Effects of serine palmitoyltransferase inhibition by myriocin in ad libitum-fed and nutrient-restricted ewes

Author(s):  
Amanda N Davis ◽  
William A Myers ◽  
Jorge Eduardo Rico ◽  
Lin Feng Wang ◽  
Crystal Chang ◽  
...  

Abstract The fungal isolate myriocin inhibits serine palmitoyltransferase and de novo ceramide synthesis in rodents; however, the effects of myriocin on ceramide concentrations and metabolism have not been previously investigated in ruminants. In our study, twelve non-lactating crossbred ewes received an intravenous bolus of myriocin (0, 0.1, 0.3, or 1.0 mg/kg/body weight [BW]; CON, LOW, MOD, or HIGH) every 48 h for 17 d. Ewes consumed a high-energy diet from d 1-14, and were nutrient-restricted (straw only) from d 15-17. Blood was collected preprandial and at 1, 6, and 12 h relative to bolus and nutrient restriction. Tissues were collected following euthanasia on d 17. Plasma was analyzed for free fatty acids (FFA), glucose, and insulin. Plasma and tissue ceramides were quantified using mass spectrometry. HIGH selectively decreased metabolizable energy intake, BW, and plasma insulin, and increased plasma FFA (Dose, P < 0.05). Myriocin linearly decreased plasma very-long-chain (VLC) ceramide and dihydroceramide (DHCer) by d 13 (Linear, P < 0.05). During nutrient restriction, fold-change in FFA was lower with increasing dose (P < 0.05). Nutrient restriction increased plasma C16:0-Cer, an effect suppressed by MOD and HIGH (Dose × Time, P < 0.05). Myriocin linearly decreased most ceramide and DHCer species in liver and omental and mesenteric adipose, VLC ceramide and DHCer in pancreas, and C18:0-Cer in skeletal muscle and subcutaneous adipose tissue (Linear, P ≤ 0.05). We conclude that the intravenous delivery of 0.3 mg of myriocin/kg of BW/48 h decreases circulating and tissue ceramide without modifying energy intake in ruminants.

1973 ◽  
Vol 16 (2) ◽  
pp. 165-171 ◽  
Author(s):  
T. H. McClelland ◽  
T. J. Forbes

SUMMARYSixty Scottish Blackface ewes were used in a 2 × 2 factorial experiment in which two levels of metabolizable energy (ME) were given during the final 6 weeks of pregnancy. In two treatments 1600 and 2000 kcal M E were given daily over the total period while in the remaining treatments daily ME intakes were 1200 and 1600 kcal ME during the first 3 weeks of the feeding period and 2000 and 2400 kcal ME during the last 3 weeks. Digestible crude protein (DCP) intakes were constant at approximately 30 g per head daily in the constant energy treatments and 15 and 45 g per head daily in the first and second periods respectively for the low-high energy treatments.Energy intake had no statistically significant effect on lamb birth weight nor on ewe net body-weight change (change from the start of the experimental feeding period to immediately post partum). Ewes on low-high energy intakes had a significantly lower net body-weight loss than did ewes on constant energy intakes. Pattern of feeding had no significant effect on lamb birth weights. Negative nitrogen balances were found during the first feeding period where the daily DCP intake was approximately 15 g per head.


2015 ◽  
Vol 99 (6) ◽  
pp. 1025-1030 ◽  
Author(s):  
M. Thes ◽  
N. Koeber ◽  
J. Fritz ◽  
F. Wendel ◽  
B. Dobenecker ◽  
...  

2002 ◽  
Vol 138 (2) ◽  
pp. 221-226 ◽  
Author(s):  
A. ALLAN DEGEN ◽  
B. A. YOUNG

Body mass was measured and body composition and energy requirements were estimated in sheep at four air temperatures (0 °C to 30 °C) and at four levels of energy offered (4715 to 11785 kJ/day) at a time when the sheep reached a constant body mass. Final body mass was affected mainly by metabolizable energy intake and, to a lesser extent, by air temperature, whereas maintenance requirements were affected mainly by air temperature. Mean energy requirements were similar and lowest at 20 °C and 30 °C (407·5 and 410·5 kJ/kg0·75, respectively) and increased with a decrease in air temperature (528·8 kJ/kg0·75 at 10 °C and 713·3 kJ/kg0·75 at 0 °C). Absolute total body water volume was related positively to metabolizable energy intake and to air temperature. Absolute fat, protein and ash contents were all affected positively by metabolizable energy intake and tended to be related positively to air temperature. In proportion to body mass, total body water volume decreased with an increase in metabolizable energy intake and with an increase in air temperature. Proportionate fat content increased with an increase in metabolizable energy intake and tended to increase with an increase in air temperature. In contrast, proportionate protein content decreased with an increase in metabolizable energy intake and tended to decrease with an increase in air temperature. In all cases, the multiple linear regression using both air temperature and metabolizable energy intake improved the fit over the simple linear regressions of either air temperature or metabolizable energy intake and lowered the standard error of the estimate. The fit was further improved and the standard error of the estimate was further lowered using a polynomial model with both independent variables to fit the data, since there was little change in the measurements between 20 °C and 30 °C, as both air temperatures were most likely within the thermal neutral zone of the sheep. It was concluded that total body energy content, total body water volume, fat and protein content of sheep of the same body mass differed or tended to differ when kept at different air temperatures.


The Condor ◽  
2001 ◽  
Vol 103 (1) ◽  
pp. 108-117
Author(s):  
James A. Robinson ◽  
Keith C. Hamer ◽  
Lorraine S. Chivers

Abstract Arctic Terns (Sterna paradisaea) and Common Terns (S. hirundo) are similar in many aspects of their breeding ecology, but Common Terns generally lay three eggs per clutch whereas Arctic Terns lay two. In our study, Common Terns had a higher rate of food delivery and energy supply to the nest and higher nest attendance, indicating that they made trips of shorter average duration. This suggests that the number of chicks raised by these two species was primarily limited by the rate at which parents could supply food. However, estimated daily metabolizable energy intake of chicks was about 30% higher in Common Terns than in Arctic Terns. Common Tern chicks apparently spent a higher proportion of daily energy intake on maintenance of body temperature. It remains unknown whether this difference was because Common Tern parents could not brood three chicks as effectively as Arctic Terns brooded two or because the energy requirements for heat production in the third-hatched Common Tern chick were particularly high. If brooding did play a less important role in the energy budgets of Common Terns, the number of chicks that Arctic Terns could raise may have been limited not only by the rate at which parents could supply food to the nest but also by the requirements of chicks for brooding. We suggest that more detailed studies on the role of brooding constraints in limiting brood size in these species are required to clarify this matter.


1982 ◽  
Vol 34 (3) ◽  
pp. 355-357 ◽  
Author(s):  
R. T. Cowan ◽  
J. J. Robinson ◽  
I. McDonald

ABSTRACTData from three comparative slaughter experiments involving a total of 73 ewes were used to study the influence of body fat content at the start of lactation (X1 kg) and of metabolizable energy intake (X2, MJ/day), on the rate of loss of body fat by lactating ewes over the first 6 weeks of lactation (Y, g/day). The relationship was described by the equation:Thus the rate of fat loss was greater for ewes with higher initial fat contents, but the differential became less as metabolizable energy intake increased. Since increases in body fatness depress food intake it was not possible to prevent loss of body fat during early lactation in fat ewes given high concentrate diets ad libitum. The likely response in milk yield to increase in body fatness at parturition is therefore strongly dependent on the relative levels of body fatness and metabolizable energy intake. The value of any improvement in condition of the ewe at parturition may be considerable when metabolizable energy intake during lactation is low but much less when it is expected to be high.


1977 ◽  
Vol 17 (86) ◽  
pp. 393
Author(s):  
DS Gillespie ◽  
JW McLaughlin

An experiment at Hamilton in western Victoria from June to October 1972 examined the feasibility of fattening two-year-old Corriedale wethers from 30 to 50 kg liveweight when fed simple rations in feedlots. Using a factorial design, treatments compared were mid-season or late cut pasture hay offered ad libitum and oat grain fed at 0, 0.25, 0.50 kg head-1 day-1 or ad libitum. Two additional groups were set stocked on green pasture; one of them was offered oat grain ad libitum. Performance of sheep in the feedlot (intake, liveweight and carcase gain, feed conversion and wool production) was influenced by hay type and level of oat feeding. Liveweight gain over the period of feeding increased linearly until oats comprised about 50 per cent of the daily dry matter intake, but the highest liveweight gain in the feedlot (127 g day-1) occurred when sheep were given a ration consisting of 25 per cent mid-season hay and 75 per cent oats. Sheep on pasture gained at an average of 146 g day-1. Irrespective of composition of the ration, liveweight gain increased by 20 g day1, carcase weight by 15 g day-1 and wool by 1.7 g day -1 for each additional MJ of metabolizable energy intake.


1991 ◽  
Vol 69 (8) ◽  
pp. 2128-2132 ◽  
Author(s):  
Scott R. Decker ◽  
Peter J. Pekins ◽  
William W. Mautz

Red oak acorns (Quercus rubra), fruits of multiflora rose (Rosa multiflora), common juniper (Juniper communis), winterberry holly (Ilex verticillata), and barberry (Berberis spp.), fertile fronds of sensitive fern (Onoclea sensibilis), corn, and apples were fed as mixed rations to eight eastern wild turkeys (Meleagris gallopavo silvestris). Crude protein content of the foods ranged from 2 (apples) to 19% (sensitive fern). Red oak acorns and juniper berries were 14% fat; other foods were 1–7% fat. Apples were lowest in gross energy content (3.9 kcal/g dry matter (1 cal = 4.1868 J)), and sensitive fern was highest (5.5 kcal/g). Little variation existed in nutrient composition and energy content of the mixed diets. Metabolizable energy values of the diets ranged from 65 to 84% of gross energy intake and from 3.1 to 4.0 kcal/g. Solution of simultaneous equations based on the mixed-diet data yielded metabolizable energy values of individual foods; juniper had the highest metabolizable energy (4.6 kcal/g) and sensitive fern the lowest (2.1 kcal/g); other foods ranged from 3.3 to 4.1 kcal/g. Acorns, corn, and shrubs with persistent fruits (juniper, winterberry, barberry, and multiflora rose) were the most nutritious foods. Metabolizable energy intake of the mixed diets, excluding the juniper-dominated diet, approximated or exceeded the predicted daily energy expenditure of wild turkeys.


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