Agaricus subrufescens and Pleurotus ostreatus mushrooms as alternative additives to antibiotics in diets for broilers challenged with Eimeria spp.

1. The effect of A. subrufescens and P. ostreatus mushrooms as an alternative to antibiotics (avilamycin or monensin sodium) on performance, intestinal morphometry, immunity, and biochemical profile of broilers challenged with Eimeria spp. was studied from 1 to 42 d old. A total of 900 male Cobb® broiler chicks were distributed, according to a completely randomised design, into five treatments with six replicates each.2. The treatments consisted of: negative control (NC) - basal diet (BD) with no anticoccidial or antibiotic (non-challenged birds); negative control challenged (NCC) - NC fed to Eimeria spp. challenged birds; BD with 0.2% A. subrufescens inclusion for challenged birds (As), BD with 0.2% P. ostreatus inclusion for challenged birds (Po); and a positive control - BD with anticoccidial and antibiotic inclusion for challenged birds (ATB).3. At 11 d.o., the birds were each inoculated orally with 1 ml solution containing 2 × 105 sporulated oocysts/ml Eimeria acervulina and 2 × 104 sporulated oocysts/ml E. maxima and E. tenella.4. Birds subjected to Eimeria spp. challenge up to 21 d of age had greater crypt depth, indicating that the presence of undesirable microorganisms had an effect on cell proliferation.5. At 21 d old, the birds receiving ATB had higher average weight gain (AWG), feed intake (AFI), and feed conversion ratio (FCR) compared to those fed diets supplemented with mushrooms (As or Po). For the total rearing period (42 days), the birds that received ATB had higher AWG and AFI (P < 0.001) compared to those that received As or Po diets. Feeding avilamycin did not affect (P = 0.0676) FCR compared to the As or Po diet groups.6. From the morphometric and blood analyses there were no differences between broilers fed ATB, Po or As diets in either rearing periods. However, Po and As supplementation lowered blood triglyceride levels. At 21d there was a difference (P < 0.05) for MCV and haemoglobin, in which the mushrooms were similar to the antibiotic. At 42 d, there was a difference (P < 0.05) in haematocrit, erythrocyte, MCV, H: L, protein and albumin variables, in which the use of mushrooms was similar to the positive control, demonstrating that both (mushrooms and antibiotics) promoted a certain improvement in the health of the chickens.7. A. subrufescens and P. ostreatus can be used in broiler diets without compromising intestinal or haematological status, however, these ingredients did not result in improvements in performance.

Feeding strategy with alternate fasting and refeeding: effects on farmed pacu production.

A 36-day trial was conducted to determine the effects of repetitive periods of food restriction and refeeding on growth and energy metabolism in pacu (Piaractus mesopotamicus). A total 264 juvenile fish (36.9±2.8 g) were fed with the experimental diet for 36 days using three regimes: (i) feeding daily to satiation (FD); (ii) no feed for 3 days, then feeding the same amount offered to the control groups for the next 3 days (NF/R controlled); and (iii) no feed for 3 days, then feeding to apparent satiation for the next 3 days (NF/R at satiation). The treatments were distributed into four tanks each. WG and SGR were higher in FD group. Fish refed showed hyperphagia just up to the second day of refeeding. The worst feed conversion rate and the lowest protein efficiency ratio were found in fish NF/R controlled. The lowest values of visceral fat somatic index were found in both fasted fish groups, particularly in NF/R at satiation. The LL and glycogen concentrations, and the hepatosomatic index were all elevated in both feed restricted fish. Muscle lipid showed a tendency to decrease after the cycle of fasting and refeeding. Plasma free fatty acids and glucose levels were elevated in fish subjected to feeding restrictions while serum triglycerides levels were reduced. Triiodothyronine levels were significantly depressed in fish from the NF/R-controlled group and remained at the same levels as the control fish in fish NF/R at satiation. Results indicated that fish subjected to cyclic periods of 3-day satiation or controlled feeding after 3-days of fasting were unable to achieve the final body weight of fish fed to satiation after 36 days.