1. Effects of an inclusion of 10% RNA into diets containing 10, 20 and 30% isolated soybean protein were examined on growth, food intake and nitrogen excretion of chicks from 6 days of age for 15 days.
2. RNA additions to the three-protein-level diets resulted in appreciable decreases in food intake and in significant growth depression throughout the experiment (10 and 20% protein diets, P<0.05), with no effect on food conversion efficiency.
3. RNA inclusions in the diets also decreased apparent nitrogen unilization {(N intake -N excretion) /N intake} (10 and 30% protein diets, P<0.05) and increased the ratio of excreted uric acid N to ingested N (10 and 20% protein diets, P<0.05).
4. Kidney weight per 100g of body weight was increased by dietary RNA (10 and 30% protein diets, P<0.05), but liver weight was unaffected.
5. Neither uric acid content in kidney nor in liver was affected by dietary RNA.
6. These results suggest that the growth depression by an inclusion of RNA into diets resulted from decreased food intake which may be caused by adverse effects of absorbed RNA-degradation products.

View full abstract

To investigate the effects of force-feeding and dietary cereals on feed conversion, hepatic lipid accumulation and plasma components, Pekin ducks were force-fed on a corn or barley based diet from 43-54 days of age, and the following results were obtained.
Force-feeding markedly increased body weight gain and decreased feed/gain ratio. No significant differences were found in body weight gain and feed/gain ratio between experimental diets.
Force-feeding significantly increased the weights of liver, pancreas, kidney, heart and abdominal fat. Ducks fed on barley based diet had a lighter liver compared to that fed on corn based diet.
Force-feeding caused a relatively higher concentration of liver total lipid and significantly lower concentration of liver non-lipid dry matter. Feeding barley based diet significantly decreased the concentration of liver total lipid and esterified cholesterols, and the ratio of esterified to total cholesterol compared to the corn-based diet. The frequency of occurence of liver fatty metamorphosis was very high in the ducks force-fed on corn based diet, while no ducks fed on barley based diet were recongnized as fatty metamorphosis in liver.
Force-feeding significantly elevated the concentration of all plasma components determined except for esterified cholesterol. Plasma urea was significantly higher in the ducks fed on barley based diet.

View full abstract

Seasonal production and consumption had been the limiting factors to economic development by the characteristic of turkey as a commodity. Since the early 1960's, U.S. turkey industry became more coordinative and complex in phases of production and marketing as well as broiler industry because of increasing per capita consumption and innovation in turkey production. Though contracts between integrator and grower began with feed-industry financing in Midwest, the type of production contract such as risk-sharing and profit-sharing were the most prevalent arrangement. Large integrators integrated through ownership of feed mill, processing plant and hatching plant.
Major areas of production have been Midwestern and Western regions. In the Midwest, comparative advantage depended on lower feed ingredient cost and in the West, high feed cost, labour cost and transportation cost declined regional market power. Compared with such regions, in the South Atlantic, production was concentrated under contract and comparative advantage depended on lower labor cost because of limited alternative employment opportunities. The Midwestern and Western's share in east market dropped and comparative advantage in the South Atlantic led to interregional shifts.
As turkey processing (slaughter) and further processing plant could increased uniform volume and utilized full plant capacity, concentration ratios by leading firms increased until the eight largest firms slaughtered 60 percent over in 1988. The large processors being the leading integrators produced various types of further processed turkey products. As a result of it, under the decline of the price mechanism in open market, the leading integrators are willing to establish packer brand.

View full abstract

In this study, the relation of estrogen to the growth of a follicle or ovulation was investigated from the correlation with an egg-laying state, the concentration of a yolk precursor in blood (based on a serum vitellin value), the growth mode of a follicle, the structure of an intraovular yolk sphere or the like by administering antiestrogen (tamoxifen, TAM) or synthetic estrogen (diethystilbestrol, DES) to a laying hen. The results obtained were as follows.
As result of once administering 20mg of TAM to the laying hen orally, the lowering of the serum vitellin values and the growth suppression of the follicle were observed over several days after adiministration. Further, small yellow yolk spheres or yellow yolk spheres of a transfer type from white yolk spheres to yellow ones are distributed at the growth supression region of the follicle and the structure of them was clearly different from that of yellow yolk spheres before administration.
DES was administered to the laying hen in ratios of 15, 30 and 60mg/a hen by intramuscular injection but no large change was confirmed in an egg-laying state in all of the administration groups. On the other hand, the serum vitellin value suddenly rose as the administration amount increased and the lasting period thereof also became long. However, the effect of the administration of DES on the growth of the follicle or the structure of intraovular yolk spheres was not confirmed at all.
From these results, it was cleared that exogenous estrogen DES itself or the serum vitellin value increased by DES exerted almost no effect on the growth of the follicle or ovulation. The growth of the follicle in a rapid growth phase is mainly prescribed by the yolk forming capacity of an egg (oocyte) and, usually, it is considered that the follicle alreay takes in the yolk precursor in the amount corresponding to the saturated amount at the growth stage thereof. However, it was cleared that a change was generated in the growth mode of the follicle or the structure of yolk spheres in the follicle when the marked reduction in the supply amount of the yolk precursor to the follicle and the change in the properties of the yolk precursor were generated.

View full abstract

To study cartilage response to thyroid hormones, we determined the concentrations of DNA, RNA, proteins and polyamines, together with ornithine decarboxylase (ODC) activity, in the trachea cartilage from sex-linked dwarf chicks which had received a daily injection of either thyroxine (T4, 200μg/kg) ortriiodothyronine (T3, 200μg/kg) for 7 consecutive days.
The thyroid hormone treatment, in particular, T3 increased RNA and DNA concentrations in the cartilage when compared with those of saline injected control chicks. The hormonal treatment also increased cartilage putrescine and spermidine concentrations, in accordance with the elevated cartilage ODC activities in treated birds. The result suggests that cartilage from sex-linked dwarf chicks may respond to thyroid hormones in a manner similar to normal embryonic chick pelvic cartilages and hence the failure in cartilage response to thyroid hormones is not a cause of the dwarfism of this chicken breed.

View full abstract

The experiment was conducted to improve the nutritive values of solvent-extracted soybean meals from China by heat treatment (85 or 100°C for 30, 60 or 90 mm). The heated soybean meals were evaluated by determination of water soluble nitrogen, true metabolizable energy (TME, TMEn) and true amino acid availability (TAAA).
The water soluble nitrogen of the meal was not significantly affected when it was heated at 85°C but the water soluble nitrogen of the meal was significantly decreased as the time in treatment increased when heated at 100°C. The metabolizability (TMEn/GE) of the meal heated at 85°C for 30 min was improved to 59%, though not significantly, compared to 57% for the unheated meal. On the avarage, TAAA value of the meal heated at 85°C for 30 min was improved to 92.5% compared to 89.4% for the unheated meal, also the availability of histidine, phenylalanine, threonine, aspartic acid, proline and serine in the meal were improved significantly (P<0.05). However, in the meal heated at 100°C for 90 min, the availability of histidine, lysine, phenylalanine, threonine, valine, aspartic acid, glutamic acid, proline and serine were significantly reduced (P<0.05) compared to those of amino acids in the meal heated at 85°C for 30 min, which was seemed to have been damaged as a result from overheating.

View full abstract

Egg laying performance of the 3rd to 5th generation of Y line SPF chickens was compared between the cage and slatted floor feeding systems.
(1) The day of first egg and the day at 50% production were earlier in chickens reared in cage system than in floor system.
(2) Egg production rate in each group was kept about to 52 to 54% except for one generation reared in floor system, showing the highest value of 67%.
(3) The transition of egg production rate showed that the persistent egg laying rate and peak of egg productivity were higher in the chickens reared in the floor than in cage system. The rate of qualified eggs was generally high in each group (95%).
(4) The feeding system did not have effect on the egg weight, but the value of the eggs weight slightly decreased with the repetition of generation. The repetition on generation seems to be one of the several causes united to the decreasing of egg weight. The results suggest that careful consideration should be given to the continuous inbreeding of SPF chickens in a closed flock.

View full abstract