Diet A1 Research Articles

INCORPORATION OF LOCAL PLANT RAW MATERIALS IN THE FEEDING OF JUVENILE NILE TILAPIA (OREOCHROMIS NILOTICUS, LINNE, 1758) IN SENEGAL, WEST AFRICA

A research for eight weekswas conducted to evaluate the effect of substituting fish meal with local agricultural products in the diet of Nile Tilapia (Oreochromis niloticus).Three treatment dietaries were prepared. The dietary composition of the tested diets is as follows: A1/plant based-diet (Groundnut cake, sesame cake, millet bran, maize meal and 0% fish meal) A2/fishmeal partial replacement diet (Groundnut cake, sesame cake, millet bran, maize meal, and 10% fish meal) and A3/fishmeal based-diet (Groundnut cake, sesame cake, millet bran, maize meal, and 25% fish meal). All the diets were isoprotein and isolipidic diets. The initial average weight of the fish was 3.45±0.5g. The fishes were fed twice a day in triplicate for eight weeks. After the experiment, the final average weights were 4.97±0.5g, 5.43±0.5g, and 5.86±0.5g for A1, A2, and A3, respectively. There were significant differences (p < 0.05) among the three diets. The Feed Conversion Ratio (FCR) of juveniles fed on the A3 diet (1.77) was significantly better (lower) compared to A1 and A2 (3.41 and 2.59, respectively). The FCR of the fish fed diets A1 and A2 were not significantly different. The Specific Growth Rate (SGR), Individual Daily Growth (IDG), and relative average weight gain of juveniles fed on A3 and A2 diets were not significantly different. However, they were significantly higher (p < 0.05) than those of the A1 diet. There were no significant differences (p > 0.05)among all the diets for average weight gain and survival rate. This study revealed the possibility of partial but not total substitution of fishmeal by plant materials in the diet of 3.45g Oreochromis niloticus fingerlings considering both growth and economic factors.

INCORPORATION OF LOCAL PLANT RAW MATERIALS IN THE FEEDING OF JUVENILE NILE TILAPIA (OREOCHROMIS NILOTICUS, LINNE, 1758) IN SENEGAL, WEST AFRICA

A research for eight weekswas conducted to evaluate the effect of substituting fish meal with local agricultural products in the diet of Nile Tilapia (Oreochromis niloticus).Three treatment dietaries were prepared. The dietary composition of the tested diets is as follows: A1/plant based-diet (Groundnut cake, sesame cake, millet bran, maize meal and 0% fish meal) A2/fishmeal partial replacement diet (Groundnut cake, sesame cake, millet bran, maize meal, and 10% fish meal) and A3/fishmeal based-diet (Groundnut cake, sesame cake, millet bran, maize meal, and 25% fish meal). All the diets were isoprotein and isolipidic diets. The initial average weight of the fish was 3.45±0.5g. The fishes were fed twice a day in triplicate for eight weeks. After the experiment, the final average weights were 4.97±0.5g, 5.43±0.5g, and 5.86±0.5g for A1, A2, and A3, respectively. There were significant differences (p < 0.05) among the three diets. The Feed Conversion Ratio (FCR) of juveniles fed on the A3 diet (1.77) was significantly better (lower) compared to A1 and A2 (3.41 and 2.59, respectively). The FCR of the fish fed diets A1 and A2 were not significantly different. The Specific Growth Rate (SGR), Individual Daily Growth (IDG), and relative average weight gain of juveniles fed on A3 and A2 diets were not significantly different. However, they were significantly higher (p < 0.05) than those of the A1 diet. There were no significant differences (p > 0.05)among all the diets for average weight gain and survival rate. This study revealed the possibility of partial but not total substitution of fishmeal by plant materials in the diet of 3.45g Oreochromis niloticus fingerlings considering both growth and economic factors.

Lack of Dose- and Time-Dependent Effects of Aflatoxin B1 on Gene Expression and Enzymes Associated with Lipid Peroxidation and the Glutathione Redox System in Chicken.

Effects of aflatoxin B1 (AFB1) on lipid peroxidation and glutathione system were investigated in chicken liver. In a three-week feeding trial, different doses (<1.0 μg/kg (control diet), 17.0 µg (diet A1), 92.0 µg (diet A2), and 182.0 µg (diet A3) AFB1 kg/feed) were used. Markers of lipid peroxidation, conjugated dienes and trienes showed higher values in A3, while amounts of thiobarbituric acid reactive substances were increased in the A1 group at day 21. Glutathione content was lower at day 14 in Group A2. Glutathione peroxidase 4 activity was increased at days 7 and 21 in the A3 group but reduced in the A2 and A3 groups at day 14. The GPX4 gene was downregulated at day 7 in the A2 group, but overregulated at days 14 and 21, and at day 14 in the A3 group. GSS was downregulated at day 14 in the A1 group but overregulated at day 21 in A1 and A2 groups. GSR was downregulated at days 7 and 21 in all treatment groups, but on day 14, induction was observed in the A3 group. The results indicated that AFB1 did not induce dose- or time-dependent effects on the glutathione redox system and its encoding genes at the dose range used, which means that oxidative stress is not the primary effect of AFB1 toxicity.

Utilization of Nannochloropsis oceanica alga for biodiesel production and the de-lipidated biomass for improving Red tilapia aquaculture

This work was carried out, firstly for investigating the different effects of various organic carbon sources [fructose (A), lactose (B), glucose (C)], and nitrogen sources [poultry manure extract (PM) and rumen liquor (RL)] which used at ratio 50:50% F/2 medium on maximizing production of biodiesel from the marine microalga Nannochloropsis oceanica. Secondly, we apply the residual lipid-free biomass as feed additives in Red tilapia aquaculture. In phase1, the biomass (DW), biodiesel contents and biochemical compositions of N. oceanica were determined. The results showed varied biomass and biochemical analysis in DW bases between treatments. However, A was achieved significantly the maximum DW for the algal biomass and protein percentage, whereas lipid accumulation was the most in RL as well as achieving the highest biodiesel content. In phase 2, algal biomass by-product (lipid-free) from the superior treatments A and RL were applied at 4 rates (1,2,3 and 4) for concentrations 25,50,75&100%, respectively that substituting soybean for feeding red tilapia larvae as compared with control CO. The initial weight and length of the larvae were 0.32g and 1.9 cm, respectively continued for a duration of 30 days of the experiment. After the end of the experimental period , growth performance, survival percentage (SR%) and biochemical analysis were estimated. The results revealed that SR% was higher significantly for RL2 than A1 (93% & 90%) as compared to control (86.7%). Accordingly, red tilapia carcass attained maximum protein contents for diets A1 & RL2 in whereas lipid content was maximum in control. Finally, authors suggesting the use of Roman liquor as a novel treatment for cost-effective promoting biodiesel content and the remained biomass with 50% substitution of soybean in the diet (RL2)achieved also good results for improving red tilapia aquaculture.

Effect of total replacement of fishmeal by earthworm and Azolla filiculoides meals in the diets of Nile tilapia Oreochromis niloticus (Linnaeus, 1758) reared in concrete tanks

In order to eliminate use of fishmeal in aquafeeds, we evaluated the effect of total replacement of fish meal by a mixture of earthworm (Eisenia foetida) and aquatic fern Azolla filiculoides in the diets of Nile tilapia Oreochromis niloticus (Linnaeus, 1758). The experiment was conducted in O. niloticus fingerlings (initial mean weight = 5.6±0.2 g) for a period of 60 days. Five experimental diets isoproteic (30.4±0.6% protein) comprising control diet A0 and four test diets (A1 to A4) without fish meal were formulated. To satisfy essential amino acids requirements in test diets, the ratios 2:1; 1:1; 1:2; 1:5 between A. filiculoides and earthworm meals were used respectively in total replacement of fish meal. The diets were tested in triplicate. On termination of the experiment, the final mean weights in the test diets (10.79 to 11.94 g) were lower than 14.9 g obtained in group fed control diet (p&lt;0.05). The best growth performance and feed utilisation were obtained in fish fed test diets A1 and A4 (SGR = 1.25 and 1.26% day-1; FCR = 2.37 and 2.31 respectively). Excess of lysine in test diets was found to affect the feed utilisation.

Aerated sea mud is beneficial for post-nursery culture of early juvenile sea cucumber Apostichopus japonicus (Selenka)

The incorporation of sea mud into formulated diets could improve sea cucumber Apostichopus japonicus (Selenka, 1867) growth in aquaculture systems. This study focused on the activation of sea mud by aeration 0, 1, 2, 3, 4, and 5 days (marked as A0, A1, A2, A3, A4, and A5) and dealt with the effects of the processing time on growth, feeding rate, and other physiological parameters of juvenile sea cucumber Apostichopus japonicus. Activation time greatly affected the proportion of potential probiotics present in sea mud. The growth, survival, ingestion rate, digestibility, and ammonia-nitrogen production of sea cucumbers increased as the percentage of probiotics increased. The growth and survival rates of juvenile sea cucumbers fed diet A1 were significantly higher than those in all other groups. These results suggest that it is beneficial to activate natural sea mud for 1 day prior to inclusion in the diet of post-nursery juvenile sea cucumbers. The findings should be helpful in the development of environmentally sustainable and healthy culture technique for holothurians.

Effect of Fish Oil Substitution with Sunflower Oil in Diet of Juvenile Catla catla (Ham) on Growth Performance and Feed Utilization

During the present investigation Catla catla fry (0.250 ± 0.008 g) were fed with five iso-nitrogenous (40%) and isolipidic (6%) diets in triplicate @ 5% of body weight, for a period of 60 days. Diet A1 (control)was without supplemented oil i.e., whereas diets A2-A5were supplemented with 3% fish oil (FO) and sunflower oil (SFO) at different proportions i.e. diet A2 with(100% FO), diet A3 (70% FO+30% SFO), diet A4 (50% FO+50% SFO) and diet A5 (70% SFO+30% FO). After the end of 60 days of feeding trail a significant difference (p 0.01) in all the growth performance parameters between oil supplemented diets i.e. A2-A5. However, diet A1 (control) registered poorest performance i.e. 42.54% (WG), 0.271 (SGR), 7.75 (FCR), 12.88 (FCE) and 93.56% survival rate. The present result thus clearly revealed that sunflower oil could be partially replace the fish oil up to 50% in supplemented diet without any adverse effect on the growth performance of Catla catla fry, as it is less expensive and easily available.

Immune responses and gut morphology of Senegalese sole (Solea senegalensis, Kaup 1858) fed monospecies and multispecies probiotics

The current study aimed to determine the effects of dietary probiotic supplementation on growth, gut morphology and non-specific immune parameters in Senegalese sole (Solea senegalensis) juveniles during a 1-month trial. Fish were fed for 1-month two diets with 1.0 or 4.6 × 106 CFU kg−1) of probiotic A (Bacillus sp., Pediococcus sp., Enterococcus sp. and Lactobacillus sp.) and two diets with 3.5 or 8.6 × 105 CFU kg−1 of probiotic B (Pediococcus acidilactici) and tested against an unsupplemented diet (control). Growth performance, as well as respiratory burst activity, nitric oxide (NO), alternative complement pathway (ACH50), lysozyme and peroxidase activities, was not affected by the dietary treatments. Probiotic supplementation tended to increased growth homogeneity between tanks having diet A1 the best possible alternative to decrease costs associated to size grading. Villous length and number of goblet cells of the anterior intestine did not vary among treatments. Muscle duodenal layer was significantly thicker in fish fed probiotic A compared to probiotic B, when included at the lowest level (A2 versus B2). The current study indicate that the use of the multispecies probiotic at 1.0 × 106 CFU kg−1 might enhance protection against pathogen outbreak and increase nutrient absorption, whereas at the highest concentration could reduced size dispersion among tanks.

Dietary probiotic supplementation modulated gut microbiota and improved growth of juvenile rainbow trout (Oncorhynchus mykiss)

In aquaculture, infectious diseases are the major cause of economic losses. Probiotic supplementation may change the microbiota of the digestive tract and modulate the immune defences and nutritional performance. This study was conducted to evaluate the dietary supplementation of multi-species (A: Bacillus sp., Pediococcus sp., Enterococcus sp., Lactobacillus sp.) and single-species probiotics (B: Pediococcus acidilactici) on growth performance and gut microbiota of rainbow trout (Oncorhynchus mykiss). A basal diet was supplemented with probiotic A or B, at two concentrations each (A1, A2, B1 and B2) or not supplemented (control treatment). Diets were distributed to 30 groups of 20 fish, 3 times a day. The gut microbiota was analysed at the end of the feeding trial (96days) with 16S rDNA denaturing gradient gel electrophoresis (16S-DGGE). Changes in gut microbial community were assessed by Shannon index (H´) and number of operational taxonomic units (OTUs). After 56days of feeding, weight gain was significantly improved in fish fed diet A1 when compared to the control group. Dietary probiotic supplementation changed the gut microbial composition. Number of OTUs (R) was higher in fish fed A1 (multi-species at lower concentration) than in control group, while H´ was higher in fish fed A1, B1 and B2.

Evaluation of bioequivalency and toxicological effects of three sources of arachidonic acid (ARA) in domestic piglets

Arachidonic acid (ARA) and docosahexaenoic acid (DHA) are routinely added to infant formula to support growth and development. We evaluated the bioequivalence and safety of three ARA-rich oils for potential use in infant formula using the neonatal pig model. The primary outcome for bioequivalence was brain accretion of ARA and DHA. Days 3–22 of age, domestic pigs were fed one of three formulas, each containing ARA at ∼0.64% and DHA at ∼0.34% total fatty acids (FA). Control diet ARA was provided by ARASCO® and all diets had DHA from DHASCO® (Martek Biosciences Corp., Columbia, MD). The experimental diets a1 and a2 provided ARA from Refined Arachidonic acid-rich Oil (RAO; Cargill, Inc., Wuhan, China) and SUNTGA40S (Nissui, Nippon Suisan Kaisha, Ltd., Tokyo, Japan), respectively. Formula intake and growth were similar across all diets, and ARA was bioequivalent across treatments in the brain, retina, heart, liver and day 21 RBC. DHA levels in the brain, retina and heart were unaffected by diet. Liver sections, clinical chemistry, and hematological parameters were normal. We conclude that RAO and SUNTGA40S, when added to formula to supply ∼0.64% ARA are safe and nutritionally bioequivalent to ARASCO in domestic piglets.

Ileal digestibility of fat and fatty acids in polar foxes (Alopex lagopus L.) fed diets used during the reproductive period

This study evaluates apparent ileal digestibility of fat and fatty acids in ‘end-to-end’ ileorectal anastomosed blue foxes fed diets used over the reproduction (diets A1 and B1) and lactation (diets A2 and B2) periods on two farms (A and B). The experimental diets A1 and A2 were composed of different animal offal and cereals, while diets B1 and B2 contained beef offal and barley. Diets B1 and B2 had a higher content of fat (315.4 and 361.0 g kg−1), SFA (164.3 and 185.7 g kg−1) and MUFA (116.7 and 133.6 g kg−1), while diets A1 and A2 contained more PUFA (13.1 and 30.4 g kg−1). Significantly higher (P < 0.05) values of ileal fat digestibility coefficients (97.33 and 96.92%), SFA (97.24 and 95.96%) and MUFA (98.69 and 98.87%) were found in diets B, whereas PUFA were better absorbed from diets A1 and A2 (85.54 and 94.42%).

Inclusion of citric acid and/or amino acid-chelated trace elements in alternate plant protein source diets affects growth and excretion of nitrogen and phosphorus in red sea bream Pagrus major

Nutrient dense diets not only challenge the physiological capabilities of fish but also result in discharge of excess amounts into the environment, causing eutrophication of the receiving water. This study investigated the effect of dietary levels of citric acid (CA) and/or amino acid-chelated trace element (AA-CTE) on growth and nutrient retention in red sea bream and loading of phosphorus (P) and nitrogen (N). Six practical diets were formulated, the control being a fish meal-based diet (F0) without addition of P, CA and AA-CTE. Diet F1 was supplemented with 1% mono calcium phosphate (0.25% P). In diets C1 and C2 fishmeal was replaced with alternate plant protein ingredients and supplemented with 1% and 2% CA, respectively. Diets A1 and A2 were akin to diets C1 and C2, respectively but contained AA-CTE instead of the inorganic trace element. Fish weighing around 12 g were offered the respective diets to satiation during the 12-week trial. Growth and feed performance were lowest for fish fed F0 diet, but significant improvement ( P < 0.05) was noticed among those fed diets supplemented with P, CA or AA-CTE. The F1 group had the best growth (final body weight 85.02 g) while A1 group had the best FCR (1). Absorption of P was significantly higher ( P < 0.01) for fish that received CA and/or AA-CTE (C1, C2, A1 and A2) compared to group that did not receive them (F0 and F1). The P and nitrogen (N) retention values in fish fed diets with CA and/or AA-CTE were significantly ( P < 0.01) greater compared to the rest and this facilitated a reduction in excretion rates. The diet supplemented with 1% CA to an alternate plant protein sources diet without inorganic P supplementation had better performance compared to the diets supplemented with 2% CA, 1% CA + AA-CTE, and 2% CA + AA-CTE. Thus, without addition of inorganic P, 1% CA supplementation to alternate plant protein sources diets significantly improved fish growth, FCR and nutrient retention, besides lowering N and P loading. An efficient level of CA is suggested to be 1% or less in alternative plant protein source diets (containing 35% fish meal). These findings would contribute to the pursuit of environment-friendly feed for red sea bream.

Raw and heat-treated culban ( Vicia peregrina ) seed as protein source for mirror carp ( Cyprinus carpio ) fingerlings

An 80-day feeding trial was conducted in a recirculation system aquarium operating at 26 ± 0.3 °C, to evaluate the nutritive value of Vicia peregrina seed as a possible protein source in the diet of mirror carp ( Cyprinus carpio ) fingerlings. Vicia peregrina seed was included in the diets at different levels, viz. 100, 200, 300 g heat-treated and 100, 200, 300 g raw seed in experimental diets designated A1, B1, C1, A2, B2 and C2, respectively. Growth parameters of the fish fed these diets were compared to fish receiving a fish meal and soyabean meal based control diet. On the basis of the specific growth rate (SGR), feed conversion ratio (FCR) and protein efficiency ratio (PER), the control and diets A1, B1, C1 and A2 were similar and significantly better than diets B2 and C2. Fish fed diets B2 and C2 showed a lower growth performance compared to those fed diets A1, B1, C1 and A2. Whole body fat content of the fish fed the diets containing the higher levels (>10%) of raw V. peregrina was significantly lower than in fish in the other treatments. Vicia peregrine seed has a potential as an alternative feed ingredient. It can be used without any adverse effects at up to 10% of the diet as a protein source in diets for fingerling mirror carp. However, the seed should be heat-treated if inclusion rates are to exceed 10% of the diet. Keywords : Culban, Vicia peregrina , nutritive value, heat treatment, mirror carp, growth South African Journal of Animal Science Vol. 36 (4) 2006: pp. 235-242

Incremento en la proteína no degradable en rumen de vacas lecheras: 2. Efectos sobre utilización y excreción del nitrógeno

SUMMARY Eight confined lactating cows at mid lactation fed diets based on silages were used in an incomplete Latin square design to evaluate the effects of increasing rumen undegradable protein (RUP) on nitrogen utilization and excretion. Four diets were used. Diets designed as A1 and B1 had, on a DM basis, 45% pasture silage and 20% alfalfa haylage, while diets A2 and B2 had 38% permanent pasture and 27% alfalfa silage. Diets A and B differed mainly on the level of RUP. Diets A were formulated accepting up to a 20% RUP deficit and included soybean meal, while B diets covered 100% of estimated RUP requirements, using fish meal as a protein source. In spite of causing a lower N intake (P < 0.05), diets higher in RUP (B diets) resulted in similar milk production. Productive N (secreted as milk nitrogen plus N in daily gain, expressed as g day–1 and as g kg–1 of N intake) was improved significantly (P < 0.05) in higher RUP diets. Faecal and urinary N excretion were also lower (P < 0.05 and P < 0.01, respectively) in these diets. Intake N used in productive functions was higher in B diets (P < 0.01). The relationship productive N v/s intake N and excreted N (faeces plus urine) per litre of milk produced, and productive N v/s excreted N were all improved with B diets. These data indicate that correcting a RUP deficit of high silage diets with fish meal, increased the efficiency of the use of N for productive functions and decreased potential contamination through a reduced N excretion.

Incremento en la proteína no degradable en rumen de vacas lecheras: 1. Efectos sobre la producción y composición de leche y utilización de nutrientes

SUMMARY One of the most limiting and expensive nutrients for high producing dairy cows is crude protein (CP) and particularly RUP. Winter diets for dairy cattle in Southern Chile are based mainly on silages. The aim of the study was to analize the effects of the level of RUP in diets which include high levels of pasture silage and alfalfa haylage. High silage diets were fed to twelve multiparous Holstein cows in two trials to establish the effects of RUP supplementation on milk production, composition and efficiency of production. A complete Latin square design was used. Diets identified as A1 and B1 included (on a DM basis) 45% grass silage (GS) and 20% alfalfa haylage (AH) while diets A2 and B2 had 38% GS and 27% AH. The B diets were adjusted considering RUP (NRC, 1989) with fishmeal in the concentrate while the A diets considered only CP requirements, accepting up to a 20% RUP deficiency, and included soybean meal. DM, NEL and CP intakes were similar between treatments Daily milk and protein yield and concentration were higher with fish meal supplemented diets (P<0.05) but fat concentration was lower (P<0.05). MUN was similar between treatments and all values were lower than 19 mg dl -1 . Apparent efficiency of utilisation of DM and NEL for milk production, FCM and milk protein were higher (P<0.05) with fish meal diets. There was no interaction between alfalfa haylage and RUP level, except for milk protein level. Therefore providing RUP with fishmeal resulted in a higher milk and protein production and improved the efficiency of nutrient utilization, and this effect was not related to alfalfa haylage level.

The effect of vitamin A supplementation in broodstock feed on reproductive performance and larval quality in Penaeus chinensis

The effect of feeding four semi-purified diets A1, A2, A3, A4, containing different vitamin A acetate levels 0, 20, 40, 60 mg kg−1 diet, respectively, on fecundity, egg hatching rate, larval survival rate and vitamin A content in eggs of Chinese shrimp (Penaeus chinensis) broodstock was compared with a fresh clam diet (control) in a 60-day feeding trial. The broodstock shrimp fed the diet with 60 mg kg−1 vitamin A acetate added exhibited significantly higher fecundity (P < 0.01). Hatching rate was highest with diet A4 (P < 0.05), whereas hatching rates were similar fed diets A1, A2, A3. Increasing levels of vitamin A in broodstock diet resulted in improvement in larval quality. The vitamin A levels in shrimp eggs from broodstock fed with diet A4 were higher compared with those from broodstock fed with diet A1, A2 (P < 0.01). The fecundity and hatching percentages were positively correlated with the vitamin A content in eggs in the present study. The results of this study showed that higher level of vitamin A in broodstock diet may have positive effects on fecundity and larval quality in P. chinensis.

Reproductive performance and offspring quality in mud crab ( Scylla paramamosain ) broodstock fed different diets

A 2-month feeding trial was conducted toevaluate the reproductive performance andoffspring quality of mud crab (Scyllaparamamosain) females fed either a mixture offresh food items (squid, shrimp, trash fish andArtemia biomass) or two experimentaldiets developed for penaeids. Before testinitiation, mud crab females with an averageindividual wet weight of 200–300 g wereacclimated for 2–3 days and reared together inone concrete tank of 2.0 × 0.5 × 8 m untilspawning. After spawning, the spent spawnerswere unilaterally eyestalk ablated and randomlydivided (20 animals/treatment) over three tanksof the same size and subjected to the dietarytreatments. Spent spawners were used toeliminate the effect of feeding history. There were only minor differences inreproductive performance between dietarytreatments. No differences were observed in theduration of the latency period from eyestalkablation to spawning. Fecundity was onlymarginally higher for the broodstock fed thecontrol diet. Also egg quality seemed onlyslightly affected by the treatments. Egghatching rates were slightly higher in crabsfed the formulated diets compared to thosecrabs fed the fresh diet. The onlystatistically significant difference (p < 0.05) observed however was in egg hatchingrate between the control diet and diet A2. Incontrast, the crabs fed the fresh diet producedstronger larvae as determined by a starvationtest. We therefore conclude that artificial dietsresulted in reproduction success comparable tothe use of fresh food. The nutritionalcomposition of the artificial diets couldhowever be improved in order to produce larvaeof optimal quality. Based on our researchfindings, the protein level and n-3 HUFA levelin the diet warrants further investigation inthis respect.

Farelo de soja na alimentação de alevinos de jundiá (Rhamdia quelen)

O trabalho foi conduzido com o objetivo de testar diferentes fontes protéicas em dietas práticas para alevinos de jundiá (Rhamdia quelen). Foram realizados dois experimentos com duração individual de 42 dias utilizando-se 320 animais com peso médio inicial de 1,18 &lt;FONT FACE=Symbol&gt;±&lt;/font&gt; 0,28 gramas e 4,00 ± 0,18 gramas, respectivamente, distribuídos em 16 unidades experimentais de um sistema com recirculação de água, testando-se quatro dietas com quatro repetições em cada experimento. No primeiro experimento, testaram-se quatro dietas isoprotéicas (34% proteína bruta) e isocalóricas (3.500 Kca&lt;img src="http:/img/fbpe/cr/v32n3/a21img01.gif" align="absmiddle"&gt; /kg de energia digestível) sendo que a dieta A1 continha levedura de cana, farelo de soja e farinha de carne e ossos, e nas demais (A2, A3 e A4) suprimiu-se uma das fontes. Alevinos alimentados com a dieta A2 (levedura de cana e farelo de soja) mostraram desempenho superior (P&lt;0,01). No segundo experimento, utilizaram-se as fontes proteicas da dieta que proporcionou o melhor desempenho no experimento I (A2), e avaliou-se o efeito da substituição da levedura de cana pelo farelo de soja em níveis crescentes (75%, 87,5% e 100%) a partir de uma dieta (B1) contendo os mesmos níveis de inclusão (36,4%) das duas fontes. A dieta B1 proporcionou um melhor crescimento e ganho de peso dos alevinos de jundiá (P&lt;0,01).

Wheatgerm flour in diets for Manila clam, Ruditapes philippinarum, spat

Various diets for the spat of Ruditapes philippinarum were assessed, consisting wholly or partially of wheatgerm flour—diet A1: 100% of the daily food ration (4 mg AFDW (100 mg LW) −1) consisted of the microalga Isochrysis galbana, clone T-ISO; diet M2: 50% of the daily ration consisted of microalgae and the other 50% of flour; diet M3: 25% microalgae and 75% flour; and diet G: 100% flour. Two control diets consisting solely of microalgae were also assayed: diets A2 and A3, consisting of 50% and 25% of the daily ration, respectively. The composition of the wheatgerm used was: 18.2% of the total organic matter consisted of protein, 71.2% of carbohydrate and 10.6% of lipids, while the microalgae consisted of 27.8% protein, 38.3% carbohydrates and 33.8% lipids. The diets prepared with these two components are characterised by an increase in their carbohydrate content and a decrease in their protein and lipid content as the proportion of wheatgerm increases. The highest growth rates were obtained for the spat fed diets A1 (final dry weight, 7.12±1.15 mg individual −1) and M2 (6.72±0.30 mg individual −1),with no significant difference being observed between the two diets. The spat fed diet M3 reached a final dry weight of 4.12±0.49 mg individual −1, a figure which is greater than that obtained with the control diets A3 (1.44±0.13 mg individual −1) and A2 (2.98±0.76 mg individual −1). The growth of the spat fed exclusively wheatgerm, diet G (1.55±0.08 mg individual −1), was similar to that obtained with control diet A3. The proportion of organic matter in the spat at the end of the experimental period is related to the nutritional value of the diet, so that the spat fed the diets with the greatest nutritional value (the highest growth rates) showed higher proportions of organic matter.

Plasma urea levels on reproductive parameters of wool-less rams (Ovis aries, LINNAEUS, 1758)

The effect of increased plasma urea levels on reproductive parameters of Santa Ines Brazilian breed rams (Ovis aries) was determined during two phases, 60 days in length each. During the first phase, 18 animals divided into three blocks according to scrotal circumference were submitted to the following treatments: diet A1- with nitrogen levels according to ARC (1980); diet B1 - nitrogen levels 133% higher than A1; and diet C1 - nitrogen levels 166% higher than A1. During the second phase, 12 animals divided into two groups received diet A2- with nitrogen levels according to ARC (1980), and diet B2 - nitrogen levels 200% higher than diet A2, respectively. The increase in protein equivalents was obtained by adding 20, 40 and 60 g of feed grade urea to treatments B1, C1 and B2, respectively. Semen was collected daily using an artificial vagina and analyzed twice a week for progressive motility; vigor, whirling, density, pH, concentration, sperm morphology, ejaculated volume and total sperm per ejaculate. Urea concentration was determined weekly in semen and plasma. Urea level increased in plasma and semen (p < 0.0001) during both phases but did not affect the parameters studied.