Improved Feed Conversion Ratio Research Articles

Productive and Physiological Response of Male Rabbits to Dietary Supplementation with Thyme Essential Oil.

Simple SummaryThe present study was carried out to compare the potential effects of the levels of thyme essential oil on the productive performance and serum metabolic profile of male rabbits. Rabbits were assigned to five dietary treatments including a basal diet as a negative control, a basal diet supplemented with an antibiotic as a positive control, and a basal diet supplemented with 60, 120, or 180 mg/kg of thyme essential oil. The main results showed that the levels of thyme essential oil contributed to the improvement of productive and the physiological response compared with the negative and positive control of male rabbits.The present study aimed at assessing the efficiency of thyme essential oil (TEO) as an alternative to antibiotics for improving the productive performance and serum metabolic profile of male rabbits. A total of one hundred and fifty 70-day-old male Californian rabbits were assigned to five dietary treatments, including a basal diet as a negative control (NC), a basal diet supplemented with an antibiotic as a positive control (PC), and a basal diet supplemented with 60, 120, or 180 mg/kg of TEO. The experiment period lasted for 60 days. Supplementation of TEO levels significantly (P < 0.01) increased daily body weight gain and improved feed conversion ratio of male Californian rabbits compared to NC and PC groups. Similarly, the TEO remarkably enhanced the semen characteristics of rabbits compared to NC and PC groups. Supplementation of TEO significantly decreased aspartate transaminase, alanine transaminase, urea, and creatinine compared with NC and PC groups. Supplementation with TEO increased serum testosterone concentration compared to NC and PC treatments. Our data demonstrate that TEO levels up to 180 mg/kg can play a major role as an alternative to dietary antibiotics, in improving the productive performance, semen quality, testosterone levels, and the kidney and liver functions in California male rabbits.

Selection for feed efficiency using the social effects animal model in growing Duroc pigs: evaluation by simulation

BackgroundTraits recorded on animals that are raised in groups can be analysed with the social effects animal model (SAM). For multiple traits, this model specifies the genetic correlation structure more completely than the animal model (AM). Our hypothesis was that by using the SAM for genetic evaluation of average daily gain (ADG) and backfat thickness (BF), a high rate of improvement in feed conversion ratio (FCR) might be achieved, since unfavourable genetic correlations between ADG and BF reported in a Duroc pig line could be partially avoided. We estimated genetic and non-genetic correlations between BF, ADG and FCR on 1144 pigs using Bayesian methods considering the SAM; and responses to selection indexes that combine estimates of indirect (IGE) and direct (DGE) genetic effects for ADG and BF by stochastic simulation.ResultsEstimates of the ratio of the variance of DGE to the phenotypic variance were 0.31, 0.39 and 0.25 and those of the total genetic variance to the phenotypic variance were 0.63, 0.74 and 0.93 for ADG, BF and FCR, respectively. In spite of this, when the SAM was used to generate data and for the genetic evaluations, the average economic response was worse than that obtained when BV predictions from the AM were considered. The achieved economic response was due to a direct reduction in BF and not to an improvement in FCR.ConclusionsOur results show that although social genetic effects play an important role in the traits studied, their proper consideration in pig breeding programs to improve FCR indirectly is still difficult. The correlations between IGE and DGE that could help to overcome the unfavourable genetic correlations between DGE did not reach sufficiently high magnitudes; also, the genetic parameters estimates from the SAM have large errors. These two factors penalize the average response under the SAM compared to the AM.

Dietary microbial muramidase improves feed efficiency, energy and nutrient availability and welfare of broilers fed commercial type diets containing exogenous enzymes

ABSTRACT 1. The aim of this study was to evaluate the effect of graded levels of the microbially derived feed lysozyme, muramidase (MUR) on feed intake (FI), weight gain (WG), feed conversion ratio (FCR), European Performance Index (EPI), dietary N-corrected apparent metabolisable energy (AMEn), footpad dermatitis score (FPD) and other welfare variables, when fed to broilers from 0 to 42d age. 2. A four-phase dietary programme and four experimental pelleted diets were used; a control diet (following breeder recommendations without MUR supplementation), and three diets based on the control diet supplemented with 25,000, 35,000 and 45,000 LSU (F)/kg of MUR, respectively. In addition, all experimental diets contained exogenous xylanase, phytase and a coccidiostat. Each diet was fed to birds in 24 pens (20 male Ross 308 chicks in each pen) following randomisation. Dietary AMEn was determined at 21 d of age, and FPD was evaluated at the end of the study. Data were analysed by ANOVA, using orthogonal polynomials for assessing linear and quadratic responses to MUR activity. 3. The inclusion of MUR did not change FI (P > 0.05), but increased WG in a linear manner (P < 0.05) and reduced FCR in a quadratic manner, with optimum WG and FCR observed in birds fed approximately 35 000 LSU (F)/kg. In accordance with the improvement in FCR, 35 000 LSU (F)/kg MUR supplementation produced the highest EPI (P < 0.05). FPD score was linearly decreased with increased addition of MUR (P < 0.05). Dietary AMEn responded in a quadratic fashion to the MUR inclusion, as the highest values were obtained with the highest inclusion rate (P < 0.05). 4. In conclusion, the results showed that inclusion of MUR improved feed efficiency and the foot health of birds.

Digestible lysine requirement for Tambaqui (Colossoma macropomum) juveniles using the diet dilution technique

This study aimed at determine the digestible lysine requirement of tambaqui juveniles using the diet dilution technique. A total of 250 juveniles tambaqui with an initial mean of 22.99 ± 1.06 g were used in a dose-response experiment with five levels of digestible lysine (0.865, 1.125, 1.383, 1.644 and 1.903%) and five replication per treatment. The digestible lysine levels evaluated did not influence the feed intake (P > 0.05), but there was a linear effect (P < 0.05) on the digestible lysine intake. Quadratic effects on weight gain, specific growth rate, feed conversion ratio, and body protein deposition were observed, estimating the requirements at 1.39; 1.37; 1.37 and 1.58% digestible lysine, respectively. Since there was no effect on the feed intake and, consequently, on energy consumption, the improvements in feed conversion ratio and weight gain occurred owing to the better amino acid balance of the rations in the requirement of digestible lysine. The requirement for digestible lysine in the diet for tambaqui juveniles was determined at 1.58% by the body protein deposition, which corresponds to 5.76% dietary crude protein.

Dietary cinnamaldehyde and Bacillus subtilis improve growth performance, digestive enzyme activity, and antioxidant capability and shape intestinal microbiota in tongue sole, Cynoglossus semilaevis

Immune stimulators are essential to the development of the aquaculture industry. Cinnamaldehyde (CA) and Bacillus spp. are promising immunostimulatory feed additives, as demonstrated by their beneficial effects in several fish species. This study investigated the effects of dietary CA and Bacillus subtilis either alone or in combination on the growth, digestive enzyme activity, and non-specific immunity of tongue sole, Cynoglossus semilaevis. A total of 240C. semilaevis (188 ± 5 g) were randomly assigned to four dietary treatments. Diets containing no additives (the control group, D), 0.1 g/100 g CA (Dcin), 107 CFU/g B. subtilis (DBac), and CA combined with B. subtilis (Dcin+Bac) were used to feed fish for 60 days. The results revealed significant improvements in the weight gain, specific growth rate, feed conversion ratio, and protein efficiency in the fish fed diets containing either CA or B. subtilis, and there were more significant improvements in the group with the combined supplementation (Dcin+Bac) compared with the control group. Fish fed diets with CA or CA combined with B. subtilis had higher intestinal proteinase, amylase, and lipase activities than the control fish. Dietary CA and B. subtilis singularly or in combination improved the antioxidant capacity and the immune status by stimulating SOD, CAT, and T-AOC activities and GSH-Px levels, by reducing malondialdehyde (MDA) content, and by increasing lysozyme activity in the serum, liver, mid kidney, and spleen. The results of the two-way analysis of variance revealed the synergistic effects of CA and B. subtilis in improving feed conversion ratio, protease activities in the foregut and midgut, and part of the antioxidant parameters. In addition, significant shifts in the overall intestinal microbial community and diversity were analyzed using high-throughput sequencing of the V3/V4 region of the 16S rRNA gene. The results showed that both dietary supplementation of CA alone or in combination with B. subtilis increased the abundance of the probiotic bacterial genera Bacillus, Lactobacillus, and Bifidobacterium. In conclusion, dietary supplementation of cinnamaldehyde and B. subtilis both solely and in combination are beneficial for improving the growth performance, digestive ability, non-specific immunity, and intestinal microbiota community of the tongue sole, Cynoglossus semilaevis.

Effect of Spirulina platensis Supplementation in Growing Rabbit's Diet on Productive Performance and Economic Efficiency

The current study carried out to assessment the effect of addition of low levels 0.3 and 0.6 g/kg diet of Spirulina platensis (SP) on the productive performance and economic efficiency parameters of growing Red Balady rabbits for 8 weeks. A total of 36 growing rabbits (6-week old) were randomly assigned into three dietary experimental treatments (12 rabbits of each), that was conducted from 6 to 14 weeks of age. The obtained results revealed that addition of SP to the diet of growing rabbits at level 0.6 g/kg diet led to significantly increased of growth performance parameters and improved feed conversion ratio, as well as led to insignificantly enhanced of carcass traits, and hematological and economic efficiency parameters compared to those fed the low level (0.3 g/kg diet) or those fed free SP diet. Thus, it could be concluded that the useful addition of SP for improving the productive and economic performance of growing Red Balady rabbits, especially at the tested level 0.6 g SP/kg diet.

Defatted yellow mealworm larvae (&lt;I&gt;Tenebrio molitor&lt;/I&gt; l.) meal as possible alternative to fish meal in quail diets

The effects of replacing fish meal (FM) in the diet with defatted mealworm larvae meal (DMLM) on growth, carcass, and biochemical constituents of serum of Japanese quail chicks were investigated. A total of 600 unsexed one-day-old chicks were allotted to five dietary treatments with six replicates of 20 chicks each. The diets were formulated by replacing FM with DMLM at the levels of 25% (D25), 50% (D50), 75% (D75), and 100% (D100). The FM, D25 and D50 diets resulted in greater final bodyweight, higher bodyweight gain, and improved feed conversion ratio compared with the other diets. Diets that contained DMLM decreased the feed intake compared with the FM diet. The FM and D25 diets increased the hot and cold carcass yields compared with the other diets, whereas the D75 and D100 diets significantly enhanced the relative weight of the small intestine and abdominal fat compared with FM, D25, and D50. The replacement of FM with DMLM reduced the serum globulin, total cholesterol and triglyceride levels, and the albumin to globulin ratio significantly. The best protein and energy efficiency ratios and European efficiency factor were obtained with the D25 and D50 diets. In conclusion, the replacement of FM with DMLM at the levels of 25% and 50% produced positive results in growth performance, in serum albumin to globulin ratio, and in nutrient use efficiency in quail.Keywords: performance, serum biochemistry, slaughtering

Nanoselenium and Selenium Yeast Have Minimal Differences on Egg Production and Se Deposition in Laying Hens.

The objective of this study was to compare the effects of nanoselenium (NS) and selenium yeast (SY) on the performance, egg selenium (Se) concentration, and anti-oxidative capacity of hens. A total of 216 Brown Hy-line hens (29-week old) were randomly allocated into three treatments (6 replicate/treatment, 12 hens/replicate). The pre-trial period lasted 7days, and the experimental period lasted 35days. Dietary treatments included corn-soybean meal basal diet (containing 0.16μg Se/g, as control group), and basal diet supplemented with 0.3mg Se/kg diet (Se was from NS or SY), called as SY group or NS group, respectively. At the end of the experiment, one hen per replicate from each treatment was slaughtered. Liver, spleen, and kidney tissues were sampled for the determination of Se concentrations. The results showed that NS or SY supplement significantly improved feed conversion ratio (P <0.05), soft broken egg rate (P <0.05), and the serum T-AOC value (P <0.05) when compared with control group. Remarkably, the deposition of Se increased significantly (P < 0.05) and equivalently in egg, liver, and kidney of hens supplemented with both NS and SY. Interestingly, SY supplement also enhanced the serum CAT and SOD activities (P < 0.05), NS but not SY significantly reduced serum MDA (P < 0.05), whereas RT-PCR results did not show significant differences in the mRNA levels of antioxidant genes among three groups (P >0.05). Taken together, dietary supplemented with SY or NS improved the Se deposition in eggs, liver and kidney of laying hens, increased antioxidant activity, and NS supplement had greater Se deposition in the kidney tissue than SY supplement. SY or NS supplement could be considered to be applied for Se-enriched egg production.

Effects of phytogenic supplementation on productive performance of broiler chickens

The present study evaluated the feed additive containing essential oils of thyme and star anise from 1 to 42 D of age on growth performance, physiological parameters, carcass traits, intestinal bacterial community, antioxidant status of meat, and economic efficiency in broilers under Egyptian weather condition. Two hundred and seventy 1-day-old Indian River broiler chicks were randomly distributed in three groups and fed a basal diet for 42 D. The control ( Co ) group, T1 group, and T2 group were fed 0.0 mg/kg diet, 150 mg/kg diet, and 300 mg/kg diet, respectively. The highest final weight and weight gain were recorded by the T2 and T1 groups compared to the control group ( P < 0.05). The feed intake was not affected by any of the treatments. Improvements in feed conversion ratio and mortality of chickens were recorded by the T2 group. Blood serum parameters were significantly affected by dietary treatments but remained within the normal range. Carcass characteristics were insignificantly different among groups. The scavenging activity of 1,1-diphenyl-2-picrylhydrazyl free radical was significantly increased in the T2 group compared to the control group. The total bacterial counts, including Lactobacillus , were not affected significantly among groups. However, The Enterococcus counts were significantly higher ( P < 0.05) in T1 and T2 groups. European production efficiency factor was increased in T1 and T2 groups compared to the control group. This implied that the addition of essential oils of thyme and star anise had a positive effect on growth performance of broiler chickens.

Efficiency of Dietary Supplementation of Flavonoid (Quercetin), Vegetable Oil and Its Combination on Growth Traits and Feed Conversion in Broilers

The study was conducted to investigate the efficiency of dietary supplementation of Flavonoid (Quercetin) compound, vegetable oil and its combination on feed intake, growth traits and feed conversion in broiler chickens. Four dietary treatments were assigned in to 192 Vencob-400 strain broiler chicks for the 35 days duration (7th-42nd days). The treatments were control (T1) without any supplementation, whereas T2, T3 and T4 supplemented with Quercetin (1g kg−1), vegetable oil (>10% of ME recommendation) and combination of Quercetin with vegetable oil, respectively. Each group comprised of four replicates (12 birds in each). All the treatment groups were fed similar corn soya based basal diet. Daily and weekly feed intake throughout the experimental period was found comparable among the dietary treatment groups except the period of 4th week, where higher (P<0.05) feed intake was observed in control (T1). During starter phase weekly body weight gain (g/bird/week) and weekly growth rate (g/bird/d) was significantly (P<0.01) differ amongst the group, which was highest in T4; while these parameters were found comparable in finisher phase. However, the cumulative weight gains and cumulative growth rate were significantly (P<0.01) higher in T3 and T4 group. Similarly, Quercetin supplementation (T2) had also revealed higher cumulative weekly weight gain and growth rate over control group (P<0.01). The feed conversion ratio was revealed better (P<0.05) in T4 group during 4th and 6th week and also for overall experiment. Thus, the supplementation of Quercetin or vegetable oil or its combination in broilers had shown a better growth performance and improvement in feed conversion ratio.

Circadian zinc feeding regime in laying hens related to laying performance, oxidation status, and interaction of zinc and calcium

This study investigated that circadian zinc (Zn) feeding regime affected laying performance, Zn and calcium (Ca) status, antioxidant capacity and gene expression of circadian clock, and Ca and Zn transporter in laying hens. In total, 162 of 21-wk Hyline Sophie laying hens were assigned randomly into 3 groups including CON group (Control Zn, basal diets supplemented 60 mg/kg Zn), HL group (high-low Zn, basal diets supplemented 120 mg/kg Zn—basal diets), and LH group (low-high Zn, basal diets—basal diets supplemented 120 mg/kg Zn), which were fed at 0,530 h and 1,530 h, respectively. Blood, tibia, duodenum, and eggshell gland samples were collected at 8 h intervals with starting at 0,000 h in 1 d after 10 wk of experiment. Compared with CON group: 1) Feed conversion ratio (FCR) of LH and HL group decreased significantly (P < 0.05); 2) in serum, total antioxidant capacity and CuZn-superoxide dismutase (SOD) at 0,000 h increased significantly, as well as Ca and Zn concentration of tibia at 0,800 h in LH group (P < 0.05); 3) in duodenum, mRNA expression of calbindin-d28k (CaBP) and NCX1 at 1,600 h in HL group upregulated significantly, as well as Per2 and Per3 at 0,000 h, CLOCK, Cry2, Per2, and Per3 at 1,600 h (P < 0.05). But, Zn5 at 0,800 h in HL group downregulated significantly (P < 0.05). 4) In eggshell gland, the mRNA expression of CaBP at 0,000 h and Zn5 at 1,600 h in HL group downregulated significantly (P < 0.05). However, SOD at 1,600 h in HL group upregulated significantly, as well as Cry1 and Per3 at 0,800 h in HL group upregulated significantly (P < 0.05). In conclusion, circadian Zn feeding diet regime was beneficial to improvement of FCR. The regulation of laying hens' circadian rhythms affected Zn and Ca transporter and interrelationship between Ca and Zn metabolism, also altered antioxidant capacity in present study. Therefore, circadian Zn feeding regime can be considered as a new method to improve laying performance in laying hens.

Corn drying temperature, particle size, and amylase supplementation influence growth performance, digestive tract development, and nutrient utilization of broilers.

Broiler live performance may be influenced by postharvest corn drying temperature, and results could depend on particle size after grinding. The supplementation with an exogenous amylase may improve performance parameters, but responses to enzymes are also affected by particle size. Two parallel experiments were conducted to evaluate the effects of hard-kernel corn dried at 2 temperatures (35°C and 120°C), ground at 2 particle sizes (coarse or fine), and 3 supplementation levels (0, 133, and 266 g ton-1) of an exogenous amylase on live performance, gastrointestinal organ development, energy utilization, and nutrient digestibility. Twelve dietary treatments resulting from a 2 × 2 × 3 factorial arrangement of drying temperature, particle size, and amylase supplementation were evaluated in both experiments. A total of 1,920 day-old male chicks were randomly allocated to 96 floor pens, while 480 chicks were distributed among 4 battery brooder units. Ileal and fecal samples were collected to determine energy utilization and nutrient digestibility using titanium dioxide as inert marker. At 42 D, organs were collected, and relative weight or length was determined. Data were analyzed using a three-way ANOVA in a randomized complete block design. Feeding fine corn-based diets showed improvements on live performance for both studies. At 40 D, supplementing 266 g ton-1 of amylase improved feed conversion ratio (P < 0.05) by 1 point compared to chickens that consumed nonsupplemented diets and feed with amylase at 133 g ton-1. Broilers fed coarse corn–based diets had heavier gizzard (P < 0.001) and liver (P < 0.05) than chickens that consumed fine corn-based diets. In addition, starch digestibility was improved by amylase (P < 0.05) at 133 g ton-1 and by feeding coarse corn-based diets (P = 0.06). For chicks raised in cages (16 D), AMEn was increased (P < 0.01) by amylase supplementation regardless of its inclusion level. In conclusion, drying temperature and particle size interactions influenced broiler live performance, gastrointestinal organ development, nutrient digestibility, and energy utilization, and these parameters were improved by supplementing amylase.

GROWTH PERFORMANCE AND IMMUNITY RESPONSE OF SUCKLING FRIESIAN CALVES FED ON RATION SUPPLEMENTED WITH ORGANIC OR NANO SELENIUM PRODUCED BY LACTIC ACID BACTERIA

Eighteen suckling Friesian calves with average live body weight of 32.70±0.79 kg were divided into three comparable groups based on sex and birth weight. All calves were fed on a whole milk, starter and berseem hay without supplement in the control group or supplemented with 0.3 mg Se/kg DM intake as organic selenium (OSe) or nano selenium (NSe) for 2nd and 3rd groups. The results showed that organic-and nano selenium groups recorded significantly (P 0.05) affected by selenium additives. While, albumin concentration and albumin to globulin ratio were significantly (P<0.05) decreased, however, globulin concentration in plasma of calves supplemented with OSe and NSe was significantly (P<0.05) higher than that of control group, Organic and nano selenium supplementation significantly decreased (P<0.05) the activity of AST and ALT enzymes and creatinine concentration in plasma compared to that of the control group. The concentrations of IgA and IgG in plasma were increased significantly (P<0.05) with OSe and NSe supplementation compared to the control group, The IgM concentration was comparable among all groups. The percentages of various disease incidence decreased significantly (P<0.05) in OSe and NSe supplemented groups than those of the control group, Morality rate was higher in the control group than that of OSe group, however no mortality was observed in calves of NSe group. Dry matter intake values were the same for different groups, whereas, values of TDN and DCP intake tended to increase with OSe and NSe supplemented diet than those of the control group. Birth weight was comparable among all groups. While, weaning weight, total weight gain and average daily weight gain were significantly (P<0.05) higher for OSe and NSe groups than to the control. Supplementation with OSe and NSe improved feed conversion ratio, which significant decreased (P<0.05), where the amounts of DM, TDN and DCP per one kg weigh gain were less than those of control group. Daily feed cost was comparable among all groups, where feed cost per kg gain was significantly (P<0.05) lower for OSe and NSe groups than control group. The cost price of daily weight gain and net revenue as well as economic efficiency were significantly (P<0.05) higher for OSe and NSe groups compared to those of control group.

In vitro Anticoccidial Study of Oregano and Garlic Essential Oils and Effects on Growth Performance, Fecal Oocyst Output, and Intestinal Microbiota in vivo.

This study investigated the in vitro effects of Greek oregano and garlic essential oils on inhibition of Eimeria parasites and their in vivo effects on production performance, intestinal bacteria counts, and oocyst output. An inhibition assay was performed in vitro using Eimeria tenella Wisconsin strain sporozoites and Madin-Darby bovine kidney (MDBK) cells. Intracellular sporozoite invasion was quantified by detection of E. tenella DNA using qPCR from cell monolayers harvested at 2 and 24 h post-infection. Parasite invasion was inhibited by the oregano essential oil at the concentration of 100 μg/ml by 83 or 93% after 2 or 24 h, respectively. Garlic essential oil reached a maximum inhibition of 70% after 24 h with the 50 μg/ml concentration. Normal morphology was observed in MDBK cells exposed to concentrations of 100 μl/ml of garlic or oregano for over 24 h. In the in vivo trial, 180 male broiler chicks (45.3 ± 0.7 g) were allocated into two treatments (6 pens of 15 chicks per treatment). Control treatment was fed commercial diets without antibiotics or anticoccidials. The ORE–GAR treatment was fed the same control diets, further supplemented with a premix (1 g/kg feed) containing the oregano (50 g/kg premix) and garlic (5 g/kg premix) essential oils. At day 37, all birds were slaughtered under commercial conditions, and intestinal samples were collected. ORE-GAR treatment had improved final body weight (1833.9 vs. 1.685.9 g; p < 0.01), improved feed conversion ratio (1.489 vs. 1.569; p < 0.01), and reduced fecal oocyst excretion (day 28: 3.672 vs. 3.989 log oocysts/g, p < 0.01; day 37: 3.475 vs. 4.007 log oocysts/g, p < 0.001). In the caecal digesta, ORE-GAR treatment had lower total anaerobe counts (8.216 vs. 8.824 CFU/g; p < 0.01), whereas in the jejunum digesta the ORE-GAR treatment had higher counts of E. coli (5.030 vs. 3.530 CFU/g; p = 0.01) and Enterobacteriaceae (5.341 vs. 3.829 CFU/g; p < 0.01), and lower counts of Clostridium perfringens (2.555 vs. 2.882 CFU/g; p < 0.01). In conclusion, the combined supplementation of oregano and garlic essential oils had a potent anticoccidial effect in vitro and a growth-promoting effect in broilers reared in the absence of anticoccidial drugs.

Effect of feeding on fresh (wet) housefly maggots (Musca domestica) with or without artificial diet on water quality and growth rates of African catfish (Clarias gariepinus Burchell, 1822) fry under laboratory conditions

No or little information on the use fresh (wet) housefly maggots (Musca domestica) in African catfish (Clarias gariepinus) fry feeding. Therefore, this study was conducted to investigate the effect of feeding on fresh (wet) housefly maggots with or without artificial diet on water quality, growth performance, survival percentage and feed utilization of African catfish fry under laboratory conditions. Housefly maggots produced from a mixture of poultry droppings and foods wastes, it was used to replace artificial feed at 0, 50 and 100% levels. Catfish were fed artificial diet alone (Feed 1), fresh (wet) housefly maggots alone (Feed 2), and 50% fresh housefly maggots with 50% artificial diet (Feed 3) were prepared and tested on triplicate groups of African catfish fry (initial weight of 0.25±0.02 g) for 60 days. Results showed that final weight (g/fish) was significantly highest (P£0.05) in fish fed feed 3 (6.03±0.08), followed by fish fed feed 2 (4.62±0.27), followed by fish fed feed 1 (3.15±0.68). Specific growth rate (%/day) was also significantly highest in fish fed feed 3 (5.31±0.10), followed by fish fed feed 2 (4.86±0.03), followed by fish fed feed 1 (4.18±0.24). The same trend was observed with total weight gain, percentage weight gain, daily growth rate and relative growth rate. Feed intake and protein intake were significantly highest (P£0.05) in fish fed feed 3 and fish fed feed 2, followed by fish fed feed 1. While, feed conversion ratio (FCR) and protein efficiency ratio were not significantly (P&gt;0.05), but the improvement in FCR recorded in catfish fry fed feed 3 and feed 2 under the experimental conditions. Survival percentage was within the range 55–75%, with insignificant differences (P&gt;0.05) among treatments. The water quality parameters such as temperature, pH, dissolved oxygen, total ammonia, nitrite and nitrate were not significantly (P&gt;0.05) among the treatments and were tolerable for fish culture. Accordingly, use of the 50% fresh (wet) housefly maggots with 50% artificial diet in African catfish fry feeding had positive effect on growth performance and reduce of the feed cost.

Effect of liquid feeding at different water-to-feed ratios on the morphological adaptations in the gastrointestinal tract of growing pigs

The study examined the morphology of the gastro-intestinal tract (GI) of growing pigs offered dry feed or liquid feed with differing water-to-feed ratios. Twenty male pigs were randomly allocated to one of four treatment groups; treatments included a standard dry pelleted diet (D) or the same diet soaked in water at a feed-to-water ratio of 1:1.5 (T1:1.5), 1:3 (T1:3) or 1:3 with the addition of lactic acid to adjust the feed to pH 4 (T1:3[4]). Animals were humanely slaughtered after 6 weeks to enable sampling and histological examination (light, scanning electron (LSEM) and binocular dissection microscope) of the GI tract. Samples were taken at the 2% position (duodenum), the 20% position and 50 % position (jejunum) along the small intestines (SI). Liquid-fed pigs were heavier (P &lt; 0.05) and exhibited improved feed conversion ratios (FCR) when compared to D animals. These differences in live weight were attributed to alterations in the weight and volume of the stomach and SI, which were also heavier and larger in liquid-fed pigs (P &lt; 0.05). However, these differences were no longer apparent when intestinal weights and stomach volumes were adjusted for animal live weight. Differences in villus type between the treatments were noted throughout, particularly in the duodenum and proximal jejunum sections. Mean villus height was taller in all liquid-fed animals when compared to D pigs (P&lt;0.05); this was particularly apparent in T1:1.5 and T1:3[4] pigs. There were no differences in crypt depths between treatment groups at the 2% and 20 % positions, but at the 50 % position the T1:1.5 group crypts were deeper (P &lt; 0.05) than those in the D and T1:3 pigs. It is concluded that liquid feeding alters the morphology of the GI tract, which may in part, explain the differences in growth performance observed between liquid and D fed pigs. The inclusion of organic acid in the diets of T1:3[4] pigs appeared to exert an effect on villus height and crypt depth when compared to those pigs receiving the T1:3 diet

Growth performance, serum lipid profile, intestinal morphometry, and growth and lipid indicator gene expression analysis of mono-sex Nile tilapia fed Moringa oleifera leaf powder

The current study aimed to assess the effect of the dietary inclusion of Moringa oleifera leaf on growth performance, serum lipid profile, and intestinal morphometric analysis along with relative mRNA levels of growth and lipid metabolism related genes in mono-sex Nile tilapia. A total of 180 mono-sex Nile tilapias (Oreochromis niloticus; average body weight, 27.98 ± 0.75 g) were used. Juvenile fish were randomly allocated into three groups with three replicates in each (20 fish/tank). For 8 weeks, groups 1, 2 and 3 were fed experimental diets containing 0%, 5%, and 10 % moringa leaf powder, respectively. We observed that the dietary inclusion of moringa leaf powder at 5 % significantly improved growth performance, evidenced by an increase in final body weight and improved feed conversion ratio. Moreover, lower serum cholesterol and triglycerides levels were reported in fish fed the moringa containing diet compared with those fed the basal diet (0% moringa). The increased body weight was accompanied with changes in intestinal morphometric parameters, including increased villus length and width as well as the inter-villus space. In addition, the improved growth performance and hypolipidemic effect following moringa leaf dietary inclusion were associated with a relative increase in mRNA levels of growth hormone receptor (GHR), insulin like growth factor (IGF), lipoprotein Lipase (LPL), and fatty acid synthase (FAS). Hence, moringa leaf powder can be included in the Nile tilapia diet as an alternative feed ingredient to promote growth and induce a hypolipidemic effect.

Aerobic swimming in intensive finfish aquaculture: applications for production, mitigation and selection

AbstractWe review knowledge on applications of sustained aerobic swimming as a tool to promote productivity and welfare of farmed fish species. There has been extensive interest in whether providing active species with a current to swim against can promote growth. The results are not conclusive but the studies have varied in species, life stage, swimming speed applied, feeding regime, stocking density and other factors. Therefore, much remains to be understood about mechanisms underlying findings of ‘swimming‐enhanced growth’, in particular to demonstrate that swimming can improve feed conversion ratio and dietary protein retention under true aquaculture conditions. There has also been research into whether swimming can alleviate chronic stress, once again on a range of species and life stages. The evidence is mixed but swimming does improve recovery from acute stresses such as handling or confinement. Research into issues such as whether swimming can improve immune function and promote cognitive function is still at an early stage and should be encouraged. There is promising evidence that swimming can inhibit precocious sexual maturation in some species, so studies should be broadened to other species where precocious maturation is a problem. Swimming performance is a heritable trait and may prove a useful selection tool, especially if it is related to overall robustness. More research is required to better understand the advantages that swimming may provide to the fish farmer, in terms of production, mitigation and selection.

Effects of replacing dietary Aureomycin with a combination of plant essential oils on production performance and gastrointestinal health of broilers

The objective of this study was to investigate the effects of replacing antibiotics with a combination of plant essential oils on the growth performances and gastrointestinal health of broilers. A total of 720 1-day-old male AA broilers were randomly divided into 3 treatments: the control treatment (CON), the Aureomycin supplementation treatment (AGP), and the combined plant oils supplementation treatment (POC), with a 42-D period feeding procedure. Growth performances, carcass performances, intestinal sections, and cecal microbiota were investigated. Results indicated that POC supplementation decreased the feed conversion ratio compared with CON and AGP treatments, though not significantly. No significant differences were found for feed intake, BW gain, and culling rate among the 3 treatments (P > 0.05). In addition, no significant differences were seen on carcass performance. For the aspects of intestinal section, POC supplementation did not make significant effects on intestinal wall thickness, villus heights, crypt depths, and the ratio of villus heights/crypt depths compared with CON and AGP treatments. Cecal microbiota results demonstrated that bacterial diversity and some representative probiotic bacteria were significantly increased in numbers (P < 0.05) after POC supplementation. In conclusion, the combination of essential oils promoted intestinal health through improving gut bacterial diversity and probiotic bacteria, as well as improving feed conversion ratio of broilers. These results indicated that the combination of essential oils may benefit the gastrointestinal health and be applied as an antibiotic alternative.

Betaine improves growth performance by increasing digestive enzymes activities, and enhancing intestinal structure of weaned piglets

This study investigated the effects of betaine on digestive enzymes and intestinal structures of weaned piglets. A total of 150 crossbred weaned piglets (Duroc × Landrace × Yorkshire), with an average initial body weight of 8.52 ± 0.26 kg and age of 39 day (weaned on day 25), were randomly divided into three dietary treatments, each of which was replicated five times with ten piglets per replicate/pen (five male piglets and five female piglets in each replicate/pen). The dietary treatments were basal diet supplemented with 0, 1250, 2500 mg/kg betaine, respectively. The experiment lasted 30 days. The results showed that supplementation of betaine in diet linearly increased average daily gain (ADG), decreased diarrhea rate, and improved feed conversion ratio (FCR). Betaine increased the apparent total tract digestibility of crude protein (CP) (linearly) and ether extract (EE) (linearly and quadratically) and the activities of amylase (linearly and quadratically), trypsin (linearly and quadratically), and lipase (linearly) in small intestine. The effect of betaine on digestive enzyme activities was more effective at 2500 mg/kg than that at 1250 mg/kg. In vitro enzymatic reaction studies found that betaine inclusion could boost the affinity of amylase and trypsin with their corresponding substrates, and counteract the inhibitory effect of hyperosmolarity induced by NaCl. Betaine also significantly increased villus height and the ratio of villus height to crypt depth of small intestine. Betaine increased the expression of tight junction proteins while decreased the plasma concentration of diamine oxidase (DAO). The effect of betaine on intestinal structure was more profound at 1250 mg/kg than that at 2500 mg/kg. Besides, betaine also increased the activity of glutathione peroxidase (GSH-Px) in the gut (linearly and quadratically). In conclusion, dietary supplementation of betaine enhanced intestinal structure and reduced diarrhea rate, increased digestive enzyme activities and promoted digestion of nutrients, and therefore, improved the growth performance of weaned piglets.