Effects of rearing system on meat quality,fatty acid and amino acid profiles of Hu lambs

To determine the effects of early rearing system on meat quality traits, fatty acid and amino acid profiles of meat, 48 Hu lambs were selected and randomly divided into four treatments: control lambs were ewe‐reared from birth to 60 days of age (ER), while treatment lambs were segregated from their dams at 10, 20 and 30 days of age, then artificially reared with milk replacer until 60 days of age (EW10, EW20 and EW30, respectively). All lambs had no access to the milk replacer or their dams from 61 to 90 days. Creep feed was supplied ad libitum to all lambs from 15 to 90 days of age. Artificially reared lambs (EW10, EW20 and EW30) had higher (p < .05) creep feed intake, average daily gain, slaughter weight, hot carcass weight, meat ether extract content, bright meat color (lightness and yellowness) than ewe‐reared lambs. The content of unsaturated fatty acids and monounsaturated fatty acids in EW10 and EW20 were greater (p < .05) than that in ER, whereas the proportions of saturated fatty acids in EW10 and EW20 were lower than that in ER (p < .05). The percentages of C18:0, C18:2, C18:3 and the ratio of polyunsaturated fatty acids and saturated fatty acids of artificially reared lambs were greater than ewe‐reared lambs (p < .05). The meat proportions of leucine, alanine and proline were higher (p < .05) in artificially reared lambs than ewe‐reared ones. Finally, the artificially reared system increased meat production and changed the fatty acid and amino acid profiles of meat, and it would be appropriate to rear Hu lambs artificially from 10 days with milk replacer.     

Effects of polyphenolic extract from Eucommia ulmoides Oliver leaf on growth performance,digestibility, rumen fermentation and antioxidant status of fattening lambs

To investigate the effects of polyphenolic extract from Eucommia ulmoides Oliver leaf (PEEU) on growth performance, digestibility, rumen fermentation and antioxidant status of fattening lambs, 30 weaned male Huzhou lambs were equally divided into three treatments and fed the basal diet supplemented with 0 (CON), 5 (PEEU5) or 10 (PEEU10) g/kg PEEU. Dietary PEEU supplementation did not affect growth performance and apparent digestibility of nutrients. Compared with the CON group, lambs in the PEEU10 group had lower ammonia nitrogen concentration (p < .01) and acetic acid to propionic acid ratio (p < .05) and higher the molar proportion of propionate (p < .05) in rumen fluid. Ammonia nitrogen concentration (p < .01) and the molar proportion of propionate (p < .05) were affected by an interaction between PEEU and sampling day. Dietary PEEU supplementation at 10 g/kg increased total antioxidant capacity (p < .05), superoxide dismutase (p < .05) and glutathione peroxidase (p < .01) activities in serum and glutathione peroxidase activity (p < .05) in liver and decreased (p < .05) malondialdehyde content in serum and liver compared with the CON group. In conclusion, dietary PEEU supplementation affected rumen fermentation patterns and improved antioxidant status of fattening lambs.     

Effects of dietary energy level on growth performance,blood parameters and meat quality in fattening male Hu lambs

This experiment was conducted to investigate the effects of different dietary energy levels on growth performance, slaughter traits, meat quality and blood biochemical parameters in fattening male Hu lambs. Sixty lambs were fed five iso-protein diets which contained different levels of metabolizable energy in a completely randomized design for 70 days. At the end of study, fifteen lambs were harvested for further study. With the increase in dietary energy level, the daily weight gain and dry matter intake extremely increased (p < .001), and feed conversion ratio decreased significantly (p < .01). The live weight before slaughter (LWBS) and carcass weight had a significant increase (p < .05), non-carcass fat ratio and routine indexes of meat quality had no significant difference. Almost no effect was observed for the amino acid profile except for glycine concentration decreased (p < .05) in longissimus dorsi (LD) muscle. The concentrations of C17:0, C18:3n-3 and n-3 PUFA (p < .01) significantly decreased with the increasing dietary energy levels, and the ratio of ∑n-6/∑n-3 (p < .01) increased, whereas the concentrations of C18:1n-9t (p < .05) decreased in LD muscle and C18:1 (p < .01) increased in biceps femoris (BF) muscle. There were no obviously differences for diameter, area and density of muscle fibres. The relative expression of MyHC-IIa and MyHC-IIx decreased significantly (p < .05) in BF muscle, and the relative expression of MyHC-IIa displayed an obviously decreasing trend (p < .10) in LD muscle. These results suggest that increasing the dietary energy level can improve the growth performance and slaughter traits, and influence meat quality and fatty acid profiles in different muscle tissues of fattening male Hu lambs. These results provide a theoretical basis for developing Hu sheep nutritional standards and designing feed formulations.     

Effect of L‐theanine on meat quality,muscle amino acid profiles,and antioxidant status of broilers

This study investigated the effect of L ‐theanine on carcass traits, meat quality, muscle antioxidant capacity, and amino acid (AA) profiles of broilers. Three hundred 1‐day‐old Ross 308 male broilers were randomly allotted to five groups with six replicates. Birds were fed the basal diet or basal diet with 300, 600, 900, or 1,500 mg/kg L ‐theanine for 42 consecutive days. The results showed that L ‐theanine quadratically increased dressing percentage, eviscerated percentage, and leg muscle yield (p < .05). Meanwhile, drip loss, cooking loss, shear force, L*_24h, and muscle lactate content decreased quadratically in response to dietary L ‐theanine supplementation (p < .05), while pH_24h and muscle glycogen content were quadratically improved by L ‐theanine (p < .05). Notably, the contents of muscle malondialdehyde and protein carbonyl, and the activities of muscle total antioxidant capacity, catalase, and glutathione peroxidase decreased quadratically in response to dietary L ‐theanine supplementation (p < .05), suggesting that the oxidative stress level of muscle was decreased quadratically. Moreover, L ‐theanine quadratically increased the concentrations of most of muscle essential AA, nonessential AA, and flavor AA (p < .05). In conclusion, L ‐theanine can be used as a valuable feed additive to modulate carcass traits, meat quality, muscle antioxidant status, and AA profiles of boilers, and its optimum addition level is 600 mg/kg based on the present study.     

Effect of alfalfa (Medicago sativa L.) saponins on meat color and myoglobin reduction status in the longissimus thoracis muscle of growing lambs

The effect of alfalfa saponins (AS) supplementation on the meat quality especially the color for growing lamb was investigated. Fifty Hu male lambs with body weights (BW, 19.21 ± 0.45 kg) were divided into five groups and supplemented AS with 0, 500, 1,000, 2,000, and 4,000 mg/kg of dietary dry matter intake. After 90 days, all lambs were slaughtered. The longissimus thoracis muscle in lamb displayed significant changes in the content of intramuscular fat, especially n-3 polyunsaturated fatty acids, and drip loss within AS treatment (p < .05) between control and treatments groups. Redness (a*) significantly improved in both 0-day and 7-day storage with the AS supplementation coupled with the percentage of met-myoglobin reduction (p < .05). The redness (a*) change may result from improved met-myoglobin reducing activity, antioxidant enzymes, lactate dehydrogenase, and succinate dehydrogenase (p < .05) by AS supplementation in muscle. These enzymes may help to protect mitochondria function and reduce met-myoglobin, which bring a bright and red meat color.     

Carcass characteristics,chemical and fatty acid composition and oxidative stability of meat from broiler chickens fed black cumin (Nigella sativa) seeds

A study was conducted to investigate the dietary supplementation of black cumin seeds (BCS) on carcass characteristics, chemical and fatty acid (FA) composition and antioxidant properties of thigh and breast meat of broiler chickens at 42 days of age. Three hundred sixty 1‐day‐old broiler chickens were allocated to five dietary treatment groups (each group containing eight replicate pens with each pen containing nine broiler chickens): basal diet (control; CON), CON + 0.05 g/kg of bacitracin methylene disalicylate (AB), CON + 5 g/kg of BCS (low dose of BCS), CON + 10 g/kg of BCS (medium dose of BCS) and CON + 20 g/kg of BCS (high dose of BCS). Weight (g) of slaughtered birds (p = .03), hot carcass (p = .007), breast (p = .03), thigh (p < .001), wing (p = .06), neck (p = .01), liver (p = .09), abdominal fat (p = .01) and total edible parts (p = .01) increased or tended to increase due to BCS supplementation compared with the CON. The concentrations of dry matter, crude protein and ether extract in chicken thigh and breast meat increased (p = .038 to <.001) with increasing doses of BCS in diets. The ferric reducing antioxidant activity in blood and meat increased linearly with increasing doses of BCS in the diets. However, peroxide values in meat were not affected by BCS and AB on both days 1 and 7 of storage at 4°C. Supplementation of BCS increased the concentrations of C14:1, C18:3n‐6, C20:1, C20:2 FA and PUFA linearly (p < .05) and tended to increase (p = .098) the concentration of C18:2cis linearly. However, the concentrations of C16:0 and C16:1 FA decreased linearly with increasing doses of BCS in the diets. In conclusion, dietary supplementation of BCS at 20 g/kg diet may improve slaughter body weight, beneficial FA concentrations and antioxidant properties of broiler chicken meat.     

The effect of grapeseed oil on performance,rumen fermentation,antioxidant status and subcutaneous adipose fatty acid profile in lambs

This experiment was carried out to examine the effect of grapeseed oil (GSO) on performance, rumen fermentation, antioxidant status and subcutaneous adipose fatty acid (FA) profile in lambs. Eighteen Baluchi lambs, 196 ± 14 days of age and 39.8 ± 1.7 kg body weight, were randomly assigned to three experimental diets: (i) diet without GSO (control), (ii) diet containing 2% of GSO (GSO2) and (iii) diet containing 4% of GSO (GSO4) for 42 days. Results showed that the experimental diets had no significant effect on dry matter intake and performance (p > 0.05). The supplemented diets with GSO had no effect on pH and NH₃‐N of rumen fluid (p > 0.05), but GSO4 increased (p = 0.003) the concentration of propionic acid and reduced (p = 0.002) the concentration of acetate acid compared to the control. Inclusion 4% of GSO to the diet increased total antioxidant activity and decreased malondialdehyde in serum and muscle (p < 0.001). The level of blood glutathione peroxidase in diets containing GSO was higher than control diet (p = 0.02), but diets had no effect on superoxide dismutase in blood and muscle tissues (p > 0.05). The concentration of vaccenic acid, rumenic acid and linoleic acid and thus polyunsaturated fatty acid in subcutaneous fat was affected by experimental diets (p < 0.001), as control had the lowest amount of these FAs and GSO4 had the highest amount of them. Therefore, it can be concluded that the use of GSO up to 4% improves the antioxidant status and adipose fatty acid profile in lambs without effects on performance.     

Effect of hay with or without concentrate or pellets on growth performance and meat quality of Ujimqin lambs on the Inner Mongolian Plateau

This study aimed to evaluate growth performance and meat quality of Ujimqin lambs fed native grass hay without or with concentrate (HC) or pellets. Ninety non-castrated 6-month-old male lambs of good health and similar body weight (26.83 ± 0.26 kg) were randomly divided into three groups (five lambs per cage). The average daily gain and intake of the pellets and HC groups were significantly greater (p < .05) than those in the hay group. The carcass weight, net meat mass, loin eye area, and backfat thickness were significantly greater (p < .05) in the HC groups. The intramuscular fat was significantly greater (p < .05) in the pellets and HC groups, while the shear force was significantly decreased (p < .05) in pellets and HC groups. The C16:0, C18:0, C18:1n9c, and C18:2n6 contents were significantly greater (p < .05) in the HC and pellet groups, while the C18:3n3 content was significantly greater (p < .05) in the hay group. Collectively, the present study suggested that feeding native grass hay with concentrate or pellets improved the growth in lambs.     

Effect of dietary polyphenol‐rich grape seed on growth performance,antioxidant capacity and ileal microflora in broiler chicks

In this study, we examined the effect of dietary supplementation with grape seed (GS) on the performance, carcass traits, plasma biochemistry, antioxidant status and ileal microflora in broilers. Experiment diets included a control diet (without additive) and three levels of GS powder (10, 20 and 40 g/kg of diet). Each diet was fed to a total of 300 one‐day‐old Cobb‐500 chicks for 42 days. The addition of 20 g/kg of GS to the basal diet increased final body weight and body weight gain, improved the feed conversion ratio and did not affect feed intake. Dietary 20 g GS significantly increased (p < .05) the percentage of carcass yield %, dressing % and gizzard. However, the addition of 40 g/kg of GS significantly reduced the percentage of abdominal fat in the birds. Diets supplemented with GS showed the lowest content of ether extract compared with the control group (p < .05). The physical characteristics of meat and the chemical composition of DM, CP and ash were not significantly influenced by treatments. In the GS groups, plasma protein, albumin, globulin, aspartate aminotransferase and alanine aminotransferase concentrations showed no significant change compared with the control group. Broilers fed a diet supplemented with GS had lower levels of plasma glucose, total lipids, triglycerides and cholesterol compared with the control birds (p < .05). The addition of 40 g of GS significantly (p < .05) enhanced the activity of reduced glutathione, catalase, superoxide dismutase, glutathione peroxidase and GST, and correlated with significantly decreased thiobarbituric acid‐reactive substances levels compared with the control group. The value of ileal pH was not significantly affected by the GS levels. Broilers fed diets supplemented with GS had lower ileal Streptococcus spp. and Escherichia coli populations but higher Lactobacillus spp. populations (p < .05). No adverse effects on birds’ health were detected due to the use of GS. Thus, GS could be recommended as an herbal supplement in the diet of broiler chickens to improve performance, reduce blood lipids, enhance antioxidant capacity and decrease detrimental bacteria in the ileum.     

Plantago ovata in broiler chicken nutrition: Performance,carcass criteria,intestinal morphology,immunity, and intestinal bacterial population

In this experiment, the effect of dietary Plantago ovata (PO) on performance, carcass criteria, intestinal morphology, immunity, and intestinal bacterial population of broiler chickens was evaluated. A total of 250 one‐day‐old male broiler chicks (Ross 308) were randomly assigned to five treatments containing 0, 5, 10, 15, or 20 g/kg of PO with five replicate pens and 10 birds in each replicate. Dietary PO increased body weight gain and decreased feed conversion ratio in the finisher period, improving the performance index (p < .05). Dietary treatments had no effects on carcass criteria, but breast meat percentage showed an increasing trend with incremental levels of PO in the diet (p = .069). The length of small intestine, especially jejunum section, as well as the villus height, villus width, villus area, and goblet cell numbers were significantly increased with supplemental PO (p < .05). Humoral and cellular immunity parameters, and oxidation stability of meat were improved due to use of dietary PO (p < .05). Dietary PO decreased the CFU of Escherichia coli, whereas the Lactobacilli population was increased (p = .001). Broken‐line regression revealed that dietary PO at the rate of 10 g/kg may results in the best performance in broiler chickens. This study showed that PO at the level of 10 g/kg could be considered as a beneficial feed additive in broiler diet.     

Effects of increasing amount of dietary Prosopis laevigata pods on performance,meat quality and fatty acid profile in growing lambs

A study with finishing lambs assessed the effect of dietary inclusion of Prosopis laevigata pods (PLPs) on performance, carcass characteristics, meat traits and fatty acid profile of subcutaneous fat. Twenty‐one Rambouillet lambs (27.0 ± 3.0 kg BW) were assigned to one of three experimental diets with 0, 150 and 300 g PLP/kg DM. Evaluation of growth performance lasted 49 days. The experimental design was completely randomized and analysed with a mixed model. Lambs fed diets with 0, 150 and 300 g PLP had similar growth performance. Lambs fed diets with 300 g PLP/kg DM had better (p < 0.05) carcass yield and classification, less (p < 0.05) fat deposition and lower lightness (L*) value (p < 0.05) in meat than lambs fed diets with 0 and 150 g PLP/kg DM. Saturated fatty acids (palmitic and stearic) decreased (p < 0.05) and unsaturated fatty acids (oleic and linoleic) increased (p < 0.05) in subcutaneous fat of lambs fed diets with 150 and 300 g pods as compared with lambs not fed PLP. Prosopis laevigata pods are a safe feedstuff that can replace a third of conventional ingredients and reduce feed costs in growing lambs. Addition of PLP reduced (p < 0.05) total feed cost by 21%.     

Carcass characteristics and meat quality of lambs fed with cassava foliage hay and spineless cactus

The objective of this study was to evaluate the influence of the total or partial replacement of Tifton 85 hay (TH) by cassava foliage hay (CH) and/or spineless cactus (SC) on the carcass characteristics and meat quality of confined lambs. Thirty-five Dorper x Santa Inês crossbred lambs were used, with an initial average weight of 16.0 ± 1.9 kg, fed with five treatment diets: 70% TH, 70% CH, 35% TH + 35% CH, 35% TH + 35% SC, and 35% CH + 35% SC. After 90 days of confinement, the animals were slaughtered and the carcass and meat data were compared using the Tukey test at 5%. The partial replacement of TH by SC increased the cold carcass weight by 3.9 kg (p < .05). The proportion of fat (%) increased (p < .05) when TH was replaced by CH + SC. The intensity of red (a*) was lower (p < .05) in the meat of animals fed with CH or CH + SC. It is recommended to partially replace TH with SC, or to replace totally with CH in association with SC.     

Effects of milk thistle meal on performance,ileal bacterial enumeration,jejunal morphology and blood lipid peroxidation in laying hens fed diets with different levels of metabolizable energy

This study was conducted to evaluate the effects of different levels of milk thistle meal on performance, blood biochemical indices, ileal bacterial counts and intestinal histology in laying hens fed diets containing different levels of metabolizable energy. A total number of 200 Leghorn laying hens (Hy‐Line W‐36) were randomly assigned to eight experimental treatments with five cage replicates of five birds each. Dietary treatments consisted of four levels of milk thistle meal (0%, 15%, 30% and 60%) and two levels of AME_n (11.09 and 12.34 MJ/kg) fed over a period of 80 days. In vitro studies revealed that the total phenolic component of milk thistle meal was 470.64 mg gallic acid equivalent/g of the sample, and its antioxidant activity for inhibiting the 2‐2‐diphenyl‐1‐picrichydrazyl free radical and reducing ferric ions was about 21% higher than that of butylated hydroxyltoluene (p < .05). Diets containing high level of AME_n led to improved egg production (p < .05), egg weight (p < .05), egg mass (p < .01) and feed conversion ratio (p < .01). In addition, offering diets containing high energy significantly enhanced (p < .01) serum triglyceride and malondialdehyde (MDA) concentrations as well as jejunal villus height. Dietary supplementation of 3% milk thistle meal resulted in the best feed conversion ratio (p < .05), reduction of ileal Escherichia coli enumeration (p < .01) and an enhancement in the villus height‐to‐crypt depth ratio (p < .05). Furthermore, feeding incremental levels of this meal led to remarkable decrease in serum cholesterol, triglyceride and MDA (p < .01) concentrations while significant increase in blood high‐density lipoprotein content and goblet cell numbers (p < .05). The present findings indicate that milk thistle meal with high antioxidant and antibacterial properties in laying hen diets may improve health indices and productive performance.     

Different levels of selenomethionine on the meat quality and selenium deposition in tissue of finishing pigs

The aim of the study was to verify the influence of selenomethionine (SM) supplementation on performance, carcass yield, characteristics of meat quality and Se tissue deposition of finishing pigs. A total of 128 hybrid pigs with an average weight of 76 kg were distributed in randomized blocks according to body weight in eight treatments and eight replicates. The experimental treatments were two Se levels from sodium selenite‐SS (0.3 and 0.6 ppm), four Se levels from SM (0.3, 0.4, 0.5 and 0.6 ppm) and two combinations of SS with SM (SS 0.15 + SM 0.15 ppm and SS 0.3 + SM 0.3 ppm) providing 0.3 and 0.6 ppm Se in the diet respectively. The feeds were based on corn and soya bean meal. After 30 days on test, were analysed the performance indices and the pigs were slaughtered at commercial slaughterhouse. The cold carcass yield, the physicochemical characteristics of the loin meat and the Se content in muscle and liver were evaluated. There was no significant difference in performance indices (p > .05); however, there was a linear effect on the increase in pig carcass yield by increasing SM (p < .05). The use of SM solely or combined with SS provided higher Se deposition in muscle compared to SS (p < .05). The highest Se deposition in muscle occurred for SM at 0.4 ppm (p < .05). The SS provided higher Se deposition in liver (p < .05). The SM presented best results for meat quality compared to other sources (p < .05). The level of 0.4 ppm Se promoted the best results for the indices of yellow, luminosity, cooking loss and pH (p < .05). The use of SM at any level promotes higher oxidation stability of pig meat (p < .05). The supplementation of SM at a level of 0.4 ppm promotes better physicochemical characteristics and higher Se deposition on swine meat.     

Magnolol additive improves carcass and meat quality of Linwu ducks by modulating antioxidative status

Magnolol rich in Magnolia officinalis is a bioactive polyphenolic compound. The aim of this study was to clarify the effects of magnolol additive (MA) on carcass and meat quality, biochemical characteristics and antioxidative capacity of Linwu ducks, by comparing it to that of antibiotic additive (colistin sulphate, CS). A total of 275 49‐d‐old ducks were randomly assigned to 5 groups with 5 cages of 11 ducks each and fed by the diets supplemented with 0, 100, 200 and 300 mg of MA/kg and 30 mg of CS/kg for 3 weeks, respectively. The results revealed that MA administration not only increased dressed percentage (calculated as a percentage of live weight), percentage of breast muscle, leg muscle and lean meat (calculated as a percentage of eviscerated weight), but also remarkably increased a*_{45 min} and pH_{45 min} of leg muscle. Moreover, MA administration decreased the percentage of abdominal fat (calculated as a percentage of eviscerated weight), 45‐min cooking loss, water loss rate of leg muscle, 45‐min cooking loss and drip loss of breast muscle at 24 hr and 48 hr. Furthermore, MA administration enhanced the activities of superoxide dismutase and catalase in serum or liver, serum total antioxidant capacity and hepatic reduced glutathione concentration significantly, compared with the basal diet or CS group (p < .05). On the other hand, triglyceride, total cholesterol, aspartate aminotransferase, malondialdehyde, protein carbonyl and 8‐hydroxy‐2'‐deoxyguanosine contents in serum and liver were significantly increased in Linwu ducks fed with CS, compared with MA groups (p < .05). Taken together, these data demonstrated that magnolol could effectively improve the carcass and meat quality of Linwu ducks by regulating the in vivo antioxidant status and would be a potential candidate to replace antibiotic.     

Effects of pearl millet silage ammoniation with urea on carcass and meat quality of lambs

This study aimed to evaluate the effect of pearl millet silage ammoniated with urea on lamb carcass characteristics and meat quality. Thirty‐two noncastrated crossbred lambs at 4–5 months of age, with an average initial body weight of 17.39 ± 2.16 kg, were distributed into four treatments in a randomized block experimental design with eight animals per treatment. Experimental diets were composed of pearl millet silage ammoniated with four levels of urea (0%, 2%, 4% and 6%, on dry matter basis (DM). Carcass conformation and fatness decreased linearly (p < 0.05). Except for the fat content, the proximate composition was not influenced (p < 0.05) by the diets. Meat lightness and yellowness increased linearly (p < 0.05). There was no effect of diets (p > 0.05) on cooking losses or shear force. The levels of oleic and erucic fatty acid levels in the meat decreased linearly (p < 0.05), whereas linoleic and eicosadienoic acids, polyunsaturated fatty acids, PUFA:SFA ratio and ω6 contents increased (p < 0.05). Pearl millet silage ammoniated with urea allows for the production of good‐quality lamb meat, with greater concentrations of polyunsaturated fatty acids. However, lambs fed diets with pearl millet ammoniated with up to 6% lead to a reduction of carcass characteristics without significantly affecting loin‐eye area possibly associated with low palatability of the additive used. The lower acceptance of the silages with higher levels of urea is due to the ammonia retention in the material is attributed to the ammonization process. Thus, in spite of the benefits on lamb meat quality, it is suggested that the use of this additive in the ammonization of tropical forages be carried out with care, in limits of up to 6%.     

Exogenous protease supplementation of poultry by‐product meal‐based diets for broilers: Effects on growth,carcass characteristics and nutrient digestibility

An experiment was conducted to investigate the effects of three levels (0%, 3% and 6%) of poultry by‐product meal (PBM) with or without protease on broiler growth, carcass characteristics and nutrient digestibility from 1 to 35 days. Two hundred and forty birds (n = 240) were fed equi‐caloric and equi‐nitrogenous (ME 2850 kcal/kg; CP 20%) diets throughout the experiment. The enzyme supplementation increased feed intake (p < .01) and body weight gain (p < .01), but feed:gain remained unaffected (p > .05) from 1 to 21 days. Increasing level of PBM decreased feed intake (p < .05), but body weight gain was improved (p < .05) at 3% PBM level during 1 to 21 days. The feed:gain was improved (p < .05) in birds fed diets containing 3% PBM. The feed:gain was also improved in birds fed diets containing 3% PBM from 1 to 35 days. However, feed intake and body weight gain in birds fed diets containing PBM remained unaffected. An interaction (p < .01) on feed intake between enzyme and PBM was noticed during 1 to 21 days. However, no interaction was recorded for body weight gain and feed:gain. The per cent carcass yield improved (p < .01) in birds fed diets supplemented with enzyme. The per cent breast meat yield was depressed (p < .005) in birds fed diets containing PBM. Apparent metabolizable energy (p < .001), nitrogen retention (p < .01), apparent metabolizable energy corrected for nitrogen (p < .001), and apparent digestibility coefficient for nitrogen (p < .01) improved in birds fed diets containing enzyme; however, a reverse was noticed in those fed diets containing only PBM. In conclusion, inclusion of 3% PBM along with supplementation of exogenous protease improved performance and nutrient digestibility in broilers.     

Effects of Moringa oleifera leaves as a substitute for alfalfa meal on nutrient digestibility,growth performance,carcass trait,meat quality,antioxidant capacity and biochemical parameters of rabbits

This contribution reports the effects of Moringa oleifera leaves (MOLs) meal on the growth performances, nutrient digestibility, carcass trait, meat quality, antioxidant capacity and biochemical parameters of growing New Zealand white rabbits. The MOL was substituted for alfalfa meal at levels of 0, 10%, 20% and 30% to obtain respective diets MOL0, MOL10, MOL20 and MOL30. Each treatment was replicated five times with 10 rabbits per replicate. Results showed the average daily weight gain (ADWG) and feed conversion ratio (FCR) of rabbits fed MOL20 diet were significantly better (p < 0.05) than those of other three dietary groups. Liver and spleen index of rabbits fed MOL20 and MOL30 diets was significantly higher (p < 0.05) than that of the groups fed with lower M. oleifera leaves (MOL0, MOL10). The meat drip loss of rabbits fed with diet MOL10 was significantly lower (p < 0.05) than that of rabbits fed other diets. All rabbits fed MOL dietary groups had lower (p < 0.05) shear force of longissimus dorsi than the group without M. oleifera leaves. No significant differences were found in the digestibility of crude fibre (CF), crude fat (EE), ash, crude protein (CP) and nitrogen‐free extract (NFE) among the dietary groups. Moringa oleifera leaves also have a significant impact on serum albumin (ALB), low‐density lipoprotein cholesterol (LDLC), triiodothyroxine (T₃) and tetraiodothyroxine (T₄) values and the activity of superoxide dismutase (SOD) and catalase (CAT) in serum and liver. The results indicated that M. oleifera leaves could be developed as a good feed source, and it not only could substitute for alfalfa meal well but also has a significant effect on growth performance, meat quality, antioxidant and biochemical parameters of rabbits.     

Effects of different stocking densities on growth performance,antioxidant ability,and immunity of finishing broilers

The study was conducted to evaluate the effects of different stocking densities on growth performance, antioxidant capacity, and immunity of broilers. One thousand four hundred and forty 22‐day‐old Lingnan Yellow broilers were randomly allotted to five different stocking density groups (8, 10, 12, 14, and 16 birds per m²). Each group consisted of three replicates. The results showed that 8 and 10 birds/m² groups had higher average daily feed intake (ADFI) than the others (p < 0.05). Heat shock protein 70 (HSP₇₀) in the group of 16 birds/m² had the highest levels (p < 0.05). The group of 16 birds/m² had the lowest total antioxidant capability (T‐AOC) and total superoxide dismutase (T‐SOD) activities in blood serum (p < 0.05), and significantly increased interleukin‐1β (IL‐1β) and interleukin‐4 (IL‐4) concentration compared to the groups of 8 and 10 birds/m² (p < 0.05). In liver, the group of eight birds/m² had higher T‐AOC levels than that of 12, 14, and 16 birds/m² (p < 0.05) and also higher catalase (CAT) activities than that of 14 and 16 birds/m² (p < 0.05); the group of 10 birds/m² had the highest T‐SOD activities among all groups (p < 0.05). In conclusion, the above results suggest that stocking density of broilers up to 8 or 10 birds/m² can prevent the negative effects on growth performance and welfare parameters in broilers.