Impact of different forms of selenium supplementation on growth and physiological performance of New Zealand white rabbits.

Forty-eight weaned male New Zealand White rabbits aged 6 weeks with an initial body weight of (709.67 ± 13 g) were randomly divided into six experimental groups (8 rabbits each) for 6-14 weeks of age experimental periods. The present study was planned to evaluate the effect of using different forms of Selenium element (inorganic, nanoparticles and organic) as dietary supplementation on productive performance of rabbits. Six experimental groups in completely randomized design were used. The first group (G1, control) was fed the basal diet to cover maintenance and production allowances. Rabbits in the other groups G2, G3, G4 and G5 were fed the basal diet supplemented with Nano- Se at 0.02, 0.03, 0.04 and 0.05 mg/kg diet, respectively. The 6th group (G6) was fed the basal diet supplemented with 0.1 mg/kg diet of salinized yeast (Se-yeast) as organic form. The results indicated that the highest values of nitrogen free extract (NFE) and crude fiber (CF) digestibility, live body weight, daily weight gain, hot carcass weight and dressing percentage were observed with those supplemented with Nano-Se at all levels compared with other treatments. However, feed conversion, net revenue and economic efficiency values were improved with Nano-Se groups followed by organic Se group in comparisons with the control group. Conclusively, the Nano-Se in rabbit's diet has a positive effect in improving rabbit's performance and economic efficiency compared to the inorganic Selenium.

Immune response enhancement by dietary supplementation with Caesalpinia sappan extract in weaned pigs challenged with porcine reproductive and respiratory syndrome virus.

BACKGROUND: At present, porcine reproductive and respiratory syndrome (PRRS) caused by the PRRS virus (PRRSV) is one of the most severe epidemics impacting pig farming globally. Despite the fact that a number of studies have been conducted on potential solutions to this problem, none have proven effective. The focus of problem solving is the use of natural ingredients such as plant extracts. Popular throughout Asia, Caesalpinia sappan (CS) is a therapeutic plant that inhibits PRRSV in vitro. Therefore, this study was performed to determine the efficacy of CS extract dietary supplementation on the productive performance, antibody levels, immunological indicators, and lung pathology of PRRSV-challenged weaned pigs. A total of 32 weaned piglets (28 days old) were randomized into 4 groups and kept separately for 14 days. The treatments were organized in a 2 × 2 factorial design involving two factors: PRRSV challenge and supplementation with 1 mg/kg CS extract. The pigs in the PRRSV-challenged groups were intranasally inoculated with 2 mL of PRRSV (VR2332) containing 104 TCID50/mL, while those in the groups not challenged with PRRSV were inoculated with 2 mL of normal saline. RESULTS: In the PRRSV-challenged group (CS + PRRSV), supplementation with CS extract led to an increase in white blood cells (WBCs) on Day 7 post infection (p < 0.05) and particularly in lymphocytes on Days 7 and 14. The antibody titer was significantly greater in the CS + PRRSV group than in the PRRSV-challenged group not administered CS (PRRSV group) on Day 14 postinfection (S/P = 1.19 vs. 0.78). In addition, CS extract administration decreased the prevalence of pulmonary lesions, which were more prevalent in the PRRSV-challenged pigs that did not receive the CS extract. CONCLUSION: The findings of this study suggest that supplementation with CS extract is beneficial for increasing WBC counts, especially lymphocytes, increasing the levels of antibodies and reducing the prevalence of lung lesions in PRRSV-infected pigs.

Effects of enzymolysis and fermentation of Chinese herbal medicines on serum component, egg production, and hormone receptor expression in laying hens.

OBJECTIVE: In the present study, we aimed to investigate the effects of enzymolysis fermentation of Chinese herbal medicines (CHMs) on egg production performance, egg quality, lipid metabolism, serum reproductive hormone levels, and the mRNA expression of the ovarian hormone receptor of laying hens in the late-laying stage. METHODS: A total of 360 Hy-Line Brown laying hens (age, 390 days) were randomly categorized into four groups. Hens in the control (C) group were fed a basic diet devoid of CHMs, the crushed CHM (CT), fermented CHM (FC), and enzymatically fermented CHM (EFT) groups received diets containing 2% crushed CHM, 2% fermented CHM, and 2% enzymatically fermented CHM, respectively. RESULTS: Compared with crushed CHM, the acid detergent fiber, total flavonoids, and total saponins contents of fermented CHM showed improvement (p<0.05); furthermore, the neutral and acid detergent fiber, total flavonoids, and total saponins contents of enzymatically fermented CHM improved (p<0.05). At 5 to 8 weeks, hens in the FC and EFT groups showed increased laying rates, haugh unit, albumin height, yolk color, shell thickness, and shell strength compared with those in the C group (p<0.05). Compared with the FC group, the laying rate, albumin height, and Shell thickness in the EFT group was increased (p<0.05). Compared with the C, CT, and FC groups, the EFT group showed reduced serum total cholesterol and increased serum luteinizing hormone levels and mRNA expressions of follicle stimulating hormone receptor and luteinizing hormone receptor (p<0.05). CONCLUSION: These results indicated that the ETF group improved the laying rate and egg quality and regulated the lipid metabolism in aged hens. The mechanism underlying this effect was likely related to cell wall degradation of CHM and increased serum levels of luteinizing hormone and mRNA expression of the ovarian hormone receptor.

Effect of dietary glycine supplementation on productive performance, egg quality, stress response, and fatty liver incidence in laying hens raised under heat stress conditions.

The current experiment aimed to investigate the effect of dietary glycine (Gly) supplementation on productive performance, egg quality, stress response, and fatty liver incidence in laying hens raised under heat stress (HS) conditions. A total of two hundred eighty 24-wk-old Lohmann Brown-Lite laying hens were randomly allotted to 1 of 4 dietary treatments with 7 replicates. The negative control (NC) diet was prepared to meet or exceed the nutrient and energy requirement for Lohmann Brown laying hens, whereas the positive control (PC) diet was formulated to increase AMEn by 100 kcal/kg compared with the NC diet. Two additional diets were prepared by supplementing 0.341% and 0.683% Gly to the NC diet. All hens were exposed to cyclic HS at 31.4 ± 1.17°C for 8 h/d and 26.7 ± 1.10°C for the remaining time for a 12-wk trial. Results indicated that increasing supplementation of Gly in diets tended (linear, P = 0.088) to decrease the FCR of laying hens. Increasing supplementation of Gly in diets increased (linear, P < 0.05) eggshell lightness and decreased (linear, P < 0.05) egg yolk color. Moreover, a tendency for a quadratic association (P < 0.10) of serum aspartate aminotransferase and alanine aminotransferase concentrations with increasing supplementation of Gly was observed. Increasing supplementation of Gly in diets decreased (linear, P < 0.05) blood heterophil:lymphocyte ratio of laying hens. Hens fed the NC diet showed higher fatty liver incidence (P < 0.05) than those fed the PC diet, but increasing supplementation of Gly decreased (linear, P < 0.05) fatty liver incidence of laying hens. In conclusion, increasing supplementation of Gly up to 0.683% in diets decreases FCR, stress response, and fatty liver incidence in laying hens raised under HS conditions.

Alternative to antibiotic growth promoters: beneficial effects of Saccharomyces cerevisiae and/or Lactobacillus acidophilus supplementation on the growth performance and sustainability of broilers' production.

Although antibiotics growth promoters (AGPs), including zinc-bacitracin (ZnB), can threaten human health due to developing antimicrobial resistance, as well as drug residue in animal and poultry products, ZnB is still widely used, particularly in developing countries, for the sustainability of poultry farming. The present investigation aims to assess the use of Saccharomyces cerevisiae and Lactobacillus acidophilus, with or without a prebiotic (mannooligosaccharide, MOS), as alternatives to ZnB. For this reason, 150 one-day-old chicks were grouped into six groups, designated negative control, LA, SC, ZnB, SA + MOS, and LA + MOS (5 replicates of 5 chicks for each group). Chicks kept in the control group were fed the basal diet. Chickens kept in LA and SC groups received L. acidophilus, S. cerevisiae at a 1 g/kg diet and 2 g/Kg, respectively. Chickens kept in ZnB received ZnB at 0.5 g/kg. Chicks kept in the SC + MOS and LA + MOS were fed a basal diet containing 2 g S. cerevisiae + 1 g MOS/kg or 1 g L. acidophilus + 1 g MOS /kg, respectively. The efficacy was assessed based on the growth performance, carcass traits, meat quality, nutrient digestibility, and blood biochemistry composition during the entire trial 1-36 days of age. Results showed that chicks kept in the SC group had greater BW than the control (p < 0.05). Chicks kept in the SC, LA, SC + MOS, and LA + MOS consumed less feed than the control and Zn-B groups (p < 0.05). Supplementation with S. cerevisiae resulted in a better (p < 0.05) feed conversion rate (FCR) than the control group. Supplementation with L. acidophilus + MOS significantly increased (p < 0.05) the relative liver weight compared to those supplemented with ZnB, S. cerevisiae, and L. acidophilus. In addition, supplementation with ZnB-induced spleen hypertrophy compared to S. cerevisiae and L. acidophilus-supplemented groups (p < 0.05). Plasma, meat, and liver cholesterol, as well as the cholesterol-to-lipid ratio of meat and liver, were significantly decreased (p < 0.05) in both SC and LA groups compared to the control group. Our research indicates that adding 2 g/kg of S. cerevisiae to broiler feed can effectively replace ZnB and enhance productive performance and economic profits, making it a viable and sustainable option for broiler farming.

Effects of Saccharomyces cerevisiae live cells and culture on growth and productive performance in lactating Nili-Ravi buffaloes.

An experimental work was conducted to evaluate the effects of Saccharomyces cerevisiae live cells and its culture on dry matter intake (DMI), milk yield, milk composition, body condition score, selected blood metabolites, feed conversion efficiency (FCE), nutrient digestibility, body weight gain, and economics of milk production in lactating multiparous Nili-Ravi buffaloes. In total, 20 buffaloes of age 5 years ± 6 months and weighing 550 ± 20 kg were selected and assigned to four dietary treatments (n=5 buffalo/treatment) under completely randomized design. The dietary treatments include treatment 1 (T1) control, treatment 2 (T2) 5g/head live yeast, treatment 3 (T3) 5g/head yeast culture, and treatment 4 (T4) 10 g/head yeast culture per day for 60 days excluding 14 days as an adjustment period. The results indicated that T4 showed significant (p<0.05) improvement in DMI, milk yield and components, blood glucose level, digestibility of nutrients, and body weight gain while significant decrease in blood urea nitrogen as compared to other treatment groups. Body condition score was not affected among treatments. In conclusion, yeast culture supplementation significantly improved (p <0.05) milk yield, milk composition, DMI, body weight gain, blood glucose level, and digestibility while significantly decreased blood urea level as compare to control. Economic return was also improved. BCS was not improved. Comparatively, yeast culture showed significant improvement in growth and productive performance as compare to live yeast. Meanwhile, 10-g yeast culture showed better results as compare to 5-g yeast culture.

Effect of Spirulina platensis on growth, hematological, biochemical, and immunological parameters of Nile tilapia (Oreochromis niloticus).

This study was conducted to evaluate the effects of Spirulina platensis in Nile tilapia diets on growth performance, blood hematological and biochemical parameters, immunological status, and intestinal histomorphometry. A total of 228 fish were randomly allocated into four groups with triplicates (19 fish per replicate). The first group was fed the control diet, which contained no Spirulina supplementation. The other three groups were fed diets containing graded levels of powdered Spirulina: 2.5%, 5.0%, and 10.0% in the second, third, and fourth group, respectively. S. platensis was added to the diets partially substituting the fish meal content. The experiment lasted for 8 weeks. The results showed that dietary Spirulina supplementation improved (P < 0.05) the body weight and length, weight gain, specific growth rate, condition factor, and feed conversion efficiency. Moreover, Spirulina increased significantly (P < 0.05) the hemoglobin, PCV, RBCs, and WBCs count. Also, it increased the lymphocytes, eosinophils, IgM level, lysozyme activity, and phagocytic activity in the blood. Additionally, the Spirulina raised (P < 0.05) the serum albumin level but reduced (P < 0.05) the creatinine and urea levels. The addition of Spirulina increased (P < 0.05) the height and width of intestinal villi and the lymphocytes and goblet cells count in the intestine. The obtained results were increased by increasing the inclusion level of Spirulina, especially for body weight and length, weight gain, FCR, phagocytic activity, and intestinal parameters. In conclusion, supplementing S. platensis can improve the growth performance of fish. Moreover, it can stimulate the immunity of fish through increasing the level of immunological blood indicators (IgM, lysozyme, phagocytic activity, lymphocytes, and eosinophils) as well as the local intestinal immunity (lymphocytes and goblet cells). So, it can be recommended to use S. platensis in fish diets not only to improve the growth performance but also to enhance the immune status.

Effect of Supplementation of Diets with L-Carnitine and Methionin on Broiler Chicken Productive Performance.

The poultry industry is one of the pillars of food security in the world, as it is relied upon to provide meat and eggs to meet the increasing food demands. Therefore, this study was designed to investigate the effect of L-carnitine and methionine supplementation to the standard diets of broiler chickens in productive performance of broiler (Ross 308). One Hundred- fifty broiler chicks unsexed (Ross 308) with an initial weight with 43 g, were obtained from Al-Habbaniya hatchery (commercial hatchery). All the animals were within an average weight of 40 g (one-day old chicks). The experimental groups were as follows: the animals in T1 group received basal diet without any addition, the animals in T1 group received basal diet supplemented with lead acetate 400 mg/kg feed , the animals in T3 group received diet supplemented with carnitine 300 mg + lead acetate 400 mg, the animals in T4 group received basal diet supplemented with methionine 100 mg + lead acetate 400 mg, the animals in T5 group received basal diet supplemented with methionine 100 mg + carnitine 300 mg + lead acetate 400 mg. Body weight gain and feed consumption were weekly recorded. Feed conversion ratio was also calculated. Results showed that Birds in (T5) fed diets with (carnitine + methionine) observed highest live body weights comparison with T3 (carnitine + lead acetate) and T4 (adding methionine+ lead acetate). Data of results showed no significant differences were recorded in body weight gain. Also, Results obtained increase with feed consumption for treatment T5, while birds in T1 and T4 recorded lowest means in feed consumed. However, birds in T4 and T5 observed best feed conversion ratio as compare with T1, T2 and T3. Therefore, it can conclude that addition carnitine and methionine enhanced broiler productive performance.

Effect of propionate, monensin, and saccharomyces cerevisiae or their combination on production and rumen fermentation of holstein steers.

This study aimed to evaluate the effects of calcium propionate (PrCa), PrCa + monensin sodium (PrCa + Mon), and PrCa + Saccharomyces cerevisiae (PrCa + Sc) on the productive performance of Holstein steers. Twenty-four Holstein steers (270.0 ± 25.85 kg) were distributed individually into four treatments of six replicates. The treatments were control (no additives), PrCa (10 g/kg), PrCa + Mon (10 g/kg + 30 mg/kg), and PrCa + Sc (10 g/kg + 12.8 × 109 cfu). The steers were fed for 43 days, and afterwards, nutrient intake and digestibility as well as volatile fatty acids were determined, while the weight gained, feed efficiency, and CH4 production were calculated. Diet of PrCa + Sc had the highest (P < 0.0001) acid detergent fiber intake and propionate acid as well as the nutrient digestibility, with lowest (P < 0.0001) rumen acetic acid, methane, and protozoa concentration versus other diets. In conclusion, dietary inclusion of PrCa + Sc (10 g/kg + 12.8 × 109 cfu) improved nutrient digestibility, rumen fermentation, and reduced methane emission, thereby enhancing the possibility of ecofriendly ruminant farming.

Effects of dietary organic or inorganic iron concentrations on productive performance, egg quality, blood measurements, and tissue iron concentrations in aged laying hens.

The objective of the current experiment was to investigate the effects of dietary organic or inorganic iron (Fe) concentrations on productive performance, egg quality, blood measurements, and tissue Fe concentrations in aged laying hens. A total of three hundred fifty 60-week-old Hy-Line Brown laying hens were allotted to one of five dietary treatments with seven replicates. Each replicate had 10 consecutive cages. Organic Fe (Fe-Gly) or inorganic Fe (FeSO4 ) was added to the basal diet at the levels of 100 or 200 mg/kg Fe. Diets were fed on an ad libitum basis for 6 weeks. Results indicated that supplementation of organic or inorganic Fe in diets increased (p < 0.05) eggshell color and feather Fe concentrations compared with no supplementation of Fe in diets. An interaction was found (p < 0.05) between Fe sources and supplemental levels in diets for egg weight, eggshell strength, and Haugh unit. Hens fed diets supplemented with organic Fe had greater (p < 0.05) eggshell color and hematocrit than those fed diets supplemented with inorganic Fe. In conclusion, dietary supplementation of organic Fe increases the eggshell color of aged laying hens. High supplemental levels of organic Fe in diets improve egg weight in aged laying hens.

Effects of dietary substitution of peanut meal for soybean meal on egg production, egg quality, oxidative status, and yolk fatty acid profile in laying ducks.

There is an urgent need to evaluate and introduce alternatives for the unsustainable and traditional feed stuffs in poultry. This study evaluated the effects of graded replacement of soybean meal (SBM) by peanut meal (PNM) on egg production, egg quality, oxidative status, and yolk fatty acid profile in laying ducks. In total, 360 Longyan ducks aged 21 weeks were allocated to five treatments, each containing six replicates of 12 birds. Birds were fed the diets containing PNM replacing 0 (control), 25, 50, 75 or 100% of SBM for 16 weeks. With the increase of PNM level, egg production was improved (quadratic, P < 0.05), egg weight and feed consumption were decreased, feed conversion ratio and egg mass were impaired at 100% PNM, and yolk colour was enhanced (quadratic, P < 0.05). Plasma malondialdehyde concentration was increased at 100% PNM, while plasma glutathione concentration was decreased (quadratic, P < 0.01) as PNM substitution increased. Total cholesterol content in yolk decreased (P < 0.01) in response to increased PNM substitution. The contents of saturated fatty acids C20:0 and C22:0 in yolk increased (linear or quadratic, P < 0.05) with increased PNM substitution, but the contents of saturated fatty acid C18:0, monounsaturated fatty acid C22:1, and polyunsaturated fatty acids C18:3n-3 and C22:6n-3 in yolk were decreased (linear, P < 0.05) as PNM replacement increased. The contents in yolk of polyunsaturated fatty acid C18:2n-6, C20:2n-6, C20:3n-6, C20:4n-6, and total amount of polyunsaturated fatty acids increased with the highest contents obtained at 75% PNM substitution. The ratio between n-6 and n-3 increased (linear, P < 0.05) as PNM substitution increased. The transcript abundance in liver of peroxisome proliferators-activated receptors γ and fatty acid synthase showed quadratic (P < 0.05) responses with PNM replacement, with the highest expression of both genes being obtained with 75% substitution with PNM. Replacement of dietary SBM with 100% PNM decreased egg production and antioxidant capacity and increased the ratio of omega fatty acid in yolk between n-6 and n-3 in laying ducks. The obtained results indicate that PNM can be used to replace up to 75% of SBM in the diet of laying ducks without negative effects on the egg-laying production or egg quality. The regression model indicated that the maximal egg mass was obtained at no more than 67.6% replacement of SBM with PNM in the diet of laying ducks.

Dietary autolysed yeast modulates blood profiles, small intestinal morphology and caecal microbiota of weaning pigs.

Yeast products are potential feed additives due to their beneficial effects on gut health. Thus, we verified the potential impacts of autolysed yeast (AY) on growth performance, blood profiles, gut morphology and microbiota in weaning pigs. In total, 72 castrated, commercial, crossbred, weaning pigs were divided into three groups, with each group consisting of eight replicates with three piglets each. The experimental diets were as follows: 1) control diet (0% AY); 2) diet with 1.0% AY; 3) diet with 3.0% AY. For the overall period, using 1.0% AY in the diet seemed to improve the feed conversion ratio (P = 0.09); whereas, other productive performance parameters were not significantly affected by the supplementations. Using 1.0% AY in the diet significantly decreased the blood urea nitrogen and neutrophil/lymphocyte ratio (N/L ratio) but increased the eosinophil count (P < 0.05). Adding AY to the diet did not influence caecal microbial diversity; using 1.0% AY in the diet decreased the abundances of the phylum Actinobacteria, the class Coriobacteriia and the family Coriobacteriaceae (P < 0.05). At the genus level, an AY inclusion level of 1.0% reduced the abundances of Collinsella, Clostridium and Catenibacterium and increased that of Marvinbryantia (P < 0.05). Furthermore, the abundance of butyrate-producing bacteria seemed to be increased by AY supplementation (P = 0.06). Pearson's correlation coefficient (r) analysis revealed that AY intake was negatively associated with the abundance of pathogens of the genera Dorea (r = -0.84; P = 0.03) and Catenibacterium (r = -0.80; P = 0.04). This indicates that AY intake potentially reduces the population of some pathogenic bacteria at family level. Thus, using an appropriate AY inclusion level (1.0%) seemed to improve the feed use of postweaning pigs and clearly improved their small intestinal morphology, blood profiles and caecal microbiota.

Effects of Music Therapy on Neuroplasticity, Welfare, and Performance of Piglets Exposed to Music Therapy in the Intra- and Extra-Uterine Phases.

The rearing environment of pigs can cause a high level of stress due to the lack of stimuli and the impossibility of carrying out natural behaviors. Music therapy is a way to enrich the environment and promote stress relief. Few studies in swine using environmental enrichers focus on functional benefits, such as stress resilience, improved biological functions, or mental status. The effect of environmental enrichment on neurobiological processes is particularly poorly understood in farm animals. Thus, our study sought to elucidate the influence of music in piglets exposed to music therapy in the intrauterine and extrauterine phase on neuroplasticity, evaluating the levels of brain-derived neurotrophic factor (BDNF). Behavioural responses were also evaluated using fear tests related to stress resilience. The productive performance of these piglets was analysed to relate the possible reduction in stress levels to greater productivity gains. Forty-eight sows were used at 90 days of gestation until the weaning of their piglets. In the gestation phase, the sows were divided into two treatments: control (without music therapy) and music (with music therapy). In the farrowing/lactation phase, the sows were separated into four treatments: control-control (no music in any phase); control-music (music only in farrowing/lactation); music-control (music only during pregnancy); and music-music (music in both reproductive phases). Music therapy did not cause a difference in the BDNF levels of piglets at birth. However, piglets born from sows of the music-music treatment did not show a reduction in BDNF between birth and weaning, unlike the other treatments. Exposure to music in the last 1/3 of pregnancy and farrowing/lactation improved the weight of piglets at birth and at weaning. Musical enrichment during pregnancy and lactation was able to cause changes in the piglets' neuroplasticity and improve their productive performances.

Effects of dietary supplementation of chromium methionine chelate on growth performance, oxidative stress, hematological indices, and carcass traits of broiler chickens.

This study was conducted to evaluate the dietary effects of chromium methionine (Cr-Meth) chelate on growth performance, oxidative stress parameters, blood biochemistry, and carcass traits of broiler chickens. An experiment was conducted on 34,000 1-day-old straight-run broiler chicks (Indian River; 42.0 ± 0.03) at a commercial farm. The chicks were divided randomly into 3 groups; the first group contained 17,000 birds, which used as a control, whereas the second and third groups consisted of 7000 and 10,000 birds, respectively, with 5 replicates per group. A completely randomized design was used. The birds were fed the experimental diets containing graded levels of Cr-Meth chelate: 0 (control), 50, and 100 g/ton. This compound consisted of chromium (0.4%) chelated with methionine, and it supply the diets with 200 and 400 ppb Cr for the used levels of 50 and 100 g/ton feed, respectively. Growth performance indices (body weight, body weight gain, feed intake, and feed conversion ratio) were measured throughout the experiment. At the end of experiment, 10 birds per treatment were slaughtered, and the carcass yield with relative weight of the internal organs was determined. Also, blood samples were taken and analyzed for glutathione peroxidase activity, malondialdehyde, ALT, AST, total protein, albumin, glucose, urea, creatinine, triglycerides, and total cholesterol. It was found that Cr-Meth improved the body weight, weight gain, feed intake, and feed conversion ratio of broilers. Moreover, it reduced the mortality rate of birds. The chelated chromium can alleviate the oxidative status of birds by increasing the plasma glutathione peroxidase activity and reducing the serum malondialdehyde level. It was observed that the effects of 100 g/ton Cr-Meth chelate on performance indices, mortality rate, and oxidative stress parameters were better than that of 50 g/ton inclusion rate. Supplementation of Cr-Meth increased the total protein level, but reduced the glucose, total cholesterol, and triglyceride concentrations in the blood serum. In addition, it increased the carcass yield and reduced the abdominal fat percentage of the birds' carcass. Therefore, chromium can be included in diets of broilers at a rate of 200 to 400 ppb, and the higher concentration was more effective than the lower one. So, it can be recommended to use Cr-Meth chelate in broiler diets at 100 g/ton to improve the productive performance and reduce the oxidative stress of birds.

Effects of dietary inclusion of cassava starch-extraction-residue meal on egg production, egg quality, oxidative status, and yolk fatty acid profile in laying ducks.

This study was designed to evaluate the effects of different dietary levels of cassava starch extraction residue meal (CReM) on egg production, egg quality, oxidative status, egg yolk fatty acid profile, and hepatic expression of fatty acid metabolism-related genes. In total, 288 Longyan laying ducks aged 21 wk with similar BW were randomly assigned to 4 dietary treatments, each consisting of 6 replicates of 12 birds. The birds were fed a typical corn-soybean meal diet, which contained 0% (control), 5%, 10%, and 15% CReM, mainly replacing wheat bran, and the experiment lasted for 16 wk. The tested CReM levels did not show significant effects on the egg production, nonmarketable egg percentage, egg weight, daily egg mass, and FCR (g feed: g egg), but daily feed intake was reduced with increased CReM level (linear P < 0.001, quadratic P < 0.05). Yolk color increased (linear and quadratic, P < 0.01) with the increase in CReM level, but the Haugh unit, yolk proportion, albumen proportion, shell proportion, eggshell thickness, and eggshell strength were unaffected. Yolk contents of C11:0 and C12:0 (linear, quadratic, P < 0.01) and total saturated fatty acids increased, and the C22:1 level decreased (linear P < 0.01, quadratic P < 0.05) with the increase in CReM level, but the total monounsaturated fatty acids, the individual and total polyunsaturated fatty acids and n-6 and n-3 fatty acids, triglycerides, and total cholesterol in egg yolk were not affected. Hepatic gene expression revealed a significant increase in peroxisome proliferators-activated receptors γ (linear, quadratic, P < 0.001), but the expression of fatty acid synthase, sterol regulatory element binding protein 1 and apolipoprotein A1 genes were unaffected by CReM level. In conclusion, the results of the current study indicated that the CReM could be included up to 15% in laying duck diets without negative effects on the egg-laying rate, egg quality, and oxidative status. Dietary inclusion of CReM increased the yolk content of total saturated fatty acids and SOD activity in the liver.

Effect of Organic Selenium-Enriched Yeast on Relieving the Deterioration of Layer Performance, Immune Function, and Physiological Indicators Induced by Heat Stress.

Heat stress (HS) induces deleterious effects on the performance of laying hens and causes economic losses for poultry industry. This study was carried out to investigate the organic effect of selenium-enriched yeast (SY) on relieving the performance, immunity and physiological deterioration induced by heat stress in laying hens. A total of 324, 28-week-old, Hy-Line Brown commercial chicken layers were randomly distributed into 4 treatments according to a 2 × 2 factorial design, with 9 hens × 9 replicates per treatment (n = 81). From 30 to 34 weeks of age, layers were exposed to 2 temperature treatments (the HS treatment groups): a thermoneutral temperature at 24°C and a heat stress at 35°C. Layers were further assigned into the 2 subgroups according to dietary supplementation with organic selenium-enriched yeast (the SY treatment groups) at either 0 or 0.4 mg/kg diet. Results indicated that all the aspects of the layer performance during the experimental period were impaired by exposure to HS, while SY supplementation improved the layer performance in both the HS and non-HS layers. Intestinal villi disruptions and liver necrotic hepatocytes were observed in the layers exposed to HS, while villi integrity and hepatocytic normality were enhanced by SY treatment. A significant (P < 0.05) decrease in the total leukocyte count, sheep red blood cell (SRBC) antibody titer, and T- and B-lymphocyte proliferation along with an increase in the heterophils/lymphocytes (H/L) ratio were observed in the HS layers compared to non-HS layers. On the contrary, SY treatment significantly (P < 0.05) improved the immune function traits in both the HS layers and non-HS layers. Furthermore, the SY treatment plays an important role in mitigating the oxidative stress and inflammation induced by HS, displaying lower levels of plasma corticosterone, lipid peroxidation, interleukin-1ß, and tumor necrosis factor-α in HS layers supplemented with SY compared to HS layers without SY supplementation. These results conclude that addition of SY to the diet of laying hens could be applied as a potential nutritional approach to relieve the deterioration effects of heat stress on the immunity, physiological status, and productive performance of laying hens.

Evaluating dynamic effects of dietary glycerol monolaurate on the productive performance and flesh quality of large yellow croaker (Larimichthys crocea).

The effects of GML (Glycerol monolaurate) supplementation with two level (0.5 and 1.0 g kg-1) on the productive performance and flesh quality of large yellow croaker (360 per group) were investigated during feeding (23,50-days) and fasting stage (23,70-days). The GML supplementation significantly increased body weight after 23-days and crude protein, inosinic acid, and yellowness after 50-days. Moreover, it increased hardness, springiness, and chewiness by increasing the collagen content, myofiber density, and decreasing myofiber diameter. The high GML supplementation increased the total free amino acids, delicate amino acids, monounsaturated fatty acids (MUFA), polyunsaturated fatty acids (n-3 PUFA), and EPA + DHA, whereas it decreased the content of saturated fatty acids/unsaturated fatty acids (SFA/UFA). During fasting, better body shape and color were shown were shown at high GML supplementation. Conclusively, high dose GML supplementation exerted promising effects on the productive performance and flesh quality of large yellow croaker.

Effects of different levels of spirulina (Arthrospira platensis) supplementation on productive performance, nutrient digestibility, blood metabolites, and meat quality of growing Najdi lambs.

In a 90-day study, 32 growing lambs aged 3 months were utilized to evaluate the effects of various levels of spirulina dietary supplement on productive performance, nutritional digestibility, and meat quality in growing Najdi lambs. The lambs were put into 4 groups of 8 lambs each at random. The diet consisted of a total mixed ration (TMR) without spirulina (CONT), and the TMR diet supplemented with spirulina at the levels of 2 ppm (SPP2), 4 ppm (SPP4), and 8 ppm (SPP8). The treatment groups, especially SPP8, showed a significant (p < 0.05) increase in body weight and average daily gain (p < 0.05) compared to the CONT group. Dry matter intake and acid detergent fiber were also significantly (p ≤ 0.05) higher in SPP8 compared to other treated groups and CONT. The N absorption, N retention, and percentage of N digestibility coefficient were greater (P < 0.05) in lambs in the treatment groups than in the CONT. Blood biochemistry variables were not significantly (p ≤ 0.05) affected by the treatments, with the exception of the serum concentration of triglyceride and bilirubin. Carcass profile and meat quality, including back fat, body wall fat, and cooking loss, were increased significantly (p ≤ 0.05) with dietary spirulina. From the results of the present study, it was concluded that spirulina dietary supplementation at the level of 8 ppm increased weight gain, nutritional digestibility, nitrogen utilization, and meat composition in growing Najdi lambs.

Effect of dietary protease supplementation on growth performance, water quality, blood parameters and intestinal morphology of Nile tilapia (Oreochromis niloticus).

This study was conducted to evaluate the effect of using protease in diets of Nile tilapia on growth performance, water quality, blood parameters and intestinal morphology. The cost of these diets and their return on fish performance was calculated. A total of 360 fish were randomly allocated into four groups with triplicates (30 fish per replicate). Four diets were formulated; two controls (without protease supplementation) and two experimental diets (supplemented with protease). The first control diet contained the normal protein requirement (30% CP; control +ve), while the second control had a low protein content (29% CP; control -ve). The third diet was supplemented with protease at a dose of 500 g/ton, and its CP content was reduced to 29.0%, by reducing the fish meal content. The fourth diet contained the same CP level as the first control (30%) and supplemented with 250 g protease per ton feed. The experiment lasted for 14 weeks. The results showed that body weight and length, weight gain, specific growth rate, feed intake and feed conversion efficiency in the control -ve group (low CP) supplemented with protease were similar (p > 0.05) to that of the control +ve with normal CP content. However, these performance parameters were lower (p < 0.05) in fish fed low CP diet without protease supplementation. Providing protease to the control +ve diet improved all measured performance indices. The ammonia and nitrite concentrations of the water were reduced (p < 0.05) in control -ve and protease-supplemented groups. The height and width of intestinal villi were increased (p < 0.05) in fish fed diets containing protease. The inclusion of protease reduced the diet cost and also the feed cost of fish weight gain. In conclusion, supplementation of protease can improve the productive performance of fish, spare dietary protein and produce economical diets. Moreover, it can help in improving the water quality of fish via lowering the ammonia and nitrite contents, or through increasing the degradation of dietary protein.

Evaluation of origanum oil, hydrolysable tannins and tea saponin in mitigating ruminant methane: In vitro and in vivo methods.

The objective of this study was to investigate the effects of origanum oil (ORO), hydrolysable tannins (HYT) and tea saponin (TES) on methane (CH4 ) emission, rumen fermentation, productive performance and gas exchange in sheep by using in vitro and in vivo methods. The ORO, HYT and TES additive levels were normalized per kg dry matter (DM) in both in vitro and in vivo experiments: ORO-0, 10, 20 and 40 ml/kg; HYT-0, 15, 30 and 60 g/kg; and TES-0, 15, 30 and 60 g/kg, respectively. During in vitro incubation, 40 ml/kg ORO linearly decreased CH4 emission (p < 0.05); 20 and 40 ml/kg ORO cubically decreased carbon dioxide (CO2 ) production (p < 0.05), and rumen pH was cubically raised with the increasing ORO additive level (p < 0.01). The 60 g/kg HYT cubically decreased CH4 production (p < 0.05). The pH of 60 g/kg HYT was higher than that of 15 and 30 g/kg (p < 0.01); the pH of 20 g/kg TES was higher than that of 5 g/kg (p < 0.05). In the in vivo experiments, 40 ml/kg ORO inhibited dry matter intake (p < 0.01) cubically and reduced average daily gain (ADG) and feed conversion ratio (FCR) cubically (p < 0.05), and 20 or 40 ml/kg ORO linearly decreased CH4 production based on per day or metabolic weight (W0.75 ) (p < 0.05). Both 30 and 60 g/kg HYT linearly inhibited CH4 emission on the bases of per day and W0.75 (p < 0.05). The 20 g/kg TES improved the apparent digestibility of crude protein (p < 0.05), 10 and 20 g/kg of TES decreased CH4 emission (p < 0.05), and 5 g/kg of TES reduced O2 consumption and CO2 production (p < 0.05). In conclusion, these three plant extracts all showed the abilities on mitigating CH4 emission of sheep with appropriate additive ranges.