The present study was conducted to investigate the effects of dietary Rhodobacter capsulatus on the laying hen. A total of forty 23-wk-old Hy-Line Brown laying hens were randomly assigned into 4 treatment groups (10 laying hens/group) and fed diets supplemented with 0 (control), 0.01, 0.02, and 0.04% R. capsulatus during the 60-d feeding period. Dietary supplementation of R. capsulatus (0.04%) reduced (P < 0.05) cholesterol and triglycerides concentration in serum (15 and 11%), as well as in egg-yolk (13 and 16%) over a 60-d feeding period. Cholesterol and triglycerides concentrations in serum as well as egg-yolk were changed linearly in accordance with increasing levels of dietary R. capsulatus. Supplementation of R. capsulatus in diets increased high-density lipoprotein cholesterol level and decreased (P < 0.05) atherogenic index in serum. Yolk color was improved (P < 0.05) in the group fed the 0.04% R. capsulatus supplemented diet compared with the control group. Hepatic cholesterol and triglycerides were reduced (P < 0.05) by 0.04% R. capsulatus. Moreover, the supplementation of R. capsulatus in layer diets did not appear to cause any adverse effects on egg production, shell weight, shell thickness, Haugh unit, yolk index, and feed conversion efficiency compared with the same parameters for the control laying hens. It is postulated that known and unknown factors are present in R. capsulatus presumably responsible for the hypocholesterolemic effect on laying hens. Therefore, the dietary supplementation of R. capsulatus may lead to the development of low-cholesterol chicken eggs as demanded by health-conscious consumers.

The study was designed to investigate the effects of dietary Rhodobacter capsulatus on cholesterol concentration and fatty acid composition in broiler meat. A total of 45 two-week-old male broiler chicks were randomly assigned into 3 treatment groups and fed ad libitum diets supplemented with 0 (control), 0.02, and 0.04% R. capsulatus for a 6-wk feeding period. The results of this study revealed that the supplementation of 0.04% R. capsulatus in diet reduced (P < 0.05) cholesterol and triglyceride concentrations in broiler meat. The concentrations (expressed as a percentage of total fatty acids) of oleic acid (18:1), linoleic acid (18:2), and linolenic (18:3) acid in thigh muscle and breast muscle were higher (P < 0.05) in the broilers fed the 0.04% R. capsulatus supplemented diet than in the broilers fed the control diet. The ratio of unsaturated fatty acids to saturated fatty acids was greater (P < 0.05) in both muscles of broilers fed the 0.04% R. capsulatus supplemented diet than the control diet. In addition, the concentrations of serum cholesterol and triglyceride, and hepatic cholesterol and triglyceride were also reduced (P < 0.05) by dietary R. capsulatus. Compared with the control diet, the 0.04% R. capsulatus supplemented diet reduced (P < 0.05) the ratio of low-density lipoprotein-cholesterol to high-density lipoprotein-cholesterol. Moreover, the supplementation of R. capsulatus in broiler diets did not show any adverse effect on production performance. Therefore, these results conclude that the application of R. capsulatus into diet may be feasible to reduce cholesterol concentration and improve the ratio of unsaturated fatty acids to saturated fatty acids in broiler meat.

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Relaxin and insulin-like growth factor (IGF)-I have pronounced effects on the male and female reproductive tracts. The aim of this study was to investigate the effects of relaxin and IGF-I on the motility, capacitation, acrosome reaction, cholesterol efflux and utilization of glucose in porcine spermatozoa. Swim-up separated spermatozoa that had been washed twice were incubated at 37°C for 1 or 4 h in modified Tyrode's albumin lactate pyruvate (mTALP) medium supplemented without (control) or with relaxin (20 ng/mL) or IGF-I (20 ng/mL) or both (10 + 10 ng/mL). Progressive motility and the induction rate of capacitation and acrosome reaction were increased ( 0.05) by relaxin and IGF-I alone or in combination, especially after 4 h of incubation. Relaxin alone or combined with IGF-I enhanced ( < 0.05) the cholesterol efflux after 4 h, whereas IGF-I alone did not show any significant effect on the cholesterol efflux compared with the control at any time point. The utilization rates of labeled and unlabeled glucose increased ( 0.05) in spermatozoa incubated with relaxin or IGF-I alone or in combination compared with the control. Thus, supplementation of relaxin alone or combined with IGF-I into the medium possibly plays a beneficial role in porcine spermatozoal prefertilization events. (Reprod Med Biol 2008; : 29-36).

Aim: The present study was designed to investigate the effect of amino acids and their dipeptides on the accumulation of ammonia in the medium during in vitro maturation (IVM) and in vitro fertilization (IVF) of porcine oocytes. Methods:The IVM and IVF media were modified North Carolina State University-37 solution and modified Tyrode's albumin lactate pyruvate, respectively. Porcine oocytes were matured in IVM medium containing 75-2400 µmol ammonia. Amino acids (1.0 mmol) or their dipeptides (2.0 mmol) related to the urea cycle were added individually to the IVM and IVF media containing 300 µmol ammonia. Oocyte maturation and fertilization were assessed using acetic-orcein staining, and the accumulation of ammonia in the media was measured using the indophenol method.Results: Percentages of metaphase II (MII) were adversely affected (P < 0.05) by ≥300 µmol concentrations of ammonia in the IVM medium. In the presence of 300 µmol ammonia in the IVM and IVF media, glutamic acid, L-alanyl-L-glutamine (AlaGln), L-glycyl-L-glutamine (GlyGln) and AlaGln + GlyGln showed the highest rate (P < 0.05) of MII, monospermic fertilization, and the lowest rate (P < 0.05) of ammonia accumulation in the media. Conclusion:AlaGln and GlyGln in IVM and IVF media were more stable and effective than the individual amino acids in reducing the accumulation of ammonia, and increased the rate of porcine oocyte MII and monospermic fertilization in vitro. (Reprod Med Biol 2007; 6: 165-170)