Averting biodiversity collapse in tropical forest protected areas

The rapid disruption of tropical forests probably imperils global biodiversity more than any other contemporary phenomenon¹⁻³. With deforestation advancing quickly, protected areas are increasingly becoming final refuges for threatened species and natural ecosystem processes. However, many protected areas in the tropics are themselves vulnerable to human encroachment and other environmental stresses⁴⁻⁹. As pressures mount, it is vital to know whether existing reserves can sustain their biodiversity. A critical constraint in addressing this question has been that data describing a broad array of biodiversity groups have been unavailable for a sufficiently large and representative sample of reserves. Here we present a uniquely comprehensive data set on changes over the past 20 to 30 years in 31 functional groups of species and 21 potential drivers of environmental change, for 60 protected areas stratified across the world’s major tropical regions. Our analysis reveals great variation in reserve ‘health’: about half of all reserves have been effective or performed passably, but the rest are experiencing an erosion of biodiversity that is often alarmingly widespread taxonomically and functionally. Habitat disruption, hunting and forest-product exploitation were the strongest predictors of declining reserve health. Crucially, environmental changes immediately outside reserves seemed nearly as important as those inside in determining their ecological fate, with changes inside reserves strongly mirroring those occurring around them. These findings suggest that tropical protected areas are often intimately linked ecologically to their surrounding habitats, and that a failure to stem broad-scale loss and degradation of such habitats could sharply increase the likelihood of serious biodiversity declines.Keywords: Ecology, Environmental scienc

Improving meat colour and oxidative stability by antioxidant supplementation of light weight lamb diets

Meat quality, as defined by its colour stability is the main sensory attribute of lamb meat that drives consumer preference and purchase decision. The ‘bright red’ colour in meat, perceived by consumers as an indicator of freshness and superior product quality, can be further enhanced by highly oxidizing packaging methods. Overtime, these packaging methods also accelerate the deterioration of colour, flavour and texture. To delay that, meat processors and retailers have adopted the use of antioxidants into animal diets. Based on the work described in this thesis, under similar experimental conditions, it was found that vitamin E is more effective than plant extracts at maintaining the colour stability of lamb meat.</p

Effect of partial exchange of lactose with fat in milk replacer on performance and blood metabolites of Holstein calves

The objective of this study was to determine the effect of dietary energy source (fat vs. carbohydrate) in calf milk replacer (MR) on growth performance parameters and feed intake in rearing calves. In a randomized complete block design, 68 Holstein calves [40 females and 28 males; (mean ± SD) body weight (BW): 43.7 ± 1.43 kg] were assigned to 17 blocks of 4 calves based on birth date and parity of the dam. Within each block, calves were randomly assigned to 1 of 2 treatments: a high-lactose MR (HL; 17% fat; 44% lactose; n = 34), or a high-fat MR (HF; 23% fat; 37% lactose; n = 34). Lactose was exchanged for fat on a weight per weight basis, resulting in a 6% difference in metabolizable energy density per kilogram of MR. The feeding plan started with 6 L/d for 7 d, then 8 L/d for 35 d, 6 L/d for 7 d, and finally, 4 L/d for 7 d. Milk replacer allowances were offered in 2 meals per day at 140 g/L. Measurements included daily MR, starter and straw intakes, weekly BW, and blood metabolites, including nonesterified fatty acids (NEFA) and glucose, on wk 4, 6, 8, and 10. Increasing fat at the expense of lactose did not affect MR intake or solid feed intake during the preweaning and weaning periods. However, HF calves tended to consume more solid feed than HL calves during the postweaning period (2.63 ± 0.08 vs. 2.52 ± 0.08 kg/d). Additionally, average daily gain (HF = 0.78 ± 0.02, HL = 0.77 ± 0.02 kg/d) and final BW (HF = 98.8 ± 1.53, HL = 97.7 ± 1.57 kg) were not affected by MR composition. Nevertheless, NEFA concentration was higher in HF calves than in HL calves (0.21 ± 0.01 vs. 0.17 ± 0.01 mmol/L), and glucose concentration was higher in HF calves (6.52 ± 0.23 vs. 5.86 ± 0.23 mmol/L). Under the conditions of this study, HF calves consumed similar amounts of solid feed and grew comparably to the HL calves; however, the isonitrogenous replacement of lactose by fat had evident metabolic effects, such as increased blood NEFA and glucose concentrations

Dietary vitamin E dosage and source affects meat quality parameters in light weight lambs

BACKGROUND: Supra-nutritional vitamin E supplementation is a commonly used approach to delay lipid oxidation and colour deterioration in lamb and beef meat marketed under modified atmosphere packaging. However, these applications lack a precise calibration of dose for the desired effect and, in addition, limited information is available regarding the use of natural vitamin E for this purpose. RESULTS: Three hundred and sixty Rasa Aragonesa lambs were fed diets supplemented with all-rac-α-tocopheryl acetate (250, 500, 1000 and 2000 mg kg–1 compound feed), RRR-α-tocopheryl acetate (125, 250, 500 and 1000 mg kg–1 compound feed) and a basal diet without vitamin E supplementation for 14 days before slaughter at 25.8 ± 1.67 kg body weight. Vitamin E supplementation had no effect (P > 0.05) on average daily weight gain, feed intake and feed efficiency. Display time had larger effects on lipid oxidation, colour stability, myoglobin forms and meat discolouration parameters compared to vitamin E supplementation. However, vitamin E source and dosage significantly extended meat shelf-life as indicated by lipid oxidation, redness, hue angle, metmyoglobin formation, deoxymyoglobin formation, A580–630 and ISO2. CONCLUSION: The quantification of these effects demonstrated that the biological activity value of 1.36 used to distinguish both vitamin E sources is not appropriate for meat quality enhancing properties

Fermi-ulam accelerator model under scaling analysis.

The chaotic low energy region of the Fermi-Ulam simplified accelerator model is characterised by use of scaling analysis. It is shown that the average velocity and the roughness (variance of the average velocity) obey scaling functions with the same characteristic exponents. The formalism is widely applicable, including to billiards and to other chaotic systems.Comment: 4 pages, 4 figures. A slightly modified version to appears in Physical Review Letter

Dietary supplementation of 11 different plant extracts on the antioxidant capacity of blood and selected tissues in lightweight lambs

BACKGROUND: Due to the growing public concern regarding the addition of chemical antioxidants to foods, focus has shifted towards natural alternatives. Because of their antioxidant potential, culinary herbs and spices have long been used to extend the shelf-life of foods. However, a better understanding of the fate of these products following intake is required to assess their use in lamb diets. RESULTS: Two hundred and eighty-eight Rasa Aragonesa male lambs (70 days old) were supplemented (5.0 g kg −1 compound feed) with bay, marjoram, oregano, rosemary, thyme, turmeric, cumin, caraway, dill, cinnamon and nutmeg extracts for 14 days before slaughter. Dietary supplementation with plant extracts had no effect on intake, growth performance or antioxidant activity in blood (TEAC values). In muscle, nutmeg supplementation increased (P • values) decreased (P < 0.05) the radical-scavenging capacity of the tissue. In kidney, a lower (P < 0.05) radical-scavenging capacity (TEAC values) was found in lambs supplemented with oregano, cumin and caraway, whereas, turmeric, cumin, caraway, cinnamon and nutmeg increased (P < 0.05) the antioxidant capacity (ORAC values) in kidney. CONCLUSION: Supplementation of lamb diets with plant extracts affected radical-scavenging activity in muscle, liver and kidney. However, due to the divergent results of the different assays for the same tissue, it is not advisable to discriminate plant extracts using this approach.</p

Fat composition of milk replacer influences postprandial and oxidative metabolisms in dairy calves fed twice daily

Milk replacers (MR) for calves contain alternative fat sources as substitute for milk fat. This substitution leads to differences in fat properties, such as the fatty acid profile and the triglyceride structure. This study evaluated how fat composition in MR affects gastrointestinal health, blood redox parameters, and postprandial metabolism in calves fed twice daily.</p

Preweaning nutrient supply alters mammary gland transcriptome expression relating to morphology, lipid accumulation, DNA synthesis and RNA expression in Holstein heifer calves

The objective of this study was to analyze the mammary gland transcriptome to determine how preweaning nutrient supply alters the molecular mechanisms that regulate preweaning mammary development. Holstein heifers were fed via milk replacer either an elevated level of nutrient intake (ELE; on average, 5.9 ± 0.2 Mcal ME in 8.4 L of milk replacer (MR)/d, n = 6) or a restricted amount of nutrients (RES; 2.8 ± 0.2 Mcal ME in 4L MR/day, n = 5) for 54 d postnatal, at which point they were slaughtered and samples of mammary parenchyma tissue were obtained. Parenchymal mRNA was analyzed and the fold changes (FC) of 18,111 genes (ELE relative to RES) were uploaded to Ingenuity Pathway Analysis (IPA) software for transcriptomic analysis. Using a threshold of P 2) and 7 were inhibited (Z < -2). In summary, feeding ELE preweaning altered the mammary transcriptome of Holstein heifers affecting cell functions involved in the morphological and physiological development of the mammary glan

Preweaning nutrient supply alters mammary gland transcriptome expression relating to morphology, lipid accumulation, DNA synthesis and RNA expression in Holstein heifer calves

The objective of this study was to analyze the mammary gland transcriptome to determine how preweaning nutrient supply alters the molecular mechanisms that regulate preweaning mammary development. Holstein heifers were fed via milk replacer either an elevated level of nutrient intake (ELE; on average, 5.9 ± 0.2 Mcal ME in 8.4 L of milk replacer (MR)/d, n = 6) or a restricted amount of nutrients (RES; 2.8 ± 0.2 Mcal ME in 4L MR/day, n = 5) for 54 d postnatal, at which point they were slaughtered and samples of mammary parenchyma tissue were obtained. Parenchymal mRNA was analyzed and the fold changes (FC) of 18,111 genes (ELE relative to RES) were uploaded to Ingenuity Pathway Analysis (IPA) software for transcriptomic analysis. Using a threshold of P 2) and 7 were inhibited (Z < -2). In summary, feeding ELE preweaning altered the mammary transcriptome of Holstein heifers affecting cell functions involved in the morphological and physiological development of the mammary glan