Nutrient digestibility, fecal output of fractionated proteins, and ruminal fermentation parameters of goats fed a diet supplemented with spent green tea and black tea leaf silage.

Spent green and black tea leaf silage (GTS and BTS, respectively) was offered as a protein supplement to goats to examine in vivo digestibility, nitrogen balance, urinary excretion of purine derivatives, and ruminal fermentation. Four castrated goats were fed a basal diet supplemented with alfalfa hay cube (AHC), GTS, or BTS in a 4 × 4 Latin square design. Digestibilities of various nutrients except for nitrogen (N) fraction were unaffected by the type of supplement. Digestibility of acid detergent insoluble N (ADIN) in BTS treatment was a negative value and significantly lower than those in other treatments. Urinary N output and retained N were not significantly affected by the diets. The fecal output of neutral detergent insoluble nitrogen (NDIN) and ADIN in the BTS treatment was significantly higher than those in other treatments. Urinary excretion of purine derivatives was not affected by the treatments. Ruminal NH3 -N concentration in AHC and GTS treatments were not significantly different, but that in the BTS treatment was significantly lower than others. These results indicated that GTS is substitutable for AHC as a protein supplement, whereas BTS was able to bind proteins tightly in the digestive tract, which lowered ruminal N degradability and increase fecal N output.

Influence of Dietary Metformin on the Growth Performance and Plasma Concentrations of Amino Acids and Advanced Glycation End Products in Two Types of Chickens.

Glycation is a non-enzymatic reaction inducing the bonding of glucose to amino acids and proteins. Glycated amino acids are not useful for protein synthesis, suggesting that glycation reduces the utilization of amino acids. Metformin (MF) is well known as a therapeutic drug for type II diabetes that inhibits glycation. It is possible that treatment with MF raises the utilization of amino acids by the inhibition of glycation, thereby improving the growth performance of chickens. In the present study, therefore, we investigated the influence of dietary MF on the growth performance, and plasma concentrations of free amino acids and N ε -(Carboxymethyl)lysine (CML), which is an advanced glycation end product, in layer (Experiment 1) and broiler (Experiment 2) chickens. From 7 d of age, chicks were allowed free access to one of the experimental diets containing MF at 3 supplementation levels (0, 150, and 300 mg/kg diet) for 14 days. Body weight and feed intake were measured every week. At the end of the experiments, blood and breast muscle (M. pectoralis major) were collected for further analysis. Dietary MF did not affect weight gain, feed intake, or feed efficiency in both layer and broiler chickens. Dietary MF at the level of 150 mg/kg diet increased breast muscle weight in both layer and broiler chickens. Dietary MF increased plasma concentrations of branched chain amino acids and decreased concentrations of CML in layer chickens, although it did not affect plasma concentrations of glucose. The present study suggested that dietary MF might have the potency to increase breast muscle weight of layer chickens with an increment in plasma concentrations of branched-chain amino acids.

Nutritive evaluation of spent green and black tea leaf silages by in vitro gas production characteristics, ruminal degradability and post-ruminal digestibility assessed with inhibitory activity of their tannins.

Spent tea leaf contains high levels of crude protein, suggesting that it may be used as an alternative source for ruminant feeding. We assessed the nutritive characteristics of spent green tea leaf silage (GTS) and black tea leaf silages (BTS) in comparison with soybean meal (SBM) and alfalfa hay cube (AHC) using in vitro assay. The effects of tannin on the nutritive characteristics were also evaluated by adding polyethylene glycol (PEG) as a tannin-binding agent. The amount of gas production was greater for SBM, followed by AHC, GTS, and BTS. A significant improvement in gas production upon addition of PEG was observed only for BTS. Ruminal protein degradability and post-ruminal digestibility was higher for SBM, followed by AHC, GTS, and BTS. The presence of PEG significantly increased ruminal degradability and post-ruminal protein digestibility for GTS and BTS, but not for AHC. The increment of protein digestibility by PEG was much greater for BTS than for GTS, indicating that GTS tannins suppress protein digestibility slightly, whereas BTS tannins do so strongly. According to these results, GTS but not BTS has a potential as an alternative to AHC as a ruminant feedstuff.

Alleviation of body weight loss by dietary methionine is independent of insulin-like growth factor-I in protein-starved young chickens.

It is well known that in protein-starved chickens, small amounts of amino acid supplement, especially methionine, reduces nitrogen excretion and thereby improves nitrogen balance. On the other hand, excess intake of methionine causes growth depression and the growth-depressive effect of excess methionine can be alleviated by consumption of dietary glycine. Insulin-like growth factor-I (IGF-I) is one of various growth-promoting factors relating to the efficiency of animal production and is known to be very sensitive to changes in nutritional status. In the present study, the interactive effect of glycine on nitrogen sparing effect of methionine in protein-starved chickens was examined. In addition, the relation of IGF-I and its specific binding protein to the nitrogen sparing effect of supplemented methionine was also investigated. Two-days refeeding of methionine supplemented to protein-free diet could promptly alleviate body weight loss in protein-starved chickens, and the alleviation of body weight loss by methionine was not improved by glycine supplements. Moreover, such acute alleviation of body weight loss by dietary methionine was independent of the change in plasma IGF-I concentration.