inorganic forms of dietary Cu supplements, fed as a bolus, when challenged by a daily bolus of dietary Mo in cattle on a low-Cu diet.

METHODS: Forty non-lactating, Friesian dairy cows of adequate Cu status were assigned to four groups and fed a basal diet of baled silage containing 5.3 mg Cu and 0.4 mg Mo/kg DM. The experimental design was a factorial of two chemical forms of supplemental Cu and two levels of Mo intake, provided as pelleted grain supplements made from crushed barley/molasses plus Cu and Mo. The supplements contained 140 mg Cu/kg as Cu sulphate pentahydrate (CS), 140 mg Cu/kg as Cu glycinate (CG), CS plus 38 mg Mo/kg as sodium molybdate (CS+Mo), or CG plus 38 mg Mo/kg (CG+Mo). Commencing on Day 0, supplements were fed once daily (offered 1–1.2 kg/cow) and were completely consumed within 5–10 minutes, which constitutes a bolus type of administration. Liver samples were collected by biopsy at Days ?24, 13, 41 or 47, and 69 for Cu determinations.

RESULTS: The diets fed to the Cu+Mo groups were roughly equivalent to 25 mg Cu and 5.7 mg Mo/kg DM. Mean initial concentration of Cu in liver for all groups was 516 (SE 54) μmol Cu/kg fresh tissue. In cows supplemented with CS and CG, the final (Day 69) concentrations increased (p<0.01) to 939 (SE 166) and 853 (SE 163) μmol Cu/kg, respectively. These values were not different (p=0.72). For groups CS+Mo and CG+Mo, the final concentrations of 535 (SE 122) and 453 (SE 102) μmol Cu/kg were not different from initial values or from each other (p>0.25). The rate of accumulation of Cu in liver following bolus Cu and Mo intake was highly variable but was not affected by initial concentration of Cu in liver (p>0.9) or by the form of Cu (p>0.6). Mean rates of accumulation of Cu in liver were 4.0 (SD 3.8) and 0.65 (SD 2.0) μmol Cu/kg fresh tissue/day for the Cu-only treatments and the Cu+Mo treatments, respectively.

CONCLUSIONS: When fed together as a bolus, high Mo intake negated the effect of supplemental Cu but it did not reduce liver Cu stores. There was no difference in the reaction of dietary Mo with chelated Cu (as glycinate) versus inorganic Cu (as sulphate) dietary supplements.     

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.     

California Golden Trout Oncorhynchus mykiss aguabonita Are Susceptible to Proliferative Kidney Disease

Abstract

An outbreak of proliferative kidney disease affecting farmed California golden trout Oncorhynchus mykiss aguabonita in the United Kingdom is described. The fish displayed the clinical signs of the disease, such as characteristic swelling of the posterior kidney and spleen. Confirmation of infection with Tetracapsuloides bryosalmonae in the renal tissue was done by means of electron microscopy and immunohistochemistry using a monoclonal antibody specific to T. bryosalmonae.     

Stability of abdominal fat and meat of broilers: The interrelationship between the effects of dietary fat and vitamin E supplements 1

1. The effect of graded increments of α‐tocopheryl acetate (ATA), in diets containing various fat supplements at different concentrations, on tissue a‐tocopherol (TOC) content and on the stability of abdominal fat and meat of broilers was determined.

2. Plasma, liver and adipose tissue TOC content increased markedly as dietary ATA concentrations rose. The type or amount of fat supplementation had no consistent effect on tissue TOC content; however, these factors affected the degree of saturation of carcass fat.

3. Stability of abdominal fat and meat was little affected by the degree of saturation of carcass fat in the absence of dietary ATA. The latter significantly improved stability of these tissues in broilers having relatively saturated carcass fat, whereas its beneficial effect was rather limited as the degree of unsaturation of carcass fat increased.     

Intestinal mucosa develops in a sex-dependent manner in Japanese quail (Coturnix japonica) fed Saccharomyces cerevisiae

ABSTRACT

1. The aim of study was to investigate whether the impact of the yeast Saccharomyces cerevisiae on the histological structure of the intestine, innervation of the small intestine wall, and basal biochemical serum parameters in Japanese quail was sex dependent.

2. One-day-old healthy male and female Japanese quail were fed either a basal diet containing no yeast (control group) or the basal diet plus 1.5% (15 g/kg of diet) of yeast (S. cerevisiae inactivated by drying). Samples from the duodenum and jejunum were taken from each bird at the age of 42 days. Blood samples were collected at this age and the concentrations of glucose, total protein, creatinine, uric acid, lipid profile (total cholesterol, low density lipoproteins (LDL), high density lipoproteins (HDL) and triacylglycerols (TG)), alanine aminotransferase (ALAT), aspartate aminotransferase (AspAT), lactate dehydrogenase (LDH), amylase (AMY), calcium, phosphorus and iron were determined.

3. Female quail fed diets supplemented with yeast had significantly lower total cholesterol and amylase activity than the control females. The concentration of HDL was higher in the male quail than in the females, irrespective of the treatment. An opposite effect was observed in LDL. The diet treatments influenced the activity of AspAT, which was significantly less in the male quail fed diets with 1.5% yeast.

4. Supplementation with S. cerevisiae increased the myenteron, submucosa and mucosa thickness, villus length and thickness and size of absorptive surface, while the number of villi and enterocytes were decreased in the duodenum in males. Female quail showed an increased absorptive surface in the jejunum. The Meissner (submucosal) plexuses were influenced by the feeding and sex to a greater extent than the Auerbach plexus (in the muscularis propria).

5. The results demonstrated that S. cerevisiae (1.5%) in the diet caused significant positive effects in Japanese quail, exerting an effect on the morphology of the small intestine in a sex-dependent manner.     

Renal embryonal nephroma exhibiting malignant features in a Dutch rabbit (Oryctolagus cuniculus)

BackgroundBenign embryonal nephromas have been documented in rabbits. However, only one case of nephroblastoma with concurrent metastasis (pulmonary), a postmortem incidental finding, has been published.Case presentationA 3-year-old neutered male Dutch rabbit (Oryctolagus cuniculus) was referred for assessment of a firm mass located in the mid-dorsal abdomen. Abdominal ultrasonography confirmed a large soft tissue mass of suspected renal origin. A left-sided nephrectomy was performed via a ventral midline approach. Multiple white macular lesions, hyperemia, and petechiae were observed in the mesenteric fat surrounding the spleen. Histopathological examination of the abnormal kidney and the mesenteric fat revealed microscopic findings consistent with an embryonal nephroma exhibiting distinct features of malignancy. At 6- and 12-month postsurgery, ultrasonographic evidence of tumor recurrence was not observed.Conclusion and case relevanceThis is the first report of successful treatment of an embryonal nephroma showing malignant behavior and metastasis to the surrounding adipose tissue with a minimum postoperative survival time of 12 months and no ultrasonographic evidence of local recurrence.     

Dietary pea protein stimulates bile acid excretion and lowers hepatic cholesterol concentration in rats

It has been shown that some dietary plant proteins beneficially influence lipid metabolism in animals. The effect of pea protein in this respect however has not yet been investigated. Therefore, we studied the effect of purified pea protein on the lipid metabolism in rats. Twenty-four rats received diets with either 200 g/kg of casein or purified pea protein for 16 days. Concentrations of triacylglycerols in liver, plasma and lipoproteins did not differ between both groups of rats. However, rats fed the pea protein diet had a lower concentration of total cholesterol in the liver and the very low density lipoproteins (VLDL) fraction than rats fed the casein diet (p < 0.05); cholesterol concentration in plasma, low density lipoproteins (LDL) and high density lipoproteins (HDL) did not differ between both groups. Rats fed pea protein moreover had an increased mRNA concentration of cholesterol-7α-hydroxylase in the liver and an increased amount of bile acids excreted via faeces compared with rats fed casein (p < 0.05). Concomitantly, mRNA concentrations of sterol regulatory element-binding protein (SREBP)-2 and its target genes 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase and LDL receptor in the liver were increased in rats fed pea protein (p < 0.05). The data of this study suggests that pea protein stimulates formation and excretion of bile acids, which leads to a reduced hepatic cholesterol concentration and a reduced secretion of cholesterol via VLDL. An increased gene expression of SREBP-2 and its target genes HMG-CoA reductase and LDL receptor may be a means to compensate for the increased loss of cholesterol for bile acid synthesis.     

Influence of dietary palm oil supplementation on serum lipid metabolites, carcass characteristics, and lipid composition of carcass tissues of growing ram and ewe lambs.

The objective of this research was to determine the influence of dietary palm oil supplementation on carcass characteristics and lipid composition of tissues from growing lambs. Twenty-eight Suffolk x Hampshire lambs were weaned at 60 d of age (average 36 kg BW) and assigned to a 2 x 2 factorial arrangement consisting of diet (control [NPO] or 10.6% added dietary palm oil [PO]) and sex (ram vs ewe). The NPO diet (77% forage and 23% concentrate) contained 11.2% CP and 2.66 Mcal of ME/kg. Palm oil replaced molasses in the PO diet. Lambs were individually given ad libitum access to feed for 60 d to a final BW average of 50.1 kg. Lipid composition of the longissimus muscle and corresponding subcutaneous (s.c.) adipose tissue was determined by gas-liquid chromatography (GLC). Lambs fed PO were fatter (P less than .01) than lambs fed NPO (.77 vs .56 cm, s.c. fat). Diet had no effect on cholesterol content of lean tissue; however, feeding PO increased the saturated fatty acids of lean tissue. The s.c. fat from lambs fed PO had less (P less than .01) cholesterol (64.79 vs 89.67 mg/100 g) and more saturated fatty acids than that from lambs fed NPO. Ewes were fatter (P less than .01) than rams, yet they had less cholesterol content in the s.c. adipose tissue (68.71 vs 85.74 mg/100 g). High amounts of dietary palm oil fed to growing lambs caused changes in fatty acid deposition and cholesterol metabolism and may be a useful investigative tool to study lipid metabolism in growing ruminants.(ABSTRACT TRUNCATED AT 250 WORDS)