Morley Muralitharan

Conjugated linoleic acid decreases fat accretion in pigs: evaluation by dual-energy X-ray absorptiometry

Thirty female Large White x Landrace pigs (average weight 57.2 (sd 1.9) kg) were allocated to one of six dietary treatments containing 0, 1.25, 2.5, 5.0, 7.5 or 10.0 g 55 % conjugated linoleic acids (CLA) isomers (CLA-55)/kg diet and fed for 8 weeks. Each pig was scanned at 0, 28 and 56 d and again at post slaughter using dual-energy X-ray absorptiometry (DXA) to determine the temporal pattern of body composition responses. Values determined by DXA were adjusted using regression equations generated from validation experiments between chemically and DXA-predicted values. Overall, there was a significant linear reduction in fat content with the increasing levels of CLA in the diet (P=0.007, P=0.011, P=0.008 at week 4, week 8 and for the carcass, respectively). The greatest improvement was recorded at the early stages of CLA supplementation and for the highest dose of CLA (week 4, -19.2 % compared with week 8, -13.7 %). In the first 4 weeks of feeding CLA, pigs receiving 10 g CLA-55/kg diet deposited 93 g less fat/d than pigs fed basal diets (P=0.002) compared with only 6 g less fat than control animals in the final 4 weeks. Lean content and lean deposition rate were maximised at 5 and 2.5 g CLA-55/kg diet for the first 4 weeks (P=0.016) and the final 4 weeks of treatment respectively. DXA estimates of bone mineral content and bone mineral density were not affected by CLA supplementation throughout the experiment. These data demonstrate that dietary CLA decreases body fat in a dose-dependent manner and that the response is greatest over the initial 4 weeks of treatment.

Dietary conjugated linoleic acid differentially alters fatty acid composition and increases conjugated linoleic acid content in porcine adipose tissue

Conjugated linoleic acids (CLA) have been shown to decrease body fat content in pigs. It is possible that feeding pigs diets rich in CLA may increase carcass lipid CLA to levels that could provide health benefits when included as a part of a healthy diet. Therefore, the aim of the present study was to determine whether dietary CLA supplementation has any effect on the fatty acid composition of subcutaneous and intramuscular adipose tissue in pigs. Thirty-five female cross bred (Large White x Landrace) pigs (initial weight 57.2 kg and initial P2 back fat 11.5 mm) were used in the present study. Pigs were housed individually and randomly allocated to one of six dietary treatments (0.00, 1.25, 2.50, 5.00, 7.50 and 10.00 g CLA55 (55 g CLA isomers/100 g total fatty acids; Natural Lipids Ltd, Hovdebygda, Norway)/kg) and fed their respective diets for 8 weeks. Twelve CLA isomers in the diet and in pig tissue lipids were separated by Ag+-HPLC. CLA was incorporated at fivefold higher levels in subcutaneous fat as compared with intramuscular fat and in a dose-dependant manner. Overall, the transfer efficiency of CLA was maximized at 5.00 g CLA55/kg. However, there was clear selectivity in the uptake or incorporation of cis,trans-9,11 isomer over the trans,cis-10,12 isomer. In general, CLA supplementation produced significant changes in skeletal muscle and adipose tissue fatty acid composition, indicating that dietary CLA had a potent affect on lipid transport and metabolism in vivo. Significant increases in myristic, palmitic and palmitoleic acids and a reduction in arachidonic acid were observed, suggesting an alteration in activity of delta5-, delta6- and delta9-desaturases in pig adipose tissue. In conclusion, feeding pigs diets supplemented with CLA increases carcass lipid CLA, but also results in changes in the fatty acid profile in pig fat that could potentially outweigh the benefits of CLA.

Effects of dietary fat and conjugated linoleic acid on plasma metabolite concentrations and metabolic responses to homeostatic signals in pigs.

Sixteen female cross-bred (Large White x Landrace) pigs (initial weight 65 kg) with venous catheters were randomly allocated to four treatment groups in a factorial design. The respective factors were dietary fat (25 or 100 g/kg) and dietary conjugated linoleic acid (CLA; 0 or 10 g CLA-55/kg). Pigs were fed every 3 h (close to ad libitum digestible energy intake) for 8 d and were bled frequently. Plasma glucose and non-esterified fatty acid (NEFA) responses to insulin and adrenaline challenges were determined on day 8. Plasma concentrations of NEFA were significantly increased (10.5 and 5.4 % for low- and high-fat diets respectively, P=0.015) throughout the experiment, suggesting that there was a possible increase in fat mobilisation. The increase in lipolysis, an indicator of ss-adrenergic stimulated lipolysis, was also evident in the NEFA response to adrenaline. However, the increase in plasma triacylglycerol (11.0 and 7.1 % for low- and high-fat diets respectively, P=0.008) indicated that CLA could have reduced fat accretion via decreased adipose tissue triacylglycerol synthesis from preformed fatty acids, possibly through reduced lipoprotein lipase activity. Plasma glucose, the primary substrate for de novo lipid synthesis, and plasma insulin levels were unaffected by dietary CLA suggesting that de novo lipid synthesis was largely unaffected (P=0.24 and P=0.30 respectively). In addition, the dietary CLA had no effect upon the ability of insulin to stimulate glucose removal.

Characterisation and application of a bovine U6 promoter for expression of short hairpin RNAs

BackgroundThe use of small interfering RNA (siRNA) molecules in animals to achieve double-stranded RNA-mediated interference (RNAi) has recently emerged as a powerful method of sequence-specific gene knockdown. As DNA-based expression of short hairpin RNA (shRNA) for RNAi may offer some advantages over chemical and in vitro synthesised siRNA, a number of vectors for expression of shRNA have been developed. These often feature polymerase III (pol. III) promoters of either mouse or human origin.ResultsTo develop a shRNA expression vector specifically for bovine RNAi applications, we identified and characterised a novel bovine U6 small nuclear RNA (snRNA) promoter from bovine sequence data. This promoter is the putative bovine homologue of the human U6-8 snRNA promoter, and features a number of functional sequence elements that are characteristic of these types of pol. III promoters. A PCR based cloning strategy was used to incorporate this promoter sequence into plasmid vectors along with shRNA sequences for RNAi. The promoter was then used to express shRNAs, which resulted in the efficient knockdown of an exogenous reporter gene and an endogenous bovine gene.ConclusionWe have mined data from the bovine genome sequencing project to identify a functional bovine U6 promoter and used the promoter sequence to construct a shRNA expression vector. The use of this native bovine promoter in shRNA expression is an important component of our future development of RNAi therapeutic and transgenic applications in bovine species.

Isolating conifer DNA: a superior polysaccharide elimination method

Genomic DNA was isolated from frozen needles of maturePinus radiata clones using a modified extraction technique incorporating cetyltrimethylammonium bromide (CTAB) for cell lysis. A high sodium chloride concentration (2 M) was used at 2 stages of the extraction procedure to eradicate polysaccharides, yielding pure genomic DNA suitable for restriction enzyme digestion and PCR amplification. Extractions were scaled down to suit 1.5-mL Eppendorf tubes, allowing easier handling and enhanced sterility.

Medicinal plants of Malaysia

This article presents information about agricultural news and studies. Pharmacologists know the medicinal properties of the tropical species of Malaysia. Areca catechu is known as a common masticatory drug. An overview of the various medicinal plants, including Andrographis paniculata, Aquilaria malaccenis, and Cassia alata is offered. Malaysian medicinal plants act as strong therapeutic agents for several human diseases.

Medicinal plants of Thailand

Introduction For thousands of years, plants have formed the basis of sophisticated traditional medicinal systems in many parts of the world and remain a repository of new remedies for mankind (Gurib-Fakim, 2006). The healing properties of various plants are not only recognized by humans but, amazingly, are also widely utilized by other primates such as monkeys and apes (Halberstein, 2005). These primates have been observed to select for consumption specific botanical species that may act as analgesics, anti-microbials, anti-inflammatories, immunostimulants, anti-diarrheals, digestive aids and fertility regulators (Baker, 1996; Glander, 1994; Plotkin, 2000). It is noteworthy that an interesting review by Huffmann (1997) draws attention to the fact that monkeys, gorillas, chimpanzees as well as humans have been found to use the same plants for the treatment of similar diseases, injuries and other health problems.

Dietary conjugated linoleic acid improves carcass leanness without altering meat quality in the growing pig

One constraint facing the pig industry is that ad libitum feeding can often result in high levels of body fat and technologies which can reduce the ratio of lean to fat deposition in the pig are continually being explored. Conjugated linoleic acids have been shown to decrease body fat content in pigs. Therefore, the aim of this study was to determine whether dietary conjugated linoleic acids supplementation has any effect on meat quality and carcass characteristics in finisher pigs. Sixty female crossbred (Large White × Landrace) pigs (average initial weight 56.6 ± 1.9 kg and average initial P2 backfat 11.4 ± 1.3 mm) were used in the present study. Pigs were individually housed and randomly allocated to 1 of 6 dietary treatments: 0, 0.125, 0.25, 0.50, 0.75 or 1.0% (w/w) of conjugated linoleic acids-55. The wheat-based diets were formulated to contain 14.3 MJ DE and 9.3 g available lysine per kg and were fed ad libitum for 8 weeks. Pigs were slaughtered and meat quality was determined on the longissimus thoracis using standard techniques. Dietary conjugated linoleic acids reduced subcutaneous back fat in a linear manner with effects being most pronounced in the middle back fat layer. There was also a linear (P<0.001) decrease in intramuscular fat with increasing dietary conjugated linoleic acids supplementation. However, there was no effect of conjugated linoleic acids on subjective measures of marbling of the loin. Also, loin muscle ultimate pH (P = 0.94), lightness values (P = 0.46) subjective colour scores (P = 0.79), cooking loss (P = 0.71), drip loss (P = 0.40), shear force (P = 0.61) and subjective measures of wetness/firmness (P = 0.19) were unaffected. Dietary conjugated linoleic acids did not alter oxidation, as measured by the level of TBARs at day 1 post-slaughter (P = 0.38) or after 9 days of simulated retail display (P = 0.35). These data confirm that dietary conjugated linoleic acids can improve carcass quality by decreasing back fat depths without having any detrimental effects on meat quality.

Effects of dietary conjugated linoleic acid on haematological and humoral responses in the grower pig

The effects of conjugated linoleic acid (CLA) on the levels of total serum leucocytes, granulocytes including neutrophils, basophils, and eosinophils, as well as on monocytes and leucocytes were measured in pigs selected from a clean (minimal disease) herd. Thirty pigs were fed different rates of dietary CLA (0, 1.25, 2.5, 5.0, 7.5, and 10.0 g CLA-55/kg diet) for 8 weeks. Blood samples were collected at the end of the study for assessment of haematological and humoral responses to CLA supplementation. No difference in total white blood cells including the neutrophil, monocyte, and lymphocyte counts was observed among different dietary groups. A dose-dependent reduction (P = 0.02) in eosinophil concentrations suggests that CLA exerts anti-inflammatory activities. A 2-fold increase in the level of basophils was recorded in pigs fed lower levels of CLA (1.25 and 2.5 g CLA/kg diet) but the levels decreased gradually (P = 0.05) and were below the detection limit at the highest rate (10 g/kg) of CLA supplementation. The level of IgG was reduced by over 50% in CLA-fed pigs (P < 0.001), although the response was quadratic in nature (P < 0.001). T-cell population analysis showed that CD4+ cells tended (P = 0.06) to be reduced linearly with increasing inclusion of CLA in the diet. Our results suggest that dietary CLA modulates haematological and humoral responses in a dose-dependent manner.

Snapshot of Malaysian Biotechnology

With highly skilled staff, world class-technologies, reliable infrastructure, good regulatory policies, low costs, government and private sector innovation and an abundance of competitively priced raw materials in agriculture, Malaysian is one of the most attractive locations for global biotechnology investment. International free trade has been a top priority for many Asian countries since early 2000. The number of significant international investments in the Asian biotechnology sector has doubled in the past few years. The incidence of niche partnerships for drug developments and agricultural trade has increased, particularly with the US, the UK, Australia and New Zealand companies. These major markets are looking more and more to Malaysia as a genuine source of innovation to achieve their business objectives for the development of global biotechnology products and outsourcing of their technology and product development. The Association of South East Asian Nation (ASEAN) countries has been working on a free trade to create a consistent, predictable production base across the region to attract foreign investment.