Search

Tropical forests face increasing pressure from logging activities, necessitating sustainable management practices to balance economic demands with ecological preservation. This study investigates the effectiveness of buffer zones in maintaining soil quality in logged tropical forests of Sarawak, Malaysia. We compared soil properties and calculated Tropical Soil Quality Index (TSQI) scores across three forest management conditions: natural forest, logged forest with buffer zones, and logged forest without buffer zones. Topsoil samples (0-20 cm depth) were collected from multiple plots within each condition and analyzed for pH, total carbon, total nitrogen, available phosphorus, and exchangeable cations. TSQI scores were calculated following established methods. Results showed that natural forests and logged forests with buffer zones achieved similar TSQI percentages of 50%, while logged forests without buffer zones scored significantly lower at 30%. Buffer zones effectively maintained soil pH, organic carbon, nitrogen, available phosphorus, and exchangeable cations at levels closer to those of natural forests. These findings highlight the importance of buffer zones in mitigating the negative impacts of logging on soil quality. The study provides valuable insights for forest managers and policymakers, supporting the implementation of buffer zones as a key component of sustainable tropical forest management practices. Further research is recommended to assess long-term effects and optimize buffer zone design for maximum soil conservation benefits. [ABSTRACT FROM AUTHOR]

Using a multitrait animal model BLUP, selection was conducted over seven generations for growth rate (ADG), real-time ultrasound LM area (LMA), backfat thickness (BF), and intramuscular fat content (IMF) to develop a new line of purebred Duroc pigs with enhanced meat production and meat quality. This selection experiment examined 543 slaughtered pigs (394 barrows and 153 gilts) from the first to the seventh generation for meat quality traits. Further, electric impedance and collagen content of loin meat were measured from the fourth to sixth generation. The present study was intended to estimate genetic parameters of the correlated traits of tenderness (TEND), meat color (pork color standard: PCS; lightness = L *), drip loss (DL), cooking loss (CL), pH (PH), electric impedance (IMP), and collagen (COL) of the LM, and the genetic trends of these traits. Respective heritability estimates for IMF, TEND, DL, CL, PCS, L *, PH, IMP, and COL were 0.39, 0.45, 0.14, 0.09, 0.18, 0.16, 0.07, 0.22, and 0.23. Genetic correlations of IMF with ADG and BF were low and positive, but low and negative with LMA. Tenderness was correlated negatively with ADG (-0.44) and BF (-0.59), but positively correlated with LMA (0.32). The genetic correlation between LMA and DL was positive and high (0.64). The genetic correlations of TEND with IMF and COL were low (-0.09 and 0.26, respectively), but a moderate genetic correlation (0.43) between COL and IMF was estimated, suggesting related increases of IMF and connective tissue. Genetic correlations among meat quality traits suggested that when IMF increases, the water holding capacity improves. Genetic trends of meat quality traits showed increased IMF and lighter meat color. Key Words: Collagen, Duroc Pigs, Genetic Parameters, Impedance, Meat Quality Traits

Spectroscopy using four types of fiber-optic probes and a sensor at wavelengths of 400 to 1,100 nm was evaluated to assess porcine fat quality. The shapes of the spectrum for the leaf fat with white color and various firmnesses differed with the type of probe: surface, contact, insertion, or transmittance. The internal reflectance ratio using the insertion probe at wavelengths from approximately 600 to 1,000 nm was positively correlated with the hardness, melting point, and saturated fatty acid content of the fat, but it was negatively correlated with the refractive index and polyunsaturated fatty acid content. The correlations between the internal reflectance ratio using the insertion probe and the monounsaturated fatty acid content were strong only near 1,100 nm. Surface reflectance at more than 650 nm was negatively correlated with refractive index. Transmittance at almost all wavelengths showed positive correlations with monounsaturated fatty acid content, but it was negatively correlated with hardness, melting point, and saturated fatty acid content. The interactance using the contact probe did not have a significant correlation with any physiochemical characteristics. The strongest relationships for hardness, refractive index, saturated fatty acid content, monounsaturated fatty acid content, polyunsaturated fatty acid content, and melting point were obtained at 650 nm (r = .88), 660 nm (r = .91), 645 nm (r = .73), 1,095 nm (r = .68), and 930 nm (r = .76), respectively using the insertion probe and 1,050 nm (r =.79) using the transmittance probe (P < .05). These results indicated that fiber-optic methods were rapid and useful techniques for the evaluation of porcine fat quality. Key Words: Pigs, Fat, Fiber Optics, Spectroscopy, Fatty Acid, Meat Quality

A study was conducted to determine whether the wavelength of a helium-neon red laser is at or near the optimum wavelength for reliable measurement of meat quality. Pork of different qualities over a range were selected from a commercial abbatoir and analyzed with spatial scanning and spectrophotometric methods. The results showed that that red laser is a reliable measure of pork quality since its wavelength (633 nm) is close to the optimum wavelength of meat quality measurements.

Sixteen pigs averaging 81.4 kg were assigned to a control diet and three test diets containing 2, 4, or 6% fish oIl. Subcutaneous fat samples from the loin were obtained by biopsy at weekly intervals and analyzed for fatty acid composition. The pigs were maintained on the diets (ad libitum access to feed) for 4 wk before slaughter at an average weight of 107.8 kg. Outer and inner layers of backfat, perirenal fat, and intermuscular fat were obtained from the carcass and analyzed for physicochemical characteristics. In the biopsy samples, the contents of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) in fat from pigs fed fish oil began to increase during the 1st wk. Rates of increase were greater during the first 2 wk than during the last 2 wk. In the carcass samples, the increase in EPA and DHA in all fat tissues analyzed became greater as the supplemental levels of fish oil were increased in the diet, whereas oleic and linoleic acids tended to be decreased by increases in EPA and DHA. Color of fat was not significantly different among the control and fish oil groups. With the increase in fish oil in the diet, the hardness of fat measured with a texturometer was decreased. The refractive index and the iodine number were increased. As for differences among anatomical locations, it was noted that EPA and DHA contents of perirenal fat were higher than those of backfat and intermuscular fat. These results indicate that porcine adipose tissues rich in EPA and DHA can be produced by feeding fish oil. Key Words: Pigs, Fat, Fatty Acids, Eicosapentaenoic Acid, Docosahexaenoic Acid, Fish Oils, Sixteen three-way-cross pigs were designated control and test diets of variable fish oil concentrations. Tissue samples were obtained and analyzed for fat characteristics. There was an increase of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) in fat from pigs fed with fish oil which are well concentrated in perirenal fat. A corresponding decrease in fat hardness and presence of oleic and linoleic acid were seen. This indicates that EPA and DHA can be produced from porcine adipose tissue by feeding pigs with fish oil.

This study examined a life expectancy of high-speed recordable optical disks (DVD-R). It is based on the Eyring acceleration model and statistical analysis. The statistical distribution of life data for the optical disk assumed a lognormal distribution. Analysis of statistical techniques based on the ISO standard is proposed as a life expectancy prediction method for CD-R disks. The results demonstrated that the statistical distribution of failure time data using the PI error number criterion can accommodate a lognormal distribution. We can estimate a standardized life expectancy of a high-speed DVD-R as the minimum lifetime of 95% survival probability at 25[degrees] C/50% RH with a 95% confidence level. Index Terms--Archival data, DVD, DVD-R, Eyring acceleration model, life expectancy, optical disk, reliability.