• Asian-Australasian Journal of Animal Sciences
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• v.28 no.8
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• pp.1140-1149
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• 2015

This research aimed to define the energy requirement of Dorper and Hu Hybrid $F_1$ ewes 20 to 50 kg of body weight, furthermore to study energy requirement changes with age and evaluate the effect of age on energy requirement parameters. In comparative slaughter trial, thirty animals were divided into three dry matter intake treatments (ad libitum, n = 18; low restricted, n = 6; high restricted, n = 6), and were all slaughtered as baseline, intermediate, and final slaughter groups, to calculate body chemical components and energy retained. In digestibility trial, twelve ewes were housed in individual metabolic cages and randomly assigned to three feeding treatments in accordance with the design of a comparative slaughter trial, to evaluate dietary energetic values at different feed intake levels. The combined data indicated that, with increasing age, the net energy requirement for maintenance ($NE_m$) decreased from $260.62{\pm}13.21$ to $250.61{\pm}11.79kJ/kg^{0.75}$ of shrunk body weight (SBW)/d, and metabolizable energy requirement for maintenance (MEm) decreased from $401.99{\pm}20.31$ to $371.23{\pm}17.47kJ/kg^{0.75}$ of SBW/d. Partial efficiency of ME utilization for maintenance ($k_m$, 0.65 vs 0.68) and growth ($k_g$, 0.42 vs 0.41) did not differ (p>0.05) due to age; At the similar condition of average daily gain, net energy requirements for growth ($NE_g$) and metabolizable energy requirements for growth ($ME_g$) for ewes during late fattening period were 23% and 25% greater than corresponding values of ewes during early fattening period. In conclusion, the effect of age upon energy requirement parameters in the present study were similar in tendency with previous recommendations, values of energy requirement for growth ($NE_g$ and $ME_g$) for Dorper and Hu crossbred female lambs ranged between the NRC (2007) recommendation for early and later maturating growing sheep.

• Journal of Animal Science and Technology
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• v.57 no.3
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• pp.8.1-8.8
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• 2015

Background: The demand for healthy, lean and consistent meat products containing low saturated fatty acid content and high quality polyunsaturated fatty acids (PUFA), especially long-chain (${\geq}C_{20}$) omega-3 PUFA, has increased in recent times. Fat deposition is altered by both the genetic background and dietary supplements, and this study aimed to assess the effect of dietary Spirulina supplementation levels on the mRNA expression patterns of genes controlling lipid metabolism in the subcutaneous adipose tissue (SAT) and Longissimus dorsi (ld) muscle of Australian crossbred sheep. Methods: Twenty-four weaned lambs belonging to four breeds under the same management conditions were maintained on ryegrass pasture and fed three levels of Spirulina supplement (control, low and high). In terms of nutrient composition, Spirulina is a nutrient-rich supplement that contains all essential amino acids, vitamins and minerals. It also is a rich source of carotenoids and fatty acids, especially gamma-linolenic acid (GLA) that infer health benefits. After slaughter, subcutaneous adipose tissue (SAT) and ld samples were subjected to mRNA extraction and reverse transcription using quantitative polymerase chain reaction (RT-qPCR) to assess the mRNA expression levels of the Aralkylamine N-acetyltransferase (AANAT), Adrenergic beta-3 receptor (ADRB3), B-cell translocation gene 2 (BTG2) and Fatty acid synthase (FASN) genes, which are associated with lipid metabolism. Results: Both low and high Spirulina supplementation levels strongly up-regulated the transcription of all the selected genes in both SAT and ld tissues (mostly in the subcutaneous adipose), but sheep breed and sex did not influence the gene expression patterns in these tissues. Conclusions: The evidence indicates that high Spirulina supplementation level resulted in a decrease in intramuscular fat content in Australian purebred and crossbred sheep due to the enhanced production of melatonin in sheep muscle tissues and strong up-regulation of mRNA expression of BTG2 in SAT which negatively affected fat deposition. In contrast, low Spirulina supplementation level strongly up-regulated the ADRB3 and FASN genes responsible for fat production. These findings are consistent with the observed phenotypic data suggesting that low Spirulina supplementation level can increase lamb production, with higher long-chain PUFA content.

• The Korean Journal of Physiology and Pharmacology
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• v.2 no.4
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• pp.435-441
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• 1998

We examined effects of interleukin $1{\alpha}$ ($IL1{\alpha}$) and phorbol 12, 13 dibutyrate (PDB), an activator of protein kinase C, on mRNA for Prostaglandin H synthase (PGHS) and prostanoid production in cultured ovine meningeal fibroblasts. Immuno- and morphologically-identified fibroblasts were derived from cerebral cortex and white matter from fetal lambs (approximately 120 days gestation) and grown to confluence on glass coverslips in 12 well plates. Levels of prostaglandin $F_{2{\alpha}}$ and the stable hydrolysis product of prostacyclin (i.e., $6-keto-PGF_{1{\alpha}}$) were determined using enzyme immunoassay. Relative amounts of mRNA were determined by in situ hybridization using ovine cDNA for PGHS1. $IL1{\alpha}$ (10 ng/ml) increased mRNA levels over baseline by $62{\pm}19%$ (p＜0.05) at 60 min., $37{\pm}12%$ (NS) at 120 min., and $36{\pm}18%$ (NS) at 240 min (n=12). Levels of $6-keto-PGF_{1{\alpha}}$ were $148{\pm}18%$ pg/ml during baseline, $246{\pm}41%$ pg/ml at 60 min., $248{\pm}40%$ pg/ml at 120 min., and $259{\pm}62%$ pg/ml at 240 min (all p＜0.05) (n=12). $PGF_{2{\alpha}}$ was increased although it wasn't statistically significant. However, $IL1{\alpha}$ decreased $PGE_2$ level significantly (all p＜0.05). PDB $(10^{-6}M)$ increased mRNA levels over baseline by $25{\pm}6%$ after 30 min., $40{\pm}6%$ after 60 min., and $20{\pm}8%$ after 90 min. (n=9) (all p＜0.05). Levels of $6-keto-PGF_{1{\alpha}}$ were $200{\pm}43%$ pg/ml during baseline, $202{\pm}43%$ pg/ml after 30 min. (NS), $268{\pm}58%$ pg/ml after 60 min. (p＜0.05), and $296{\pm}60%$ pg/ml after 90 min. (p＜0.05) (n=9). Levels of $PGF_{2{\alpha}}$ were $178{\pm}26%$ pg/ml during baseline, $300{\pm}30%$ pg/ml after 30 min., $299{\pm}35%$ pg/ml after 60 min., and $355{\pm}32%$ pg/ml after 90 min (all p＜0.05) (n=6). Actinomycin-D (1 mg/ml) prevented increases in mRNA, $6-keto-PGF_{1{\alpha}}$, and $PGF_{2{\alpha}}$ at 60 min. for both $IL1{\alpha}$ and PDB. We conclude that cerebral fibroblasts are avid producers of prostanoids, and that enhanced production of PGHS is responsible for augmented $PGF_{2{\alpha}}$ and prostacyclin production in the presence of an activator of protein kinase C and for decreased $PGE_2$ and increased prostacyclin production in the presence of $IL1{\alpha}$.