Response of common carp (Cyprinus carpio L.) to supplemental DL-methionine and different feeding strategies

Ad libitum versus step-up feeding during late lactation: The effect on feed consumption, body composition and production performance in dry fed loose housed sows

Processing organic waste using black soldier fly (BSF)-based technology offers a promising alternative for sustainable organic waste management and urban sanitation. This study was conducted to assess the influence of feeding strategies on the efficacy of BSF larvae to recycle organic wastes into value products. Fruit waste and chicken manure were used as organic waste samples while commercial chicken feed was used as a control, and were processed for 15 days in circular plastic containers (Ø 30 × 12 cm) with 50; 100; 150; and 200 mg/larva/day continuous and batch feeding diets, using 500 four-day-old larvae per diet, repeated four times. Larval survival rates were not significantly affected by the feeding strategies. However, average larval biomass of 83.69 ± 13.04 g and 82.46 ± 08.52 g was achieved for the continuous and batch feeding strategies, respectively, under favorable conditions. Larval feed reduction rates ranged from 24.65 ± 03.48% to 72.78 ± 01.48% and 24.52 ± 0.27% to 72.25 ± 12.13% with continuous and batch feeding strategies, respectively, and were significantly affected by the different daily diets. On the other hand, the bioconversion rates ranged from 13.34 ± 0.26% to 50.82 ± 02.27%, and the highest values were observed with the continuous feeding diets. This study confirms the efficacy of BSF larvae to thrive in different organic substrates and shows that the continuous feeding strategy can be better and enhance a sustainable small-scale organic waste management.

Response of growth performance, serum biochemical parameters, antioxidant capacity, and digestive enzyme activity to different feeding strategies in common carp (Cyprinus carpio) under high-temperature stress

Ammonia accumulation is a major challenge in intensive aquaculture, where fish are fed protein-rich diets in large rations, resulting in increased ammonia production when amino acids are metabolized as energy source. Ammonia is primarily excreted via the gills, which have been found to harbor nitrogen-cycle bacteria that convert ammonia into dinitrogen gas (N2) and therefore present a potential in situ detoxifying mechanism. Here, we determined the impact of feeding strategies (demand-feeding and batch-feeding) with two dietary protein levels on growth, nitrogen excretion, and nitrogen metabolism in common carp (Cyprinus carpio, L.) in a 3-week feeding experiment. Demand-fed fish exhibited significantly higher growth rates, though with lower feed efficiency. When corrected for feed intake, nitrogen excretion was not impacted by feeding strategy or dietary protein, but demand-fed fish had significantly more nitrogen unaccounted for in the nitrogen balance and less retained nitrogen. N2 production of individual fish was measured in all experimental groups, and production rates were in the same order of magnitude as the amount of nitrogen unaccounted for, thus potentially explaining the missing nitrogen in the balance. N2 production by carp was also observed when groups of fish were kept in metabolic chambers. Demand feeding furthermore caused a significant increase in hepatic glutamate dehydrogenase activities, indicating elevated ammonia production. However, branchial ammonia transporter expression levels in these animals were stable or decreased. Together, our results suggest that feeding strategy impacts fish growth and nitrogen metabolism, and that conversion of ammonia to N2 by nitrogen cycle bacteria in the gills may explain the unaccounted nitrogen in the balance.

Carbohydrate Utilization by Rainbow Trout Is Affected by Feeding Strategy

Dietary β-glucan stimulate complement and C-reactive protein acute phase responses in common carp (Cyprinus carpio) during an Aeromonas salmonicida infection

Heredity of stress-related cortisol response in androgenetic common carp ( Cyprinus carpio L.)

Improved production of 1,3-propanediol from biodiesel-derived crude glycerol by Klebsiella pneumoniae in fed-batch fermentation

Objetivo. Evaluar el efecto que ejerce la suplementación con alimento balanceado sobre la ganancia diaria de peso (GDP) y el consumo de alimento (CA) en terneros lactantes y su impacto económico en una empresa ganadera manejada bajo un sistema vacuno de doble propósito, en el municipio de Sincé, Sucre–Colombia. Materiales y métodos. Se suplementaron 14 crías (6 machos y 8 Hembras) entre 3 y 5 meses de edad, con alimento balanceado comercial al 1.5% del peso vivo (Tratamiento 1) y se compararon con un grupo igual sin suplementar (Tratamiento Testigo), durante 113 días en época de lluvias. La GDP y CA fueron evaluados mediante prueba t de Student. Se determinó Relación beneficio: costo y rentabilidad. Resultados. La GDP de las crías lactantes fue afectada de manera altamente significa por la suplementación con alimento balanceado comercial (p0.05), encontrándose el mismo resultado para el consumo de alimento balanceado (p>0.05) explicando así la no diferencia estadística en la GDP entre sexos. El análisis económico confirmó que la estrategia alimenticia es viable al presentarse una relación B:C del 1.1. y una rentabilidad trimestral del 9.27%. Conclusiones. La suplementación de terneros lactantes es una práctica viable, que permite obtener ganancias adicionales.

Common carp (Cyprinus carpio) were fed food with different protein concentrations following different feeding regimes, which were previously shown to affect growth, nitrogen excretion and amino acid catabolism. 16S rRNA gene amplicon sequencing was performed to investigate the gut microbiota of these fish. Lower dietary protein content increased microbial richness, while the combination of demand feeding and dietary protein content affected the composition of the gut microbiota. Hepatic glutamate dehydrogenase (GDH) activity was correlated to the composition of the gut microbiota in all dietary treatments. We found that demand-fed carp fed a diet containing 39% protein had a significantly higher abundance of Beijerinckiaceae compared to other dietary groups. Network analysis identified this family and two Rhizobiales families as hubs in the microbial association network. In demand-fed carp, the microbial association network had significantly fewer connections than in batch-fed carp. In contrast to the large effects of the feeding regime and protein content of the food on growth and nitrogen metabolism, it had only limited effects on gut microbiota composition. However, correlations between gut microbiota composition and liver GDH activity showed that host physiology and gut microbiota are connected, which warrants functional studies into the role of the gut microbiota in fish physiology.

Bronchiolitis is the most common cause of hospitalization for children < 12 months of age.1 Treatments such as bronchodilators, corticosteroids, or antiviral agents are ineffective and supportive measures remain the mainstay of treatment. The American Academy of Pediatrics clinical practice guideline includes a strong recommendation to meet the child’s hydration needs by either nasogastric (NG) or intravenous fluids.1 NG hydration is the preferred route for nonoral hydration in many parts of the world2–6 where it is recognized as an option that offers cost benefits, avoids painful intravenous sticks, and provides better nutrition than isotonic fluids.2–4,6,7 Best practice for administering NG fluids in infants with bronchiolitis has yet to be established.The randomized control trial in this month’s Hospital Pediatrics by Courtney et al8 is the first study to compare bolus and continuous NG feeds in infants with bronchiolitis. NG tube placement for rehydration and provision of nutrition was already standard practice in this large freestanding children’s hospital in Australia; however, there was variation in the use of continuous versus bolus feeding. This practice variation was ascribed to theoretical concerns related to increased risk of respiratory effort and possible aspiration in infants with full stomachs.In this open, parallel-group superiority trial, infants < 12 months of age who had a 50% decrease of expected oral intake over the previous 12 to 24 hours were randomized to either bolus or continuous NG feeds. Patients were recruited from the emergency department and general care units. Most infants were judged to have moderate illness, and about half of them were on room air. However, 44% received high flow nasal canula (HFNC) support. Using an intention to treat model, authors found that there was no difference in the primary outcome of length of stay (LOS) between bolus and continuously fed infants (median [interquartile range] 54.2 [40.25–82.00] vs 56 [38.0–78.8]). However, surprisingly, they noted an association of increased admissions to the PICU (28.6% vs 11.2%, P = .004) in the continuously fed group compared with the bolus group. No infant had clinically significant aspiration in either group and vital signs taken near feeding initiation were similar.A strength of this study is the randomized, parallel-group superiority design. However, it is not feasible to blind the providers to the nature of feeds (bolus versus continuous), and the open design may have introduced unconscious bias among providers. In many institutions, continuous feeds are commonly used in children on HFNC support. For example, 43% of children with bronchiolitis on HFNC had continuous feeds compared with 15.8% on bolus feeds in a study by Babl et al.6 Thus, children on continuous feeds may be perceived to be sicker, leading to a higher rate of intensive care admissions in this population. More investigation is needed to clarify the association found in this study between increased intensive care admissions and continuous feeds. Furthermore, discharge was delayed past “fit for discharge” criteria in a slightly higher proportion of children (36% vs 26%) with continuous feeds compared with bolus feeds. Delays were primarily ascribed to awaiting discharge clearance by the medical team. The difference does not reach statistical significance; however, it may be another indication that these children are viewed as sicker, or that there are underlying factors in the clinical course of children on continuous feeds that lead to hesitancy in clearing them for discharge.Clinically significant differences in LOS are considered to be 24 hours in this study. However, many children admitted for bronchiolitis stay only 36 to 48 hours,9 and a more granular assessment of LOS would be helpful because a difference of 6 to 8 hours may be significant to families and health care systems. Finally, practitioners in Australia restrict the diagnosis of bronchiolitis to those < 12 months of age, leading to the exclusion of children older than 12 months of age in this study. However, the American Academy of Pediatrics clinical practice guideline includes this older age group (up to 24 months of age); therefore, a practice gap remains for many patients who we care for in the inpatient setting. Exploring these issues in future studies is important to determine enteral feeding options in this population (12–24 months).The study by Courtney et al8 helps address a common clinical question where there is limited evidence: the best mechanism of enteral feeding for infants hospitalized with bronchiolitis who cannot orally feed. Previous studies comparing these strategies have focused on birth hospitalizations of preterm infants and those with low birth weights.10,11 Applying this research to otherwise healthy infants who need short-term nutritional and hydration support is problematic because the physiology and needs of older infants and those with an acute respiratory illness may be different than preterm and low birth weight infants. A small study comparing NG feeds in mechanically ventilated children of various ages found that bolus feeds were associated with higher energy and protein delivery without aspiration.12 In studies of longer-term NG feeding plans, continuous feeds may be associated with loss of breast milk nutrients,13 increased feeding residuals,10 mismatch with hormonal cues, less patient mobility, and additional cost.14 However, these concerns are less of a consideration in the scenario of an acute, short hospitalization for bronchiolitis, which is the focus of this current study.Another important concern is the risk of clinically significant aspiration, which is a commonly cited barrier when considering oral or NG feeds in infants with bronchiolitis.15,16 Although proving safety in rare events is challenging, multiple studies of children with bronchiolitis fed while on HFNC suggest aspiration is rare.6,17,18 Furthermore, in a study of mechanically ventilated children with a variety of illnesses who were fed by NG versus postpyloric feeds, aspiration was not detected in either group.19 It is reassuring that the current study by Courtney et al8 of patients also found no episodes of clinically significant aspiration in infants receiving continuous or bolus feeds.Nutritional support and hydration using NG tubes have been evaluated in bronchiolitis; however, previous studies have lacked a standard administration approach2,3,16,20 or have described a mixed approach that limits interpretation.4–6 Without a firm recommendation, providers may default to their personal or institutional practice, which feels like the standard of care but is largely based upon anecdotal experience. Furthermore, in the absence of evidence, we often default to what might theoretically be the “safest.” However, in the best-case scenario, this anecdotal approach can prevent us from moving forward and, at its worst, it may actually be harmful. The findings of Courtney et al8 strengthen the existing evidence that pulmonary aspiration is rare in continuous and bolus feeds, and in addition, these feeding strategies are associated with equivalent LOS. With these observations, we can decrease the complexity of the “how” of NG feeding an infant and enable operationalizing nutrition. In many instances, NG bolus feeds may be optimal. They more closely mimic the timing and natural rhythm of bottle and breastfeeding, and they can be easily paired with oral feeding, both of which may appeal to parents.Decisions to feed infants with respiratory distress because of bronchiolitis can be complex and involve many different provider types. Qualitative study of parent, nursing, and physician perspectives may be beneficial to illuminate opportunities and barriers that inform choices about bolus and continuous NG feeds. Understanding these factors may improve success rates of quality improvement projects that seek to increase NG bolus feeds in patients admitted with bronchiolitis.A key component of quality improvement methodology is to reduce variation in practice, followed by moving it in the desired direction. This study by Courtney et al8 is an important step toward standardizing the approach to NG feeds using bolus feeds in patients admitted with bronchiolitis who cannot orally feed. Although future studies may explore nutrition-related innovations that improve outcomes, LOS, and patient experience, this current study suggests that NG bolus feeds are well-tolerated and should be considered as an important starting point in patients with bronchiolitis who cannot orally feed.

Digestive enzyme activities of Yellow Rasbora (Rasbora lateristriata) had been reported, but only focused on a daily feeding strategy. The effect of starvation and refeeding on the growth, body composition, and digestive enzyme activities in Yellow Rasbora has never been reported. This study aimed to know the most efficient feeding strategy for growth, body composition, and digestive enzyme activities of Yellow Rasbora. The experiment was conducted in 20 aquariums using two months old fingerling. Four different feeding strategies were tested; twice feeding a day, one-day starvation and six days refeeding, two days starvation and five days refeeding, and four days starvation and ten days refeeding. The result showed that different feeding strategies had no significant effect on all growth parameters. The result proved that Yellow Rasbora could compensate for starvation through absolute growth, with the highest value achieved in two days of starvation and five refeeding. No significant value was also observed on crude protein, and lipid contents indicate that starvation does not affect the utilization of protein and lipid reserves. This result was consistent with fish condition factors which did not differ among treatments. The feeding strategy did not significantly affect total protease, trypsin, and amylase activities, but significantly affected chymotrypsin, lipase, and alkaline phosphatase activities. All parameter indicated that two days starvation and five days refed duration showed similar values to daily feeding. Therefore, it is concluded that two days starvation and five days refeeding method is the most efficient feeding strategy for Yellow Rasbora cultivation.

The present study was conducted to evaluate the efficacy of wood betony (WB), Stachys lavandulifolia extract on growth performance and some immune responses in common carp, Cyprinus carpio. Different concentrations of the WB extract 0, 2, 4 and 8% (g per 100 g of diet) were added to commercial diet. Each treatment was randomly assigned to triplicate groups of fish having average initial weight of 44 ± 0.62 g for 10 weeks. The results showed that final weight, food conversion ratio, specific growth rate and condition factor were significantly improved by WB in a dose dependent manner, where the best growth parameters were achieved in the group of fish receiving the highest concentration of WB (P<0.05). Feeding fish at 2 and 4% W/W by WB in the diet improved lysozyme activity, ACH50 and IgM levels significantly in comparison to the control (P<0.05). Group of fish fed on 4% WB in the diet had the best levels of the immune characteristics (P<0.05). Based on the results of this study, it is recommended to feed common carp with WB to improve growth and non-specific immunity.

The impact of semi-continuous and alternating microbial feeding patterns on methane yield from UASB reactors

La tilapia gris (Oreochromis niloticus L.) es una excelente opción para la producción acuícola debido a su resistencia a condiciones adversas, enfermedades y sus hábitos alimenticios. Se evaluaron dos estrategias de alimentación durante la etapa de engorde, la cual finaliza al alcanzar un peso ideal de 1,085 g a la cosecha. Las estrategias de alimentación fueron ad libitum y alimentación al 90 % del ad libitum. El ensayo se realizó en AquaFinca Saint Peter Fish, Cortés, Honduras. Las variables medidas fueron: índice de conversión alimenticia (ICA), índice de alimentación (IA), días a cosecha (Decos) y ganancia de peso diario (GDP). Las unidades experimentales fueron doce jaulas flotantes, seis jaulas ad libitum y seis jaulas con el 90 % del ad libitum; cada jaula tenía un volumen de 1,380 m3 con una capacidad de 50,000 peces. El análisis estadístico se realizó por medio de una prueba t (P ≤0.05). La alimentación ad libitum y al 90 % del ad libitum no presentaron diferencias en ICA (1.88 y 1.82 respectivamente), tampoco se presentaron diferencias en GDP con 6.39 g ad libitum y 6.16 g con 90 % del ad libitum. El tratamiento ad libitum presentó un IA de 3.19 y el 90 % del ad libitum de 3.06; Decos fueron 157 y 165 respectivamente. El tratamiento al 90 % del ad libitum, además de representar un ahorro en alimento no tuvo efecto sobre el ICA, pero si se retrasó ocho días para llegar al peso ideal de cosecha con una diferencia de 26,270 kg de alimento entre ambos tratamientos.