Improving effects of dietary rumen protected γ‐aminobutyric acid additive on apparent nutrient digestibility,growth performance and health status in heat‐stressed beef cattle

This study was aimed to investigate the effects of rumen‐protected γ‐aminobutyric acid (RP‐GABA) on apparent nutrient digestibility, growth performance and health status in heat stressed beef cattle. Fifty Jinjiang Yellow cattle were randomly assigned to 5 treatments (10 animals/treatment). Treatments 1 to 5 were basal diets affixed with 0 (control), 8, 16, 24 and 32 mg of RP‐GABA/kg of body weight (BW) respectively. The trial lasted 45 days. Apparent digestibility of crude protein (CP), crude fiber (CF) and calcium (Ca) quadratically increased with increasing RP‐GABA (p < .01), while apparent digestibility of phosphorus (P) tended to quadratically increase (p = .09). Dietary supplementation with increasing RP‐GABA linearly increased DM digestibility and average daily gain (ADG) (p < .01), whereas the feed to gain (F:G) ratio linearly decreased with increasing RP‐GABA (p < .01). The average daily feed intake (ADFI) value tended to linearly increase with RP‐GABA supplementation (p = .08). Total protein (TP), blood urea nitrogen (BUN) and malondialdehyde (MDA) levels quadratically decreased (p < .01) with increasing RP‐GABA, however albumin (ALB), glucose (GLU), superoxide dismutase (SOD), triiodothyronine (T3) and thyroxine (T4) levels quadratically increased (p ≤ .01). In conclusion, the present results indicated that dietary supplementation with RP‐GABA led to improved nutrient digestibility, growth performance and antioxidant status in heat stressed beef cattle.     

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.     

Utilization of unpeeled cassava (Manihot esculenta Crantz) root meal supplemented with or without charcoal by broiler chickens

A 42‐day feeding trial was conducted using 480‐day‐old, male Marshall broilers to study the utilization of unpeeled cassava root meal (UCRM) supplemented with or without 6 g/kg charcoal. The experimental design was laid out in a 3 × 2 factorial arrangement of treatments having three inclusion levels of UCRM (0, 100 and 200 g/kg) with or without 6 g/kg charcoal supplementation. Each treatment consisted of 80 birds replicated eight times with 10 birds per replicate. Main effect of inclusion level of UCRM and supplementation of charcoal showed reduced (p < 0.05) final live weight, weight gain, feed intake and apparent crude protein digestibility of the birds with increasing inclusion levels of UCRM. Birds fed diets supplemented with charcoal showed higher (p < 0.05) final live weight, weight gain and feed intake than birds fed diets without charcoal. Supplementation of charcoal in diet containing 100 g/kg UCRM resulted in improved (p < 0.05) weight gain when compared with birds fed similar diet but not supplemented with charcoal. Broilers fed diet containing no UCRM but supplemented with charcoal had the highest overall (p < 0.05) final live weight and weight gain, while birds fed diet containing 200 g/kg UCRM supplemented with charcoal recorded the poorest (p < 0.05) final live weight and weight gain. Serum glutamate oxaloacetate transaminase (SGOT) and serum thiocyanate concentration increased (p < 0.05) with increasing dietary inclusion levels of UCRM. Dietary supplementation of charcoal resulted in increased (p < 0.05) concentration of serum glucose and cholesterol and reduced (p < 0.05) SGOT concentration. Birds fed diets containing UCRM had high (p < 0.05) serum thiocyanate concentration irrespective of dietary supplementation or not with 6 g/kg charcoal. In conclusion, supplementation of diet containing up to 100 g/kg UCRM with 6 g/kg charcoal showed improved weight gain without any deleterious effect on serum metabolites.     

Supplementation of broiler diets with high levels of microbial protease and phytase enables partial replacement of commercial soybean meal with raw,full‐fat soybean

A 3 × 3 + 1 factorial, involving three levels of protease (0, 15,000 or 30,000 PROT/kg) and three levels of phytase (1,000, 2,000 or 3,000 FYT/kg), was used to evaluate the effect of replacing commercial soybean meal (SBM) with raw, full‐fat soybean (RFSB) at 75 g/kg of diet for broilers. A control diet was used for comparison. Each treatment was replicated six times, with nine birds per replicate. The concentration of trypsin inhibitors (TIs) in the test diets was approximately 10,193.4 TIU/kg. Regardless of enzyme supplementation, feed intake (FI) and body weight gain (BWG) of birds in the control group were superior to those on the test diets. Birds that received the protease‐free test diets had reduced FI and BWG, but when supplemented with protease, were similar to the control diet in BWG, FI (except 0–35 days) and feed conversion ratio (FCR). When the test diet was supplemented with elevated levels (extradose) of protease and phytase, the BWG was improved during 0–10 days (p = .05) and 0–24 days (p < .01). Regardless of protease supplementation, the weight of thighs was lower for birds fed the test diets. Birds that received the control diet had smaller weight of pancreas. Increasing the level of phytase supplementation reduced (p < .05) the weight of the pancreas. The apparent ileal digestibility (AID) of CP and AA was higher in birds on the control diets, but this was also improved in test diets by protease supplementation. The activities of trypsin (7%), general proteolytic (11%) and lipase (12%) were slightly increased because of protease supplementation. Mucosal depth and apparent villus surface areas were increased by about 2.9% and 20%, respectively, due to supplementation of elevated level of phytase. It can be concluded that RFSB could partially replace SBM in broiler diets, provided the diets are supplemented with elevated levels of protease and phytase.     

Influence of exogenous acid protease in broiler chickens fed corn–soybean meal-based diets

This study was conducted to determine the influence of exogenous acid protease (EAP) on growth performance, blood profiles, excreta noxious gas emissions, ileum digesta viscosity and apparent ileal digestibility in broilers. A total of 600 1-d-old broilers with average initial body weight of 47.0 ± 0.2 g were used in a 5-week feeding trial. The broilers were randomly allotted to 1 of 4 treatments with 10 replicate pens per treatment and 15 birds per cage. Dietary treatments consisted of: CON, basal diets; EAP1, CON + 2,700 exogenous acid protease unite (APU)/kg; EAP2, CON + 5,400 APU/kg; EAP3, CON + 8,100 APU/kg. The body weight gain (BWG) had a linear improvement when chicks fed 8,100 AP/kg diets from d 18 to 35 and overall (p < .05). Lower feed conversion ratio (FCR) was obtained in broilers fed 5,400 APU/kg and 8,100 APU/kg as compared with the CON during overall (p < .05). Birds fed diets supplemented with EAP diet led to a linear increase in the ileal digestibility of crude protein, energy and amino acids (lysine, methionine, cystine, threonine, isoleucine, leucine, histidine and tryptophan) compared with CON group (p < .05). In conclusion, based on our results, we suggest that supplementation with EAP diet was effective in improving growth performance through increasing ileal digestibility of some nutrients (crude protein, energy and amino acids) in broilers.     

Essential oils improved weight gain,growth and feed efficiency of young dairy calves fed 18 or 20% crude protein starter diets

The objective was to evaluate interactions between starter protein (180 vs. 200 g/kg, DM basis) and a mixture of essential oils (EOs; containing thymol, eugenol, vanillin, limonene and guaiacol) on growth, metabolic and ruminal functions of Holstein dairy calves. In a completely randomized 2 × 2 factorial design, 48 calves, 3 days old (averaging BW 42.7 ± 1.9 kg), were allocated into groups fed the following diets: (i) 180 g/kg CP with no EO (180P‐NEO); (ii) 180 g/kg CP with EO (180P‐EO); (iii) 200 g/kg CP with no EO (200P‐NEO); and (iv) 200 g/kg CP with EO (200P‐EO). The EO was supplemented as 1 g/kg of starter DM. Calves were fed ad libitum starter diet and were weaned at day 59 of age, but diets continued until day 80. There were no interactive effects of CP and EO on intake and growth. Pre‐weaning feed efficiency tended to be increased for 200P‐EO (p = .09). Average daily gain and feed efficiency during pre‐weaning period as well as weaning weight were increased (p < .05) by EO, whereas wither height was increased by EO (p = .03) and tended to be increased for 200P vs. 180P (p = .06). Post‐weaning blood urea nitrogen concentration tended to be lower in 180P vs. 200P (p = .08). Ruminal short‐chain fatty acids concentration was greatest in 200P‐EO. The EO increased both butyrate (p = .02) and propionate proportions (p = .01) and reduced acetate proportional ratio (p < .01). Ruminal ammonia‐N was tended to be lower in calves‐fed EO (p = .05) and was lower in those fed 180P vs. 200P (p < .01). In conclusion, supplementation of the starter diet with essential oil improved weight gain, growth and feed efficiency of dairy calves, irrespective of dietary protein content.     

Effect of oak (Quercus persica) acorn level on apparent digestibility,ruminal fermentation,nitrogen balance and urinary purine derivatives in pregnant goats

The aim of this experiment was to investigate the effect of dietary oak (Quercus persica) acorn (OA) level on dry matter intake (DMI), apparent nutrient digestibility, nitrogen (N) utilization, ruminal fermentation, protozoa population and urinary purine derivatives (PD) during the last 60 days of goat pregnancy. Twenty‐four multiparous pregnant goats (41.7 ± 2.3 kg BW) were assigned to one of three experimental diets consisted of control diet (C, without OA) and diets containing 20 (OA₂₀) or 40 g/100 g of OA (OA₄₀) on a DM basis in a completely randomized block design. Goats fed OA₄₀ had lower DMI (p < .01), DM (p < .01), OM (p < .01) and NDF (p < .05) digestibility, ruminal NH₃‐N concentration (p < .01), N intake (p < .01) and N retention (p < .01). Crude protein digestibility and ruminal acetate and total volatile fatty acid (VFA) concentration were lower in animals fed OA‐contained diets (p < .01), whereas ruminal propionate concentration was higher in goats fed the C diet (p < .01). Animals fed OA₄₀ had higher faecal N excretion and lower urinary N excretion (p < .01). Urinary PD was lower in goats fed diets containing OA in relation to those fed the C diet (p < .01). Total protozoa population decreased linearly with increasing OA level in the diet (p < .05). These results suggest that feeding OA, especially high level, has negative impacts on DMI, nutrient digestibility, VFA concentration, N retention and urinary PD excretion that may have adverse effects on metabolism and performance of pregnant goats.     

Marginal deficiencies of dietary arginine and methionine could suppress growth performance and immunological responses in broiler chickens

The present study was conducted to investigate the effects of different levels of dietary arginine (Arg) and methionine (Met) on performance, immune responses, and carcass characteristics of broiler chickens. A total of 540 day‐old Ross 308 broiler chicks were randomly assigned into the nine experimental diets, consisting five replicates of 12 birds each. Dietary treatments included three different levels (90%, 100%, and 110% of National Research Council [NRC] specifications) of either dietary Arg or Met, which were fed to the birds according to a 3 × 3 factorial arrangement of treatments during a 42 days feeding trial. Results showed that supplementation of Arg and Met into the deficient‐diets increased (p < .01) weight gains during all trial periods. Although average daily feed intake (ADFI) was not influenced by dietary treatments, increasing Arg up to 100% of NRC recommendations improved (p < .05) feed conversion ratio (FCR) throughout the trial period. Similarly, supplementation of deficient‐diets with Met improved FCR values. There was a significant (p < .01) Arg × Met interaction for ADFI during the starter period; increasing the dietary Arg level increased ADFI when the diets were deficient in Met, while had an opposite effect in diets containing higher dietary Met levels. On the other hand, dietary Met fortification improved (p = .067) FCR values to a greater extent in 110% Arg‐diets during the entire trial period. Although different levels of Arg and Met had no marked effects on carcass yield and abdominal fat percentage, supplemental Arg up to 100% of NRC values increased (p < .01) the relative weights of spleen and bursa of Fabricius. Furthermore, bursa weight was affected by Arg × Met interaction (p < .01), so that supplemental Arg level of 100% of NRC increased the relative bursa weight in birds that were fed diets containing 90% and 110% of Met. Serum uric acid level was decreased (p < .05) as a result of dietary Arg fortification up to 110% of NRC recommended values. Supplementation of deficient‐diets with Met decreased (p < .05) serum cholesterol level. Although Newcastle antibody titer was not affected by dietary Arg or Met levels, Arg fortification of deficient‐diets increased (p < .001) antibody responses against infectious bronchitis (IBV) and bursal (IBD) disease viruses. Similarly, Met supplementation of deficient‐diets increased IBD antibody titer. There were significant (p < .05) Arg × Met interactions for IBV and IBD titers; Met fortification of 110% Arg‐diets was more effective in increasing antibody titers. An increase in dietary Met level up to 100% of NRC values increased (p < .001) serum concentration of γ‐globulins. The present findings imply that supplemental Arg could affect feed efficiency and antibody responses when the diets were already fortified with a sufficient Met level.     

Growth,nutrient digestibility,ileal digesta viscosity,and energy metabolizability of growing turkeys fed diets containing malted sorghum sprouts supplemented with enzyme or yeast

Growth, apparent nutrient digestibility, ileal digesta viscosity, and energy metabolizability of growing turkeys fed diets containing malted sorghum sprouts (MSP) supplemented with enzyme or yeast were investigated using 120, 28‐day‐old male turkeys. Six treatments were laid out in a 3 × 2 factorial arrangement of treatments with three dietary inclusion levels of MSP (0, 50, and 100 g/kg) and supplemented with 200 mg/kg yeast (Saccharomyces cerevisiae) or 200 mg/kg of a commercial enzyme. The experiment lasted for the starter (day 28–56) and grower phases (day 57–84) of the birds. Each treatment group consisted of 20 turkeys replicated four times with five birds each. Data were analysed using analysis of variance while polynomial contrast was used to determine the trends (linear and quadratic) of MSP inclusion levels. Irrespective of dietary supplementation with enzyme or yeast, final body weight (BW), total BW gain, and feed intake for turkey poults from day 29–56 was reduced (p < 0.05) with increasing inclusion level of MSP. Dietary supplementation with yeast resulted in increased (p < 0.05) feed intake while enzyme supplementation improved (p < 0.05) feed conversion ratio of the poults. Turkeys fed enzyme‐supplemented MSP diets had higher (p < 0.05) BW gain than their counterparts fed yeast‐supplemented MSP diets. Apparent ash digestibility reduced linearly (p < 0.05) with increasing inclusion levels of MSP. Apparent metabolizable energy (AME) did not vary significantly (p > 0.05) with MSP inclusion levels . Enzyme supplementation reduced (p < 0.05) ileal viscosity but had no effect (p > 0.05) on AME. Inclusion of MSP resulted in poor growth performance. This confirms earlier studies that utilization of MSP by poultry is rather poor. Supplementation with enzyme or yeast did not lead to any appreciable improvement in performance of turkeys in this study.     

Physiological and health‐related response of broiler chickens fed diets containing raw,full‐fat soya bean meal supplemented with microbial protease

A 2 × 3 factorial study (protease: 0 or 1,5000 PROT/kg and raw full‐fat soya bean meal [RSBM] replacing the commercial SBM at 0, 45 and 75 g/kg of diet) was conducted to examine the performance of broilers. Phytase (2000 FYT/kg) was uniformly added to each diet, each also replicated six times, with eight birds per replicate. Birds were raised in climate‐controlled rooms using sawdust as the bedding material and offered starter, grower and finisher diets. Feed intake (FI) and body weight gain (BWG) were reduced (p < .05) due to increasing levels of RSBM, but feed conversion ratio (FCR; 0–35 days) was unaffected. Over the first 24 days, neither RSBM nor protease supplementation affected (p > .05) mortality, footpad dermatitis or intestinal lesions in birds. At day 24, the weight, length, width and strength of tibia bone were reduced in chickens that received an elevated level of RSBM (75 g/kg of diet), but this was not significant at day 35. At day 24 (p < .05) and 35 (p < .01), Ca concentration in the litter was reduced when the RSBM level was increased in the diet, but P content was not affected. On days 24 (p < .05) and 35 (p < .01), the N content in litter was also increased with increase in dietary RSBM. Protease supplementation increased (p < .05) the uric acid concentration in the litter (at day 35), but the reverse was the case for ammonia concentration. Overall, the results of this study indicate that there are no major health‐related risks, associated with the replacement of commercial SBM with RSBM (≤25%) in broiler diets.     

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.     

Performance and nutrient digestibility in growing pigs fed wheat dried distillers’ grain with solubles‐containing diets supplemented with phytase and multi‐carbohydrase

Effect of supplementing wheat dried distillers’ grain with solubles (DDGS)‐containing diet with enzymes on nutrient utilization by growing pigs was evaluated in two experiments. In Experiment 1, 60 pigs weighing ~30 kg were fed five diets that included a corn‐based diet (Control), Control with 10% wheat DDGS (DDGS‐PC), DDGS‐PC without inorganic P source (DDGS‐NC), and DDGS‐NC plus phytase alone or with multi‐carbohydrase for 4 weeks to determine average daily gain (ADG), average daily feed intake (ADFI) and gain‐to‐feed ratio (G:F). In Experiment 2, 30 barrows weighing 22 kg were fed five diets fed in Experiment 1 to determine nutrient digestibility and retention. Pigs fed DDGS‐PC and Control diets had similar ADG and G:F. The ADG and G:F for DDGS‐PC diet were higher (P < 0.05) than those for DDGS‐NC diet. Phytase improved (P < 0.05) ADG, G:F, total tract P digestibility and P retention by 6.6, 8.7, 86.0 and 85.5%, respectively. Addition of multi‐carbohydrase to phytase‐supplemented diet did not affected growth performance, but reduced (P < 0.05) P retention. In conclusion, inclusion of 10% wheat DDGS in growing pig diet may not affect growth performance of growing pigs. Phytase supplementation to wheat DDGS‐containing diet can eliminate the need for inorganic P supplement in pig diets.     

Significant effect of NSP‐ase enzyme supplementation in sunflower meal‐based diet on the growth and nutrient digestibility in broilers

The response of broiler chickens to 3 levels of sunflower meal and 2 levels of NSP‐ase enzyme combination (with and without) was investigated in 3 × 2 factorial arrangement under complete randomized design (CRD). A total of 240 Hubbard broiler chicks were fed on practical mash diets having 2950 kcal of ME and 21% CP from 1 to 42 days of age. The BW gain was not significantly reduced when 25% SFM was added in the diets during 1 to 42 days of age. Supplementation of NSP‐ase in broiler diets (day 1–42 overall) demonstrated non‐significant differences (p < 0.05) across the treatments in terms of FI and BWG. The difference in feed:gain at 15% or 20% SFM was observed to be non‐significant. Replacement of SBM with SFM or inclusion of SFM at higher level (25%) increased/deteriorated FCR. The addition of exogenous NSP‐ase showed a significant improvement (p < 0.01) in feed:gain. The improvement was clearly demonstrated when SFM was added to the experimental diet at 15% or even 20%. Supplementation of NSP‐ase at the 25% inclusion level could not, however, sustain the beneficial effect, which was possibly due to excessively high dietary CF. No difference was noted across the treatments regarding carcass response. Relative gizzard weight and intestinal weight were observed to be improved in birds consuming higher levels of SFM (p = 0.00). The digestibility of CF was observed to improve when SFM was used at 20% and 25% in the diets. No improvement in the digestibility of CF was observed with NSP‐ase supplementation, which meant other factors were clearly involved. Supplementation of NSP‐ase improved FCR up to 20% SFM. At 25% SFM, no improvement in the digestibility of CF was observed with NSP‐ase supplementation.     

Effect of lemon verbena powder and vitamin C on performance and immunity of heat‐stressed broilers

An experiment was conducted to investigate the effect of lemon verbena powder and vitamin C on performance and immunity of broilers under heat stress. The experiment was carried out with a total of 160‐day‐old male Ross 308 broiler chickens in a completely randomized design. From 25 days of age, the birds were assigned to four diets including control diet and treatment diets which were supplemented with 2 levels of lemon verbena (0.5% and 1.0%) and one level of vitamin C (250 mg/kg) in 16‐floor pens with 10 chickens each and reared to 42 days of age. To induce chronic heat stress, birds were exposed to an ambient temperature of 35 ± 2 °C for 8 h daily (from 09:00 AM until 17:00 PM) between 25 and 42 days of age. At the end of experiment, one chick/pen was randomly selected, and the performance and blood parameters were evaluated. Dietary supplementation of 1.0% lemon verbena increased (p < 0.05) average weight gain and feed intake by 5.81% and 3.29%, and reduced feed conversion ratio by 2.59% respectively compared to control group. Birds fed diets containing 1.0% lemon verbena had significantly higher relative weight of bursa of fabricius and breast (p < 0.05). LDL decreased by 15.85% and 17.57%, for birds fed 0.5% and 1.0% lemon verbena respectively. The ratio of heterophyl to lymphocyte was reduced (p < 0.05) by 20.68% via significant decrease in heterophyl by 15.55% and significant increase in lymphocyte by 4.51% in birds fed lemon verbena at the rate of 1.0% compared to those fed the control diet. 1.0% lemon verbena and vitamin C elevated (p = 0.0005) the level of glutathione peroxidase by 51.81% and 27.90%, respectively. In conclusion, lemon verbena and vitamin C improved some performance data and blood metabolites which somehow suppressed the negative effects of heat stress.     

Effects of different forage sources as a free‐choice provision on the performance,nutrient digestibility,selected blood metabolites and structural growth of Holstein dairy calves

The objective of this study was to determine the effects of different forage sources on the growth performance, nutrient digestibility and blood metabolites of dairy calves. Individually housed calves (n = 40; body weight = 41.2 ± 3.5 kg) were randomly allocated (n = 10 calves per treatment: five males and five females) to one of the following four treatments: (i) starter without forage provision (CON), (ii) starter plus chopped alfalfa hay (AH), (iii) starter plus chopped wheat straw (WS) and 4) starter plus dried sugar beet pulp (BP) flakes. Calves fed AH diets had lowest (p < 0.05) starter intake than those fed other diets, and WS promoted a significant increase (p < 0.01) in starter intake during 43–80 days. Forage intake was greatest (p < 0.01) for calves fed AH than those fed WS and BP. Calves in the AH treatment consumed less (p < 0.01) total dry matter intake than those offered other forage treatments. Final body weight was greatest (p < 0.05), and age of weaning was lowest for calves fed BP than other treatments. Calves in the BP treatment had greater (p < 0.05) average daily gain (ADG) than CON and WS treatments, but similar to AH calves. Digestibility of NDF and ADF was greater (p < 0.05) in BP treatment than other treatments. Calves fed BP had greater (p < 0.05) digestibility of DM and OM than those fed CON diets and similar to those fed AH and WS diets. Calves in the AH treatment had greater (p < 0.05) CP digestibility than CON, but similar to WS and BP calves. Blood beta‐hydroxybutyrate concentration was lower in forage‐offered calves than CON one. Body measurements (with the exception of body barrel) did not differ across treatments. It was concluded that BP improves final body weight, ADG and nutrient digestibility of calves than starter without forage provision during weaning transition.     

Yellow mealworm,Tenebrio molitor (Col: Tenebrionidae), larvae powder as dietary protein sources for broiler chickens: Effects on growth performance,carcass traits,selected intestinal microbiota and blood parameters

This study was conducted to evaluate the effects of dietary Tenebrio molitor larvae meal (TM meal) inclusion on the performance, carcass traits, caecum microbiota and blood parameters of broiler chickens. A total of 180-day-old chickens were allocated to three dietary groups with five replicate pens (12 birds/pen). Experimental diets were included a corn-soybean basal diet, and two diets with 2.5% and 5% TM. TM-included diets have been administered for periods of starter (1–10 days) and grower (11–25 days). A regular finisher diet was given to all groups during the 26–42 days of age. Diets containing TM meal did not influence feed intake and mortality percentage. Feed conversion ratio was lower with the 2.5% TM meal diet compared with the control group at starter period (p < .05). Besides, broiler chickens fed TM meal included diet had a higher body weight gain than the control group during 1–10 days of age (p < .05). The carcass characteristics and length and weight of different parts of small and large intestines were not influenced by diets. TM meal inclusion decreased the albumin-to-globulin ratio compared with the control group (p < .05). Additionally, lower total count of aerobic and Escherichia coli bacteria was observed in response to diet inclusion of 5% TM meal. Overall, the inclusion of TM meal in broilers' diet improved body weight gain and feed conversion ratio in the starting period, decreased albumin-to-globulin ratio and E. coli bacteria content.     

Processing traits and digestibility of extruded dog foods with soy protein concentrate

Soya bean protein concentrate (SPC) with two particle sizes were evaluated on extrusion parameters, kibble formation, digestibility and palatability of dog foods. Eight diets were extruded: PBM—control diet based on poultry by‐product meal (PBM); GM—a diet in which corn gluten meal (GM) replaced 45% of the diet protein; cSPC15%, cSPC30% and cSPC45%—diets in which SPC of coarse particle size (600 μm) replaced 15%, 30% and 45% of the diet protein; and sSPC15%, sSPC30% and sSPC45%—diets in which SPC of small particle size (200 μm) replaced 15%, 30% and 45% of the diet protein. The digestibility of nutrients was evaluated for the PBM, GM, cSPC45% and sSPC45% diets, using six dogs per food. The PBM, GM and cSPC45% diets were compared for palatability. Data were submitted for analysis of variance, and the means were compared by polynomial contrasts or Tukey's test (p < .05). The cSPC increased the specific mechanical energy (SME) application, extrusion temperature and pressure linearly, resulting in lower kibble density and higher expansion and starch gelatinization (SG) (p < .01). When comparing the PBM, GM, cSPC45% and sSPC45% diets, higher SME, extrusion temperature and pressure, SG and kibble expansion were verified for the cSPC45% diet (p < .05). The DM, fat and crude protein digestibility were similar among diets. Faecal pH, ammonia and lactate did not differ, demonstrating that the removal of oligosaccharides and soluble non‐starch polysaccharides of SPC produces an ingredient with mostly non‐fermentable fibre. Dogs preferred the PBM to the GM diet (p < .05), but consumed the PBM and cSPC45% foods equally. In conclusion, SPC exhibited good extrusion functionality, favouring kibble expansion and SG, with high digestibility, similar to that of PBM. The removal of soluble compounds from soya beans resulted in an ingredient with low fermentable fibre content, which did not alter faecal formation or characteristics.     

Interactive effect of corn particle size and insoluble fiber source on performance,nutrient utilization and intestine morphology in broilers fed pelleted diets

The effects of corn particle size and dietary fibre on the performance, coefficient of apparent ileal digestibility (CAID) and intestinal characteristics in broiler starters fed pelleted diets were studied. The experiment included 10 treatments arranged as a 2 × 5 factorial with two corn particle sizes (GMD of 1071 [CGC] vs. 534 [FGC]) and five diets that consisted in a low-fibre diet and four extra diets resulting from the inclusion of insoluble fibre sources (10 g/kg of lignocellulose (LC), and 30 g/kg of oat hulls; OH, rice hulls; RH, and sunflower hulls; SFH). In coarse grinding, all-fibre sources improved body weight gain and feed intake compared to the control diet (p < 0.01). Feed conversion ratio (FCR) improved with fibre supplementation (p < 0.01) and fine grinding of corn (FGC) (p < 0.01). Coarse grinding of corn (CGC) and inclusion of RH, SFH and OH reduced gizzard pH (p < 0.01). Fibre inclusion increased ileal fat and Ca digestibility (p < 0.01), gizzard weight (p < 0.01), digesta transit time (p < 0.01) and length of duodenum and small intestine (p < 0.01). The CAID of phosphorus increased in CGC fed birds and inclusion of RH, SFH and OH (p < 0.05). The weight of gizzard, proventriculus and pancreas (p < 0.01) was greater in CGC fed birds. Feeding SFH, RH and OH (p < 0.01), and CGC (p < 0.01) increased the villus height (VH) of the duodenum. The OH, RH and SFH supplementation increased the caecal population of Lactobacillus spp. and total anaerobic bacteria (p < 0.01) only in FGC fed birds. Overall, birds fed pelleted diets containing RH, OH and SFH (3%) exhibited improved performance, and increased nutrient digestibility, which may be caused by developed gizzards and intestine. Furthermore, coarse grinding of corn is beneficial to gizzard development.     

Effect of lactic acid bacteria‐treated King grass silage on the performance traits and serum metabolites in New Zealand white rabbits (Oryctolagus cuniculus)

This study examined the effects of Lactobacillus plantarum and Pediococcus acidilactici‐treated silage of King grass (Pennisetum purpureophoides) on the productive traits and blood biochemistry of New Zealand white (NZW) rabbits. King grass was ensiled without or with L. plantarum (T1), P. acidilactici (T2) and P. acidilactici + L. plantarum (T3). A total of 72 male NZW rabbits (6 weeks) of similar weight and appearance were housed in groups in metallic cages in a completely randomized design. The performance traits, daily feed intake, body weight gain and feed convention ratio were not affected by the silage treatment. Triglyceride and alanine aminotransferase (ALT) concentration was increased (p < .05) in T2 (0.92 mmol/L) compared to the other treatments. The superoxide dismutase (SOD), phosphorous (P) and magnesium (Mg) increased (p < .05) in T1 (658.01 nmol/ml, 5.1 mg/kg and 2.43 mg/kg, respectively) compared to the control and other experimental groups. Cu and Mn decreased (p < .05), while Zn increased (p < .05) in the treated groups compared to the control. The CP decreased (p < .05) in the treatment groups compared to the control. Neutral detergent fibre (NDF) increased (p < .05) in T2 (54.40%) compared to the other treatments. The inoculation of lactic acid bacteria‐treated King grass silage supplementation positively affected rabbit performance and improved blood cholesterol profile, antioxidant status and improve nutrients digestibility.