Study organisms in chronic toxicological bioassays are often provided with excessive resources to remove food limitations as a confounding experimental variable. Under more ecologically realistic situations, resources are often less abundant and such restrictions may alter the responses of organisms to environmental contaminants. Here, we investigated the interaction between resource level and ...

Many marine invertebrates with complex life cycles produce planktonic larvae that experience environmental conditions different from those encountered by adults. Factors such as temperature and food, known to impact the larval period, can also affect larval size and consequently the size of newly settled juveniles. After documenting natural variation in the size of cyprids (the final larval sta...

In a series of three experiments, we tested the effects of short-term food variability on the larval development of Petrolisthes cabrilloi. We first reared seven sibling clutches of zoeae at 19°C in ten constant food rations (ranging 2-40 Artemia nauplii d) to determine maximal and minimal values for age and size at metamorphosis to the megalops stage. Mean age at metamorphosis ranged between 1...

vitro digestibility tended to be greater with ammoniation. In the second trial, very high levels of ammonia, urea or glucose were added. Levels of insoluble protein were much higher in this trial than the other. This reflects the high variability of corn silage. Recovery of nitrogen added as ammonia averaged 82 percent while all of the nitrogen added as urea was recovered. The amounts of insolu...

This research aimed to find out how the effect of replacing BR1 with BR2 on broiler performance. The method was experimental using a Completely Randomized Design (CRD) 5 treatments consisted R1: giving aged 1 35 days, R2: R3: 7 days and 8 R4: 14 15 R5: 21 22 days. Each treatment replicated times. observed variables were daily ration consumption, body weight gain, conversion. Data analyzed by va...

This study aimed to assess the main factors affecting goat milk yield and composition from Northwest region of Tunisia. A survey a sampling campaign were conducted over four months (February-May, 2018), within 112 farms in 3 regions. Individual daily (DMY) was registered samples taken duplicate be analysed for fat (FC), protein (PC), solid not (SNF), density lactose contents. Results showed tha...

An in vitro study was conducted to evaluate the optimum roughage to concentrate ratio in complete rations using sorghum stover (SS) as a roughage source since it is a main feed resource for urban and peri-urban dairies. Eight complete rations were prepared with roughage (R) to concentrate (C) ratio of 100R:0C to 30R:70C. In vitro gas production (ml) at 24 h incubation, in vitro organic matter d...

The problem of designing a balanced diet for primary school-aged children as very important lever to improve the health and adults is considered. It demonstrated that children's nutrition differs from adult in several signs, particular, it needs calcium an easily digestible form, more nutrients energy per unit body weight, requires use gentle processing methods such cooking, stewing baking, rem...

Conventionally, maximum capacities for energy assimilation are presented as daily averages. However, maximum daily energy intake is determined by the maximum metabolizable energy intake rate and the time available for assimilation of food energy. Thrush nightingales (Luscinia luscinia) in migratory disposition were given limited food rations for 3 d to reduce their energy stores. Subsequently, ...