Comparative study on milt quality features of different finfish species

The aim of this research was to study the main sperm characteristics of three different finfish species. Twenty-one gilt- head sea bream (Sparus aurata), 20 brown trout (Salmo trutta, morpha fario) and 15 rainbow trout (Oncorhynchus mykiss) male broodstocks, farmed under optimal conditions for each species and fed standard diets for broodstocks, were manually stripped. Brown trout yielded small amounts of sperm (4.5 vs18.13 ml) that were very concentrated (≅8.5 x 109 vs 1.24 x 109 Szoa/ml) with respect to the other species. The duration of spermatozoan motility for gilthead sea bream sperm was significantly longer (almost 50 min), in comparison to the one-minute motility of Salmonids. Single fatty acids of brown trout sperm were higher than in the other two species for almost all detected fatty acids. In partic- ular, eicosapentaenoic acid (EPA) was at least three times more concentrated in brown trout than in rainbow trout or gilt- head sea bream sperm (1238.3 µg/g vs305.6 and 333.3 µg/g, respectively; P < 0.01). Saturated, polyunsaturated and total unsaturated fatty acid classes were significantly higher in brown trout sperm than in the other two species - almost double with respect to gilthead sea bream sperm and more than double in comparison to RT sperm (P < 0.01)

Effects of vitamin E and phosphatidylcholine on qualitative and quantitative parameters of rainbow trout (Oncorhynchus mykiss) milt

The aim of this work was to investigate the effects of vitamin E and phosphatidylcholine on rainbow trout (Oncorhynchus mykiss) milt. One hundred and twelve rainbow trout (RB) broodstock (2n, 1030± 20g body weight, male:female ratio = 50:50) were fed four isoproteic and isolipidic diets for 110 days. Diets were differing for the type of vitamin premix and phosphatidylcholine supplied: Control (vitamin premix without Vit. E, no phosphatidylcholine); Vit.E (a premix with Vit. E, no phosphatidylcholine); PhC, (vitamin premix without Vit. E, phosphatidylcholine 2.5%); Vit.E +PhC, (vitamin premix with Vit. E and phosphatidylcholine 2.5%). Sperm total volume, in sexually mature males (3+; 966±114g body weight), ranged between 18.57ml (Control) and 34.31ml (Vit. E). Sperm density varied between 1.76x109 Szoa/ml (Control) and 1.16x109 Szoa/ml (Vit. E+PhC), while relative density (related to male body weight) tended to increase with Vit. E (>50x109 Szoa/ml) and to reduce with Vit. E + PhC (85% in all treatments, while motility duration was around 2.37min for Vit. E and Control reached only 0.97min. After overnight storage (+4°C, for 18 hours) motility decreased, 75-80% in gamete motility and 3.39- 56.7% in time motility. PhC dietary supplements significantly increased arachidonic acid contents of sperm with respect to Control (>120 vs 73μg/ g), while Vit. E caused a huge increase in C20:3 n-3 (10.25 vs 2.27ppm). DHA/EPA ratio was significantly lower in Control (>2; p<0.05), while n-3/n-6 ratio was significantly the highest for Vit. E (9.46 vs <7.3)

Evaluation of carcass and meat traits of Muscovy duck fed with black soldier fly partially defatted meal

The aim of this study was to evaluate the carcass characteristics and breast meat quality in Muscovy duck (Cairina moschata domestica) fed different inclusion levels of a partially defatted black soldier fly larva (BSF) meal. A total of 256 Muscovy ducklings (average live weight, LW: 71.32\ub12.70 g) were reared from day 3 to day 48 and randomly allotted in 32 pens (8 replicates/treatment). Four different diets were formulated with increasing substitution level of corn gluten meal with BSF larva meal (0, 3, 6 and 9%; BSF0, BSF3, BSF6 and BSF9, respectively) and divided in 3 feeding phases: starter (1-14 days), grower (14-35 days) and finisher (35-48 days). At day 48, 2 animals/replicate were slaughtered and dissected to determine their carcass yields. The weights of spleen, bursa of Fabricius, liver, heart and abdominal fat were recorded. Breast and thigh muscles were then excised from 16 ducks/treatment and weighted. Ultimate pH (pHu) and L*, a*, b* colour values were then measured on breast muscle. The collected data were tested by means of oneway ANOVA evaluating the effect of dietary BSF inclusion level by polynomial contrasts. Significance was declared at P<0.05. The inclusion of BSF did not affect final LW (2,515.68\ub192.42 g on average). Hot and cold carcass weights showed a quadratic response (P<0.05) to increasing BSF larva meal, with a minimum corresponding to BSF6; however, refrigeration losses were not affected by treatments. Weight of spleen, bursa of Fabricius, liver and heart did not differ among treatments. The weight of abdominal fat showed a quadratic response to increasing BSF meal with a minimum corresponding to BSF6 group (P<0.05). Breast and thigh yields, pHu and L*, a*, b* colour values did not differ among groups. With the exception of BSF6, the inclusion of BSF meal did not affect meat traits and carcass characteristics, confirming the potential use of BSF meal in Muscovy duck diets

Apparent digestibility of insect protein meals for rainbow trout

Insect meals are considered to be promising future ingredients for aquaculture feeds. In past feeding trials in rainbow trout, insect meals were included in diets only on the basis of their nutrients content and energy density without taking into account their biological availability due to the lack of their digestible values. Apparent digestibility (ADC) provides good indication of the bioavailability of nutrients and energy thus providing rational basis for the correct inclusion of feedstuffs. The aim of this research was to assess, in an in vivo trial on rainbow trout, the ADC of five full fat insect meals: one Tenebrio molitor (TM), two Hermetia illucens obtained through two different process (HI1 and HI2), one Musca domestica (MD), and one Alphitobius diaperinus (AD). Fish were fed a high-quality reference diet (R) and test diets obtained mixing the R diet with each of the test ingredients at a ratio of 70:30. Diets contained 1% celite as inert marker. Fish were fed to visual satiety twice a day and faecal samples collected using a continuous automatic device. Faeces were freeze dried and frozen (-20 \ub0C) until analyses. The ADC of dry matter, crude protein and ether extract of each insect meal diet were calculated. ADC for dry matter varied between 70.07 (HI1) and 80.85 (TM). ADC for protein was above 84% in all treatments and resulted the highest in MD, TM and AD treatments. Ether extract apparent digestibility significantly differed among diets with the highest value reported for TM treatment. All treatments reported values higher than 96%. Observed differences could be due to the insect species and meal treatment but in general, tested insect meals were highly digestible for rainbow trout. The results from this research could be useful to optimize the diet formulation

The normalized difference vegetation index (NDVI) as indicator of the soil degradation.

In this work we presenl lhe lemporal evolulion 01 lhe vegelalion and Iheir relalionship wilh lhe soil degradalion in an area loealed in Northeasl 01 lhe Madrid Communily (Spain)

effects of a natural extract of chestnut wood on digestibility performance traits and nitrogen balance of broiler chicks

Currently, feed ingredients containing tannin are attracting more interest as substitutes for antibiotic growth promoters in animal and poultry feeding. This study investigated the influence of a natural extract of chestnut wood (Silvafeed ENC) on broiler digestibility (experiment 1) and on the growth performance, carcass quality, and nitrogen balance of broilers (experiment 2). Results showed that the inclusion of ENC did not influence the apparent digestibility of organic matter, CP, and ether extract. Chick growth performance showed a quadratic or cubic response with increasing levels of ENC. When chicks were fed ENC from 14 to 56 d of age, the ENC had a positive effect on average daily gain in the first 2 wk of addition, whereas this effect was not evident in the last 2 wk compared with the control group. Similar trends were also shown for daily feed intake. Overall, the chicks fed 0.20% ENC had significantly better growth performance than the control group. Carcass analysis showed no gross lesions in organs and no significant differences in thigh and breast composition among groups. Noteworthy is the fact that the ENC-treated groups had less total litter nitrogen; in particular, chicks fed 0.15 and 0.20% ENC showed a significant difference in total litter nitrogen compared with the control group. No significant difference in nitrogen balance was observed. Addition of 0.20% ENC seemed to have a positive influence on chick feeding