Supplementation of a low-protein diet with tryptophan, threonine, and valine and its impact on growth performance, blood biochemical constituents, immune parameters, and carcass traits in broiler chickens

Research (Published online: 30-06-2020)

30. Supplementation of a low-protein diet with tryptophan, threonine, and valine and its impact on growth performance, blood biochemical constituents, immune parameters, and carcass traits in broiler chickens

Reham Abou-Elkhair, Hamada Ahmed, Sara Ketkat and Shaimaa Selim

Veterinary World, 13(6): 1234-1244

Aim: This study aimed to investigate the effects of protein reduction with supplementation of limiting amino acids (AA, tryptophan, threonine, and valine) on growth performance, blood biochemical, immunity parameters, and carcass traits in broiler chickens.

Materials and Methods: Three hundred one-day-old broiler chicks were randomly allotted into three treatment groups, with five replicates per treatment and 20 broiler chickens per replicate. The three experimental diets were formulated with different dietary crude protein (CP) %, (control [CON] and CON with 1% [CP-1%] or 2% [CP-2%] less CP units) during the starter, grower, and finisher phases. The CP of the experimental diets were 22, 21, and 20% for the starting period (day 1-14); 20, 19, and 18% CP for the growing period (day 15-28); and 18, 17, and 16% CP for the finishing period (day 29-35) in CON, CP-1%, and CP-2%, respectively. The low-CP diets (CP-1% and CP-2%) were supplemented with combined AA, threonine+tryptophan+valine, to meet the respective levels of the CON diet.

Results: The CP-2% group had greater (p<0.05; linear, p<0.05) final body weight and gain and better feed conversion ratio. The combined AA inclusion in the low-CP diet (CP-1% and CP-2%) increased (p<0.001; linear, p<0.001) carcass and breast meat yield as well as CP% of breast meat. The reduction of CP% with AA supplementation (CP-2%) decreased (p<0.05; linear, p<0.05) serum triglycerides, glutamate oxaloacetate transaminase, glutamate pyruvate transaminase, and alkaline phosphatase, while increased (p<0.01; linear, p<0.01) phagocytic activity and phagocytic index. The mRNA expression of splenic and cecal tonsil interleukin 4 and interferon gamma was upregulated (p<0.001; linear, p<0.001) in the low-CP diets supplemented with AA (CP-1% and CP-2%). Dietary supplementation with AA to low-protein diets improved (p<0.01; linear, p<0.01) the economic returns of broiler chickens.

Conclusion: A reduction of dietary CP and increased synthetic AA such as threonine, valine, and tryptophan should be considered to improve performance, health, and immunity in broiler chickens.

Keywords: amino acids, broiler chickens, immune-related genes, meat composition, performance.

Assessment of cardiac variables using a new electrocardiography lead system in horses

Research (Published online: 29-06-2020)

29. Assessment of cardiac variables using a new electrocardiography lead system in horses

Worakij Cherdchutham, Kanoklada Koomgun, Suchanan Singtoniwet, Napattra Wongsutthawart, Napass Nontakanun, Wipasitnee Wanmad and Soontaree Petchdee

Veterinary World, 13(6): 1229-1233

ABSTRACT

Aim: The objective of this study was to assess a new lead system method to improve electrocardiographic measurement in horses.

Materials and Methods: Twenty-two horses with an average age of 8.8±0.8 years were enrolled in this study. Horses were divided into two groups, consisting of a control group (n=11) and athlete group (n=11). Electrocardiography (ECG) and echocardiography were performed to provide information on the structure and function of the heart. Two lead systems, base apex and modified precordial leads, were used for the electrocardiogram to assess the cardiac electrophysiological functions.

Results: PR interval, QT interval, and QRS-T angle presented significant differences between the control and athlete groups when the modified precordial lead system was used. However, significant variations in the mean electrical axis were found when the base apex lead system was used. The modified precordial lead system resulted in more significant differences in cardiac electrophysiological parameters than the base apex lead system. In the athlete group, echocardiography showed cardiac adaptations such as increases in the left atrial and left ventricular dimensions and stroke volume and a decrease in heart rate in response to exercise and training. The observed differences in cardiac morphology and function between groups suggested differences in health performance in the athlete group.

Conclusion: These data provided the first evidence that the modified precordial lead system improved statistical variation in ECG recording and provided the most reliable method for health screening in horses.

Keywords: echocardiography, electrocardiography, horse, non-invasive cardiac evaluation.

Prevalence, seasonality, and antimicrobial resistance of thermotolerant Campylobacter isolated from broiler farms and slaughterhouses in East Algeria

Research (Published online: 28-06-2020)

28. Prevalence, seasonality, and antimicrobial resistance of thermotolerant Campylobacter isolated from broiler farms and slaughterhouses in East Algeria

Mohamed Baali, Mohamed Lounis, Hanan Laidouci Al Amir, Ammar Ayachi, Ahcen Hakem and Ahmed Kassah-Laouar

Veterinary World, 13(6): 1221-1228

ABSTRACT

Aim: The current study was carried out to determine the prevalence, seasonality, and antimicrobial profile of thermotolerant Campylobacter isolated from broiler chickens in Batna, East Algeria, from June 2016 to June 2018.

Materials and Methods: A total of 960 samples, including 480 cloacal swabs, 240 cecal contents, and 240 neck skin samples collected from 6 poultry farms and 12 slaughterhouses, were included in this study. After isolation and identification, susceptibility to seven antimicrobial agents was tested by the disk diffusion method. The seasonality of Campylobacter infection at broiler farms was statistically analyzed.

Results: The data showed that 65%, 55%, and 70% of the cloacal swab, neck skin, and cecal content samples were contaminated with thermotolerant Campylobacter strains, respectively (p<0.05). Among the isolated campylobacteria, Campylobacter jejuni was the predominant species (73.5%). Sampling season exhibited a significant impact on the prevalence of Campylobacter (p<0.01), with peak occurrence in summer. All of the isolates were susceptible to gentamicin and resistant to ampicillin and amoxicillin/clavulanic acid, while 83.3% of them were resistant to erythromycin. Interestingly, 16 different resistance profiles were noted, with the combination of "ampicillin, amoxicillin/clavulanic acid, chloramphenicol, erythromycin, and tetracycline" being the most common, identified in 20.7% of isolated strains.

Conclusion: This study demonstrates the presence of a high contamination rate of multidrug-resistant Campylobacter in farms and slaughterhouses in East Algeria. These findings underscore the need to apply strict control measures to avoid any associated public health hazard among Algerian consumers. This initial finding of the contamination of poultry with this zoonotic pathogen in East Algeria suggests the value of periodic comprehensive evaluation of associated disease in poultry as well as in humans in this region.

Keywords: antimicrobial resistance, broilers, poultry farms, slaughterhouses, thermotolerant Campylobacter.

Genetic characterization and phylogenetic study of Lakor goat from Southwest Maluku Regency based on mitochondrial COI gene

Research (Published online: 28-06-2020)

27. Genetic characterization and phylogenetic study of Lakor goat from Southwest Maluku Regency based on mitochondrial COI gene

Maman Rumanta, Rony Marsyal Kunda, Slamet Diah Volkandari, Indriawati Indriawati and Pieter Kakisina

Veterinary World, 13(6): 1209-1220

ABSTRACT

Aim: This study is aimed at characterizing the genetic and phylogenetic structure of Lakor goats as indigenous livestock from the Southwest Maluku Regency based on mitochondrial COI gene sequences.

Materials and Methods: The genomes of 103 follicle samples from Lakor goats, collected from Lakor Island, were analyzed. The polymerase chain reaction was used to amplify 1548 bp of the mitochondrial COI gene using two primer pairs (COIA and COIB). Following sequencing, genetic variation and phylogenetic relationship were established using MEGA version X software.

Results: The results of multiple COI gene alignment of the total sequences identified four polymorphic nucleotides that function as genetic markers between individual animals within the Lakor goat population. These correspond to positions 228 (A-G), 519 (G-A), 900 (C-T), and 1266 (T-C). Phylogenetic signals based on the COI gene showed that Lakor goat breed is a monophyletic group or single clade with a bootstrap value of 100% by the neighbor-joining (NJ) and maximum likelihood (ML) evolutionary models. This data indicated that evolutionarily, the Lakor goat breed has a very close kinship with three goat breeds from China: The Meigu goat (KM 244714.1), Chinese Tibet (Capra hircus) (KJ 940969.1), and C. hircus (KP 677510.1). Phylogenetic information based on the cladistics system classified the Lakor goat as a single clade (monophyletic group). The low-genetic diversity within populations indicates that there has been an inbreeding depression occurring at a very high frequency.

Conclusion: We conclude that the Lakor goat may be divided into a single clade or monophyletic group based on the COI gene sequence. Four nucleotides were identified that can be used as genetic markers among individual animals within the Lakor goat population, as well as C. hircus and others as derived from GenBank data. The Lakor goat population has a high level of inbreeding depression as a result of geographical isolation, which supports the formation of a monophyletic group with different genetic characteristics, and does not allow the introduction of males from other breeds. Phylogenetic signals indicated that Capra aegagrus (bezoar) is the ancestor of the native goats in Indonesia, including the Lakor goats.

Keywords: artiodactyla, CO1 gene, Lakor goat, mitochondrial, phylogenetic study.

Occurrence of Vibrio spp. along the Algerian Mediterranean coast in wild and farmed Sparus aurata and Dicentrarchus labrax

Research (Published online: 26-06-2020)

26. Occurrence of Vibrio spp. along the Algerian Mediterranean coast in wild and farmed Sparus aurata and Dicentrarchus labrax

Sonia Arab, Luca Nalbone, Filippo Giarratana and Ali Berbar

Veterinary World, 13(6): 1199-1208

ABSTRACT

Background and Aim: Vibrio bacteria are autochthonous inhabitants of aquatic and marine environments. Certain strains are responsible for important seafood-borne outbreaks in developed nations. The aim of this study was to investigate the occurrence of Vibrio spp. along the Algerian Mediterranean coast in several samples of two prominent wild and farmed marine fishes, Sparus aurata and Dicentrarchus labrax.

Materials and Methods: A total of 350 S. aurata (n=280 farmed and n=70 wild) and 340 D. labrax (n=250 farmed and n=90 wild) were sampled among three different locations along the Algerian Mediterranean coastal area. The samples were processed for Vibrio research according to the ISO methods. Isolated colonies were identified utilizing biochemical tests and consecutively confirmed with matrix-assisted laser desorption ionization-time-of-flight mass spectrometry, combined with polymerase chain reaction (PCR) analysis when appropriate, or confirmed with PCR analysis alone.

Results: A total of 42 Vibrio spp. were detected only among the farmed fishes. Taking into account, all 690 fishes sampled, the incidence of Vibrio spp. was 6.08% (with peaks up to 7.92%) among the total number of farmed fishes. Overall, 25 strains were isolated from S. aurata and 17 strains were isolated from D. labrax. The isolated strains belonged to four different species and were represented as follows: Vibrio alginolyticus (n=20), Vibrio cholerae (n=15), Vibrio fluvialis (n=5), and Vibrio hollisae (n=2). The incidence of Vibrio was higher in places characterized by greater levels of anthropogenic contamination of seawater.

Conclusion: Considering the growing production and consequent rising consumption of farmed fish in Algeria, the reported incidence of Vibrio and the presence of potentially pathogenic strains of Vibrio such as V. cholerae cause particular concern for food safety matters. Even if innovative and natural techniques are desired in aquaculture, proper hygiene and manufacturing practices are essential for the correct management of Vibrio infection risk in farmed fishes at both industrial and domestic levels.

Keywords: Algeria, gilt head sea bream, Mediterranean sea, sea bass, Vibrio spp.

Prevalence of enterotoxins and other virulence genes of Staphylococcus aureus caused subclinical mastitis in dairy cows

Research (Published online: 26-06-2020)

25. Prevalence of enterotoxins and other virulence genes of Staphylococcus aureus caused subclinical mastitis in dairy cows

Rania M. Ewida and Amira A. T. Al-Hosary

Veterinary World, 13(6): 1193-1198

ABSTRACT

Background and Aim: Milk production is one of the main props for the national economy. One of the crucial problems in this industry is subclinical mastitis, which harms this industry that considered the backbone of the economy. It is an infectious and zoonotic disease; the infection can spread between dairy animals through milkers' hands, and milking machines, while the human infection occurs due to the consumption of apparently hygienic milk. Staphylococcus aureus is one of the main causative agents of clinical and subclinical mastitis. It is also considered one of the bacteria incriminated in food intoxication of humans due to its virulence factors as enterotoxins and toxic shock syndrome. The current study was designed to assess the prevalence of S. aureus and its enterotoxins, as well as, its other virulence factors in milk collected from cows that suffer from subclinical mastitis.

Materials and Methods: Sixty cows were collected from different dairy farms located in Assiut Governorate, Egypt. These cows were subjected to the clinical examination of the udder and its lymph nodes before sampling. Milk samples were collected from clinically healthy udders. All the milk samples were examined by California mastitis test (CMT), polymerase chain reaction (PCR), and enzyme-linked immunosorbent assay (ELISA) for confirmation subclinical mastitis, presence of S. aureus and its enterotoxins genes and other virulence factors in the examined milk samples.

Results: The cows included in the current study had healthy udders. The sixty collected milk samples were tested by CMT. 48/60 (80.0%) were positive samples; from the 48 positive samples, 46 (95.83%) samples were confirmed positive by S. aureus 16s rRNA PCR assay. Multiplex PCRs confirmed the presence of staphylococcus enterotoxin gene C (sec) in one sample, staphylococcus enterotoxin gene D (sed) in 23 samples, while ELISA assay confirmed the presence of the same enterotoxin in only two samples. On the other hand, other groups of genes responsible for some other virulence factors of S. aureus like the extracellular thermostable nuclease (nuc) gene were found in 33 samples, while toxic shock syndrome (tsst) gene and methicillin restraint S. aureus (mecA) gene were not detected in this study.

Conclusion: Subclinical mastitis is one of the hidden factors that adversely affect the health of both animals and humans. The milk is usually appeared good and may be consumed by humans especially children; however, it causes severe public health problems. In addition, the infected animals with this form of mastitis can spread the infection to other dairy animals and may be turned to a clinical case of contagious mastitis that may be ended by animal culling or death. S. aureus is one of the main causes of subclinical mastitis in cattle. In addition to extracellular thermostable nuclease (nuc) gene, staphylococcus enterotoxin gene C (sec) and staphylococcus enterotoxin gene D (sed) are the most common virulence genes confirmed in subclinical mastitis milk. These results highlighted the need to apply more hygienic measures in the dairy farms to avoid spreading the infection between animals to ensure the production of safe and healthy food to humans.

Keywords: enterotoxins, mecA, nuc, polymerase chain reaction, Staphylococcus aureus, subclinical mastitis.

Effects of different sterilization methods of herbal formula on phytochemical compounds and antibacterial activity against mastitis-causing bacteria

Research (Published online: 25-06-2020)

24. Effects of different sterilization methods of herbal formula on phytochemical compounds and antibacterial activity against mastitis-causing bacteria

Dian Wahyu Harjanti, Fajar Wahyono and Vincentia Rizke Ciptaningtyas

Veterinary World, 13(6): 1187-1192

ABSTRACT

Background and Aim: The current phytobiotic industry is struggling to determine a proper sterilization method for an herbal formula that comprises multiple plant extracts. Hence, this study aims to investigate the effects of two sterilization methods of herbal formula on phytochemical compounds and antibacterial activity against mastitis-causing bacterial isolates.

Materials and Methods: The herbal formula comprised the extracts of Piper betle leaves, Curcuma domestica, and Curcuma zanthorriza. We applied two sterilization methods – sterilization using 0.45 μM syringe filter and sterilization using an autoclave at 121°C for 15 min. After sterilization, we measured phytochemical contents (phenol and flavonoid) of the herbal formula. Using the disk diffusion method, the antibacterial susceptibility test of the sterilized herbal formula against mastitis-causing bacterial isolates was conducted. Tetracycline, erythromycin, and penicillin – common antibiotics for mastitis therapy in dairy farms – were used as standard antibiotics.

Results: Compared with autoclave sterilization, syringe filter sterilization resulted in less (p<0.05) phenolic and flavonoid contents. Against Escherichia coli and Staphylococcus aureus, the filter sterilized herbal formula (E. coli: 65.9%-73%; S. aureus: 6.2%-18.1%) markedly reduced the antibacterial activity than the autoclave-sterilized herbal formula (E. coli: 2.1%- 3%; S. aureus: 4.5%-10.7%).

Conclusion: This study establishes that autoclave sterilization of the herbal formula is the best sterilization method that exerts minimal adverse effects on the phytochemical compounds and could sustain the antibacterial efficacy against mastitis-causing bacteria. Hence, the herbal formula could be used as an alternative treatment for bovine mastitis.

Keywords: herbal extract, mastitis, phytobiotic, phytochemical compound, sterilization method.