Grow-out Period Research Articles

Evaluation of a cellulose-based industrial wastewater byproduct as broiler bedding

SUMMARY The increased cost and decreased availability of pine shavings—the traditional poultry bedding material—has facilitated the need to identify alternative bedding materials for poultry growers. The objective of this study was to evaluate mixtures of pine shavings and an industrial wastewater cellulose byproduct based on broiler performance, paw quality, litter bulk density, moisture, and pH over a 6-week flock grow-out period. The experimental design consisted of 25 pens (40 ft2 or 3.7 m2 each) containing 55 Cobb broilers (0.75 ft2 or 0.07 m2/bird) for a total of 1,375 birds. Five treatments of 3-inch (8 cm) depth bedding consisting of 0 (control with 100% pine shavings), 25, 50, 75 and 100% cellulose byproduct with 5 replications were tested. Results showed that the cellulose byproduct material performed comparatively to pine shavings in terms of the broiler performance parameters of body weight gain, feed efficiency, and mortality. Paw quality was improved during the early stages of growth on the cellulose byproduct material, but the improvement was not significant by the end of the grow-out period. An evaluation of litter moisture versus paw quality scores produced a correlation coefficient of 0.73, indicating a strong cause-and-effect relationship between increasing litter moisture and decreasing paw quality. Litter characteristics of bulk density, compaction, pH, and ammonia generation were not significantly different between the cellulose byproduct material and pine shavings by the end of the 6-week study. An economic analysis of the use of the cellulose byproduct material is still needed due to the reduction in initial moisture content that was required for the cellulose byproduct material prior to use as broiler bedding.

Evaluation of protection induced by Riemerella anatipestifer-E. coli O78 bacterin in white pekin ducks

SUMMARY Riemerella anatipestifer infection accounts for the most significant economic losses due to infectious disease in commercial White Pekin ducks in the United States. An inactivated bacterin and a live attenuated vaccine are approved for use against R. anatipestifer in the United States. This study aimed to evaluate the duration of protection induced by the commercial bacterin containing formalin-inactivated strains of R. anatipestifer serotype 1, 2, 5 (RA1, RA2, RA5) combined with E. coli 078 (RA-EC). Pekin ducks were vaccinated twice at 2 and 3 wk of age with 0.5 mL of RA-EC bacterin containing approximately 108 colony forming units (CFU) of E. coli and 109 CFU of RA1, RA2 and RA5 per dose (0.5 mL). Four-, 6-, and 8-week-old vaccinated and non-vaccinated control ducks were subsequently challenged with virulent strains of either: E. coli 078, RA1, RA2 and RA5. Evaluation of the vaccine protective index, histopathology, and bacteriology indicate RA-EC bacterin provides protection against virulent stains of RA1, RA2, RA5, and E. coli O78 throughout the 8-wk commercial Pekin grow-out period.

Evaluation of Stocking Density during Second‐Year Growth of Largemouth Bass, Micropterus salmoides, Raised Indoors in a Recirculating Aquaculture System

AbstractLargemouth bass (LMB), Micropterus salmoides, are a highly desirable food fish especially among Asian populations in large cities throughout North America. The primary production method for food‐size LMB (>500 g) has been outdoor ponds that require two growing seasons (18 mo). Indoor, controlled‐environment production using recirculating aquaculture system (RAS) technologies could potentially reduce the growout period by maintaining ideal temperatures year‐round. Researchers conducted a 26‐wk study to evaluate optimal stocking densities for growout of second‐year LMB to food‐fish size in an indoor RAS. LMB fingerlings (112.0 ± 38.0 g) were randomly stocked into nine 900‐L tanks to achieve densities of 30, 60, or 120 fish/m3 with three replicate tanks per density. The RAS consisted of a 3000‐L sump, ¼ hp pump, bead filter for solids removal, mixed‐moving‐bed biofilter for nitrification, and a 400‐watt ultraviolet light for sterilization. Fish were fed a commercially available floating diet (45% protein and 16% lipid) once daily to apparent satiation. At harvest, all fish were counted, individually weighed, and measured. Total biomass densities significantly increased (P ≤ 0.05) with stocking rate achieving 6.2, 13.2, and 22.9 kg/m3 for fish stocked at 20, 60, and 120 fish/m3, respectively. The stocking densities evaluated had no significant impact (P > 0.05) on survival, average harvest weight, or feed conversion ratio which averaged 92.9 ± 5.8%, 294.5 ± 21.1 g, and 1.8 ± 0.3, respectively. After approximately 6 mo of culture, LMB did not attain target weights of >500 g. Observed competition among fish likely resulted in large size variability and overall poor growth compared to second‐year growth in ponds. Additional research is needed to better assess the suitability of LMB for culture in RAS.

Production of market-size North American strain Atlantic salmon Salmo salar in a land-based recirculation aquaculture system using freshwater

There is interest in culturing Atlantic salmon Salmo salar to market-size in land-based, closed containment systems that use recirculation aquaculture systems (RAS), as this technology often enables facilities to locate near major markets, obtain permits, exclude obligate pathogens, and/or reduce environmental impacts. Use of land-based RAS to intensively culture market-size Atlantic salmon is a relatively new frontier and little information is available. Three trials were conducted to evaluate the performance of two North American strains of Atlantic salmon raised from post-smolt to market-size (4–5kg) in a near-commercial scale (260m3), land-based RAS using only freshwater. St. John River (SJR) salmon were reared during the first trial, and Cascade salmon (CS1 and CS2) were evaluated during two subsequent trials. Salmon were received as fertilized “eyed” eggs and cultured on-site through the entire production cycle. The grow-out period began at 14–16 months post-hatch when salmon post-smolt weighed 0.34–0.75kg on average. CS1 and SJR salmon grew 386–393g/month to a mean size of 4.1–4.2kg and CS2 salmon grew 413g/month to a mean size of 4.9kg prior to first harvest. Thereafter, weekly salmon harvests commenced for the next 6–19 weeks. The grow-out period, excluding harvest, lasted 9–10 months for each trial. Average water temperature was maintained at 15–16°C. Consistently linear growth rates were achieved by each population suggesting that growth was relatively independent of fish cohort/genetic strain, fish size, and maximum biomass density, which was 35, 100, and 118kg/m3 for SJR, CS1, and CS2, respectively. Feed conversion ratios ranged from 1.07 to 1.10. Fish mortality (including culls) for SJR, CS1, and CS2 was 9.5, 6.6, and 7.5% of the original number of stocked fish, respectively. No obligate fish pathogens, kudoa, sea lice, or pervasive parasites were detected. Salmon were not vaccinated against specific pathogens; and no antibiotics, pesticides, or harsh chemotherapeutants were used. Hydrogen peroxide (50–100ppm) and salt (10 ppt) were occasionally used to treat fungus during pre-smolt production, and salt (2–3 ppt) was used to treat fungus or ameliorate stress after handling events. No salmon escaped the facility due to built-in fish exclusion barriers. Early male maturation was observed during each trial. Male salmon began to exhibit maturation traits (kype, darkened skin coloration) at a mean weight of 1.5–2kg and were removed from the grow-out system when they weighed 2–3kg. SJR, CS1, and CS2 populations exhibited 37.0, 38.5, and 17.0% maturity, respectively. Fillet yield and product quality of immature, market-size salmon were comparable to reported measurements for commercially available salmon reared in net pens. This research suggests that it is biologically and technologically feasible to culture Atlantic salmon from post-smolt to market-size in a land-based RAS of suitable commercial scale; however, early male maturation could represent a production barrier. As of 2016, all-female Atlantic salmon eggs are commercially available and could provide an expedient solution to the problem of early male maturation in RAS.

Overview of the biology of Flexopecten glaber in the North Western Adriatic Sea (Italy): A good candidate for future shellfish farming aims?

To assess the potential for rearing in smooth scallops (Flexopecten glaber) from the North Western Adriatic Sea, various biological traits were studied in both fished and reared individuals. Condition and gonadosomatic indices, gonadic cycle, biochemical components and histopathological conditions were investigated in adults from commercial fishing. Throughout two consecutive years, juvenile scallops were collected by means of artificial collectors and maintained in an experimental rearing facility. Growth, onset of sexual maturity, size/age at first maturity were investigated in reared individuals. In fished scallops, spawning and resting periods occurred mostly between July and September and from October to December, respectively. Gonadosomatic index and condition index increased from January to June and decreased from July to October; these main variations corresponded to gametogenesis and spawning, respectively. In both somatic and gonadic tissues, proteins were the major biochemical component (about 80%), with no evident seasonal variation. In somatic tissues, total carbohydrates were always higher than lipids; in gonads, lipids exceeded total carbohydrates for most of the year, peaking at maximum values when only mature or spawning animals were found. Observation and quantification of abnormal features of gonadic tissues, like oocyte atresia, haemocytic infiltration, neoplasia, and presence of parasites, suggest the overall good health conditions of scallops in the study area, no serious threat due to diseases being evident. In reared scallops, sexual maturity was attained within the first year, thus indicating F. glaber as a fairly early maturation species compared with other scallop species. The first maturity event occurred in about 330days from the immersion of the collectors, at mean shell height values ranging from 22.4 to 25.1mm, well below the minimum landing size (40mm) established by the EU for queen scallop fishery in Atlantic waters. Appreciable growth rates and a relatively short grow-out period, precociousness in maturation, high availability of wild spat, easily and inexpensively collected, absence of diseases and other mortality factors are promising elements to introduce the cultivation of F. glaber in the North Western Adriatic coastal waters. Statement of relevanceTo assess the potential for rearing in smooth scallops (F. glaber) from the North Western Adriatic Sea, various biological traits in both fished and reared individuals were studied for the first time. The overall results indicate this species as a potential candidate to diversify Italian marine bivalve aquaculture.

Effects of Dietary Nucleotide Yeast on Immune Responses and Antioxidant Enzyme Activities of Rainbow Trout Juveniles (Oncorhynchus mykiss)

This study aimed at demonstrating the effects of dietary supplementation of nucleotide yeast base protein (Nu-Pro®) (NP) on the antioxidant enzyme activities and immune response in liver and blood tissues of rainbow trout (Oncorhynchus mykiss). Fish with an average initial weight of 27.75±0.26 g were randomly assigned to four groups with three replicates. Throughout the 60 day grow-out period the control group was fed a fish meal based basal diet, and three other groups were fed diets in which 20 (NP 20), 40 (NP 40) and 60 % (NP 60) fish meal was substituted with nucleotide (Nu-Pro® (NP) yeast). There were no significant changes of superoxide dismutase (SOD) and catalase (CAT) activities in liver among the experimental groups. A significant decrease (P<0.05) in malondialdehyde (MDA) level of tissue was observed in all nucleotide supplemented groups when compared to the control group. Serum lysozyme (LYZ) and myeloperoxidase (MPO) activities and nitric oxide (NO) level of liver tissue were significantly (P<0.05) increased in fish fed with nucleotide yeast based protein diets. The results showed that the fish in all nucleotide supplemented groups showed significantly better antioxidant activity and immune responses.

Phân tích khía cạnh kỹ thuật và hiệu quả tài chính của mô hình nuôi tôm càng xanh - lúa luân canh với tôm sú ở v

This study was conducted in 2013 through the interview of 60 households applying the giant freshwater prawn - rice - tiger shrimp farming systems in Bac Lieu province. The study aimed to evaluate the effects of different factors on the efficiency of the prawn farming in order to contribute to sustainable development of faming system in the brackish water area of the Mekong Delta. The results showed that the farms were in average area of 2.2ha; ditch area of 29.1% of total farm area. Water salinity of the farming region during the cropping season were in range of 2-10ppt. Prawn seeds were stocked at average density of 1.1 inds/m2, and only 50% of the prawn farms were fed with by-products or trash fish. After 6-8 months of culture, average prawn yield of 110 kg/ha/crop and net income of 11.5 millions VND/ha/crop were obtained. Prawn farming covers only 11.8% of total production cost of the whole system including prawn, rice, and tiger shrimp but contribute up to 22.7% of total net income of the prawn-rice-tiger shrimp system. Short grow-out period, prawn seed nursing, supplementary feeding and partial harvest improved the efficiency of the farming. Water salinity in the range of 2-10 ppt did not affect significantly on prawn yields but higher salinity (5-10 ppt) improved the cost-benefit ratio. The results indicated this system could be good potential for further development.

Oral Vaccination of Fish – Antigen Preparations, Uptake, and Immune Induction

The oral route offers the most attractive approach of immunization of fish for a number of reasons: the ease of administration of antigens, it is less stressful than parenteral delivery and in principle, it is applicable to small and large sized fish; it also provides a procedure for oral boosting during grow-out periods in cages or ponds. There are, however, not many commercial vaccines available at the moment due to lack of efficacy and challenges associated with production of large quantities of antigens. These are required to stimulate an effective immune response locally and systemically, and need to be protected against degradation before they reach the sites where immune induction occurs. The hostile stomach environment is believed to be particularly important with regard to degradation of antigens in certain species. There is also a poor understanding about the requirements for proper immune induction following oral administration on one side, and the potential for induction of tolerance on the other. To what extent primary immunization via the oral route will elicit both local and systemic responses is not understood in detail. Furthermore, to what extent parenteral delivery will protect mucosal/gut surfaces and vice-versa is also not fully understood. We review the work that has been done on the subject and discuss it in light of recent advances that include mass production of antigens, including the use of plant systems. Different encapsulation techniques that have been developed in the quest to protect antigens against digestive degradation, as well as to target them for appropriate immune induction are also highlighted.

Model-predicted ammonia emission from two broiler houses with different rearing systems

Ammonia (NH3) emissions from broiler production can affect human and animal health and may cause acidification and eutrophication of the surrounding environment. This study aimed to estimate ammonia emissions from broiler litter in two systems of forced ventilation, the tunnel ventilation (TV) and the dark house (DH). The experiment was carried out on eight commercial broiler houses, and the age of the birds (day, d), pH and litter temperature were recorded. Broilers were reared on built-up wood shaving litter using an average flock density of 14 bird m–2. Temperature and relative humidity inside the broiler houses were recorded in the morning during the grow-out period. A factorial experimental design was adopted, with two types of houses, four replicates and two flocks with two replicates each. A deterministic model was used to predict ammonia emissions using the litter pH and temperature, and the day of grow-out. The highest litter temperature and pH were found at 42 d of growth in both housing systems. Mean ambient air temperature and relative humidity did not differ in either system. Mean model predicted ammonia emission was higher in the DH rearing system (5200 mg NH3 m−2h−1 at 42 d) than in the TV system (2700 mg NH3m−2 h−1 at 42 d). TV presented the lowest mean litter temperature and pH at 42 d of growth. In the last week of the broilers’ grow-out cycle, estimated ammonia emissions inside DH reached 5700 mg m−2h−1 in one of the flocks. Ammonia emissions were higher inside DH, and they did not differ between flocks. Assuming a broiler market weight in Brazil of close to 2 kg, ammonia emissions were equivalent to 12 g NH3 bird-marketed−1. Model-predicted ammonia emissions provided comprehensible estimations and might be used in abatement strategies for NH3 emission.

Viability of tallow inclusion in Atlantic salmon diet, as assessed by an on-farm grow out trial

The results of a recent increase in research interest directed at the inclusion of tallow in fish feed formulations are suggesting tallow is viable as a potential substitute for other alternative lipid sources such as poultry by-product oil. Although strong growth performance data has been shown, reservations still exist regarding reduced digestibility and the potential impacts this could have on performance over the duration of a grow-out period in low temperature conditions. Also little information is yet available on the potential effect of dietary tallow inclusion on final product quality. A large scale farm based study testing the inclusion of tallow at 40% inclusion, partially replacing poultry by-product oil, in commercial diets of Atlantic salmon over a winter grow-out period in southern Tasmania, Australia was conducted. Tallow inclusion had no impact on growth performance or nutrient digestibility. Tallow resulted in a slight improvement in fillet quality exhibiting a significant reduction in n−6 PUFA and the n6:n3 ratio, and an increased n−3LC-PUFA tissue deposition. Consumers were unable to display any preference in liking between 3 salmon products (cold smoked, hot smoked, and cooked) as a result of tallow inclusion. This study demonstrates the viability of partial inclusion of tallow in Atlantic salmon diets over a winter grow-out period. Statement of relevanceImproved knowledge of alternative dietary energy sources (oils and fats) to be used in aquafeed, (replacing the increasingly expensive, and diminishingly available, fish oil) is a key area of research towards improved environmental sustainability and economic viability of the aquaculture sector. Following a promising laboratory based, research scale, in vivo trial aimed at assessing the viability of tallow in salmon feed, a larger and longer duration farm-based trial was implemented to validate initial findings. Consumer test of final products (fresh–cooked, hot smoked and cold smoked fillets) showed no modification of sensorial attributes. Tallow is hereto shown to be a highly viable alternative oil for the salmon aquafeed industry.

The effects of adding microbial biomass to grow-out and maturation feeds on the reproductive performance of black tiger shrimp, Penaeus monodon

A 40-day reproductive performance trial was conducted to assess the effect of targeted supplementation of Penaeus monodon broodstock grow-out and maturation diets with microbial biomass (MB). Over a seven month grow-out period, shrimp were fed a typical pelleted grow-out diet with or without 10% MB. Broodstock were then transferred to a maturation facility and a subset of animals from each grow-out diet fed on a typical fresh-frozen maturation diet that included a pellet ration with or without 30% MB (5.5% of total diet fed). At nine months of age, female broodstock were unilaterally eyestalk-ablated and reproductive assessments commenced. No significant difference in ovary maturation, hepatosomatic index, spawning and egg and nauplii production parameters was found between diet treatments (p=>0.05). However, females originating from control ponds displayed a higher gonadosomatic index at first spawn, whilst the percentage of eggs that hatched was lower in females fed a MB-inclusive maturation diet (p=<0.05). These results indicate that the inclusion of MB within broodstock grow-out and maturation diets (at the rates presented in this study) did not enhance reproductive performance of domesticated broodstock.

Genetic parameters for survival during the grow-out period in the GIFT strain of Nile tilapia (Oreochromis niloticus) and correlated response to selection for harvest weight

The aims of this study were the estimation of genetic parameters for survival rate from tagging until harvest and the evaluation of the correlated response in survival rate to selection for harvest weight in the genetically improved farmed tilapia (GIFT) strain. The heritability for survival rate was low (0.038), and so was its genetic correlation with harvest weight (0.065), suggesting that selecting for the latter trait would have had no effect on survival. The calculation of the probability of survival by spawning season and line, fitting a model that included the random effects of individual animal and common environment, confirmed this prediction. There were very small and variable between line differences in the probability of survival, which generally favoured the selection line. We conclude that the focus of the GIFT programme on improving harvest weight was not detrimental to the survival of the fish during the grow-out phase.

Genetic evaluation of a selective breeding program for common carp Cyprinus carpio conducted from 2004 to 2014.

BackgroundThe study evaluated genetic progress of a breeding program for common carp undergoing four generations of selection for increased harvest body weight from 2004 to 2014. The pedigree included 17,351 individual fish which were offspring of 342 sires and 352 dams. Genetic parameters for body weight at about two years of age and survival rate during grow-out period were also estimated using the residual maximum likelihood method applied to a two-trait linear mixed model. Direct response in body weight and correlated changes in survival were measured as the differences in: i) estimated breeding values (EBVs) between the two lines; and ii) EBVs of the selection line between successive generations.ResultsDirect gain in body weight ranged from 0.20 to 0.90 genetic standard deviation units and averaged 7 % of the base population per generation (two years per generation). Correlated changes in survival were negligible, indicating that the selection program for high growth did not have any adverse effect on this trait in the present population. The heritability for body weight was moderate (0.17, s.e. 0.05), whereas the estimate for survival was low (0.05–0.17) but significantly different from zero across linear mixed and threshold generalised statistical models. Our results predict that body weight or/and other growth related traits will continue to respond to selection and that there is potential to improve survival through direct genetic means. Correlated improvement in survival to selection for increased body weight was hardly achieved, as the genetic correlation between the two traits was not different from zero.ConclusionsIt is concluded that selection for increased harvest body weight resulted in significant improvement in growth performance of the present population of common carp Cyprinus carpio.Electronic supplementary materialThe online version of this article (doi:10.1186/s12863-015-0256-2) contains supplementary material, which is available to authorized users.

Effects of 500 and 1000 FTU/kg phytase supplementation of maize-based diets with two tiers of nutrient specifications on performance of broiler chickens

Abstract Starter, grower and finisher maize-based diets (Diets A) were formulated to marginal nutrient specifications and offered to broilers from 1 to 14, 15 to 27, and 28 to 40 days post-hatch, respectively. Nutrient specifications were reduced (Diets B) and offered to broilers without and with 500 FTU/kg phytase; specifications were further reduced to create a second tier of reduced nutrient specifications (Diets C) without and with 1000 FTU/kg phytase. The study was conducted using 240 male Ross 308 chicks with each of the 5 treatments consisting of 8 replicates of 6 birds per replicate. Growth performance was monitored during each phase of the grow-out period, mineral retentions were determined in the grower phase and nutrient utilisation in the finisher phase. Apparent digestibility coefficients of nitrogen were determined in the proximal jejunum, distal jejunum, proximal ileum and distal ileum in broilers at 40 days post-hatch. In addition, N digestion rates ( K nitrogen ) were determined. Over the 40-day feeding period, declining nutrient specifications decreased weight gains in broilers offered non-supplemented diets from 2721 (Diets A) to 2627 (Diets B) and 2525 g/bird (Diets C) and increased FCR from 1.551 to 1.577 and 1.605 in the corresponding diets. The differences in weight gain (7.20%) and FCR (3.48%) between Diets A and Diets C were significant ( P P P P P P P P P P P P K nitrogen ) of 64% from 2.59 to 4.24 × 10 −2 min −1 . Phytase supplementation of diets C increased N digestibility in the distal ileum by 7.63% ( P −2 min −1 ( P

Pathogen re-colonization of in-house composted and noncomposted broiler litter

In-house litter composting has been reintroduced to the industry and shown to reduce bacteria by as much as 2 orders of magnitude. Other industries have demonstrated that pathogens can recolonize a waste-residual when microbial competition has been reduced or inhibited following composting. Poultry growers, in the process of shifting to in-house composting for pathogen control, should be aware of this potential problem. A laboratory microcosm study investigated pathogenic bacteria recolonization into composted and noncomposted broiler litter over a simulated broiler grow-out cycle. Objectives were to: 1) determine colonization potential for zoonotic and poultry bacterial pathogens, 2) identify beneficial bacteria which reduce pathogen recolonization, and 3) identify the effects of ammonia on pathogen recolonization. Composted broiler litter allowedListeria andCampylobacter to colonize within the first 2 wk of the grow-out period while noncomposted litter resisted colonization. Colonization was nearly identical by the end of the grow-out period, and showed that bacterial pathogens had essentially been overtaken by commensal or normal bacteria. 16S rRNA libraries demonstrated reductions in Proteobacteria associated with composted litter (48 vs. 16%), which may indicate that this phylum occupies a niche which zoonotic pathogens prefer to occupy. Ammonia generation neither inhibited nor promoted bacterial colonization, as levels were high for both litter treatments. This study neither suggests nor condemns the continued use of this cost-effective, litter-treatment process; findings suggest that while the beneficial microbial population was initially reduced, it quickly recovered and pathogen colonization was neither enhanced nor inhibited because of this. This study demonstrates that the recently adopted in-house composting process may continue to be used, provided poultry health gains continue to be seen.

Expression of the myostatin gene in the adductor muscle of the Pacific lion-paw scallop Nodipecten subnodosus in association with growth and environmental conditions.

The cDNA sequence of the myostatin gene in the Pacific lion-paw Nodipecten subnodosus (Ns-mstn) was characterized, and the temporal expression during grow-out was analyzed for the first time in a scallop. Ns-mstn encodes a 459-amino-acid protein in which two propeptide proteolytic sites were identified, the previously recognized (RSKR) and a second one at position 266-269 aa (RRKR). The alternative furin cleavage site could be related with post-translational processing, or it could be a tissue-specific mechanism for signaling activity. The Ns-mstn transcript was located by in situ hybridization in sarcomeres and around the nucleus of muscle fibers. The temporal expression analysis by qPCR in the adductor muscle showed that Ns-mstn expression was significantly different (P < 0.05) between months during the grow-out period, increasing largely during the summer months when both biomass and muscle weight did not increase or even decreased; muscle fiber size and number were found to decrease significantly. Exogenous and endogenous factors such as high temperature and low food availability, as well as gametogenesis and reproduction, can be associated with the growth pattern and Ns-mstn expression changes. Our results indicate that MSTN is involved in adductor muscle growth regulation in N. subnodosus as it occurs in vertebrate skeletal muscle although Ns-mstn expression in non-muscle organs/tissues suggests additional functions.

PRODUCTION ECONOMICS OF CATTLE FATTENING IN NEW VALLEY GOVERNORATE

Fattening cattle projects represents an important role in the agricultural economy, as these activities contribute by about 36% of the total value of agricultural production, amounting to about 159.09 billion Egyptian pounds. The average value of medium term livestock loans presented by the Bank of Development and Agricultural Credit during the period (2000-2012) was about (3 – 7.8) million Egyptian pounds, respectively. The search was a problem in that in spite of the availability of many economic possibilities and productive conditions that support and strength the chances of success of fattening cattle projects New Valley Governorate it was shown that Governorate has a Weak Contribution in Live stock Production. The objectives of these research is studying productive and economic efficiency for fattening cattle through some economic and technical relations to identify the most important factors that affect the economic efficiency in production. These objectives has been realizing depending on two methods of data collection, the first depends on secondary data, and the second depends on the primary data through using questionnaires to collect data a sample of cattle breeders at (Mott, acement, balat villages) at Dakhla district. The study used qualitative and quantitative statistical methods to achieve the objectives of the study, such as the equations of time trend in it's linear and quadratic, cubic, forms and use multi-phased regression method. The most important results that research can be summarized as follows: Decrease in short-term current value animal loans by annual rate of about 0.37 million pounds. Decrease in short-term real terms animal loans by an annual rate of about 0.23 million pounds. Decrease in medium-term current value animal loans by an annual rate of about 0.95 million pounds. Decrease in medium-term real terms animal loans by an annual rate of about 0.34 million pounds. Increase numbers of cows by an annual rate of about 11.1 thousand units. Decrease the numbers of buffalo by an annual rate of about 0.03 thousand units. Increase the numbers of sheep by an annual rate of about 4.9 thousand units. It shows also the in significance of increasing the numbers of goats. Declining numbers of camels by an annual rate of about 0.28 thousand units. Results of calculating the production function of calves for total sample of the study shows a statistical significant positive relationship between gross flesh and the quantity of each of green fodder, concentrated and dry, employment and the weight of the animal at the beginning of the grow-out period, as an increase in the amount of those variables respectively by 1% leads to an increase in the amount of output by about 0.055%, 0.692%, 0.161%, 0.008%, 0.037%. Results showing also that the marginal product of feed for total sample was about 7.79, 75.68, 17.39 kg live weight of feed green, concentrated, dry, respectively, means that the marginal product of concentrated feed greater than the marginal product of other feed refers to preferential use of concentrated feed production red meat. The optimum weight and maximizing profit weight for the total sample was about 445, 495 kg. In light of results, the research recommends the following: Expansion in the establishment of livestock production projects, and work to support and encourage breeders by increase loans, and to facilitate the procedures for obtaining it. 2. Increasing the concentrated feed production in deferent areas to be compatible with the geographical distribution of animal wealth.

Farm-raised tiger shrimp, Penaeus monodon, fed commercial feeds with added organic acids showed enhanced nutrient utilization, immune response and resistance to Vibrio harveyi challenge

The threat of disease in the aquaculture industry, coupled with greater restrictions or ban on antibiotic use, has increased interest in evaluating antibiotic alternatives. A promising alternative is organic acids, which have been used for decades in the livestock feed industry as an antimicrobial and growth promoter. However, very limited information exists on their applications to the shrimp aquaculture industry. The aim of the current study was to examine the potential beneficial effects of a novel microencapsulated organic acid blend (OAB) to the production of tiger shrimp, Penaeus monodon, in earthen ponds at a commercial farm when fed commercial feeds without (Diet A) or with (Diet B) organic acid supplementation at 2% OAB throughout the grow-out period. Farm-raised shrimp were randomly sampled and transferred to the laboratory to examine any effects on nutrient utilization, resistance of shrimp to Vibrio harveyi and associated hepatopancreatic histopathology and phenoloxidase (PO) activity. Results showed that after 22weeks of culture in ponds, shrimp growth was similar between treatments. Lower nitrite-N and nitrate-N concentrations in the pond water indicated potential improved protein utilization from shrimp fed Diet B. This was supported by data from the digestibility trial, demonstrating crude protein, but also dry matter, ash and phosphorous utilization was significantly enhanced (P<0.05). Total viable bacteria and presumptive Vibrio spp. counts were lower at the end of the grow-out period in the pond water of shrimp fed Diet B. Shrimp fed Diet B showed significantly higher survival to V. harveyi challenge, likely due to enhanced PO activity and less hepatopancreatic damage. Total viable bacterial and Vibrio counts in the hepatopancreas of shrimp fed Diet B were significantly lower compared to Diet A. This study provides the first reported data on the use of dietary organic acids in a commercial shrimp farm setting. The enhancement to nutrient utilization may reduce feeding costs and improve water quality while the higher resistance of shrimp to pathogenic bacteria such as Vibrio spp. may provide shrimp farmers with an effective method to mitigate disease outbreaks in the global shrimp aquaculture industry.

Recent Changes in the Bioeconomic of Finfish Mariculture in Vietnam

Finfish mariculture farmers in Vietnam are making careful practice change decisions in reaction to a number of economic drivers. These economic drivers are centred on trends of increasing input costs and decreasing output prices. In general, mariculture farmers are adapting to the cost-price squeeze in a number of ways, including increasing stocking densities and area, and by adopting risk-reducing strategies (decreasing grow-out periods and using a larger number of smaller ponds to spread mortality risk). However, there is still a shortage of good quality low-cost fingerlings which is constraining farmers’ ability to adapt to the cost-price squeeze. The dominant input cost source is feed. Most farmers are still reliant on trash-fish feeds. With low and decreasing feed conversion ratios for trash-fish, there is decreasing incentive for these farmers to change to pelleted diets. Southern Asian seabass farmers have made the practice change to pellets, but feed conversion ratios are high preventing significant economic gains from making the change. This research highlights two key areas where policy, research and extension initiatives can have a significant impact on the long-term economic and environmental viability of mariculture operations in Vietnam while protecting fish stocks: firstly, ensuring the widespread availability of low-cost hatchery-produced fingerlings, and secondly, encouraging practice change from trash-fish diets to the well-managed use of manufactured pelleted diets.

Effect of TEX-OE® treatment on the development of heat shock proteins in commercial broiler chicks and the impact on performance indicators in the grow-out period

1. Heat shock proteins (HSPs) are highly conserved proteins, shown to protect organisms against physical and physiological stress.2. TEX-OE® is a patented total extract of the fruit of Opuntia ficus indica, which has been demonstrated to accelerate the development of HSPs in several animal species.3. One-day-old commercial broiler chicks were treated with TEX-OE®; HSP was measured by enzyme-linked immunosorbent assay (ELISA), and a large commercial field trial investigated key performance indicators (KPIs) in treated versus untreated controls chicks.4. TEX-OE® significantly increased HSP concentrations in treated chicks versus controls. Final cumulative mortality, liveweight and percentage factory-rejects were better than in controls.5. The accelerated HSP response may enable chicks to cope with early stressors, which is reflected in improved KPIs.