One of the essential factors to be addressed in the development of aquaculture is the feeding regime. This study was investigated to assess the effects of feeding rate on growth performance, feed utilization, chemical body composition survival rate, cannibalism and morphological indices of Asian Seabass, Lates calcarifer. Intended for the trial, one hundred forty sea bass individuals with an average weight 5.47 ± 0.11 g were randomly distributed in 4 concrete tanks (914 cm × 183 cm 122 cm) each; length × width × depth) and volume 18,399 L, for total 68 days. The fishes were fed with a pelleted diet containing 46% crude protein for different feeding groups designated as (T1, T2, T3 and T4). The feed was supplied with a rate of (T1) 3%, (T2) 4%, (T3) 6%, and (T4) 9% of fish biomass per day and feeding frequency were maintained three times per day to all the groups. At the end of the trial water physicochemical parameters was in acceptable range for Asian sea bass growth. The average daily weight gain (g), weight gain (g) and specific growth rate (%) was significantly higher (p < 0.05) in T3 and T4 as compared to T1 and T2 group. The poorest feed conversion ratio was recorded in T1 group with 3% biomass per day. The cannibalism rate was significantly (p < 0.05) higher in T1 (3%) compared to T3 and T4 treatment. The morphological indices, condition factors (CF), viscerosomatic index and hepatosomatic index (HSI) was significantly higher in T4 group as compared to other treatments. The protein, moisture and ash contents of the whole biomass of the Asian sea bass were not significantly influenced by feeding rate. The fat levels in the fish bodies increased significantly (p < 0.05) with increasing feeding ratio. The phenomenal regression indicates that 6.5% feeding rate per day is optimum for best growth performance, survival and minimum cannibalism rate for Asian sea bass in captivity. The outcome of the finding will help in promotion for not only the coastal aquaculture in Pakistan abut also elsewhere.

A 70-day rearing trial was done to determine the optimal frequency of feeding on growth performance (GP), feed conversion rate (FCR), cannibalism, survival rate (SR), body chemical composition and economic efficiency of the Asian sea bass. This study tested four different treatments of feeding frequencies (FF), once (T1), twice (T2), three times (T3), and four times (T4) per day. An average initial weight of Asian sea bass fry was 0.2 g (SD = ±0.12) were stocked 10 individuals per m³ (9.14 m × 1.82 m × 1.22 m, L × W × H; water depth 0.61 m) with two replicates per treatment (4 × 2 = 8). Fry were fed a mixture of larval commercial feed and shrimp with a pellet diet containing (46% CP). Initially, the feeding rate of 8% biomass per day was further adjusted according to fish biomass on a weekly basis. Results showed that, the FF significantly affected (p < 0.05) on growth indictors and survival rate (SR). Specifically fry fed three times a day (T3) had the best FBW, FL, SGR, ADWG and FCR followed by T4 and T2 while fry fed one time a day was the lowest in these parameters. Also, VSI, HSI and CF (k) significantly differed among the treatments. The fish whole body content of protein, moisture and ash did not significantly (p < 0.05) be affected by feeding frequency, but lipid content differed and both T3, T4 were the highest. It could be concluded that, increasing FF up to three times a day had a positive effect on weight gain, survival rate and feed utilization of Lates calcarifer. The second degree polynomial regression indicates that fed three times a day is optimum for best growth performance and survival for Asian sea bass.

Bovine mastitis is a widespread and costly disease that affects dairy farming globally, characterized by mammary gland inflammation. Bovine intramammary gland infection has been associated with more than 135 different pathogens of which Staphylococcus aureus is the main etiology of sub-clinical mastitis (SCM). The current study was designed to investigate the prevalence, antibiotic resistance pattern, and the presence of antibiotic resistance genes (mecA, tetK, aacA-aphD and blaZ) in S. aureus isolated from the raw milk of cows with subclinical mastitis. A total of 543 milk samples were collected from lactating cows such as Holstein Friesian (n = 79), Sahiwal (n = 175), Cholistani (n = 107), and Red Sindhi (n = 182) from different dairy farms in Pakistan. From the milk samples microscopic slides were prepared and the somatic cell count was assessed to find SCM. To isolate and identify S. aureus, milk was streaked on mannitol salt agar (MSA) plates. Further confirmation was done based on biochemical assays, including gram staining (+ coccus), catalase test (+), and coagulase test (+). All the biochemically confirmed S. aureus isolates were molecularly identified using the thermonuclease (nuc) gene. The antibiotic resistance pattern of all the S. aureus isolates was evaluated through the disc diffusion method. Out of 543 milk samples, 310 (57.09%) were positive for SCM. Among the SCM-positive samples, S. aureus was detected in 30.32% (94/310) samples. Out of 94 isolates, 47 (50%) were determined to be multidrug resistant (MDR). Among these MDR isolates, 11 exhibited resistance to Cefoxitin, and hence were classified as methicillin-resistant Staphylococcus aureus (MRSA). The S. aureus isolates showed the highest resistance to Lincomycin (84.04%) followed by Ampicillin (45.74%), while the least resistance was shown to Sulfamethoxazole/Trimethoprim (3.19%) and Gentamycin (6.38%). Polymerase chain reaction (PCR) analysis revealed that 55.31% of the isolates carried blaZ gene, 46.80% carried tetK gene, 17.02% harbored the mecA gene, whereas, aacA-aphD gene was found in 13.82% samples. Our findings revealed a significant level of contamination of milk with S. aureus and half (50%) of the isolates were MDR. The isolated S. aureus harbored various antibiotic resistance genes responsible for the absorbed phenotypic resistance. The alarmingly high prevalence of MDR S. aureus isolates and MRSA strains in these cases possess a serious risk to public health, emphasizes the urgent need to address this issue to protect both human and animal health in Pakistan.

Staphylococcus aureus is a prominent cause of food-borne diseases worldwide. Enterotoxigenic strains of this bacteria are frequently found in raw milk, and some of these strains are resistant to antimicrobials, posing a risk to consumers. The main objectives of this study were to determine the antimicrobial resistance pattern of S. aureus in raw milk and to detect the presence of mecA and tetK genes in it. A total of 150 milk samples were obtained aseptically from lactating cattle, including Holstein Friesian, Achai, and Jersey breeds, maintained at different dairy farms. The milk samples were checked for the presence of S. aureus, and it was detected in 55 (37%) of them. The presence of S. aureus was verified by culturing on selective media, gram staining, and performing coagulase and catalase tests. Further confirmation was performed through PCR with a species-specific thermonuclease (nuc) gene. Antimicrobial susceptibility testing of the confirmed S. aureus was then determined by using the Kirby–Bauer disc diffusion technique. Out of the 55 confirmed S. aureus isolates, 11 were determined to be multidrug-resistant (MDR). The highest resistance was found to penicillin (100%) and oxacillin (100%), followed by tetracycline (72.72%), amikacin (27.27%), sulfamethoxazole/trimethoprim (18.18%), tobramycin (18.18%), and gentamycin (9.09%). Amoxicillin and ciprofloxacin were found to be susceptible (100%). Out of 11 MDR S. aureus isolates, the methicillin resistance gene (mecA) was detected in 9 isolates, while the tetracycline resistance gene (tetK) was found in 7 isolates. The presence of these methicillin- and tetracycline-resistant strains in raw milk poses a major risk to public health, as they can cause food poisoning outbreaks that can spread rapidly through populations. Our study concludes that out of nine empirically used antibiotics, amoxicillin, ciprofloxacin, and gentamicin were highly effective against S. aureus compared to penicillin, oxacillin, and tetracycline.

The present study aimed to estimate the growth pattern through length-weight relationships (LWRs), condition (Fulton’s condition factor, KF) and prey-predator status through relative weight (WR) of 9 fish species e.g., Netuma thalassina, Epinephelus coioides, Acanthopagrus berda, Acanthopagrus latus, Acanthopagrus bifasciatus, Parastromateus niger, Aluterus monoceros, Sphyraena putnamae, and Lates calcarifer belong 7 families from the Arabian Sea of Pakistan. Occasionally samples were collected from marine waters of the Arabian Sea connected to Baluchistan and Sindh province from June 2018 to May 2019 by bottom and midwater trawl nets, gill nets, and trammel nets. Individual whole body weight (BW) and total length (TL) were measured. The growth pattern either allometric (+/-) or isometric was calculated as LWR: BW = a × TLb. a and b were the LWR parameters. Condition factor was calculated as KF = (BW/TL3) ×100 and prey-predator status was as WR = (W/WS) × 100, where WS = a×TLb. This study recorded a new maximum TL (150.0 cm) for S. putnamae. The b values of LWR ranged from 2.02 to 2.76 with r2 ≥ 0.95 that indicated a negative allometric growth pattern. Additionally, the study estimated KF mostly above 1.0 except A. bifasciatus, A. monoceros, and S.putnamae. The prey-predator status was mostly balanced except for L. calcarifer. The findings of this study will be valuable for fishery managers to impose sustainable fishery management in the Arabian Sea (Baluchistan and Sindh), Pakistan, and adjacent ecosystems.