Population Trends of a Mixed-Species Colony of Humboldt and Magellanic Penguins in Southern Chile after Establishing a Protected Area

Worldwide marine protected areas (MPAs) have been designated to protect marine resources, including top predators such as seabirds. There is no conclusive information on whether protected areas can improve population trends of seabirds when these are further exploited as tourist attractions, an activity that has increased in past decades. Humboldt Penguins (Spheniscus humboldti) and Magellanic Penguins (S. magellanicus) breed sympatrically on Puñihuil Islets, two small coastal islands off the west coast of Chiloé Island (41° S) in southern Chile that are subject to exploitation for tourism. Our goal was to compare the population size of the mixed colony of Humboldt and Magellanic Penguins before and after protection from unregulated tourism and freely roaming goats in 1997. For this purpose, two censuses were conducted in 2004 and 2008, and the numbers compared with those obtained in 1997 by other authors. The proportion of occupied, unoccupied, and collapsed/flooded burrows changed between years; there were 68% and 34% fewer collapsed burrows in 2004 and 2008, respectively, than in 1997. For the total number of burrows of both species, we counted 48% and 63% more burrows in 2004 and 2008, respectively, than in 1997. We counted 13% more burrows of Humboldt Penguins in 2008 than in 1997, and for Magellanic Penguins, we estimated a 64% increase in burrows in 2008. Presumably, this was as a result of habitat improvement attributable to the exclusion of tourists and the removal of goats from the islets. Although tourist visits to the islets are prohibited, tourism activities around the colonies are prevalent and need to be taken into account to promote appropriate management.

Social interactions and resource ownership in two private protected areas of Paraguay

This paper describes the results of field research to dissect how social interactions differ between two reserves in Paraguay having very different styles of governance. The two reserves were Mbaracayu Natural Forest Reserve (Reserva Natural del Bosque de Mbaracayti, RNBM) and San Rafael Managed Resource Reserve (Reserva de Recursos Manejados San Rafael, RRMSR). RNBM is a private reserve owned by a non-governmental organisation. while RRNISR is a publicly-managed reserve, albeit with a substantial degree of private land ownership. Both reserves are intended to protect Atlantic Forest, one of the five world biodiversity 'hotspots', and also one of the most highly threatened. Each reserve and its buffer zone comprises a set of stakeholders, including indigenous communities and farmers, and the paper explores the interactions between these and the management regime. Indeed, while the management regimes of the two reserves are different, one being highly top-down (RNBM) and the other more socially inclusive (RRMSR), the issues that they have to deal with are much the same. However, while both management regimes will readily acknowledge the need to address poverty, inequality appears to be a far more sensitive issue. Whereas this may be expected for the privately-owned RNBM it is perhaps more surprising in RRNISR even when allowing for the fact that much of the land in the latter is in private hands. It is argued that the origins of this sensitivity rest within the broader features of Paraguayan society, and the prevalence of private land ownership. Yet ironically, it is the inequality in land ownership that is perhaps the most significant threat to conservation in both reserves. Therefore, while reserve-level analyses can provide some insight into the driving forces at play in the interaction between conservation and sustainable management, larger scales may be necessary to gain a fuller appreciation of the dynamics operating at site level. Even in a society with a history of centralised control these dynamics may be surprising. (c) 2005 Elsevier Ltd. All rights reserved.

Digestion, rumen fermentation and circulating concentrations of insulin, growth hormone and IGF-1 in steers fed diets based on different proportions of maize silage and grass silage

Replacing grass silage with maize silage results in a fundamental change in the ratio of structural to non-structural carbohydrates with commensurate changes in rumen fermentation patterns and nutrient utilisation. This study investigated the effects of feeding four forage mixtures, namely grass silage (G); 67 g/100 g grass silage133 g/100 g maize silage (GGM); 67 g/100 g maize silage133/100 g grass silage (MMG); maize silage (M) to four ruminally and duodenally canulated Holstein Friesian steers. All diets were formulated to be isonitrogenous (22.4 g N/kg DM) using a concentrate mixture. Dietary dry matter (DM) and organic matter (OM) digestibility increased with ascending maize silage inclusion (P,0.1) whereas starch and neutral detergent fibre digestibility declined (P,0.05). Ratio of non-glucogenic to glucogenic precursors in the rumen fluid increased with maize silage inclusion (P,0.01) with a commensurate reduction in rumen pH (P,0.05). Mean circulating concentrations of insulin were greatest and similar in diets MMG and GGM, lower in diet M and lowest in diet G (P,0.01). There were no effects of diet on the mean circulating concentration of growth hormone (GH), or the frequency, amplitude and duration of GH pulses, or the mean circulating concentrations of IGF-1. Increasing levels of DM, OM and starch intakes with the substitution of grass silage with maize silage affected overall digestion, nutrient partitioning and subsequent circulating concentrations of insulin.

The effect of incremental replacement of wheat with soya hulls in diets for Jersey cows on lactational performance, diet digestibility and feeding behaviour

Eight Jersey cows were used in two balanced 4 x 4 Latin Squares to investigate the effects of replacement of dietary starch with non-forage fibre on productivity, diet digestibility and feeding behaviour. Total-mixed rations consisted of maize silage, grass silage and a soyabean meal-based concentrate mixture, each at 250g/kg DM, with the remaining 250g consisting of cracked wheat/soya hulls (SH) in the ratios of 250:0, 167:83; 83:167 and 0:250 g, respectively, for treatments SH0, SH83, SH167 and SH250. Starch concentrations were 302, 248, 193 and 140g/kg DM, and NDF concentrations were 316, 355, 394 and 434g/kg DM, for treatments SHO, SH83, SH167 and SH250, respectively. Total eating time increased (p < 0.05) as SH inclusion increased, but total rumination time was unaffected. Digestibility of DM, organic matter and starch declined (p < 0.01) as SH inclusion increased, whilst digestibility of NDF and ADF increased (p < 0.01). Dry-matter intake tended to decline with increasing SH, whilst bodyweight, milk yield and fat and lactose concentrations were unaffected by treatment. Milk protein concentration decreased (p < 0.01) as SH level increased. Feed conversion efficiency improved (p < 0.05) as SH inclusion rose, but it was not possible to determine whether this was due to the increased fibre levels alone, or the favourable effect on rumen fermentation of decreasing starch levels. (c) 2006 Elsevier B.V. All rights reserved.

Estimation of the stoichiometry of volatile fatty acid production in the rumen of lactating cows

The purpose of this study was to improve the prediction of the quantity and type of Volatile Fatty Acids (VFA) produced from fermented substrate in the rumen of lactating cows. A model was formulated that describes the conversion of substrate (soluble carbohydrates, starch, hemi-cellulose, cellulose, and protein) into VFA (acetate, propionate, butyrate, and other VFA). Inputs to the model were observed rates of true rumen digestion of substrates, whereas outputs were observed molar proportions of VFA in rumen fluid. A literature survey generated data of 182 diets (96 roughage and 86 concentrate diets). Coefficient values that define the conversion of a specific substrate into VFA were estimated meta-analytically by regression of the model against observed VFA molar proportions using non-linear regression techniques. Coefficient estimates significantly differed for acetate and propionate production in particular, between different types of substrate and between roughage and concentrate diets. Deviations of fitted from observed VFA molar proportions could be attributed to random error for 100%. In addition to regression against observed data, simulation studies were performed to investigate the potential of the estimation method. Fitted coefficient estimates from simulated data sets appeared accurate, as well as fitted rates of VFA production, although the model accounted for only a small fraction (maximally 45%) of the variation in VFA molar proportions. The simulation results showed that the latter result was merely a consequence of the statistical analysis chosen and should not be interpreted as an indication of inaccuracy of coefficient estimates. Deviations between fitted and observed values corresponded to those obtained in simulations. (c) 2005 Elsevier Ltd. All rights reserved.

Effect of condensed tannins from tropical legumes on the activity of fibrolytic enzymes from the rumen fungus Neocallimastyx hurleyensis

A study was conducted to assess the effect of condensed tannins on the activity of fibrolytic enzymes from the anaerobic rumen fungus, Neocallimastix hurleyensis and a recombinant ferulic acid esterase (FAE) from the aerobic fungus Aspergillus niger. Condensed tannins were extracted from the tropical legumes Desmodium ovalifolium, Flemingia macrophylla, Leucaena leticocephala, Leucaena pallida, Calliandra calothyrsus and Clitoria fairchildiana and incubated in fungal enzyme mixtures or with the recombinant FAE. In most cases, the greatest reductions in enzyme activities were observed with tannins purified from D. ovalifolium and F macrophylla and the least with tannins from L leucocephala. Thus, whereas 40 mu g ml(-1) of condensed tannins from C. calothyrsus and L. leucocephala were needed to halve the activity of N. hurleyensis carboxymethylcellulase (CMCase), just 5.5 mu g ml(-1) of the same tannins were required to inhibit 50% of xylanase activity. The beta-D-glucosidase and beta-D-Xylosidase enzymes were less sensitive to tannin inhibition and concentrations greater than 100 mu g ml(-1) were required to reduce their activity by 50%. In other assays, the inhibitory effect of condensed tannins when added to incubation mixtures containing particulate substrates (the primary cell walls of E arundinacea) or when bound to these substrate was compared. Substrate-associated tannins were more effective in preventing fibrolytic activities than tannins added directly to incubations solutions. It was concluded that condensed tannins from tropical legumes can inhibit fibrolytic enzyme activities, although the extent of the effect was dependent on the tannin, the nature of its association with the substrate and the enzyme involved. (c) 2005 Elsevier Inc. All rights reserved.

Use of fibrolytic enzymes to improve the nutritive value of ruminant diets - A biochemical and in vitro rumen degradation assessment

Two commercial enzyme products, Depol 40 (D) and Liquicell 2500 (L), were characterised from a biochemical standpoint and their potential to improve rumen degradation of forages was evaluated in vitro. Enzyme activities were determined at pH 5.5 and 39 degreesC. Analysis of the enzyme activities indicated that L contained higher xylanase and endoglucanase, but lower exoglucanase, pectinase and alpha-amylase activities than D. The Reading Pressure Technique (RPT) was used to investigate the effect of enzyme addition on the in vitro gas production (GP) and organic matter degradation (OMD) of alfalfa (Medicago sativa L.) stems and leaves. A completely randomised design with factorial arrangement of treatments was used. Both alfalfa fractions were untreated or treated with each enzyme at four levels, 20 h before incubation with rumen fluid. Each level of enzyme provided similar amounts of filter paper (D1, L1), endoglucanase (D2, L2), alpha-L-arabinofuranosidase (D3, L3) and xylanase units (D4, L4) per gram forage DM. Enzymes increased the initial OMD in both fractions, with improvements of up to 15% in leaves (D4) and 8% in stems (L2) after 12 h incubation. All enzyme treatments increased the extent of degradation (96 h incubation) in the leaf fractions, but only L2 increased final OMD in the stems. Direct hydrolysis of forage fractions during the pre-treatment period did not fully account for the magnitude of the increases in OMD, suggesting that the increase in rate of degradation was achieved through a combined effect of direct enzyme hydrolysis and synergistic action between the exogenous (applied) and endogenous (rumen) enzymes. (C) 2003 Elsevier Science B.V. All rights reserved.

In vitro evaluation of fibrolytic enzymes as additives for maize (Zea mays L.) silage - II. Effects on rate of acidification, fibre degradation during ensiling and rumen fermentation

A study was carried out to determine the influence of fibrolytic enzymes derived from mesophilic or thermophilic fungal sources, added at ensiling, on time-course fermentation characteristics and in vitro rumen degradation of maize silage. The mesophilic enzyme was a commercial product derived from Trichodenna reesei (L), whereas the thermophilic enzyme was a crude extract produced from Thermoascus aurantiacus (Ta) in this laboratory. The fungus was cultured using maize cobs as a carbon source. The resulting fermentation extract was deionised to remove sugars and characterised for its protein concentration, main and side enzymic activities, optimal pH, protein molecular mass and isoelectric point. In an additional study, both enzymes were added to maize forage (333.5 g DM/kg, 70.0, 469.8, 227.1 and 307.5 g/kg DM of CP, NDF, ADF and starch, respectively) at two levels each, normalized according to xylanase activity, and ensiled in 0.5 kg capacity laboratory minisilos. Duplicate silos were opened at 2, 4, 8, 15, and 60 days after ensiling, and analysed for chemical characteristics. Silages from 60 days were bulked and in vitro gas production (GP) and organic matter degradability (OMD) profiles evaluated using the Reading Pressure Technique (RPT), in a completely randomised design. The crude enzyme extract contained mainly xylanase and endoglucanase activities, with very low levels of exoglucanase, which probably limited hydrolysis of filter paper. The extract contained three major protein bands of between 29 and 55 kDa, with mainly acidic isoelectric points. Ensiling maize with enzymes lowered (P < 0.05) the final silage pH, with this effect being observed throughout the ensiling process. All enzyme treatments reduced (P < 0.05) ADF contents. Treatments including Ta produced more gas (P < 0.05) than the controls after 24 h incubation in vitro, whereas end point gas production at 96 h was not affected. Addition of Ta increased (P < 0.01) OMD after 12 h (410 and 416 g/kg versus 373 g/kg), whereas both L and Ta increased (P < 0.05) OMD after 24 h. Addition of enzymes from mesophilic or thermophilic sources to maize forage at ensiling increased the rate of acidification of the silages and improved in vitro degradation kinetics, suggesting an improvement in the nutritive quality. (C) 2003 Elsevier B.V All rights reserved.

Technical note: A proposed method to determine the extent of degradation of a feed in the rumen from the degradation profile obtained with the in vitro gas production technique using feces as the inoculum

A method is proposed to determine the extent of degradation in the rumen involving a two-stage mathematical modeling process. In the first stage, a statistical model shifts (or maps) the gas accumulation profile obtained using a fecal inoculum to a ruminal gas profile. Then, a kinetic model determines the extent of degradation in the rumen from the shifted profile. The kinetic model is presented as a generalized mathematical function, allowing any one of a number of alternative equation forms to be selected. This method might allow the gas production technique to become an approach for determining extent of degradation in the rumen, decreasing the need for surgically modified animals while still maintaining the link with the animal. Further research is needed before the proposed methodology can be used as a standard method across a range of feeds.

Impact on CVD risk of modifying milk fat to decrease intake of SFA and increase intake of cis-MUFA

Despite the acknowledged benefits of reducing SFA intake few countries within the EU meet recognised targets. Milk and dairy products represent the single largest source of dietary SFA in most countries, yet epidemiological evidence indicates that milk has cardioprotective properties such that simply reducing consumption of dairy foods to meet SFA targets may not be a sound public health approach. The present paper explores the options for replacing some of the SFA in milk fat with cis-MUFA through alteration of the diet of the dairy cow, and the evidence that such changes can improve the indicators for CHD and CVD in general for the consumer. In addition, the outcome of such changes on risk factors for CHD and CVD at the population level is examined in the light of a modelling exercise involving data for eleven EU member states. Given the current and projected costs of health care, the results indicate that urgent consideration should be given to such a strategy.

Impact on CVD risk of modifying milk fat to decrease intake of SFA and increase intake of cis-MUFA

Despite the acknowledged benefits of reducing SFA intake few countries within the EU meet recognised targets. Milk and dairy products represent the single largest source of dietary SFA in most countries, yet epidemiological evidence indicates that milk has cardioprotective properties such that simply reducing consumption of dairy foods to meet SFA targets may not be a sound public health approach. The present paper explores the options for replacing some of the SFA in milk fat with cis-MUFA through alteration of the diet of the dairy cow, and the evidence that such changes can improve the indicators for CHD and CVD in general for the consumer. In addition, the outcome of such changes on risk factors for CHD and CVD at the population level is examined in the light of a modelling exercise involving data for eleven EU member states. Given the current and projected costs of health care, the results indicate that urgent consideration should be given to such a strategy.

The income requirements of marine protected areas

Given the growing impact of human activities on the sea, managers are increasingly turning to marine protected areas (MPAs) to protect marine habitats and species. Many MPAs have been unsuccessful, however, and lack of income has been identified as a primary reason for failure. In this study, data from a global survey of 79 MPAs in 36 countries were analysed and attempts made to construct predictive models to determine the income requirements of any given MPA. Statistical tests were used to uncover possible patterns and relationships in the data, with two basic approaches. In the first of these, an attempt was made to build an explanatory "bottom-up" model of the cost structures that might be required to pursue various management activities. This proved difficult in practice owing to the very broad range of applicable data, spanning many orders of magnitude. In the second approach, a "top-down" regression model was constructed using logarithms of the base data, in order to address the breadth of the data ranges. This approach suggested that MPA size and visitor numbers together explained 46% of the minimum income requirements (P < 0.001), with area being the slightly more influential factor. The significance of area to income requirements was of little surprise, given its profile in the literature. However, the relationship between visitors and income requirements might go some way to explaining why northern hemisphere MPAs with apparently high incomes still claim to be under-funded. The relationship between running costs and visitor numbers has important implications not only in determining a realistic level of funding for MPAs, but also in assessing from where funding might be obtained. Since a substantial proportion of the income of many MPAs appears to be utilized for amenity purposes, a case may be made for funds to be provided from the typically better resourced government social and educational budgets as well as environmental budgets. Similarly visitor fees, already an important source of funding for some MPAs, might have a broader role to play in how MPAs are financed in the future. (C) 2007 Elsevier Ltd. All rights reserved.

Digestion, rumen fermentation and circulating concentrations of insulin, growth hormone and IGF-1 in steers given maize silages harvested at three stages of maturity

Advancing maturity of forage maize is associated with increases in the proportion of dry matter (DM) and starch and decreases in the proportions of structural carbohydrates in the ensiled crop. Three maize silages (286 (low, L), 329 (medium, M) and 379 (high, H) g DM per kg fresh weight) plus a concentrate formulated to give isonitrogenous intakes were offered to Holstein-Friesian steers fitted with a cannula in the dorsal sac of the rumen and a 'T' piece cannula in the proximal duodenum in an experiment with a cross-over design that allowed four collection periods. Nutrient flow to the duodenum was estimated using chromium-EDTA. Steers consumed approximately 0(.)6 kg DM per day less of diet L compared with the other two diets (P=0(.)026), resulting in less DM being digested (P=0(.)005) but digestibility did not differ between diets. Similar results were obtained for organic matter. There were no differences between diets in the intake or digestibility of neutral-detergent fibre. Intake, duodenal flow and faecal output of starch were greater for steers offered diets M and H compared with those given diet L (P < 0(.)05). In all diets rumen digestion contributed to over 90% of total digestion of starch, although rumen digestibility declined significantly with advancing maize maturity (P=0(.)002). Molar proportions of acetic acid were higher in diet H (P < 0(.)05) whilst proportions of propionic acid and n-butyric acid were higher in diets M and L. There were no significant differences between diets in mean rumen pH or ammonia concentrations. Mean circulating concentrations of insulin were higher (P=0(.)009) in cattle given diets L and M compared with diet H. There were no differences between diets in the mean circulating concentration of growth hormone, or the frequency, amplitude and duration of growth hormone pulses, or the mean circulating concentrations of IGF-1. Changes in forage composition that accompany advancing maize maturity affect overall silage digestion and circulating concentrations of insulin.

Effect of breed, gender, housing system and dietary crude protein content on performance of finishing beef cattle fed maize-silage-based diets

Maize silage-based diets with three dietary crude protein (CP) supplements were offered to 96 finishing cattle of contrasting breed (Holstein Friesian (HF) v. Simmental x HF (SHF)) and gender (bull v. steer) housed in two types of feeding system (group fed v. individually fed). The three protein supplements differed either in CP or protein degradability (degradable (LUDP) v. rumen undegradable (HUDP)) and provided CP concentrations of 142 (Con), 175 (LUDP) and 179 (HUDP) g/kg dry matter (DM) respectively, with ratios of degradable to undegradable of 3.0, 1.4 and 0.9:1 for diets Con, LOP and HUDP respectively. DM intakes were marginally higher (P = 0. 102) for LOP when compared with Con and HOP Rates of daily live-weight gain (DLWG) were higher (P = 0.005) in LUDP and HOP when compared with Con. HF had higher DM intakes than SHF although this did not result in any improvement in HF DLWG. Bulls had significantly better DM intakes, DLWG and feed conversion efficiency than steers. Conformation scores were better in SHF than HF (P < 0.001) and fat scores lower in bulls than steers (p < 0.001). There was a number of first order interactions established between dietary treatment, breed, gender and housing system with respect to rates of gain and carcass fat scores.