Immune Responses to Vibrio anguillarum in Yellowtail Kingfish,Seriola lalandi,Fed Selenium Supplementation

Effects of dietary selenium (Se) on immune competence of yellowtail kingfish, Seriola lalandi, were investigated. The fish were fed one of the three experimental diets including a control diet without Se supplementation and two diets supplemented with Se from Se‐yeast (Selplex) at 2 and 4 mg/kg. After feeding for 6 wk, the fish were challenged by injecting Vibrio anguillarum and observed for 2 wk. Dietary Se had no effect on feed intake, feed conversion ratio, and survival over the course of 6‐wk feeding; however, it significantly increased weight gain and Se content in muscle. Following the bacterial infection, the immune‐stimulating effects of Se were observed in antibody, lysozyme, and bactericidal responses, and there was a corresponding increase in survival and hematocrit by Se. Under infectious condition, antioxidant capacity of fish as measured in terms of resistance of red blood cells to peroxidation and glutathione peroxidase activity also increased by supplementation of Se. Liver necrosis and kidney melano‐macrophages were only seen in surviving fish fed the control diet after the challenge. Furthermore, there was evidence of myopathy in fish fed the diet without Se supplementation. This study suggests that Se, supplemented at 2 or 4 mg/kg, can improve growth and health of yellowtail kingfish.     

Effect of conservation agriculture on soil organic and inorganic carbon sequestration and lability: A study from a rice–wheat cropping system on a calcareous soil of the eastern Indo-Gangetic Plains

Increasing soil carbon (C) in arable soils is an important strategy to achieve sustainable yields and mitigate climate change. We investigated changes in soil organic and inorganic carbon (SOC and SIC) under conservation agriculture (CA) in a calcareous soil of the eastern Indo-Gangetic Plains of India. The treatments were as follows: conventional-till rice and wheat (CT-CT), CT rice and zero-till wheat (CT-ZT), ZT direct seeded rice (DSR) and CT wheat (ZT-CT), ZTDSR and ZT wheat without crop residue retention (ZT-ZT), ZT-ZT with residue (ZT-ZT+R), and DSR and wheat both on permanent beds with residue (PB-PB+R). The ZT-ZT+R had the highest total SOC in both 0–15 and 15–30 cm soil layers (20% and 40% higher (p < .05) than CT-CT, respectively), whereas total SIC decreased by 11% and 15% in the respective layers under ZT-ZT+R compared with CT-CT. Non-labile SOC was the largest pool, followed by very labile, labile and less labile SOC. The benefits of ZT and residue retention were greatest for very labile SOC, which showed a significant (p < .05) increase (~50%) under ZT-ZT+R compared with CT-CT. The ZT-ZT+R sequestered ~2 Mg ha⁻¹ total SOC in the 0–15 cm soil layer in 6 years, where CT registered significant losses. Thus, the adoption of CA should be recommended in calcareous soils, for C sequestration, and also as a reclamation technique.     

Frequency and fertility restoration efficiency of Rf3 and Rf4 genes in Indian rice

Identification of new parental lines is crucial for developing ecology‐specific hybrids with ideal agronomic performance. We screened a total of 570 different ecology‐specific Indian rice varieties for the presence of fertility restorer genes, Rf3 and Rf4 using tightly linked markers DRRM Rf3‐10 and RM6100, respectively. Among these varieties, 13% carried Rf3Rf3/Rf4Rf4, 31% carried rf3rf3/rf4rf4, 6% carried Rf3Rf3/rf4rf4 and remaining 50% carried Rf4Rf4/rf3rf3 allelic combinations. A mini set of 40 varieties with variable allelic combinations of fertility restorer genes were testcrossed with WA and Kalinga‐based CMS lines. All the 80 F₁s were evaluated for spikelet fertility and fertility restoration ability. Rf3Rf3/rf4rf4 genotypes mostly behaved as partial maintainers or partial restorers. In contrast, rf3rf3/Rf4Rf4 genotypes were partial or effective restorers. However, double dominant genotypes showed better fertility restoration than the genotypes containing Rf3 or Rf4 individually. Some of the genotypes showed unexpected restoration pattern implying occurrence of other fertility restorer(s) apart from Rf3 and Rf4. The perfect restorers and maintainers identified in this study can be directly used in hybrid rice breeding.     

Prevalence of Salmonella antibodies among goats slaughtered for chevon in Bareilly (Northern India)

We screened serum samples of 1024 goats slaughtered for chevon in Bareilly in Northern India for Salmonella antibodies with indirect ELISA, MAT-H (microagglutination test using flagellar antigens e, n, x and 1, 5) and MAT-O (microagglutination test using somatic antigens 4, 12 and 3, 10, 15). Salmonella antibodies were detected in 48, 8 and 40%, goats using Salmonella-cytotoxi-I ELISA, MAT 'H' and MAT 'O', respectively. After adjusting for test accuracy, the seroprevalence were highest for Salmonella-cytotoxi-I ELISA (46%) followed by agglutinins against 'O' 3, 10, 15 (15%) and negligible for other agglutinins. With all 5 tests, prevalence of Salmonella antibodies was significantly higher in females than in males. No significant difference was evident in prevalence of Salmonella antibodies to different antigens in different age groups of male goats except for e, n, x agglutinins that were significantly more prevalent in young adult (<6-18 months) males than in adult (>18 months of age) or young (< or =6 months of age) goats. On the other hand, in females, prevalence of Salmonella-cytotoxin-I antibodies and e, n, x agglutinins differed significantly among three age groups, being the most prevalent in adult goats. As expected, the results of different tests had little or no correlation because the different tests targeted antibodies to different antigens.     

Modelling interactions amongst people and forest resources at the landscape scale

FLORES, the Forest Land Oriented Resource Envisioning System, is a framework to facilitate quantitative modelling of ecological, economic and social issues at the landscape scale. This issue ofSmall-scale Forest Economics, Management and Policy describes the evolution of FLORES from a concept to a series of models calibrated for diverse locations, and documents the lessons learned. The idea to construct and use landscape-scale models of the forest frontier, based on simulating household decisions and land use at a spatial scale close to the field level, arose from a desire to add rigour to land-use policy research at CIFOR, the Center for International Forestry Research (Vanclay 1995). This simulation modelling approach to addressing interdisciplinary issues, where people are strongly interacting with forest resources, became known as FLORES, the Forest Land Oriented Resource Envisioning System (Vanclay 1998). Muetzelfeldtet al. (1998) constructed a simple prototype of a FLORES model to illustrate the concept and demonstrate the ability of a system-dynamics modelling environment to animate such a model (Muetzelfeldt and Taylor 1997, 2001, Muetzelfeldt and Massheder 2003). In 1999, FLORES became a reality, when 50 scientists from diverse disciplines met in Bukittinggi, Indonesia to construct the first FLORES model styled on this prototype (CIFOR 1999, Vanclayet al. 2003). The research reported in this special issue was made possible by generous financial support from the Department for International Development (UK), the European Community, the Asian Development Bank (under RETA 5812) and the Center for International Forestry Research. The views expressed herein are those of the authors alone. We would like to thank the following people who have assisted in the production of this special issue by acting as anonymous referees for these and other papers: Andy Warner, Brendan Moran, Bruno Verbist, Chris Dake, Chris Legg, Doug Sheil, Euan Mason, Francois Bousquet, Frank Vanclay, Geoff Slaughter, James Gambiza, John Herbohn, John Poulsen, Jungho Suh, Mike Spilsbury, Paul Phillips, Paul van Gardingen, Phil Norman, Philip Nyhus, Roger Wheate, Ross Sigley, Steve Harrison and Tom Evans. Thanks also to the editorial staff, especially Steve Harrison, John Herbohn and Jungho Suh, for making this special issue possible.     

Influence of high dose of phytase and an emulsifier on performance,apparent metabolisable energy and nitrogen retention in broilers fed on diets containing soy oil or tallow

1. The effects of high dose of microbial phytase and an emulsifier on the performance, apparent metabolisable energy (AME) and nitrogen (N) retention in broilers fed on diets containing different fat sources were examined in a 5-week trial. Two fat sources (soy oil and tallow), two inclusion levels of E. coli phytase (500 or 1000 phytase units (FTU)/kg diet) and two inclusion levels of lysolecithin emulsifier (0 or 3.5 g/kg of diet) were evaluated in a 2 × 2 × 2 factorial arrangement of treatments.

2. Throughout the 5-week trial, soy oil supplementation improved weight gain and feed per gain compared with tallow, but had no effect on feed intake.

3. The high dose of phytase increased the weight gain and feed intake and lowered the feed per gain during d 1–21, but had no effect on performance parameters over the whole trial period.

4. An effect of emulsifier was observed for feed intake during d 1–21 and over the whole trial period. Addition of emulsifier increased feed intake compared with diets without emulsifier.

5. During weeks 1, 2, 3 and 5, birds fed on soy oil–based diets had higher nitrogen-corrected AME (AME_N) compared with those fed on tallow-based diets. During weeks 2, 3 and 5, the effect of phytase was significant for AME_N, with the high dose increasing the AME_N. During week 2, AME_N was increased with emulsifier addition.

6. During weeks 1, 2, 3 and 5, birds fed on soy oil–based diets had higher fat retention compared with those fed on tallow-based diets. The high dose of phytase improved the retention of fat during week 5 and the addition of emulsifier resulted in higher fat retention during week 1.

7. During weeks 2, 3 and 5, an interaction between fat source × phytase × emulsifier was observed for N retention. In soy oil–based diets, emulsifier plus 1000 FTU/kg phytase increased N retention compared with other groups, while in tallow-based diets, emulsifier addition increased N retention in diets with 500 FTU/kg, but not in 1000 FTU/kg diet.

8. Overall, the present data suggest that the dietary fat source influenced performance, AME_N and fat retention in broiler chickens. There is opportunity to improve bird performance during d 1–21, AME_N and fat retention with higher doses of microbial phytase. Addition of the emulsifier increased the AME_N during week 2 and tract retention of fat during week 1, but this effect was not translated into improvements in performance.

     

Comparison of effectiveness of introduced barn owls,Tyto javanica javanica,and rodenticide treatments on rat control in oil palm plantations

Journal of Pest Science - In Peninsular Malaysia, barn owls (Tyto javanica javanica) have been utilized as biological control of rats since the 1960s. In this study, the impact of introduced barn...     

Effect of dietary protein and lipid source on the growth, survival, condition indices, and body composition of marron, Cherax tenuimanus (Smith)

A trial was conducted in 12 purpose-built, commercial, drainable, earthen ponds to evaluate the effect of fish and plant protein and lipid source on the growth, condition indices, and body composition of marron (Cherax tenuimanus). Juvenile marron (1.3±0.28 S.E. g) at the stocking densities of three per square meter were fed for a period of 1 year with four different formulated isoenergetic practical diets (D₁, D₂, D₃, and D₄). Three of the test diets (D₁, D₂, and D₃) were isonitrogenous whereas the fourth test diet (D₄) was protein-free. Protein and lipid sources in D₁ were from Lupin (Lupinus albus) whereas protein and lipid sources in D₂ and D₃ were from fish meal. Fish oil (3.5%) was added to D₁, D₃, and D₄ whereas sunflower oil was added to D₂ and D₄ in order to make them isoenergetic. The four test diets were randomly allocated to three replicate ponds.

The lack of protein in D₄ did not significantly influence (P>0.05) the mean final weight and specific growth rate of marron. Survival was low in all ponds (13.82–34.66%) but feeding with D₄ resulted in a significantly (P<0.05) higher survival than marron fed with D₁ and D₂. Feeding a diet containing a combination of fish protein and fish oil (D₃) resulted in significantly higher (P<0.05) wet tail muscles-to-body weight ratio than was observed with other diets. Tail muscles protein level of all marron was significantly lower (P<0.05) at the end of the trial than at the beginning. EPA and DHA in hepatopancreas and tail muscles of marron were affected by the four test diets. The inclusion of plant protein in formulated diets had a negative impact on the pond environment due to significantly higher unionised ammonia levels that resulted in lower survival. Juvenile marron fed with a plant protein diet had significantly lower protein levels in their hepatopancreas compared to those fed with diets containing animal protein. Feeding marron with lupin protein source (D₁) and plant oil (D₂) for 1 year did not alter the lipid content of their hepatopancreas. Four test diets had no influence on the fat content of marron hepatopancreas; however, these test diets significantly reduced the protein content of the tail muscles of marron.

Environmental variables, particularly temperature, nitrogen metabolites, and the natural productivity of the ecosystem, greatly influenced the nutritional requirements of the juvenile marron under culture.     

Secretion of Homoarginine into the Gut of Chickens

Angkanaporn, K., Ravindran, V., Mollah, Y. and Bryden, W.L., 1997. Secretion of homoarginine into the gut of chickens. Veterinary Research Communications, 21(3), 161-167A technique, based on the homoarginine present in guanidinated proteins, has been used to distinguish between endogenous secretions and exogenous dietary amino acids in the ileal digesta of monogastric animals. This technique assumes that the ingested homoarginine is not recycled into the small intestine after absorption, but this assumption is yet to be experimentally validated in chickens. The secretion of homoarginine into the gut of broilers that were intravenously infused with 20 and 40 mmol/L homoarginine solutions was assessed. The plasma concentrations of homoarginine increased with increasing concentrations of homoarginine infused. However, only negligible levels of homoarginine (7.0 to 45.2 µg/g dry matter) were found in the digesta. Less than 0.01% of the intravenously infused homoarginine was recovered in the intestinal digesta, indicating that the secretion of homoarginine into the gut of chickens was insignificant.