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Biomedical subjects

J T Huber

Publications and source records attributed to J T Huber.

At least 109 records · Page 6Linked to original sources
PubMed1980

Influence of time after ensiling on distribution of nitrogen in corn silage treated with ammonia.

Chopped whole corn plant was treated before ensiling with 1.4% ammonia (of dry matter) to which .36% atom excess of 15N had been added. About 50 kg of material (14 kg dry matter) were placed in .5-mm polyethylene bags (of double thickness) which were evacuated and served as experimental silos. Silage samples were taken on days 0, 3, 7, 14, 21 and 50 and analyzed for N fractions. The 15N content of these fractions was analyzed by a mass spectrophotometer. N fractions of untreated silage were also determined. Between days 0 and 7 of fermentation, ammonia N decreased from 50 to 39% of the total silage N, with a corresponding increase in nonammonia N, from 50 to 60%. Thereafter, little change was noted in these fractions. Approximately 40% of the increase in non-ammonia N was in the soluble portion and 60% was in the insoluble portion. Insoluble N of treated silage was 50% higher than that of control silage. Initially, 89% of the N from added ammonia was recovered as ammonia, but this proportion decreased to 68% by day 7 and changed little thereafter. There was immediate incorporation of 43% of the ammonia into the insoluble N fraction. Most of the initial binding was as intact ammonia, with a subsequent release during fermentation. Because direct ammonia incorporation accounted for a higher percentage of the insoluble N increase on day 0 than on subsequent days, these data support earlier studies which showed that ammonia decreased breakdown of protein of the ensiled corn plant.

Ammonia↗
PubMed1980

Ammonia versus urea-treated silages with varying urea in concentrate.

In four factorial experiments, 96 lactating Holstein cows averaging 100 days postpartum were fed corn silage (21 to 31% dry matter) ad libitum treated with aqueous ammonia (.3 to .4%) or urea (.5 to .7%). Concentrates fed at 1 kg/3 kg milk contained 0, .7, or 1.4% urea in Experiment 1 and 0 or 1.4% in Experiments 2, 3, and 4. Following 14-day pretreatment, experimental rations were fed for 65 days in Experiment 1 and 84 days in Experiments 2, 3, and 4. Urea in grain and urea in silage depressed intakes of silage and total dry matter. Milk persistences were lowered only by the diet containing urea in both grain and silage. Bodyweight changes, percent milk fat, and feed efficiencies were not altered significantly by treatments.

Ammonia↗
PubMed1980

Effect of feeding isoacids with urea on growth and nutrient utilization by lactating cows.

In the growth study 10 g each of isobutyrate, isovalerate, 2-methylbutyrate, n-valerate, and phenylacetate were mixed with 80 g of urea, 50 g of molasses, and 270 g of ground hay and fed to nine dairy heifers for 90 days. The control group was fed the same diet minus isoacids and phenylacetate. All animals were fed ad libitum timothy hay as the sole roughage. In the digestion trial, two mixtures of isoacids and a control ration were fed to nine lactating cows in a 3 X 3 Latin square design with 28-day feeding periods. Corn silage was the sole roughage, and concentrate was fed in proportion to milk production. Collection of feces and urine was for the last 5 days of each period. Mixture 1 of isoacids contained on a molar basis 28, 24, 24, and 24% of isobutyrate, isovalerate, 2-methylbutyrate, and n-valerate, respectively. Corresponding for mixture 2 were 36, 17, 17, and 30%. Addition of isoacids increased growth rate of younger animals but not older ones. The isoacid mixtures improved utilization of nitrogen by lactating cows. Urinary nitrogen decreased, and retention of absorbed nitrogen increased. Digestibility of dry matter and nitrogen were not affected by isoacid additions.

Animals↗
PubMed1980

Supplemental niacin for lactating cows fed diets of natural protein or nonprotein nitrogen.

Thirty-two Holstein cows, 16 in early and 16 in midlactation, were assigned to four treatments: 1) soybean meal protein plus niacin; 2) soybean meal without niacin; 3) nonprotein nitrogen plus niacin; and 4) nonprotein nitrogen without niacin. Niacin dose was 6 g per day, and nonprotein nitrogen supplied 20% of total nitrogen for those treatments. Differences between treatments in milk yields were not significant, but milk persistencies tended to be highest for cows in early lactation fed niacin during wk 9 and 10 of treatment. Intakes of dry matter did not differ significantly, but cows fed nonprotein nitrogen without niacin had lowest intakes per 100 kg bodyweight. Differences between treatments in feed utilization, milk composition, bodyweight changes, plasma ammonia, rumen pH, rumen volatile fatty acids, dry matter digestibilities, nitrogen digestibilities, and retained nitrogen were not significant.

Animal Feed↗
PubMed1975

Fungal growth and acid production during fermentation and refermentation of organic acid treated corn silages.

Chopped corn (35% dry matter) treated with either propionic, formic, 60% propionic plus 40% formic, or 80% propionic plus 20% acetic acids at 0, .5, 1, and 2%, was placed in polyethylene bags inside metal drums, and evacuated. During fermentation silages were sampled and temperatures determined. On day 40 of fermentation silages were placed in open containers at 25 C and were sampled during refermentation. All samples were analyzed for volatile and lactic acids, pH, and number and type of fungi. Lactate fermentation was totally inhibited at 2% addition of all acids, but formic acid was more effective than propionic acid at .5 and 1%. Acerate production was equally depressed by both propionic and formic additions. Heating, growth of fungi, and days until spoilage were delayed by all acid additions during refermentation, with propionic more effectivethan formic. The large increases in lactate and acetate of treated silages during refermentation reflect a protection of soluble sugars during fermentation and subsequent use by microbes after exposure to air. Silages treated with more than 1%propionic (as propionic or a mixture) did not increase in fungal colonies during refermentation. At initiation of fermentation yeasts werehigher than other fungi but decreases by day 40. During refermentation, yeasts again grew. Geotrichum comprised 35% on day 40 of refermentation but was lower at other times. Aspergillus proliferated during refermentation and few Penicillium were detected.

Acetates↗