Effects of “Bioactive” amino acids leucine, glutamate, arginine and tryptophan on feed intake and mRNA expression of relative neuropeptides in broiler chicks

Feed intake control is vital to ensuring optimal nutrition and achieving full potential for growth and development in poultry. The aim of the present study was to investigate the effects of L-leucine, L-glutamate, L-tryptophan and L-arginine on feed intake and the mRNA expression levels of hypothalamic Neuropeptide involved in feed intake regulation in broiler chicks. Leucine, glutamate, tryptophan or arginine was intra-cerebroventricularly （ICV） administrated to 4d-old broiler chicks respectively and the feed intake were recorded at various time points. Quantitative PCR was performed to determine the hypothalamic mRNA expression levels of Neuropeptide Y （NPY）, agouti related protein （AgRP）, pro-opiomelanocortin （POMC）, melanocortin receptor 4 （MC4R） and corticotrophin releasing factor （CRF）. Our results showed that ICV administration of L-leucine （0.15 or 1.5 μmol） significantly （P〈0.05） increased feed intake up to 2 h post-administration period and elevated both hypothalamic NPY and AgRP mRNA expression levels. In contrast, ICV administration of L-glutamate （1.6 μmol） significantly （P 〈 0.05） decreased feed intake 0.25, 0.5 and 2 h post-injection, and increased hypothalamic CRF and MC4R mRNA expression levels. Meanwhile, both L-tryptophan （10 or 100 μg） and L-arginine （20 or 200 μg） had no significant effect on feed intake. These findings suggested that L-leucine and L-glutamate could act within the hypothalamus to influence food intake, and that both orexigenic and anorexigenic Neuropeptide genes might contribute directly to these effects.

The Influence of Feed Intake and Conditioned Reflex on Exocrine Pancreatic Function in Broiler Chicks

The data of an experimental study of the influence of feeding and the conditional stimulus on digestive function in birds is presented. It is stated that feed consumption is a powerful stimulator of pancreatic secretion in broiler chicks. The secretory response of the pancreas was the highest in the morning when secretion of pancreatic juice was 1.8 times higher, amylase activity 3.2 times, proteases activity 3.3 times, lipase activity 2.1 times higher than before feeding (basal levels). The regulation of pancreatic activity is known to be complex-reflex with conditioned-reflex component being very important since it provides 25% higher juice secretion and 42% - 74% higher enzyme secretion compared to the basal levels during few minutes after the conditional signal.

Phytotherapic Potentials of Xylopia aethiopica Dried Fruits （Grains of Selim） as Additive in Broiler Production

Xylopia aethiopica dried fruits （gains of selim） as an additive in starter broilers production was investigated. For this purpose, a total of 195-day old broiler chicks （Arbor acres） were randomly allocated into five treatments groups with 39 chicks and three replicates of 13 chicks in each. Blended grains of selim was given through drinking water on treatments T2, T3, T4 and T5 at concentrations of 0.4, 0.6, 0.8 and 1,0 g/L, while chicks on treatment T1 （control） received antibiotics （Doxy-gen 20/20 WSP： Doxycycline hyclate 200 mg and Gentamicine sulfate 200 mg） at 0.3 g/L of water. All the experimental chicks were fed ad libitum with diet containing 23% crude protein and 2,851.55 kcal/kg metabolizable energy for 28 d. The results revealed that there were similarities （P 〉 0.05） in final body weight, total weight gain, daily weight gain, total feed intake, daily feed intake and feed conversion ratio among the treatments. There were significant （P 〈 0.05） differences in the microbial count of faeces before the birds received antibiotics and grains of selim, but count were similar （P 〉 0.05） after grains of selim and antibiotics were administered. Cost of total feed consumed, cost of per kg feed and cost of per kg weight were significantly （P 〈 0.05） higher in treatment T1, but cost differential and relative cost benefit were similar （P 〉 0.05）. Results indicate that grains of selim have antimicrobial and anthelminthic properties, and promote growth in broiler chickens.

Effectiveness of dietary xylo-oligosaccharides for broilers fed a conventional corn-soybean meal diet

An experiment was conducted to investigate the effect of dietary supplementation of xylo-oligosaccharides（XOS） on growth performance, meat quality, immune functions, duodenal morphology and intestinal microbial populations of broilers fed a conventional corn-soybean meal basal diet. A total of 450 1-day-old commercial Arbor Acres male broiler chicks were randomly allocated by bodyweight to 1 of 5 treatments with 6 replicate cages（15 broilers per cage） for each of 5 treatments in a completely randomized design. Chicks were fed the basal corn-soybean meal diets supplemented with 0, 25, 50, 75, or 100 mg of XOS kg–1 of diet, respectively, for an experimental duration of 42 days. The results showed that supplementation of XOS affected feed conversion rate（feed/gain, F/G） during days 22–42 and 1–42（P〈0.03）, drip loss in thigh muscle（P=0.02）, and duodenal crypt depth（P=0.005） on day 42, but had no effect（P〉0.05） on all other measured indices. The chicks fed the diet supplemented with 100 mg of XOS kg–1 had the lowest（P〈0.05） F/G and drip loss in thigh muscle. The drip loss in thigh muscle decreased linearly（P=0.003） as the supplemented XOS increased. Duodenal crypt depth decreased（P〈0.05） at the supplemental level of 75 mg of XOS kg–1. The results indicate that dietary supplementations of 75 and 100 mg of XOS kg–1 are beneficial to broilers fed a conventional corn-soybean meal diet.

Effect of Nano Red Elemental Selenium on GPx Activity of Broiler Chick Kidney Cells in vitro

A new selenium source, Nano red elemental selenium (Nano-Se) was used to study the effect on the GPx activity of broiler chick kidney cells (BCKC) in vitro, Sodium selenite (Na_ 2 SeO_ 3 ) and seleno-1-methionine (Se-Met) were used as the controls. The results showed that the effects of three kinds of Se forms on the GPx activity of BCKC were accordant(p>0.05) compared with each other at 0.01,0.05 and 0.10 μmol/L Se concentrations treatments. In the range of 0.00-0.10 μmol/L Se concentrations, the GPx activity increased with elevation of Se concentrations in medium. For the three kinds of Se forms, the GPx activity reached the climax at 0.10 μmol/L Se concentration. At 0.20 and 0.30 μmol/L Se concentrations, the influnces of three kinds of Se forms were not accordant with one another. For Nano-Se, the GPx activity at 0.20 and 0.30 μmol/L Se concentrations remained the same as that at 0.10 μmol/L Se concentration treatment. For Se-Met, the GPx activity at 0.20 μmol/L Se concentration treatment remained the same with 0.10 μmol/L treatment; the GPx activity at 0.30 μmol/L Se concentration treatment was declined significantly(p<0.05) compared with 0.10 or 0.20 μmol/L treatment. For Na_ 2 SeO_ 3 , the GPx activity falled gradually with Se concentration increasing from 0.10 μmol/L to 0.30 μmol/L, and at 0.30 μmol/L Se concentration treatment, the GPx activity was less than the original of BCKC. The results implicated, on the GPx activity of BCKC in vitro, the ranking of width range of the most suitable Se concentration for nutrition curve of the three Se formes is Nano-Se>Se-Met>Na_ 2 SeO_ 3 .