strategy describes a feed forward regime based on a con- stant specific growth rate μ [1-5]. This strategy results in an exponential feeding profile and does not require complex instrumentation, but μ is also not controlled, and since the cells capacity may change over time, the feeding profiles consider a large safety margin. Another feedingstrategy is based on a controlled μ and requires laborious continuous culture investigations and an effec- tive computer controlled operation, based on established growth models and a feedback algorithm requiring expensive online measurement sensors for methanol [2,6-8]. Employing these strategies, the outcome regard- ing specific productivity and specific growth rate was diverse; some studies showed that the maximal specific productivity did not relate to the maximal specific growth rate [1,3,6,7], whereas another study showed a more or less growth associated productivity .
Abstract: A phase-feedingstrategy of nutrients based on requirements of Chlorella vulgaris in different physiological phases was examined to maximize the biomass and lipid productivity. This strategy includes reduction of duration in adaption phase (stage-I), enhancement of biomass in growth phase (stage-II) and improvement of lipid productivity in stationary phase (stage-III). The duration of microalgae in adaption phase was reduced from 52 h to 34 h at nitrogen and phosphorus feeding rates of 5.11 mg/(L·d) and 0.54 mg/(L·d), whereas the maximum biomass concentration during growth phase was improved to (4.03±0.25) g/L at nitrogen and phosphorus feeding rates of 20.04 mg/(L·d) and 4.21 mg/(L·d). In stationary and decline phases, a maximum lipid productivity of 132.30 mg/(L·d) was achieved when nutrients supply was stopped at 128 h, which was 28.86 mg/(L·d) higher than that when nutrients supply was stopped at 104 h. This multi-phase cultivation could be a promising strategy for simultaneous enhancement of microalgae biomass and lipid productivity.
2011). Two feeding strategies were adopted; in the first strategy the fish larvae were fed newly hatched Artemia urmiana nauplii (N) for 5 days followed by gradual replacement with a commercial formulated trout starter diet (FD). The basal diet containing 40% protein, 14% lipid, 4% fiber, vitamin and mineral premixes, was purchased from Chineh Co., Iran. In the second strategy the fish larvae were fed different combinations of newly hatched Artemia nauplii and FD from the first day of exogenous feeding. Feeding rations were based on wet body weight: initially 35% of body weight (first 5 days), followed by 25% (days 6-10), 15% (days 11-15) and 10% of body weight (days 16- 20) (Agh et al., unpublished data). To determine the daily feeding rations, actively swimming newly hatched Artemia nauplii were transferred into a big beaker, aerated and 15 sub-samples (250 µl each) were collected, weighed, dried and weighed again in order to calculate their wet and dry weight. Daily rations were divided into six equal portions fed at intervals of four hours. The feeding rates were adjusted according to the daily mortalities in each tank. Each feedingstrategy included several feeding treatments which varied in the rate of transition from a live food to a formulated diet. Additionally, two controls were included in the experimental set-up, one with live food, and one with formulated diet throughout the entire culture period. All feeding treatments were continued for 20 days until transition to FD had been completed for all of them.
Feeding experiment to understand the feedingstrategy of selected copepod species when fed with natural mixed phytoplankton diet were performed using Acartia erythraea, Paracalanus indicus, Oithona brevicornis, Microsetella rosea and Microsetella norvegica as subject species. The main aim of the study was to observe feeding pattern of the chosen species and to understand their food preferences. Acartia erythraea and Paracalanus indicus represented the calanoid group. Microsetella rosea and Microsetella norvegica represented the harpacticoid group whereas Oithona brevicornis represented the cyclopoid copepods. The results obtained from the experimental trials provided a preliminary idea about their feeding habit with respect to the mixed phytoplankton concentrate that was used for feeding the copepods. The experimental data has been provided in the form of tables and figures in support of the results obtained during the research work.
1962), although some species are known to directly consume plant debris (Wolff, 1976). Foraminifers have been reported in the guts of some asellote species, and were assumed to have been incidentally swallowed along with detritus (e.g. Wolff, 1962). However, Svavarsson et al. reported that Ilyarachna hirticeps and Eurycope inermis (Family: Munnopsidae) from 1200 to 2000m were actually selectively preying upon benthic foraminifers rather than consuming detritus (Svavarsson et al., 1993), a strategy reiterated in mouthpart morphology (Wilson and Thistle, 1985). Scavenging is a feedingstrategy used by some shallower isopod genera, notably Natatolana (Wong and Moore, 1995; Svane and Barnett, 2008), which also occur and scavenge as deep as 2500m (Albertelli et al., 1992; Kaïm- Malka, 1997), and the giant isopod Bathynomus giganteus (Perry et al., 1995; Soong and Mok, 1994), which is known to occasionally consume fish and squid remains (Chamberlain et al., 1986; Barradas- Ortiz et al., 2003). However, these species belong to another suborder, Flabellifera, and the family Cirolanidae, which are a specialized group of sighted and active carnivorous scavengers.
a global phylogenetic analyses of Sycophaginae (Cruaud et al. 2011b). The molecular clock analyses that used I. thanatos as a calibration point (Cruaud et al. 2011a) estimated Idarnes to have originated 29.2 – 18.2 Ma. According to this analysis, Idarnes probably arose after the break-up of Gondwanaland, between the Oligocene and Miocene (Cruaud et al. 2011a), a conclusion consistent with its New World distribution. Dominican amber cannot be dated accurately, but I. thanatos clearly dates to a period close to the origins of the genus, and indicates that distinct species groups, with differing ecologies, had already diverged by that time. Recent analyses suggested that the ovipositor morphology is correlated with feeding regime (Elias 2013) in Idarnes species. Idarnes thanatos’ ovipositor shows heterogeneously spaced
3. 3. Uncoupled Carbon and Nitrogen FeedingStrategy In the FF&unCN reactor, the carbon source is fed at the beginning of the feast phase which is consumed at the initiation of the famine phase. Consequently, in the feast phase, the microbial growth is prevented since an essential nutrient for growth (nitrogen) was not available and thus only storing organisms can grow in the absence of carbon source in the famine phase. Similar to the literature [21, 29-31], imposing nitrogen limitation favored the metabolism of PHA-storing organisms from the first cycle. It should be noted that using only conventional feast and famine regime requires a number of cycles for accumulating storing-organisms in the biomass . Conceivably, the FF&unCN reactor could reach the culture with PHA- storing species quicker than the FF reactor . Figure 6 reports COD, PHA, ammonical nitrogen and MLSS concentration profiles obtained over a 16th cycle of the selection stage using acetate. As expected, PHA content was degraded as an internal source of carbon and energy for microbial growth throughout the famine phase. In fact, some residual substrate (380 mg COD/L) was present at the end of feast phase, which used over the famine period, thus hindering a real famine. To provide a real famine, the elimination of the supernatant after a settling period is strongly recommended which is not done in this work. From the Figure 6, a slight increase in biomass concentration was observed during the famine phase by adding a gradual increase in the nitrogen source. The decrease in the accumulated PHB concentration was due to the biomass growth. The microbial growth yield (Y X/S ) and PHA production yield (Y PHA/S ) were obtained
pH is a key culture parameter for growth of Streptococcus suis and formation of lactate, and an appropriate pH is important to increase the cell density of S. suis. Here, we investigated the effect of pH on S. suis fermentation, and the results indicated that the optimum pH range was 7.0-7.5 and pH controlled using a two-stage strategy [pH 7.0 (0-4 h) and pH 7.5 (4-10 h)] had a positive impact on improvement of cell density. Specifically, NaOH was used to adjust pH during the initial 4 h and mixture of NaOH and KOH (2:1, v/v) were used to control pH during 4-10 h, which resulted in the concentrations of Na + and K + below the threshold for inhibiting S. suis fermentation. Furthermore, a pH feedback feedingstrategy was applied in S. suis fermentation, the concentration of residual glucose was maintained at approximately 0.10 g/L, and the accumulation of lactate decreased to 4.17 g/L, and the concentration of Na + and K + were 70.2 mmol/L and 30.1 mmol/L. which was accompanied by a high cell density (2.347) and viability (8.42x10 9 colony forming units/mL) because of the reduction of lactate accumulation and proper levels of pH, Na + and K + .
The maximum concentration of PHA in cell mass that we observed was only 31%, following a lengthy incuba- tion when glycerol water was used as the carbon source. A majority of the carbon source fed to the P. putida was evidently used for maintenance energy (or possibly other products not detected). This low PHA level would likely lead to poor extraction economics, as current industrial processes target a 90% PHA level. However these pro- cesses are primarily based on PHB-PHHx copolymers, and utilize starch-derived sugars for growth. Use of lower costs carbon sources may lead to more economi- cally PHA production processes, however additional re- search is needed to improve microbe performance and feedingstrategy.
Our aim was enhancing the content of beneficial fatty acids in intramuscular fat of beef and improving the meat quality for the consumer. In our experiments on the one hand the feedingstrategy (extensive or intensive diet, different forage to concentrate ratio and feeding concentrates with/without n-3 fatty acids), on the other hand the effect of breed (old: Hungarian Grey (HG), dual purpose: Hungarian Simmental (HS), dairy: Hungarian Holstein-Friesian (HF)) were analyzed on the fatty acid composition of intramuscular fat of beef.
Feeding kinematic studies inform our understanding of behavioral diversity and provide a framework for studying the flexibility and constraints of different prey acquisition strategies. However, little is known about the feeding behaviors used by many marine mammals. We characterized the feeding behaviors and associated kinematics of captive bearded (Erignathus barbatus), harbor (Phoca vitulina), ringed (Pusa hispida) and spotted (Phoca largha) seals through controlled feeding trials. All species primarily used a suction feedingstrategy but were also observed using a biting strategy, specifically pierce feeding. Suction feeding was distinct from pierce feeding and was characterized by significantly faster feeding times, smaller gapes and gape angles, smaller gular depressions and fewer jaw motions. Most species showed higher variability in suction feeding performance than in pierce feeding, indicating that suction feeding is a behaviorally flexible strategy. Bearded seals were the only species for which there was strong correspondence between skull and dental morphology and feedingstrategy, providing further support for their classification as suction feeding specialists. Harbor, ringed and spotted seals have been classified as pierce feeders based on skull and dental morphologies. Our behavioral and kinematic analyses show that suction feeding is also an important feedingstrategy for these species, indicating that skull morphology alone does not capture the true diversity of feeding behaviors used by pinnipeds. The ability of all four species to use more than one feedingstrategy is likely advantageous for foraging in spatially and temporally dynamic marine ecosystems that favor opportunistic predators.
The following two experiments were under- taken to evaluate the effects of fl at-rate vs. step-up feeding strategies with alternative feeds on the performance of mature suckler cows during a long indoor feeding period and subsequent grazing. The aim was to study if fl at-rate feedingstrategy in- stead of step-up feeding can be successfully car- ried out during the indoor feeding period, and if grass silage and straw can be replaced with other feeds. In Experiment 1 (Exp1), the infl uence of feedingstrategy on the performance of Aberdeen Angus × Ayrshire (AbAy) and Charolais × Ayrshire (ChAy) cows was studied using either straw or a fl our-mill industry by-product (BP) in the winter diet. In Experiment 2 (Exp2), the effects of feedingstrategy on the performance of the Hereford (Hf) cows were studied using either grass silage (GS) or whole-crop barley silage (WCBS) as a sole winter feed. The effects of treatments on cow feed intake, diet digestibility (Exp2), live weight (LW), body condition score (BCS), milk production (Exp1), incidence of dystocia and calf performances are discussed in this paper.
Controlled grazing is one of modern concept of animal husbandry. Due to uncontrolled grazing on pastures there is a great threat to the existence of pastures. Uncontrolled grazing prevents auto reseeding of grass lands which results in rapid decrease in grass land areas. By mixing different feeding practices like grazing, dry fodder and concentrate feeding practices balance can be maintained and milk production can be improved. In Table 3 an attempt was made to study the adoption of grazing practices by the milk producers. Table 3. reveals that 83.3 percent members and 100 percent of non- members allow their animals to graze for less than 5 hours with dry fodder and concentrates 3.33 percent members allow their animals to graze more than 5 hours without dry fodder and concentrates, 40 percent of members allow their concentrates among the non-members 62.5 percent allowed their animals to graze less than 5 hours without dry fodder and concentrates, 15 percent allowed their animals to graze less than 5 hours with dry fodder and concentrates, 15 percent allowed their animals to graze more than 5 hours with dry fodder and concentrates, and another 7.5 percent allowed their animals to graze more than 5 hours without dry fodder and concentrates. A large chunk of non-members (62.5%) were allowing their animals to graze less than 5 hours without dry fodder and concentrates, this shows improper maintenance of dairy animals by non-members.
20. Ghosh S, Tano-Debrah K, Aaron GJ, Otoo G, Strutt N, Bomfeh K, et al. Improving complementary feeding in Ghana: reaching the vulnerable through innovative business-the case of KOKO Plus. Ann N Y Acad Sci. 2014;1331:76-89. 21. Issaka AI, Agho KE, Burns P, Page A, Dibley MJ. Determinants of inadequate complementary feeding practices among children aged 6-23 months in Ghana. Public Health Nutr. 2015;(4):669-78. 22. Pelto GH , Armar-Klemesu M. Balancing
(McDonald 1 948) of pH (Kaufmann, Hagemeister and Dirksen 1 980; Thomas and Rook 1 98 1 ) of VF A (Kaufmann, Hagemeister and Dirksen 1 980; Sutton 1 980 , 1 98 1 ; Sutton et al 1 985, 1 986) of osmolality (Phillip et al 1 980) and of phosphate (Sniffen and Robinson 1984). The findings suggest that feeding infrequently will lead to increased diurnal variation in many rumen fluid characteristics. It is logical to assume that reduction of this variation is desirable and will lead to improved cattle perfonnance (Sniffen and Robinson 1 984; Sutton 1 985). Of importance here in milk production or weight gain is the energy as volatile fatty acids (VF A) in terms of quantity and proportion between acetic acid plus butyric acid and propionic acid. There is now evidence that when low-roughage diets are fed, to ruminants, increasing the frequency of feeding reduces milk fat depression by altering aspects of VFA production in the rumen (Sutton, Hart and Broster 1 982). Not all studies had similar results. The responses between growing sheep or cattle and lactating cows have been varied.