Positive Control Diet Research Articles

Effects of added phytase on growth performance, carcass traits, and tibia ash of broiler chickens fed diets with reduced amino acid, crude protein, and phosphorus concentration

This experiment was conducted to investigate the effect of phytase supplementation in diets reduced in amino acids ( AA ), crude protein ( CP ), and phosphorus ( P ) on growth performance, carcass traits, and tibia ash of broiler chickens. A total of 2,240 unsexed Ross 308 broiler chickens were used in 56 floor pens with 40 birds each and fed one of eight dietary treatments in seven replicates until 35 d of age. A positive control ( PC ) diet and diets with dietary AA/CP level reduced by 2, 4, and 6% were used with and without supplementation with 1,500 FTU phytase/kg. Starter, grower, and finisher diets were fed from d 1 to 10, d 10 to 25, and d 25 to 35, respectively. For the total period, no significant interaction effects between AA/CP level and phytase supplementation were detected for any measured traits. The ADG, ADFI, carcass weight, breast weight, and tibia ash weight were lower and FCR was higher compared to the PC diets when the AA/CP level was reduced by more than 2%. Phytase supplementation increased ADG, ADFI, final BW, and tibia ash weight. Tibia ash measurements showed that birds were adequately supplied with digestible phosphorus in all treatments, although dietary phosphorus and calcium were reduced in the phytase-supplemented diets. This enabled the feeding of broiler chickens without mineral phosphate supplements in grower and finisher diets. The results showed that supplementation with 1,500 FTU phytase/kg diminished the growth-decreasing effect of lower dietary AA/CP at all reduction steps.

Evaluation of a threonine fermentation product as a digestible threonine source in broilers

In the present experiment, a Thr fermentation product ( FP ) (75% minimum digestible Thr) was evaluated as a replacement for crystalline L-Thr (98.5% minimum digestible Thr) as a source of digestible Thr and other nutrients to support broiler performance (0–48 d) and processing characteristics. Five phase-fed diets included 1) a positive control ( PC ) diet containing L-Met, L-Lys•HCl, and L-Thr, 2) a reduced protein control ( RPC ) diet with added L-Val, L-Ile, and L-Arg, 3) a negative control ( NC ) identical to the RPC except that cellulose was added at the expense of L-Thr, 4) a RPC diet with Thr-FP used in place of L-Thr with only accounting for digestible Thr and energy contributions of the FP ( TFP ), and 5) a RPC diet with Thr-FP used in place of L-Thr and accounting for the full nutrient matrix of the FP ( TFP-FM ). Overall, broilers fed the RPC diet had similar growth performance compared to birds fed the PC diet, whereas broilers fed the NC diet had reduced BW gain and increased FCR compared to the RPC-fed birds. Birds fed either the TFP or TFP-FM diet had similar growth performance to the RPC-fed birds. At processing, broilers fed the RPC diet had similar parts yields, excluding wings, to the PC group. Parts yields for the Thr-FP and NC groups were similar to the RPC group. These data confirmed the importance of adequate dietary Thr concentration in maximizing broiler performance and that Thr provided by the Thr-FP supported equivalent performance to L-Thr.

Growth performance, bone mineralization, nutrient digestibility, and fecal microbial composition of multi-enzyme-supplemented low-nutrient diets for growing-finishing pigs.

A study evaluated the effects of adding multi-enzyme mixture to diets deficient in net energy (NE), standardized ileal digestible (SID) amino acids (AA), standardized total tract digestible (STTD) P, and Ca on growth performance, bone mineralization, nutrient digestibility, and fecal microbial composition of grow-finish pigs. A total of 300 pigs (initial body weight [BW] = 29.2 kg) were housed by sex and BW in 45 pens of 7 or 6 pigs and fed 5 diets in a randomized complete block design. Diets were positive control (PC), and negative control 1 (NC1) or negative control 2 (NC2) without or with multi-enzyme mixture. The multi-enzyme mixture supplied at least 1,800, 1,244, 6,600, and 1,000 units of xylanase, β -glucanase, arabinofuranosidase, and phytase per kilogram of diet, respectively. The PC was adequate in all nutrients. The NC1 diet had lower content NE, SID AA, STTD P, and Ca than PC diet by about 7%, 7%, 32%, and 13%, respectively. The NC2 diet had lower NE, SID AA, STTD P, and Ca than PC diet by 7%, 7%, 50%, and 22%, respectively. The diets were fed in four phases based on BW: Phase 1: 29-45 kg, Phase 2: 45-70 kg, Phase 3: 70-90 kg, and Phase 4: 90-120 kg. Nutrient digestibility, bone mineralization, and fecal microbial composition were determined at the end of Phase 1. Pigs fed PC diet had greater (P < 0.05) overall G:F than those fed NC1 diet or NC2 diet. Multi-enzyme mixture increased (P < 0.05) overall G:F, but the G:F of the multi-enzyme mixture-supplemented diets did not reach (P < 0.05) that of PC diet. Multi-enzyme mixture tended to increase (P = 0.08) femur breaking strength. Multi-enzyme mixture increased (P < 0.05) the ATTD of GE for the NC2 diet, but unaffected the ATTD of GE for the NC1 diet. Multi-enzyme mixture decreased (P < 0.05) the relative abundance of the Cyanobacteria and increased (P < 0.05) relative abundance of Butyricicoccus in feces. Thus, the NE, SID AA, STTD P, and Ca could be lowered by about 7%, 7%, 49%, and 22%, respectively, in multi-enzyme mixture-supplemented diets without negative effects on bone mineralization of grow-finish pigs. However, multi-enzyme mixture supplementation may not fully restore G:F of the grow-finish pigs fed diets that have lower NE and SID AA contents than recommended by 7%. Since an increase in content of Butyricicoccus in intestine is associated with improved gut health, addition of the multi-enzyme mixture in diets for pigs can additionally improve their gut health.

Efficacy of three heat-stable microbial phytases on growth performance and bone development and strength of broilers fed diets deficient in available phosphorus

A total of 2340 as-hatched Cobb500 chicks were allocated to 9 treatments, each with 13 replicate pens to evaluate the effects of either three phytase enzymes in a P-deficient diet. Starter and finisher diets consisted of a positive control (PC) and negative control 1 and 2 (NC1 and NC2, respectively). The PC, NC1, and NC2 diets had Ca:avP (available phosphorus) ratios of 0.50, 0.33, and 0.43 in the starter feed, and 0.46, 0.22, and 0.35 in the finisher feed, respectively; NC1 diets were then supplemented with Phytaverse, Quantum Blue, and Axtra-PHY at 500 and 1000 FTU/kg. Enzyme type had significant effects on body weight gain, feed conversion ratio, and production efficiency factor during the 0–7-day period. Interactions between enzyme type and inclusion levels had a significant effect on feed intake (FI) at 1–21-day ( P = 0.02) and 1–35-day ( P = 0.031) age. While FI decreased as Axtra-PHY inclusion levels increased from 500 to 1000 FTU/kg feed, FI increased in birds supplemented with Quantum Blue, but with no effects on Phytaverse-supplemented birds. Increasing the enzyme dose to 1000 FTU/kg feed improved bone-breaking strength but did not affect growth performance, tibia ash, Ca, or P concentration of the birds.

Dietary inclusion of ruminally protected linseed oil as a means to mitigate heat and slaughter-induced stress in feedlot cattle.

There is evidence of a relationship between increased energy intake and the development of metabolic inflammation and insulin resistance (IR), and between the aforementioned metabolic state and impaired tolerance to heat stress. Based on the anti-inflammatory properties and mitigating effects on IR and stress of n-3 polyunsaturated fatty acids (n-3 PUFA), an experiment was performed to evaluate the effect of n-3 PUFA supplementation to feedlot-finished steers during summer on animal performance, physiological and biochemical variables associated with glucose metabolism, heat and preslaughter-induced stress, and meat quality. A total of 48 Angus steers (388±2kg) were fed one of three corn-based finishing diets containing (dry matter basis) 0% added oil (CON; negative control), or 1.90% of sunflower oil-calcium salt (SUN; positive control), or 1.92% of linseed oil-calcium salt (LIN). There was a trend (P = 0.08) for greater dry matter intake (DMI) and greater (P = 0.02) average daily gain (ADG) in LIN-fed animals compared with the average between those that received the CON or SUN diets, whereas no differences (P ≥ 0.34) were observed between the latter. No other performance, physiological, or carcass variables were affected (P ≥ 0.12) by treatment. Blood glucose and insulin were similar (P ≥ 0.14), though the homeostatic model assessment (HOMA) which gauges IR tended (P = 0.06) to be reduced for LIN-fed animals compared with the average between those that received the CON or SUN diets. Blood insulin and HOMA increased linearly (P ≤ 0.01) with days on feed. An interaction between the study phase (feeding period or slaughter) and treatment was observed (P ≤ 0.05) for glucose and cortisol. While the magnitude of glucose increase (P < 0.01) from the end of the feeding period to slaughter was greater for CON- and SUN-fed animals compared with LIN-fed ones, cortisol increased (P < 0.05) only in animals that received CON or SUN diets. Meat quality attributes were not affected (P ≥ 0.16) by treatment. The concentration of n-3 PUFA was greater (P < 0.01) and n-6:n-3 ratio was lesser (P < 0.01) in meat from LIN-fed animals compared with that resulting from the average between the animals that received the negative (CON) or positive (SUN) control diets. Results suggest that n-3 PUFA supplementation mitigated metabolic alterations associated with IR and preslaughter-related stress. It may have also improved tolerance to heat, resulting in greater DMI and ADG of steers fed a high-energy diet during summer. Results also indicate that glucose metabolism and heat stress tolerance worsen with time when feeding concentrate-based diets.

Long-term Feeding Effects of Calcium-bentonite Clay in Aflatoxin B1 Contaminated Diet on Egg Production, Egg Quality and Immune Status of Laying Hens

Background: This experiment was conducted to determine the effect of synthetic aflatoxin B1 and calcium bentonite clay as a mycotoxin binder in the laying hen diet on performance, egg quality and immune response to vaccination. Methods: A total of 144 Lohmann brown classic hens (22 weeks old) were divided into 4 groups of 6 replications with 6 hens each. This experimental design was completely randomized design and there were 4 experimental diets: (1) Basal diet (Positive control), (2) Basal diet +0.25% calcium bentonite clay, (3) Basal diet+200 ppb aflatoxin B1 (negative control) and (4) Basal diet+200 ppb aflatoxin B1 and +0.25% calcium bentonite clay. All hens were vaccinated with Newcastle (ND) and Infectious bronchitis (IB) vaccines during 24 weeks feeding trial. Result: At the end of the 24 weeks of feeding trial, dietary treatments did not influence the egg production, egg mass, feed conversion ratio (FCR) and IB titer of hens; however, aflatoxin B1 significantly (P less than 0.05) deceased final body weight and deceased the eggshell color score (P less than 0.05). Moreover, the ND titer was reduced by aflatoxin B1 at 8th and 12th weeks of trial (P=0.05 and less than 0.05; respectively). Thus, supplementation of 0.25% calcium bentonite clay in feed improved body weight, eggshell color and ND titer of laying hens similar to those fed the positive control diet.

Effects of dietary supplementation of ginger, garlic and onion on semen profile, haematological and serum antioxidant status of rabbit bucks raised in the dry season of the humid tropic

Purpose: The study evaluated the semen, haematological and antioxidant status of rabbit bucks fed ginger, garlic and onion supplemented diets under a severely heat stressed condition. This is to evaluate the effect of heat stress and spice supplementation on seminal parameters, haematology and antioxidant capacity of rabbit buck raised in the tropics. Research method: Fifty - five bucks were allotted to 11 treatments comprising of control diet, three each of ginger, garlic and onion at 5g, 10g and 15g/kg feed plus positive control diet. Seminal, haematological and antioxidant traits of the bucks and their pen's Temperature – Humidity index (THI) were observed for 8 weeks. Findings: THI (29.30 - 31.10°C) recorded during the study indicated the prevalence of severe to very severe heat stress. Heat stress impacted negatively more on sperm morphology than on other seminal parameters. Sperm cell motility, viability and abnormality were similar within supplemented groups and the controls. Semen volume and concentration were highest in animals fed garlic at 10 and 15g/kg feed respectively. Spice supplementation had no significant effect (p&gt;0.05) on the haematology and total antioxidant capacity (TAC) of the experimental animals. Originality/value: The study concluded that spice supplementation mitigated heat stress effect on sperm cell morphology and was not deleterious on haematology and TAC of the bucks.

Oxidative damage in Nile tilapia, Oreochromis niloticus, is mainly induced by water temperature variation rather than Aurantiochytrium sp. meal dietary supplementation.

We investigated whether dietary supplementation with Aurantiochytrium sp. meal, a DHA-rich source (docosahexaenoic acid, 22: 6 n-3), fed during long-term exposure to cold-suboptimal temperature (22°C, P1), followed by short-term exposure to higher temperatures (28°C, P2, and 33°C, P3), would promote oxidative damage in Nile tilapia (Oreochromis niloticus). Two supplementation levels were tested: 1.0g 100g-1 (D1) and 4.0g 100g-1 (D4). A control diet, without the additive (D0, 0g 100g-1), and a positive control diet supplemented with cod liver oil (CLO) were also tested. The concentrations of DHA and total n-3 PUFAs in the CLO diet were similar to those found in diets D1 and D4, respectively. The parameters analyzed included hemoglobin (Hb), the antioxidant enzymes catalase, glutathione peroxidase, total glutathione, non-protein thiols, and the oxidative markers protein carbonyl and erythrocyte DNA damage. Nile tilapia did not present differences in Hb content, regardless of diet composition, but the temperature increase (P1 to P2) led to a higher Hb content. Likewise, the temperature increases promoted alterations in all antioxidant enzymes. The dietary supplementation with 1.0g 100g-1 Aurantiochytrium sp. meal after P1 caused minor DNA damage in Nile tilapia, demonstrating that the additive can safely be included in winter diets, despite its high DHA concentration.

Phosphorus availability in broilers given phosphorus deficient diets containing phytase with and without citric acid

In the present study, the effects of phytase supplementation with and without citric acid (CA) on growth performance, carcass characteristics and serum minerals concentration, tibia and shank characteristics, and phosphorus (P) retention were determined in broilers fed non-phytate P deficient diets. Ninety six one day old male broilers (COBB-500) were divided into four groups (twenty four birds each, and were fed one of the following diets until they were 35 days old: positive control (PC) diet formulated based on the NRC (1994) recommendations, negative control (NC) diet containing 0.20 % lower non-phytate P than that in the PC diet, and two other diets were formulated by adding only phytase (500 FTU/kg of feed) or phytase with CA (500 FTU/kg of feed with 2 % CA). At the age of 36 day, birds were sacrificed, samples were collected, processed, and then analyzed. Compared with the PC group, NC group showed impaired growth performance (final BW, BW gain, and FCR), serum P concentration, tibia and shank characteristics (dry weight, contents of ash and P). However, in most cases, these impairments were ameliorated (P&lt;0.05) by the addition of phytase, and the restoration magnitude was non-significantly greater in phytase with CA group. Retention of total P increased (P&lt;0.05) in phytase added groups compared with NC group, and was comparable with PC group, although non-phytate P level was lower in those groups. In conclusion, broilers fed phytase added non-phytate P deficient diets (without any dietary synthetic source of P) showed the growth performance, mineral (P) concentration in blood and bone, and relative retention of P comparable with broilers fed recommended one. Addition of CA along with phytase in diet was a costlier affair without any significant beneficial effects.

Óleos essenciais de Foeniculum vulgare (erva doce) e Cymbopogon winterianus (citronela) em substituição a um promotor de crescimento na dieta de codornas europeias

ABSTRACT The objective of this study was to evaluate the replacement of a growth-promoting antibiotic by fennel (Foeniculum vulgare) and citronella (Cymbopogon winterianus) essential oils in the quail diet on performance variables (weight gain, feed intake, feed conversion), as well as the carcass and cut yield. To do so, 240 one-day-old male and female European quails were distributed in a completely randomized design with four treatments, five replications and 12 animals per experimental unit. The treatments consisted of: PC – positive control diet without fennel or citronella essential oils and with the growth promoter (zinc bacitracin); NC – negative control diet without essential oils and without growth promoter; CEO - Diet with +0.078% citronella essential oil without the growth promoter; and FEO - Diet with +0.078% fennel essential oil without the growth promoter. The experiment lasted 42 days, in which the performance variables were analyzed in three periods (1-14 days; 14-21 days; and 22-42 days) and the carcass and cut yield in two periods (at 21 and 42 days). The observed data were submitted to analysis of variance and the comparison of means was performed using the Tukey’s test at 5% significance. The presence of essential oils positively influenced (P&lt;0.05) the performance variables and the carcass and cuts yield in all analyzed periods. The use of fennel and citronella essential oils to replace zinc bacitracin in the diet of European quails improves performance and the carcass and cut yield.

Efficacy of enhanced Escherichia coli phytase on growth performance, bone quality, nutrient digestibility, and metabolism in nursery pigs fed corn-soybean meal diet low in calcium and digestible phosphorous.

Efficacy of Escherichia coli phytase (ASP) was evaluated in nursery pigs fed low Ca and digestible P corn and soybean meal diet. Piglets were weaned on day 21, fed a common commercial starter diet for 7 d, and assigned to pens (4 pigs/pen: 2 ♀ and 2 ♂) based on day 7 BW. Positive control (PC) and negative (NC) diets were formulated with similar energy and nutrients with exception of total Ca, total P, and digestible P concentrations being 79%, 67%, and 55% that of PC diet, respectively. Two other diets were formulated by adding ASP in NC at 500 and 1,000 FTU/kg. All diets had 0.2% TiO2 indigestible marker. The diets were allocated to pens to give 6 replicates per diet and fed for 42 d. Feed intake and body weight were monitored at 14-d intervals. On day 42, 1 pig/pen was bled and euthanized to access blood and tissue samples. Analyzed total Ca and P in NC diet was 71% and 69% of concentration in PC diet. Recovery of phytase in pelleted diets was 66.2% and 73.5% for NC+500 FTU/kg and NC+1,000 FTU/kg diets, respectively. Between days 15 and 42, pigs fed NC diet grew slower and ate less feed than pigs fed the other diets. Overall (days 0–42), phytase in NC increased (P ≤ 0.05) ADG linearly and quadratically. On day 42, pigs fed PC, NC+500 FTU/kg, and NC+1,000 FTU/kg were +6.1, +5.9, and +7.1 kg heavier (P < 0.05) than pigs fed NC, respectively. Pigs fed PC and NC plus phytase exhibited higher (P = 0.003) G:F relative to NC pigs between days 15 and 28. Pigs fed NC diet had lower (P < 0.001) plasma P concentration, apparent total tract digestibility (ATTD) of Ca and P, and metacarpal and metatarsal bone attributes than pigs fed any other diets. Supplementation of phytase in NC linearly increased (P < 0.05) plasma P concentration, ATTD of Ca and P, and bone attributes. Specifically, phytase increased (P ≤ 0.025) dry weight, length, and ash weight in metacarpals and metatarsals. In conclusion, low total Ca and digestible P diet depressed growth and P utilization in piglets. Supplemental phytase improved performance in pigs fed NC linked to enhanced nutrients uptake and metabolism commensurate to pigs fed adequate total Ca and digestible P from inorganic source.

The Efficiency of Probiotics Administrated via Different Routes and Doses in Enhancing Production Performance, Meat Quality, Gut Morphology, and Microbial Profile of Broiler Chickens.

Simple SummaryAntimicrobial growth promoters (AGPs) have been used in the animal production industry around the world for decades, with the consequence of a high potential of antibiotic-resistant bacteria transfer to humans. Efficiently raising broiler chickens in an antibiotic-free production system is a challenge, and identifying an effective nutritional alternative to support growth performance, gut health, and functionality without administrating AGPs is of essence. Several antimicrobial alternative options that are commercially available include herbal essential oils, exogenous enzymes, organic acids, plant secondary metabolites, probiotics, and prebiotics. Probiotics in animal feed is projected to attain a massive global growth, reaching USD 6.24 billion by 2026. This study tested the efficiency of probiotics when supplemented via different administration routes (feed or water) and doses, or in combination with prebiotics, on growth performance, meat quality, gut morphology, and microbial profile of broiler chickens. The outcomes revealed that probiotics enhance production performance, and compared to AGPs, do not reduce the beta-diversity of the gut microbial community. Water-soluble probiotics seemed to be more effective in improving growth performance.To study the efficiency of Bacillus spp. probiotics administered via different routes and doses, a 6-week grow-out trial was conducted using a total of 378 day-old mixed-sex ROSS308 broiler chickens in a completely randomized block design. Six experimental diets included probiotics added at two different inclusion rates into the feed (250 g/ton; PRO250, or 500 g/ton; PRO500), or in the drinking water (25 g/L; PRO-WS), or as a feed synbiotic (250 g probiotic + 250 g/ton prebiotic; SYN), compared to a negative (NC; without additives) and positive control (PC; with antibiotics) diets. The PRO-WS enhanced feed intake (p < 0.05) and tended to improve average daily gain and final body weight (p = 0.14). Broiler gut morphology in the duodenum including the villus height (p = 0.04), villus width (p = 0.05) and crypt depth (p = 0.02) were improved by PRO500. Firmicutes was the most abundant phylum, followed by Bacteroidetes. Streptococcaceae, Lachnoospiraceae, Peptostreptococcaceae, Ruminococcaceae, and Erysipe-lotrichaceae were the top five most abundant families. Antibiotic inclusion in PC reduced microbial beta-diversity and increased similarity compared to probiotic inclusion (p = 0.05). Probiotic inclusion reduced the relative abundance of Bacteroides fragilis, which is a commonly isolated pathogen and is considered as a marker for antimicrobial resistance. Overall, probiotic supplementation via feed or water may potentially improve the production performance of the broiler chickens, and water-soluble probiotics are potentially more effective. Probiotics, especially when added to water, suggest a promising feed additive to support gut microbial maturation and diversity, and may reduce resistant bacteria in broiler chickens. However, it is suggested that the best route for the administration of probiotics be further examined under commercial conditions to find the most effective and practical application method that yields the most consistent results.

Evaluation of the responses of broiler chickens to varying concentrations of phytate phosphorus and phytase. Ⅱ. Grower phase (day 12–23 post hatching)

A randomized complete block design study used 768 male broiler chickens to investigate the effects of phytate P (PP) and a novel consensus bacterial phytase variant (PhyG) concentration on growth performance, bone mineralization, apparent ileal digestibility (AID), and total tract retention (TTR) of nutrients in broiler chickens. Treatments were arranged in a 1 + 3 × 5 factorial with a nutrient-adequate positive control diet (PC) with 2.8 g PP/kg, 3 nutrient-reduced negative control diets (NC: PC minus 88 kcal/kg ME, 0.8 g/kg dig. Lys, 2.0 g/kg available P, 2.0 g/kg Ca and 0.5 g/kg Na) with varying PP (g/kg) levels, mainly from rice bran, at 2.3 (NC1), 2.8 (NC2), or 3.3 (NC3) and 5 PhyG doses at 0, 500, 1,000, 2,000, or 4,000 FTU/kg. All treatments had 6 replicate cages with 8 birds/cage. A commercial starter diet was fed from d 0 to 12 and the experimental diets from d 12 to 23 post hatching. Birds fed the NC2 diet without phytase had lower (P < 0.01) BW, BW gain, and feed intake (FI) as compared with birds fed the PC with the same PP level. With increasing phytate, there was a decrease (P < 0.05) in BW, BW gain, and FI. Phytase increased (P < 0.01) BW and feed efficiency of broiler chickens. An interaction (P < 0.05) between PP and phytase concentrations was observed on the AID of Met, Cys, and Thr. Linear decrease (P < 0.01) in the AID and TTR of P and Ca with increasing PP concentrations were observed. Phytase supplementation increased (P ≤ 0.05) the AID of P, Ca, and all AA. The TTR of P, Ca, and Zn was linearly increased (P < 0.01) by 112, 123, and 46%, respectively, when birds fed NC diets with 0 and 4,000 FTU/kg were compared. In conclusion, phytate reduced the growth performance and nutrient utilization of broiler chickens from d 12 to 23 post hatching while phytase ameliorated these negative effects.

Supplemental Effects of Phytase on Modulation of Mucosa-Associated Microbiota in the Jejunum and the Impacts on Nutrient Digestibility, Intestinal Morphology, and Bone Parameters in Broiler Chickens.

Simple SummaryA positive modulation of the gut microbiota is associated with benefits regarding intestinal health and subsequent growth performance. The supplementation of phytase has been studied for improving nutrient digestibility, bone parameters, and growth performance. This study aimed to determine the effects of increasing doses of phytase on the modulation of mucosa-associated microbiota in the jejunum enhancing intestinal health and the impacts on nutrient digestibility, bone parameters, and growth performance of broiler chickens. It was demonstrated that the use of phytase enhanced the intestinal health of the broiler chickens by potentially increasing beneficial and reducing harmful bacteria, enhancing intestinal morphology, and consequently improving nutrient digestibility and bone parameters. Our results suggest that the use of phytase can positively modulate the jejunal mucosa-associated microbiota in the jejunum, enhance intestinal integrity, nutrient digestibility, and bone parameters of broiler chickens.This study aimed to determine supplemental effects of phytase on modulation of the mucosa-associated microbiota in the jejunum, intestinal morphology, nutrient digestibility, bone parameters, and growth performance of broiler chickens. Three hundred and sixty newly hatched broiler chickens (Ross 308) (44 ± 2 g BW) were randomly allotted in 6 treatments with 10 birds per cage based on a completely randomized design and fed for 27 d. The treatments consisted of one negative control (NC), diet formulated meeting the requirements suggested by Ross recommendations (2019), and without phytase supplementation. The other treatments consisted of a positive control diet (PC) formulated with 0.15% deficient Ca and P and split into 5 treatments with different phytase inclusion levels (0, 500, 1000, 2000, 4000 FTU/kg feed). Titanium dioxide (0.4%) was added to feeds as an indigestible marker to measure apparent ileal digestibility (AID) of nutrients. On d 27, 3 birds were randomly selected from each cage and euthanized to collect samples for analyzing the mucosa-associated microbiota in the jejunum, oxidative stress status, AID, and bone parameters. Data were analyzed using the proc Mixed of SAS 9.4. Phytase supplementation tended to have a quadratic effect (p = 0.078) on the overall ADG (maximum: 41 g/d at 2833 FTU/kg of feed). Supplementation of phytase at 2,000 FTU/kg increased (p < 0.05) the relative abundance of Lactobacillus and reduced (p < 0.05) Pelomonas. Moreover, it tended to reduce Helicobacter (p = 0.085), Pseudomonas (p = 0.090) Sphingomonas (p = 0.071). Phytase supplementation increased (p < 0.05) the villus height and the AID of CP; and tended to increase (p = 0.086) the AID of P. Phytase supplementation increased (p < 0.05) breaking strength and P content in the tibia. In conclusion, phytase supplementation showed potential benefits on the modulation of the mucosa-associated microbiota in the jejunum by tending to reduce harmful bacteria (Pelomonas, Helicobacter, and Pseudomonas) and increase beneficial bacteria (Lactobacillus). In addition, it showed positive effects increasing apparent ileal digestibility of CP and P, enhancing intestinal morphology (villus height), and improving the bone parameters (bone breaking strength, ash, and P content). Phytase supplementation at a range of 38 to 59 FTU/d or 600 to 950 FTU/kg of feed provided the most benefits related to nutrient digestibility.

Glutamic acid supplementation recovers the reduced performance of weanling pigs fed reduced crude protein diets.

This study was conducted to evaluate the supplementation of glutamic acid (Glu) to reduced protein diets on the performance of weanling pigs. One hundred and eighty crossbred weanling pigs ([Yorkshire × Landrace] × Duroc, 21 d old) having similar body weight (BW) of 6.45 kg were randomly allotted to 1 of 6 dietary treatments (5 pigs per pen [2 barrows and 3 gilts]; 6 pens per treatment) based on BW and sex during a 6-week trial. Dietary treatments consisted of positive control (PC) diet formulated to have 226.9, 205.6, and 188.8 g crude protein (CP) during phases 1, 2, and 3, respectively, and negative control (NC) diets with 20 g CP reduction from PC diets and addition of Glu with increasing levels, resulting in the calculated Lys-to-Glu ratios of 1:2.25, 1:2.30.1:2.35, 1:2.40, and 1:2.45, designated as NC, NC1, NC2, NC3, and NC4, respectively. The BW of pigs receiving PC diet was higher (P < 0.05) than those receiving NC diet at d 7, 21 and 42. A higher (P < 0.05) average daily gain (ADG) from d 1 to 7, 8 to 21, 22 to 42 and during the overall experiment period was observed in pigs fed PC than NC diet. Pigs fed NC diets including the graded level of Glu linearly increased (P < 0.05) BW at d 42, ADG and gain-to-feed ratio (G:F) during the overall experimental period. In addition, trends in linear increase in BW (P = 0.056) at d 7 and ADG from d 1 to 7 and d 22 to 42 (linear effect, P = 0.081, P = 0.058 respectively) were observed. A tendency in the linear increment of NH3 (P = 0.082) at d 21 and linear reduction in methyl mercaptans (P = 0.054) emission at d 42 was observed in pigs fed NC diets supplemented with graded level of Glu. In conclusion, supplementing the reduced protein diet with Glu enhanced the growth performance in weanling pigs suggesting that supplementation of Glu can compensate the reduction of 2% CP in the basal diets.

PSVI-4 Effect of phytase on mineral digestibility and growth performance of pigs fed diets with pharmacological levels of Zn

Abstract An experiment was conducted to test the hypothesis that increasing levels of phytase increases mineral digestibility and growth performance of pigs fed diets with 3,000 mg/kg of Zn. A positive control (PC) diet that met nutrient requirements and a negative control (NC) diet that was deficient in total Ca (-0.16%), digestible P (-0.14%), metabolizable energy (-50 kcal/kg), and digestible amino acids (-0.02%) were formulated. Eight additional diets were formulated by adding 500, 1,000, 1,500, or 2,000 phytase units/kg of a novel bacterial 6-phytase (PhyG) or a commercial Buttiauxella phytase (PhyB) to the NC diet. A randomized complete block design with 400 weanling pigs (5.82 ± 0.70 kg), 10 diets, 4 pigs per pen, and 10 replicate pens per diet was used. Pigs were fed the experimental diets for 28 d. Fecal samples were collected from 1 pig per pen on d 26 to 28. Linear and quadratic effects of PhyG and PhyB were determined using polynomial contrast statements. Contrast statements were used to compare effects of PC diet with NC diet, and to compare effects of PhyG diets with PhyB diets. Overall, pigs fed the NC diet had reduced growth performance (P &amp;lt; 0.05) compared with pigs fed the NC diet (Table 1). Linear (P &amp;lt; 0.01) and quadratic (P &amp;lt; 0.05) increases in overall average daily gain and average daily feed intake of pigs were observed as dietary concentrations of PhyG or PhyB increased. Increasing levels of PhyG or PhyB linearly increased (P &amp;lt; 0.01) the apparent total tract digestibility (ATTD) of P and Ca. PhyG increased ATTD of P more (P &amp;lt; 0.05) than PhyB. In conclusion, both phytases are effective in increasing mineral digestibility and growth performance in pigs fed diets with pharmacological levels of Zn; however, PhyG improved P digestibility more than PhyB.

PSX-A-11 Late-Breaking: Effects of phytogenic supplementation on growth performance and intestinal barrier function in nursery pigs challenged with E. coli

Abstract The objective of this study was to investigate the health-promoting effects of red osier dogwood (ROD) extract as an alternative to antibiotics in weaned piglets challenged with enterotoxigenic Escherichia coli (ETEC). Twenty-eight weaned piglets (9.15±0.95 kg BW) confirmed to genetically susceptible to ETEC were individually assigned to one of the four dietary treatments in a completely randomized design. Experimental diets were, negative control (NC), corn-wheat soybean meal diet with no additives; positive control (PC), NC plus antibiotics; ROD1, NC plus 0.1% ROD extract; ROD2, NC plus 0.2% ROD extract. Piglets were orally challenged on d 7 with ETEC F4. Feed disappearance, body weight, fecal score, and rectal temperature were recorded. On d 14, piglets were euthanized to collect intestinal tissue samples for histomorphology and Ussing chamber analysis. Data were analyzed using the MIXED procedure of SAS using individual piglet as the experimental unit. There were no differences (P &amp;gt; 0.10) in histomorphology and intestinal permeability. Piglets fed the NC diet tended (P &amp;lt; 0.10) to have higher average daily gain, post-inoculation than those fed ROD1 or ROD2. Fecal score of piglets fed the PC diet tended to (P &amp;lt; 0.10) or was significantly lower (P &amp;lt; 0.05) than for piglets fed ROD1 or ROD2 on 0 and 2 days post-inoculation (dpi), respectively. On 0 dpi, piglets fed the ROD1 diet had significantly higher (P &amp;lt; 0.05) body temperature than those fed PC or ROD2. In conclusion, ROD extract supplementation might have some health-promoting effects on ETEC challenged piglets but could not improve gut health to the same extent as antibiotics.

Influence of phytate and phytase on performance, bone, and blood parameters of broilers at 42 days old

The objective was to evaluate the effect of diets containing various levels of phytate and phytase on broilers from 1 to 42 days old. The treatments consisted of a combination of diets containing high (HP), medium (MP) and low (LP) phytate with positive control diet (PC) and a negative control diet (NC) that was similar to the PC in energy and protein but with less calcium and phosphorus. Three additional diets, based on the NC were supplemented with 500, 1000, or 1500 FTU kg-1 of phytase. Broilers that received the NC diet exhibited the lowest weight gain (WG), whereas those supplemented with 1000 FTU kg-1 obtained 2.84% higher WG compared with PC. Broilers that received NC had the lowest breaking strength and dry matter. Birds fed HP diets that received NC and NC + 500 FTU kg-1 had a higher concentration of serum Ca and P than birds fed LP diets. Broilers fed the NC and NC + 500 and 1000 FTU kg−1 had lower tibia Ca levels compared with birds fed the PC. Broilers fed HP diets had higher tibia Ca content than MP. Phytase supplementation had a positive response in diets with reduced Ca and P. Based on regression analysis the optimum inclusion of phytase to improve broiler performance parameters was calculated as 952 FTU kg-1.

Protease supplementation in maize-based diet influenced net energy and nutrient digestibility in broilers

This experiment evaluated the effects of supplemental protease in maize-based diets formulated with reduced density of digestible amino acids (dAA) on net energy (NE) utilisation and nutrient digestibility in broilers. A total of 312, one-day-old, male broilers (Ross 308) were randomly distributed into 24 floor pens and fed one of three treatments, with eight pen replicates per treatment throughout the starter (1 to 14 d of age) and grower (15 to 28 d of age) phases. Dietary treatments consisted of a positive control (PC) reference diet, a negative control diet (NC; dAA density 60 g/kg less than PC diet), and a NC diet with supplemental protease (200 mg/kg). All diets contained supplemental phytase (200 mg/kg) and xylanase (200 mg/kg). The reduction in dAA density between the PC and NC did not affect (P&gt;0.05) NE, but protease supplementation in the NC diet increased (P&lt;0.05) NE by 0.27 MJ/kg, compared with those receiving the NC diet without protease. The reduction in dAA for broilers fed the NC and PC diets did not (P&gt;0.05) affect nitrogen, starch, or DE in the jejunum or ileum. Likewise, no differences (P&gt;0.05) in jejunal (nitrogen, starch, and DE) and ileal (starch and DE) digestibility values were observed between those offered the NC diets without or with protease, but a small difference (P&lt;0.05) in ileal nitrogen digestibility was observed.

Macro‐ and microalgal extracts as functional feed additives in diets for zebrafish juveniles

The search for natural immunotherapeutic agents has become increasingly important for fish disease treatment and prophylaxis. The present research explored the effects of macro- and microalgal extracts on zebrafish juvenile growth and immune status. A plant-based diet was used as a control (diet C), and seven other diets were prepared similar to diet C, supplemented with 10 g Kg−1 of each algal extract (Fucus vesiculosus, F; Nannochloropsis gaditana, N; and Ulva rigida, U), or a combination of extracts (diets FN, FU, NU and FNU). A fishmeal-based diet was included as a positive control (diet C+). Diet C+ outperformed the remaining dietary treatments, growth-wise. None of the extracts improved diet C negative effects. However, the inclusion of U. rigida and N. gaditana extracts promoted an immunomodulatory action after 1 week of trial, by upregulating cytokine expression. This effect subsided after 30 days, suggesting tolerance may be developed over time. In contrast, effects on growth-related genes were still observed after 5 weeks of feeding F, N, U and FN diets. Algal extract dietary inclusion did not compromise intestinal integrity. These findings support the potential of algal extracts as functional feed additives during short periods (<30 days) to enhance immunomodulation.