G.P. Mandal

Effect of black cumin seeds on growth performance, nutrient utilization, immunity, gut health and nitrogen excretion in broiler chickens

BACKGROUND Use of antibiotic growth promoters (AB) as feed additives in broiler chickens poses risks due to cross-resistance amongst pathogens and residues in tissues. The aim of this study was to evaluate the effect of dietary supplementation of black cumin seeds (BCS) as a natural growth promoter in chickens on nutrient utilization, intestinal microbiota and morphology, immunity, antioxidant status, protein deposition in muscles and nitrogen excretion. RESULTS Broiler chickens were fed BCS at 0, 5, 10 and 20 g kg-1 diet. Body weight gain tended to increase (P = 0.10) and daily feed intake increased quadratically with increasing concentrations of BCS in the diets. Supplementation of BCS resulted in a tendency to decrease feed conversion efficiency on days 28-42. Metabolizability of nutrients increased linearly with increasing doses of BCS. Protein deposition in thigh and breast muscles was increased and nitrogen excretion was reduced by BCS and AB compared with the control (CON). Intestinal morphology in the duodenum, jejunum and ileum was not generally affected by BCS. Counts of total bacteria, Escherichia coli, Lactobacillus spp. and Clostridium spp. were not affected by BCS and AB compared with CON, but Salmonella spp. decreased linearly (P = 0.05) with increasing doses of BCS. Antibody titers against Newcastle disease virus on day 35 increased quadratically (P < 0.001) with increasing doses of BCS. Concentrations of glucose and triglyceride in blood were not affected by BCS. Concentrations of cholesterol decreased linearly while the concentration of total protein increased linearly with increasing doses of BCS. CONCLUSION The use of dietary BCS may improve growth performance, immunity and nutrient utilization in broiler chickens.

Effects of dietary supplementation of cinnamaldehyde and formic acid on growth performance, intestinal microbiota and immune response in broiler chickens

An experiment was conducted to investigate the effects of replacing antibiotic growth promoter (AGP) with a combination of essential oil and organic acids (EO + OA) on growth performance, gut microbiota and immune response in broiler chickens. In Experiment 1, 320 day-old broiler chicks were randomly distributed to 32 pens with 10 birds in each pen and the pens were equally allotted to four treatment groups. In Experiment 2, 120 day-old chicks were divided into the same four treatment groups, each group containing three replicated pens with 10 birds in each pen. The groups were (1) Negative Control (NC) without AGP or other growth-promoting feed additives; (2) AGP (NC + enramycin; 125 mg/kg feed; (3) OA (NC + OA; 500 mg/kg feed); and (4) EO + OA (NC + a combination of cinnamaldehyde and calcium formate; 500 mg/kg feed). Experiment 1 lasted for 40 days, whereas Experiment 2 continued for 28 days. In Experiment 2, all birds were orally challenged with Escherichia coli (108 bacteria/bird) on Day 14. Overall intake, growth and feed conversion ratio (FCR) on Day 40 had no difference (P > 0.05) among the groups in Experiment 1. In Experiment 2, growth, feed intake and FCR were not affected by any dietary treatments until Day 14, but after being challenged with E. coli, bodyweight gain and FCR improved (P 0.05) the counts of total bacteria, E. coli and Lactobacillus in the contents of ileum and caecum. However, Salmonella counts in the ileal and caecal contents decreased (P < 0.001) for AGP, OA and EO + OA compared with NC group. Clostridium counts were lower for EO + OA group than for NC and AGP groups in the ileum, and for AGP, OA and EO + OA groups than for NC in the caeca (P < 0.05). Antibody titer on Day 35 against Newcastle disease vaccine was higher in EO + OA group than in NC, AGP and OA groups (P < 0.001). In conclusion, EO + OA did not affect growth and FCR in broilers. However, AGP and EO + AO improved growth performance and FCR after being challenged with E. coli. Moreover, EO + OA was effective in reducing the Clostridium count in the small intestine and caecum and increasing the villus height and antibody titer against Newcastle disease vaccine.

Effect of Zinc Supplementation With or Without Phytase on Performance, Mineral Accumulation in Tissues and Immune Response of Broiler

The present study was undertaken to assess the effect of supplementation of Zn with or without phytase on the performance, accumulation of mineral in tissues and immune response of broiler chickens. Two hundred Vencobb 400 unsexed day-old broilers were randomly divided into 4 groups with 5 replicates each. The starter (1–10 d), grower (11–22 d), finisher (23–35 d) diet was formulated to meet or exceed the recommendations of standard commercial broiler chicken except Zn which was not added in diet. The four experimental treatments resulted from a 2x2 factorial arrangements, where factors include Zn (0, 15 mg/kg form zinc sulphate) and phytase (0, 500 U/kg). BW at day 21 and 35 were significantly (P≤0.01) higher in zinc supplemented groups, however feed intake and FCR were unaffected. Phytase supplementation did not alter the BW, feed intake and FCR. Deposition of Zn in bone and liver was significantly (P≤0.05) higher in Zn and phytase supplemented birds. Tibia ash, Zn content of muscle and Cu and Mn content of bone, liver and muscle were unaffected by Zn or phytase addition. Antibody titre against Newcastle Disease virus vaccine was significantly (P<0.01) higher in Zn supplemented group, however was unaltered due to phytase supplementation. Results indicated that Zn supplementation to a maize-soyabean based diet improved BW, mineral deposition in tissue and immune response. However there is no additional benefit from the use of phytase.

Effects of different vegetable oils on rumen fermentation and conjugated linoleic acid concentration in vitro

Aim: The objective of this study was to investigate the effect of different vegetable oils on rumen fermentation and concentrations of beneficial cis-9 trans-11 C18:2 conjugated linoleic acid (CLA) and trans-11 C18:1 fatty acid (FA) in the rumen fluid in an in vitro condition. Materials and Methods: Six vegetable oils including sunflower, soybean, sesame, rice bran, groundnut, and mustard oils were used at three dose levels (0%, 3% and 4% of substrate dry matter [DM] basis) in three replicates for each treatment in a completely randomized design using 6 × 3 factorial arrangement. Rumen fluid for microbial culture was collected from four goats fed on a diet of concentrate mixture and berseem hay at a ratio of 60:40 on DM basis. The in vitro fermentation was performed in 100 ml conical flakes containing 50 ml of culture media and 0.5 g of substrates containing 0%, 3% and 4% vegetable oils. Results: Oils supplementation did not affect (p>0.05) in vitro DM digestibility, and concentrations of total volatile FAs and ammonia-N. Sunflower oil and soybean oil decreased (p<0.05) protozoal numbers with increasing levels of oils. Other oils had less pronounced effect (p>0.05) on protozoal numbers. Both trans-11 C18:1 FA and cis-9, trans-11 CLA concentrations were increased (p<0.05) by sunflower and soybean oil supplementation at 4% level with the highest concentration observed for sunflower oil. The addition of other oils did not significantly (p>0.05) increase the trans-11 C18:1 FA and cis-9, trans-11 CLA concentrations as compared to the control. The concentrations of stearic, oleic, linoleic, and linolenic acids were not altered (p>0.05) due to the addition of any vegetable oils. Conclusion: Supplementation of sunflower and soybean oils enhanced beneficial trans-11 C18:1 FA and cis-9, trans-11 CLA concentrations in rumen fluid, while sesame, rice bran, groundnut, and mustard oils were ineffective in this study.

Pig farm environment as a source of beta-lactamase or AmpC-producing Klebsiella pneumoniae and Escherichia coli

The present study was undertaken to detect the occurrence of beta-lactamase-/AmpC-producing Klebsiella and Escherichia coli in healthy pigs, feed, drinking water, and pen floor or surface soil. The study also intended to detect the clonal relationship between the environmental and porcine isolates to confirm the route of transmission. Rectal swabs and environmental samples were collected from apparently healthy pigs kept in organized or backyard farms in India. The pigs had no history of antibiotic intake. Production of phenotypical beta-lactamase, associated genes, and class I integron gene was detected in E. coli and Klebsiella isolates. The phylogenetic relationship among the isolates was established on the basis of Random amplification of polymorphic DNA banding pattern. Beta-lactamase-producing Klebsiella were isolated from healthy pigs (20.0%), pen floor swabs/surface soil swabs (14.0%), and drinking water (100%). Escherichia coli isolated from healthy pigs (14.4%), pen floor/surface soil (8.0%), and drinking water (33.3%) were detected as beta-lactamase producers. Majority of beta-lactamase-producing isolates possessed blaCTX-M-9. Further, 35 (81%) Klebsiella and all the E. coli isolates were detected as AmpC beta-lactamase ACBL producers and possessed blaAmpC. Sixteen beta-lactamase-producing Klebsiella (37.20%) and 13 E. coli (86.67%) possessed class I integron. Few resistant isolates from environmental sources (surface soil swab and drinking water) and the studied pigs were detected within the same cluster of the dendrogram representing their similarities. The study indicated about the possible role of contaminated environment as a source of beta-lactamase/AmpC-producing Klebsiella and E. coli in pigs.