Use of red grape pomace and Aloe vera gel as nutraceuticals to ameliorate stocking density-induced stress in commercial male broilers.

The combined effect of Aloe vera gel (AVG) administered through drinking water and dietary red grape pomace powder (RGP) on growth performance, physiological traits, welfare indicators, and meat quality in densely stocked broilers was evaluated. A total of 750, two-week-old male Ross 308 broilers (317.7 ± 10.12 g live weight) were randomly assigned to 25 cages, with each cage as an experimental unit. The broilers were stocked at a density of 30 birds per cage with a floor space of 1.32 m2. Dietary treatments were a standard grower or finisher diet (CON); CON containing 30 g RGP /kg diet plus either 1 (GPA1), 2 (GPA2), 3 (GPA3), or 4% (GPA4) AVG in drinking water. Treatment GPA1 promoted higher (P < 0.05) overall weight gain and overall feed conversion ratio (FCR) than CON. Positive quadratic effects (P < 0.05) were noted for mean corpuscular hemoglobin, basophils, 24-hour breast meat yellowness, chroma, and hue angle. The GPA2 group had the lowest (P < 0.05) gait score while the CON group had the highest score. Concurrent supplementation with a 30 g RGP /kg diet plus 1% AVG in drinking water enhanced weight gain, FCR, and finisher weight of densely stocked broilers. However, AVG doses beyond 1% did not enhance performance and physiological traits in densely stocked broilers.

Comparative genomics and proteomics analysis of phages infecting multi-drug resistant Escherichia coli O177 isolated from cattle faeces.

The increasing prevalence of antimicrobial-resistant (AMR) pathogens has become a major global health concern. To address this challenge, innovative strategies such as bacteriophage therapy must be optimised. Genomic characterisation is a crucial step in identifying suitable phage candidates for combating AMR pathogens. The aim of this study was to characterise seven phages that infect the Escherichia coli O177 strain using a whole genome sequencing. The analysis of genome sequences revealed that these phages had linear dsDNA, with genome sizes spanning from 136, 483 to 166,791 bp and GC content varying from 35.39 to 43.63%. Taxonomically, the phages were classified under three different subfamilies (Stephanstirmvirinae, Tevenvirinae, and Vequintavirinae) and three genera (Phapecoctavirus, Tequatrovirus, and Vequintavirus) within the class Caudoviricetes. In silico PhageAI analysis predicted that all the phages were virulent, with confidence levels between 96.07 and 97.26%. The phage genomes contained between 66 and 82 ORFs, which encode hypothetical and putative functional proteins. In addition, the phage genomes contained core genes associated with molecular processes such as DNA replication, transcription modulation, nucleotide metabolism, phage structure (capsid and tail), and lysis. None of the genomes carried genes associated with undesirable traits such as integrase, antimicrobial resistance, virulence, and toxins. The study revealed high genome and proteome homology among E. coli O177 phages and other known Escherichia phages. The results suggest that the seven phages are new members of the genera Phapecoctavirus, Tequatrovirus, and Vequintavirus under the subfamilies Stephanstirmvirinae, Tevenvirinae, and Vequintavirinae, respectively.

Stocking density-induced changes in growth performance, blood parameters, meat quality traits, and welfare of broiler chickens reared under semi-arid subtropical conditions.

Broiler production in semi-arid tropics must contend with high levels of heat stress, which have implications on stocking density, bird welfare, and profitability. Under these conditions, optimal stocking densities are likely to be lower than expected, thus must be experimentally determined. Therefore, this study investigated growth performance, haematology, serum biochemistry, carcass and meat quality, sizes of internal organs, and stress biomarkers in response to different stocking densities in broilers reared under semi-arid subtropical conditions. Five hundred, day-old Ross 308 broilers (44.0 ± 5.24 g live-weights) were randomly distributed to 25 replicate pens (1.32 m2 floor space each) to create five stocking densities: 1) 10 birds/pen (SD10); 2) 15 birds/pen (SD15); 3) 20 birds/pen (SD20); 4) 25 birds/pen (SD25); and 5) 30 birds/pen (SD30). There was a linear decrease (P < 0.05) in overall feed intake and weight gain in weeks 2 and 3 as stocking density increased. However, weight gain showed positive and negative quadratic responses (P < 0.05) in weeks 5 and 6, respectively, as stocking density increased. No linear or quadratic effects (P ˃ 0.05) were observed for overall feed conversion ratio, haematological parameters, and meat quality traits in response to stocking density. Symmetric dimethylarginine, alanine transaminase, and albumin levels quadratically increased (P < 0.05) in response to increasing stocking densities. Serum glucose and thigh weight were not affected (P < 0.05) while final body, drumstick, breast, and wing weights linearly declined with stocking density. Increasing stocking density linearly reduced (P < 0.05) the weights of gizzard, proventriculus, caecum, and colon. Stocking density had no effect (P ˃ 0.05) on latency-to-lie. It was concluded that higher stocking densities compromised feed intake, resulting in poor weight gains. Based on weight gain trends observed in week 5, it was determined that Ross 308 broilers should be reared at no more than 20 birds/pen (~15 birds/m2 or 27.27 kg/m2) under the experimental ambient conditions compared to the much higher globally accepted industry standard of 20 birds/m2.

Physical Treatment Reduces Trypsin Inhibitor Activity and Modifies Chemical Composition of Marama Bean (Tylosema esculentum).

The utility of the marama bean (MB) as an alternative protein source to soybean (SB) can be limited by the high concentration of trypsin inhibitors (TI). The physical treatment of MB has the potential to ameliorate the antinutritional activities of TI and modify other chemical components. Thus, this study investigated the effects of physical treatments on the chemical components and trypsin inhibitor activity (TIA) of raw MB and SB. The bean substrates were subjected to each of the following treatment methods: (1) room temperature (20−22 °C) soaking for 24 h; (2) electric stove cooking at 100 °C for 10, 20, and 30 min; (3) steam autoclaving at a temperature of 110 °C and pressure of 7 pounds per square inch (psi), as well as a temperature of 121 °C and 7 psi for 5, 15, and 30 min; (4) pre-soaked autoclaving at 110 °C (7 psi) and 121 °C (17 psi) for 5, 15, and 30 min. Treated MB and SB had greater (p < 0.05) crude protein content than untreated samples. All the treatments (except 24 h soaking of MB) reduced (p < 0.05) the TIA and ash content. Marama and SB are similar in protein content, but their amino acids profile and TIA are quite different. Soaking for 24 h was less effective in reducing TIA in MB and SB, compared to the thermal methods, and it was detrimental to the ash and amino acids profile of the two beans. Soaking prior to autoclaving yielded beans with the lowest TI concentrations. In conclusion, thermal methods reduced the TI contents and modified the level of proximate components and amino acids profile of the beans.

Data on complete genome sequence and annotation of two multidrug resistant atypical enteropathogenic Escherichia coli O177 serotype isolated from cattle faeces.

Atypical enteropathogenic E. coli belonging to the serotype O177 is a rare strain found in ruminants, especially cattle. When compared to shiga toxin producing E. coli (STEC) O157 and non-O157 STEC (O26, O45, O103, O104, O111, O121, and O145) serotypes, the antimicrobial resistance, virulence factors, and genomic structure of E. coli O177 are poorly understood. Therefore, in this article, we present the whole genome sequence data of two aEPEC E. coli O177 isolates (E. coli O177_CF-154-A and E. coli O177_CF-335-B) generated using Illumina MiSeq platform. The raw data were generated, cleaned, and assembled using Trimmomatic and SPAdes. Genome data analysis yielded 5,112,402 and 5,460,435 bp, comprising contigs 101 and 191 with GC contents of 50.7% and 50.5% for E. coli O177_CF-154-A and E. coli O177_CF-335-B, respectively. Prokaryotic Genome Annotation Pipeline (PGAP) and Rapid Annotation using Subsystem Technology (RAST) showed that the complete genome of E. coli O177_CF-154-A contained 5040 coding sequences (CDS), 5146 genes, 4896 proteins, 90 RNAs, and 78 tRNA while that of E. coli O177_CF-335-B contained 5463 CDS, 5570 genes, 5230 proteins, 92 RNAs, and 80 tRNA for. A total of 426 and 425 subsystem features with 5190 and 5662 CDS were obtained for E. coli O177_CF-154-A and E. coli O177_CF-335-B, respectively. Several genes encoding virulence and antimicrobial resistance were identified in both genomes. Complete genome sequence data of both isolates have been deposited in the National Center for Biotechnology Information (NCBI), GenBank: accession numbers, VMKH00000000 (E. coli O177_CF-154-A) and VMKG00000000 (E. coli O177_CF-335-B). This data can be used as a reference for determining the virulence and antimicrobial resistance in E. coli O177 isolates from different sample sources.

Genetic diversity and whole genome sequence analysis data of multidrug resistant atypical enteropathogenic Escherichia coli O177 strains: An assessment of food safety and public health implications.

Atypical enteropathogenic E. coli (aEPEC) strains are emerging pathogens responsible for fatal diarrhoea in humans worldwide. The purpose of this study was to investigate genetic diversity, virulence and antimicrobial resistance profiles of aEPEC O177 strains isolated from faeces of cattle reared in intensive and extensive production systems in South Africa. A total of 96 multidrug resistant (MDR) aEPEC O177 isolates were typed using enterobacterial repetitive intergenic consensus (ERIC) and random amplified polymorphism DNA (RAPD) typing. The resistome, virulome and mobilome of two aEPEC O177 isolates were investigated using WGS analysis. The ERIC typing was efficient and reproducible with a discriminatory index of 0.95. RAPD typing had poor reproducibility with satisfactory discriminatory power of 0.859. The dendrograms constructed based on ERIC and RAPD banding patterns produced 9 and 8 clusters, respectively, which indicate genetic variation among E. coli O177 isolates. WGS analysis revealed that CF-154-A and CF-335-B) isolates belonged to the O177 serotype with H7 and H21, respectively. Both isolates harboured several virulome genes such as intimin (eaeA), haemolysin (hlyA and hlyE), translocated iron receptor (tir), Type III secretion system (eprH, gspL and prgH), bssR and bssS. However, genes encoding shiga toxins were not found in either isolate. Antibiotic resistance genes such as ampC, tet, ermB, sul2, strB AcrD, aph(6)-Ic, aph(6)-Ib, aph(3″)-I, ant (3″)-1a AcrA and acrE were found in the E. coli O177 strains. Furthermore, genome annotation results indicated that both isolates carried plasmids, insertion sequences, prophages and cluster of regularly interspaced short palindromic repeats (CRISPR) type I. Based on in silico multi locus typing (MLST) analysis, the two isolates were assigned to different sequence types (CF-154-A, ST-1308 and CF-335-B, ST-58). Whole genome multi locus typing tree showed that our isolates clustered with E. coli O177:H21 (reference), suggesting the close genomic relatedness among the strains. Overall, these findings showed that cattle carry genetically diverse E. coli O177 strains, which harbour a repertoire of virulome, resistome and mobilome genes. This highlights a need for multidrug resistant E. coli O177 strain surveillance in cattle.

Effect of dietary red grape pomace on growth performance, hematology, serum biochemistry, and meat quality parameters in Hy-line Silver Brown cockerels.

Red grape (Vitis vinifera L.) pomace's (RGP) beneficial bioactive compounds could improve growth and meat quality traits in chickens and thus valorize RGP waste that is usually disposed in landfills to the detriment of the environment. This study investigated the effect of RGP inclusion in diets of Hy-line Silver Brown cockerels on physiological and meat quality responses. Five isonitrogenous and isocaloric diets were formulated by mixing a standard grower diet with RGP at 0 (G0), 15 (G15), 30 (G30), 45 (G45) and 60 g/kg (G60). A total of 250, 5-week-old cockerels (304.6 ± 6.57 g live-weight) were evenly allocated to 25 pens replicated 5 times per experimental diet. No linear and quadratic trends (P > 0.05) were observed for overall feed intake, body weight gain, feed conversion ratio, and meat quality traits as dietary RGP levels increased. Erythrocytes linearly decreased (P < 0.05), whereas mean corpuscular hemoglobin and urea linearly increased (P < 0.05) with RGP levels. There were significant quadratic effects for glucose, phosphorus, total protein, albumin, globulin, and cholesterol, from which a maximum RGP inclusion level was calculated to be 43 g/kg. In conclusion, dietary red grape pomace had no adverse effect on physiological parameters and meat quality traits of Hy-line Silver Brown cockerels. However, including red grape pomace beyond 43 g/kg could compromise serum biochemical parameters of the birds.

Effect of Pre-Treating Dietary Green Seaweed with Proteolytic and Fibrolytic Enzymes on Physiological and Meat Quality Parameters of Broiler Chickens.

The use of seaweeds as nutraceuticals in chicken diets is limited by high fibre levels and low protein digestibility. Therefore, we tested the effect of pre-treating dietary seaweed (Ulva sp.) with a combination of protease and fibrolytic enzymes on physiological and meat quality parameters of Cobb 500 broilers. Five dietary treatments were formulated by including untreated (T1); fibrolytic (12 g/kg) enzyme-treated (T2); fibrolytic (12 g/kg) and protease (5 g/kg) enzyme-treated (T3); fibrolytic (12 g/kg) and protease (10 g/kg) enzyme-treated (T4); fibrolytic (12 g/kg) and protease (15 g/kg) enzyme-treated (T5) seaweed (35 g/kg) in a standard broiler diet. Three hundred, two-week-old chicks (239.3 ± 8.57 g live weight) were evenly distributed to 30 replicate pens to which the diets were then randomly allocated. Birds fed diet T1 had the highest feed intake (1144.5 g/bird). Neither linear nor quadratic trends were recorded for growth performance and carcass traits in response to protease pre-treatment levels. Gizzard weight linearly increased, while symmetric dimethylarginine, calcium, meat pH24, and hue angle24 quadratically responded to protease levels. Diet T1 promoted the lowest serum phosphorus levels (3.37 mmol/L). In conclusion, pre-treatment of seaweed with a combination of protease and fibrolytic enzymes did not improve diet utilization, physiological parameters, and meat quality in broilers.

An Assessment of the Viability of Lytic Phages and Their Potency against Multidrug Resistant Escherichia coli O177 Strains under Simulated Rumen Fermentation Conditions.

Preslaughter starvation and subacute ruminal acidosis in cattle are known to promote ruminal proliferation of atypical enteropathogenic Escherichia coli strains, thereby increasing the risk of meat and milk contamination. Using bacteriophages (henceforth called phages) to control these strains in the rumen is a potentially novel strategy. Therefore, this study evaluated the viability of phages and their efficacy in reducing E. coli O177 cells in a simulated ruminal fermentation system. Fourteen phage treatments were allocated to anaerobic serum bottles containing a grass hay substrate, buffered (pH 6.6-6.8) bovine rumen fluid, and E. coli O177 cells. The serum bottles were then incubated at 39 °C for 48 h. Phage titres quadratically increased with incubation time. Phage-induced reduction of E. coli O177 cell counts reached maximum values of 61.02-62.74% and 62.35-66.92% for single phages and phage cocktails, respectively. The highest E. coli O177 cell count reduction occurred in samples treated with vB_EcoM_366B (62.31%), vB_EcoM_3A1 (62.74%), vB_EcoMC3 (66.67%), vB_EcoMC4 (66.92%), and vB_EcoMC6 (66.42%) phages. In conclusion, lytic phages effectively reduced E. coli O177 cells under artificial rumen fermentation conditions, thus could be used as a biocontrol strategy in live cattle to reduce meat and milk contamination in abattoirs and milking parlours, respectively.

Complete replacement of maize grain with sorghum and pearl millet grains in Jumbo quail diets: Feed intake, physiological parameters, and meat quality traits.

In sub-Saharan Africa, the use of maize (Zea mays L.) grain as an energy source in poultry feeds has become unsustainable due to competing demands and suboptimal growing conditions for the maize crop. Sorghum (Sorghum bicolor Moench L.) and pearl millet (Pennisetum glaucum) grains are potential sustainable alternatives, given their tolerance to local growing conditions. Therefore, this study evaluated the effect of total replacement of maize grain with whole or crushed sorghum and pearl millet grains on feed intake, and physiological and meat quality parameters of Jumbo quail. Five experimental diets were formulated by completely replacing crushed maize grain in a commercial grower diet (CON) with whole sorghum (WSG), crushed sorghum (CSG), whole millet (WMG), or crushed millet (CMG). Three hundred and fifty, two-week-old Jumbo quail chicks (74.7 ± 8.81 g live-weight) were evenly distributed into 35 replicate pens to which the experimental diets were allotted. Statistically similar (P > 0.05) weight gain and FCE values were observed between birds reared on the control and pearl millet-based diets. However, birds fed with sorghum-based diets had the lowest FCE and weight gain. Blood parameters fell within the normal ranges reported for healthy quail. Birds fed the whole sorghum grain diet had the least (P < 0.05) serum calcium and higher monocytes, cholesterol, and alkaline phosphatase (ALP) concentrations compared to those reared on the control diet. Compared to the control, the whole sorghum-containing diet reduced (P < 0.05) carcass, breast, wing, thigh, drumstick, liver, gizzard, and large intestine weights of the birds. Complete replacement of maize grain with pearl millet grain (whole or crushed) did not compromise feed intake, growth performance, and meat quality traits of the Jumbo quail birds. However, whole sorghum grain reduced growth performance of the birds.

Cultivating oyster mushrooms on red grape pomace waste enhances potential nutritional value of the spent substrate for ruminants.

The use of red grape pomace (GP; Vitis vinifera L. var. Shiraz) as a source of beneficial bioactive compounds in ruminant diets is limited by high levels of indigestible compounds in the grape skin matrix. This problem demands innovative, inexpensive, and easy-to-use strategies that improve the digestibility of GP. The bioconversion of GP using edible oyster mushrooms (Pleurotus ostreatus) is one such strategy that has not been previously explored. Therefore, this study evaluated the effect of cultivating oyster mushrooms on GP on chemical composition and in vitro ruminal fermentation parameters of the spent mushroom substrate. The GP was inoculated with oyster mushroom spawns at 0, 200, 300, 400, or 500 g/kg, and incubated for 4 weeks. Organic matter, acid detergent lignin, sodium, manganese, cobalt, and copper linearly declined (P < 0.05) as spawn rates increased. A quadratic trend was observed for crude protein, neutral detergent fibre, acid detergent fibre, magnesium, phosphorus, and calcium content in response to increasing spawn rates. Higher spawning rates (20-50%) had a positive effect (P < 0.05) on gas production from the immediately fermentable fraction (a), rate of gas production from the slowly fermentable fraction (c) and effective gas production. However, gas production from the slowly fermentable fraction (b) and potential gas production linearly declined in response to increasing spawning rates. There was a linear increase (P < 0.05) in the immediately degradable fraction (a), while quadratic effects were observed for partition factors, effective degradability, and in vitro organic matter degradability at 48 h in response to spawning rates. It can be concluded that inoculating GP with oyster mushroom spawn reduced fibre content while increasing crude protein content and in vitro ruminal fermentation efficiency of red grape pomace. Based on the quadratic responses of partition factors at 48 hours post-inoculation, the optimum spawning rate for maximum ruminal fermentation efficiency of GP was determined to be 300 g/kg.

Growth performance and carcass characteristics of finishing male lambs fed barberry pomace-containing diets.

Barberry (Berberis vulgaris) fruits contain bioactive compounds with antimicrobial, antioxidant and hepatoprotective effects. The inclusion of barberry pomace (BP) in finishing diets could potentially enhance growth performance and carcass characteristics of sheep. To test this hypothesis, 21 male Balouchi lambs (24.5 ± 4 kg initial live weight; 5 ± 0.6 months of age) were randomly assigned to three BP-containing experimental diets to determine their effects on feed intake, live weight gain and carcass characteristics. The experimental diets were formulated to meet nutrient requirements for a targeted daily weight gain of 200 g as follows: (1) control diet (BP0), (2) control diet in which 7.5% of alfalfa hay and wheat straw were replaced with BP (BP75), (3) control diet in which 15% of alfalfa hay and wheat straw were replaced with BP (BP150). Lambs were fed the experimental diets for 75 days during which feed intake and live weight changes were recorded. At the end of the feeding period, lambs were fasted for 16 h, weighed and then slaughtered in order to determine carcass characteristics. Experimental diets had no effect on feed intake and growth performance of lambs. Similarly, diets had no effect (p > 0.05) on weight of carcass, commercial cuts (neck, shoulder, loin, leg, fat-tail, brisket, flank) and non-carcass components (head, skin, feet, lung and trachea, heart, liver, spleen, gastro-intestinal, kidney, bladder and testicles) but linearly increased (p < 0.05) warm and cold dressing percentage as well as heart weight. These results do not support the hypothesis that feeding BP-containing diets enhances growth performance and carcass characteristics of male Balouchi lambs. However, inclusion of BP had no negative effects on animal performance and carcass characteristics.

Efficacy of novel phages for control of multi-drug resistant Escherichia coli O177 on artificially contaminated beef and their potential to disrupt biofilm formation.

Contaminated beef is a prominent source of foodborne pathogens such as Escherichia coli O177. Susceptibility of nine multi-drug resistant E. coli O177 strains against eight individual phages and six phage cocktails was assessed using polystyrene microplate titer plate. Further, 180 beef samples were independently inoculated with E. coli O177 cells in triplicates and treated with eight individual phages and six phage cocktails to determine their efficacy in inhibiting bacteria growth at 4 °C over a 7-day incubation period. Results revealed that all E. coli O177 strains were susceptible to the phages. A significant log reduction in viable E. coli O177 cell counts was observed on beef samples upon phage treatment over the 7-day incubation period. Two individual phages and three phage cocktails reduced E. coli cell counts to levels below the detection limit (1.0 log10 CFU/g). Log reduction of viable E. coli cell counts ranged from 2.10 to 7.81 CFU/g for individual phages and from 2.86 to 7.81 CFU/g for cocktails. Individual phages and phage cocktails inhibited E. coli O177 biofilm formation with phage cocktails showing high efficacy. Furthermore, phage cocktails showed greater efficacy in destroying pre-formed biofilm than individual phages. Based on these findings, we concluded that phage cocktails developed in this study could be used to reduce E. coli O177 contamination and extend the shelf-life of stored raw beef.

Replacement of Soybean Meal with Heat-Treated Canola Meal in Finishing Diets of Meatmaster Lambs: Physiological and Meat Quality Responses.

The study investigated whether heat treatment (190 °C for 90 min) could improve the quality of expeller canola meal (CM) protein in finishing diets of Meatmaster lambs. Five isonitrogenous and isoenergetic diets were formulated by partially (50%) or completely replacing SBM as the major protein source with untreated or heat-treated CM in a commercial lamb finishing diet. Diets were randomly allocated to 40 lambs (24.73 ± 1.311 kg; 4.5 months old) for 77 days. No dietary differences were observed for growth performance, carcass characteristics and meat quality. Diets had no effect (p > 0.05) on blood parameters, except for hemoglobin and aspartate aminotransferase (AST). Lambs that were fed the control diet had higher hemoglobin concentration compared with lambs on CM-containing diets. The highest AST value was observed when SBM was completely replaced with untreated CM (159.88 IU/L), while complete replacement with heat-treated CM resulted in the lowest AST value (103.25 IU/L). All lambs had a body condition score of 3 at slaughter. It was concluded that heat treatment did not improve the protein value of CM. However, CM inclusion promoted similar growth performance and meat quality parameters in lambs as SBM. Untreated CM can be used to completely substitute SBM in finishing diets of Meatmaster lambs.

Nutrient Digestibility, Growth Performance, and Blood Indices of Boschveld Chickens Fed Seaweed-Containing Diets.

Seaweeds possess a wide range of bioactive compounds that can be beneficial in sustainable intensification systems. This study explored the effect of green seaweed (Ulva spp.) meal (SWM) on apparent nutrient digestibility and physiological responses of Boschveld indigenous chickens. Two-hundred and seventy-five hens (202.4 ± 6.65 g live-weight; 4-weeks-old) were reared on five isoenergetic and isoproteic diets formulated by adding SWM at 0 (SW0), 20 (SW20), 25 (SW25), 30 (SW30), and 35 g/kg (SW35). Neutral detergent fibre digestibility quadratically responded (R2 = 0.244; p = 0.042) to SWM levels. No significant dietary influences were observed on apparent nutrient digestibility values. Repeated measures analysis showed significant diet × week interaction effect on weekly feed intake and growth performance. Dietary inclusion of SWM increased (p < 0.05) feed intake and overall body weight gain but not feed conversion efficiency. No significant linear and quadratic trends were observed for blood parameters except for basophils (R2 = 0.172; p = 0.047), which linearly declined with SWM levels. Dietary SWM inclusion only influenced (p < 0.05) mean corpuscular volume, mean corpuscular concentration, and mean corpuscular haemoglobin concentration. We concluded that seaweeds have the potential to be used as a feed ingredient for indigenous chickens.

Evaluating Alternatives to Zinc-Bacitracin Antibiotic Growth Promoter in Broilers: Physiological and Meat Quality Responses.

This study evaluated different combinations of a probiotic (Bacillus licheniformis), an organic acid mixture (benzoic and fumaric acids), a protease enzyme, and chelated minerals (Cu, Zn, and Mn) as alternatives to zinc-bacitracin antibiotic. Eight hundred Cobb 500 chicks (42.02 ± 2.207 g liveweight) were distributed into 40 pens to which five diets: 1. Commercial broiler diet with no antibiotics (CON); 2. CON + zinc-bacitracin antibiotic (ZnB); 3. CON + chelated minerals + protease enzyme (MinEnz); 4. CON + chelated minerals + protease + organic acids (MinEnzOrg); and 5. CON + chelated minerals + protease + probiotic (MinEnzPro) were allocated. Probiotic, minerals, protease enzyme, and organic acids were included in diets at 0.2 g/kg, 0.3 g/kg, 0.5 g/kg, and 5 g/kg, respectively. Diets promoted a similar feed intake, weight gain, and feed conversion ratio. Birds on MinEnz had the highest basophil content (2.04 × 109/L), while those on ZnB had the highest alanine aminotransferase (8.50 IU/L). Chickens on MinEnz had the heaviest spleens and the largest proventriculi. Meat from CON birds had the highest water holding capacity (22.32%) and cooking losses (27.15%). We concluded that the investigated combinations of feed additives could replace ZnB in broiler diets as they promoted similar growth performance and carcass characteristics.

The First Isolation and Molecular Characterization of Shiga Toxin-Producing Virulent Multi-Drug Resistant Atypical Enteropathogenic Escherichia coli O177 Serogroup From South African Cattle.

Atypical enteropathogenic E. coli (aEPEC) is a group of diarrhoeagenic Escherichia coli with high diversity of serogroups, which lack the bundle-forming pili (BFP) and genes encoding for shiga toxins. The aim of this study was to isolate, identify and determine virulence and antibiotic resistance profiles of aEPEC O177 strains from cattle feces. A total of 780 samples were collected from beef and dairy cattle and analyzed for the presence of E. coli O177. One thousand two hundred and seventy-two (1272) presumptive isolates were obtained and 915 were confirmed as E. coli species. Three hundred and seventy-six isolates were positively confirmed as E. coli O177 through amplification of rmlB and wzy gene sequences using multiplex PCR. None of these isolates harbored bfpA gene. A larger proportion (12.74%) of the isolates harbored hlyA gene while 11.20, 9.07, 7.25, 2.60, and 0.63% possessed stx2, stx1, eaeA, stx2a , and stx2d , respectively. Most of E. coli O177 isolates carried stx2/hlyA (9.74%). Furthermore, 7.40% of the isolates harbored stx1/stx2 while 7.09% possessed stx1/stx2/hlyA genes. Only one isolate harbored stx1/stx2/hly/eaeA/stx2a/stx2d while 5.11% of the isolates harbored all the four major virulence genes stx1/stx2/hlyA/eaeA, simultaneously. Further analysis revealed that the isolates displayed varied antimicrobial resistance to erythromycin (63.84%), ampicillin (21.54%), tetracycline (13.37%), streptomycin (17.01%), kanamycin (2.42%), chloramphenicol (1.97%), and norfloxacin (1.40%). Moreover, 20.7% of the isolates exhibited different phenotypic multi-drug resistance patterns. All 73 isolates harbored at least one antimicrobial resistance gene. The aadA, streA, streB, erm, and tetA resistance genes were detected separately and/or concurrently. In conclusion, our findings indicate that environmental isolates of aEPEC O177 strains obtained from cattle in South Africa harbored virulence and antimicrobial resistance gene determinants similar to those reported in other shiga-toxin producing E. coli strains and suggest that these determinants may contribute to the virulence of the isolates.

Valorization of Red Grape Pomace Waste Using Polyethylene Glycol and Fibrolytic Enzymes: Physiological and Meat Quality Responses in Broilers.

The amount of grape pomace (GP) waste that can be included as a functional feed in broiler diets is limited by anti-nutritional compounds such as fiber and condensed tannins. This study evaluated the effect of pre-treating GP with polyethylene glycol (PEG) and a cellulolytic enzyme mixture on physiological and meat quality parameters of broilers. Cobb 500 broilers (249.2 ± 20.31 g live-weight) were reared on five isoenergetic and isonitrogenous diets: 1. Commercial chicken diet (CON); 2. CON containing untreated GP at 100 g/kg (dGP); 3. CON containing 100 g/kg GP pre-treated with PEG (50 g/kg) (dPEG); 4. CON containing 100 g/kg GP pre-treated with enzyme (1 g/kg) (ENZ); and 5. CON containing 100 g/kg GP pre-treated with PEG (50 g/kg) and enzyme (1 g/kg) (PENZ). Overall body weight gains were similar in broilers reared on the CON, dPEG, ENZ and PENZ diets but lower in dGP chickens. The meat of birds reared on dPEG, ENZ, dGP and CON had a similar water-holding capacity, which was lower than in PENZ chickens. Diets influenced the size of duodenum, ileum, jejunum and caeca. Polyethylene glycol treatment promoted similar body weight gains and hot carcass weights as the commercial control diet, suggesting that the anti-nutritional effects of condensed tannins were successfully ameliorated.

Nutrient digestibility, haemo-biochemical parameters and growth performance of an indigenous chicken strain fed canola meal-containing diets.

Canola meal (CM) is a potential alternative dietary protein source for indigenous chickens but its utility may be limited by anti-nutrients such as fibre and phytochemical compounds. This study, therefore, explores the effects of replacing soy-based feedstuffs (SB) with graded levels of CM on apparent nutrient digestibility, growth performance and haemo-biochemical parameters in Potchefstroom koekoek (PK) cockerels. Five isonitrogenous and isoenergetic diets were formulated by replacing 0 (CM), 3.75 (CM1), 6.25 (CM2), 8.75 (CM3) and 17.5% (CM4) of SB with CM. One hundred and seventy-five cockerels (342.6 ± 15.2 g live weight, 5 weeks old) were evenly distributed into 25 replicate pens to which experimental diets were randomly allocated. Feed intake, apparent nutrient digestibility, weight gain, feed conversion ratio and protein efficiency ratio (PER) were determined. Blood was collected for serum and haematological analysis at 16 weeks of age. There was a significant quadratic trend [y = 2.56 (± 0.067) + 0.04 (± 0.019)x - 0.002 (± 0.0010)x2] for average weight gain from which an optimum canola inclusion level was calculated to be 7.8%. Neutrophils linearly increased (P < 0.05) with CM levels, but there were no significant linear and quadratic trends for serum biochemical components with the exception of total calcium and triglycerides, which decreased linearly in response to incremental levels of CM. However, feed intake, feed utilisation efficiency, growth performance and serum biochemistry parameters were not affected by experimental diets. Based on weight gain response, it was concluded that replacing soy-based dietary ingredients with CM in poultry diets up to 7.8% does not result in adverse effects on diet utilisation, growth performance and health status of PK cockerels.

A multi-strain probiotic administered via drinking water enhances feed conversion efficiency and meat quality traits in indigenous chickens.

Whereas the use of probiotics is commonplace in commercial production of improved chicken strains, little is known about the impact of these live microbial feed additives in indigenous chickens in South Africa. This study investigated the effect of a multi-strain probiotic (containing Bacillus safensis, Bacillus subtilis, Bacillus megaterium and Cupriavidus metallidurans, total bacteria number was 1.4 × 108 cfu/mL), administered via drinking water, on growth performance, blood parameters, and carcass and meat quality characteristics of Potchefstroom koekoek cockerels for a period of 12 weeks. A total of 140 five-week-old cockerels were randomly allocated to 4 experimental diets formulated to have similar energy and protein levels as follows: 1) negative control diet (CON; commercial chicken grower diet without both antibiotics and probiotics), 2) positive control diet (ANTIB; commercial chicken grower diet with antibiotics [0.05% Coxistac and 0.04% olaquindox] but no probiotics), 3) negative control diet plus 2.5 mL of probiotics per litre of water (PROB25) and 4) negative control with 5.0 mL of probiotics per litre of water (PROB50). There was a significant (P < 0.05) week and diet interaction effect on average weekly feed conversion efficiency. At 9 weeks of age, cockerels in PROB50 group had higher (P < 0.05) feed conversion efficiency than those in CON and ANTIB groups. However, 14-week-old cockerels in PROB50 group had lower (P < 0.05) feed conversion efficiency than those in ANTIB group. Treatments had no significant (P > 0.05) effect on overall feed intake, overall weight gain and haemato-biochemical parameters of cockerels. Gizzard and spleen weights were similar (P > 0.05) in PROB50, CON and PROB25 groups. Cockerels in PROB50 group had shorter (P < 0.05) small intestine than those in CON and PROB25 groups. Cockerels in PROB50 group had larger (P < 0.05) breast weight than those in PROB25 group. Cockerels in ANTIB and PROB50 groups had greater (P < 0.05) wing and thigh weights than those in CON and PROB25 groups. Shank weight was similar (P > 0.05) in PROB50, CON and ANTIB groups. Meat pH measured after 24 h of slaughter was the highest (P < 0.05) in CON and ANTIB groups followed by PROBO25 and PROB50 groups. Cockerels in CON group had lower (P < 0.05) cooking losses than those in ANTIB, PROB25 and PROB50 groups. It was concluded that probiotics can be used in place of prophylactic antibiotics in Potchefstroom koekoek cockerels.