• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 204
  • 106
  • 37
  • 25
  • 25
  • 25
  • 25
  • 25
  • 25
  • 15
  • 2
  • 2
  • 1
  • Tagged with
  • 452
  • 452
  • 436
  • 163
  • 130
  • 96
  • 77
  • 76
  • 74
  • 63
  • 55
  • 51
  • 48
  • 40
  • 38
  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
321

Evaluation of endophyte-infected tall fescue products, their interaction with Senecio jacobaea in ruminants, and detoxification of alkaloids by ammoniation or ensiling after grinding

Debessai, Woldu T. 26 August 1997 (has links)
Graduation date: 1998
322

Transforming shrimp and crab waste into dairy heifer feed

Evers, Dale J. 30 August 1994 (has links)
The goal of these experiments was to ensile combinations of shrimp or crab waste with perennial ryegrass straw and analyze it for silage quality and ruminal degradability. The rapid deterioration of seafood wastes required initial preservation prior to ensiling to minimize odor production and protein breakdown. Eight experiments were conducted to preserve, ensile and test the ruminal degradability of shrimp and crab waste. The first three experiments attempted to preserve crab waste with the addition of 0 to 15% molasses for 14 days or shrimp waste with molasses at 0 to 25% for 6 or 21 days. In all three experiments, the addition of molasses decreased crude protein, crude protein loss, and pH, and improved odors. Although a lactic acid fermentation began, the high pH and acetic and butyric acid concentrations indicate fermentation was not completed. The crude protein loss and odor production warrants a quicker method of preservation. In Experiments 4 and 5, shrimp or crab waste were combined with 6 levels of salt from 0 to 12.5% for 6 days. The addition of salt decreased crude protein percentage, crude protein loss and all volatile fatty acid concentrations while increasing the pH and improving the odors. The 7.5% salt-preserved shrimp and crab wastes had 29.9 and 30.7% crude protein, respectively. Experiments 6 and 7 ensiled the salt-preserved shrimp and crab waste with grass straw, molasses and an inoculant in 15 L mini-silos for 40 days. Shrimp waste was combined at 37, 47 or 52% dry matter while crab waste was combined at 43, 46 or 52% dry matter. Molasses at 0, 10, or 20% and an inoculant were added to both silages. The 47% dry matter, 20% molasses non-inoculated shrimp silage had the following analysis on a dry matter basis: crude protein, 16.1%, acid detergent fiber. 27.0%. acetic acid, 1.37%. butyric acid, .01%, lactic acid, 7.17%, and a pH of 7.0 and a good silage odor. The 46% dry matter, 10% molasses, inoculated crab silage had the following analysis on a dry matter basis: crude protein. 21.1%, acid detergent fiber, 19.6%, acetic acid, 1.68, butyric acid, .00%, lactic acid, 2.86% and a questionable odor score. In Experiment 8, the ruminal degradability of shrimp and crab waste and shrimp and crab silage were tested using two fistulated steers and sampled at nine time points ranging from 0 to 96 hr. Shrimp waste had a ruminally available DM%, CP%, ADF%, and %ADIN of 36.9, 43.0, 44.2, and 43.6% respectively. Crab waste had a ruminally available DM%, CP%, ADF%, and %ADIN of 38.9, 53.3, 41.0, and 33.0% respectively. Ensiling the shrimp and crab wastes improved the percentage of ruminally available DM and CP and lowered the percentage of ruminally available ADF and ADIN. This indicates that ensiling promotes the degradation of chitin and the release of nitrogen to the rumen. Effective preservation of shrimp and crab waste with salt and then adequate fermentation of the wastes with grass straw, molasses and inoculant has increased the ruminal degradability of the wastes and led to successful transformation of the waste into a dairy heifer feedstuff. / Graduation date: 1995
323

The effect of cattle winter feeding systems on soil nutrients, forage growth, animal performance, and economics

Jungnitsch, Paul F. 26 May 2008
Overwintering of cows is a major cost in a cow-calf production system on the prairies. Winter feeding hay and straw directly on pasture is a potentially more efficient and economical system compared to conventional drylot feeding in a yard. The objectives of the research described in this thesis were to compare winter feeding cattle directly on pasture to traditional drylot over-wintering of cattle and the associated mechanized spreading of manure on pasture. This trial compared the effects of winter feeding systems on pasture nutrient distribution, nutrient recovery in soil and forage, pasture forage response, cattle performance, and economics. <p>The experiment was conducted at Lanigan, SK, on an old russian wildrye grass pasture. Pasture nutrient levels and distribution were measured before and after winter feeding, as well as forage yield, and cattle weight and condition. Nutrient capture and cycling was assessed along with the economics of the different systems. In the pasture fed systems, cattle were fed by either bale processing or bale grazing methods over the winter of 2003-2004. Cattle concentration was 2080 cow-days ha-1, with the cattle in the field for 130 d. In the intensive system used for comparison, cattle were fed in a drylot and 67 tonnes ha-1 of raw manure or 22 tonnes ha-1 of compost was mechanically spread on the pasture in the fall of 2003.<p>Soil inorganic nitrogen (N) levels (0-15 cm) measured in the spring where the cattle were winter fed on pasture were 3 to 4 times the unfertilized, unmanured control treatment, with a mean gain of 117 kg N ha-1. Soil inorganic N was not significantly elevated where manure or compost had been spread by machine. Soil extractable potassium (K) was doubled on the winter feeding sites, with a mean gain of 1209 kg K ha-1. Soil extractable K did not increase where manure or compost had been spread mechanically. Soil distribution patterns of both nutrients were highly uneven following pasture feeding, with levels of inorganic soil N ranging from 12 to 626 kg ha-1 and extractable soil K ranging from 718 to 6326 kg ha-1. Additional nutrients in surface residue from uneaten feed, bedding, and manure were also heavy and variable following pasture feeding. Greater retention of N and K from urine added directly to the soil in the field in the bale grazing and bale processing systems compared to the drylot system is believed to be responsible for high soil available N and K levels compared to manure hauled from the drylot into the field.<p>Soil extractable phosphorus (P) levels (0-15 cm) were measured in the fall of 2005. The compost treatment had the largest increase at 2.6 times the control, an additional 46 kg ha-1. Mean soil P levels did not increase significantly where the cattle were wintered.<p> Over 18 months and 3 harvests, forage dry matter yields where the cattle were fed on pasture were 3 to 5 times the control where the cattle were fed on the pasture, and 1.4 to 1.7 times the control where raw manure or compost was mechanically spread. Also, protein content of the forage was increased to a greater extent in the in-field feeding compared to hauled raw manure or compost, reflecting a greater conservation of N.<p>The gain of N in the forage over 18 months on the winter feeding sites was 200 kg ha-1 of N, almost double what was measured in soil inorganic forms. Fourteen kg ha-1 of P was also recovered. This represented 34% of original feed N and 22% of original feed P that was imported into the field. Recovery of nutrients applied in the raw manure and compost sites was much lower, with only 7% recovery of N and 4% recovery of P in the forage. This was calculated to be 1% of original feed N and 3% of original feed P.<p>The system by which the cattle were overwintered had little influence on cattle weight and condition. All systems performed favorably in maintaining body weight and condition over the winter. Some slight advantages in cattle weight gain and condition were found on the winter feeding systems compared to the in-yard drylot that appeared to be related to slightly increased feed intake.<p>Economic calculations favored winter feeding directly on the pasture by 25% over the drylot systems when the feed value of additional pasture growth over 18 months was included and by 56% when the value of additional soil nutrients was factored in. Feed costs were similar between the systems but pasture feeding had savings in machinery use, fuel consumption and manure handling costs, and gains in pasture productivity.<p>Systems that winter fed cattle directly on pasture provided gains in nutrient cycling efficiencies, pasture growth, and economic savings compared to drylot feeding systems, while maintaining similar cattle growth and condition.
324

The effect of cattle winter feeding systems on soil nutrients, forage growth, animal performance, and economics

Jungnitsch, Paul F. 26 May 2008 (has links)
Overwintering of cows is a major cost in a cow-calf production system on the prairies. Winter feeding hay and straw directly on pasture is a potentially more efficient and economical system compared to conventional drylot feeding in a yard. The objectives of the research described in this thesis were to compare winter feeding cattle directly on pasture to traditional drylot over-wintering of cattle and the associated mechanized spreading of manure on pasture. This trial compared the effects of winter feeding systems on pasture nutrient distribution, nutrient recovery in soil and forage, pasture forage response, cattle performance, and economics. <p>The experiment was conducted at Lanigan, SK, on an old russian wildrye grass pasture. Pasture nutrient levels and distribution were measured before and after winter feeding, as well as forage yield, and cattle weight and condition. Nutrient capture and cycling was assessed along with the economics of the different systems. In the pasture fed systems, cattle were fed by either bale processing or bale grazing methods over the winter of 2003-2004. Cattle concentration was 2080 cow-days ha-1, with the cattle in the field for 130 d. In the intensive system used for comparison, cattle were fed in a drylot and 67 tonnes ha-1 of raw manure or 22 tonnes ha-1 of compost was mechanically spread on the pasture in the fall of 2003.<p>Soil inorganic nitrogen (N) levels (0-15 cm) measured in the spring where the cattle were winter fed on pasture were 3 to 4 times the unfertilized, unmanured control treatment, with a mean gain of 117 kg N ha-1. Soil inorganic N was not significantly elevated where manure or compost had been spread by machine. Soil extractable potassium (K) was doubled on the winter feeding sites, with a mean gain of 1209 kg K ha-1. Soil extractable K did not increase where manure or compost had been spread mechanically. Soil distribution patterns of both nutrients were highly uneven following pasture feeding, with levels of inorganic soil N ranging from 12 to 626 kg ha-1 and extractable soil K ranging from 718 to 6326 kg ha-1. Additional nutrients in surface residue from uneaten feed, bedding, and manure were also heavy and variable following pasture feeding. Greater retention of N and K from urine added directly to the soil in the field in the bale grazing and bale processing systems compared to the drylot system is believed to be responsible for high soil available N and K levels compared to manure hauled from the drylot into the field.<p>Soil extractable phosphorus (P) levels (0-15 cm) were measured in the fall of 2005. The compost treatment had the largest increase at 2.6 times the control, an additional 46 kg ha-1. Mean soil P levels did not increase significantly where the cattle were wintered.<p> Over 18 months and 3 harvests, forage dry matter yields where the cattle were fed on pasture were 3 to 5 times the control where the cattle were fed on the pasture, and 1.4 to 1.7 times the control where raw manure or compost was mechanically spread. Also, protein content of the forage was increased to a greater extent in the in-field feeding compared to hauled raw manure or compost, reflecting a greater conservation of N.<p>The gain of N in the forage over 18 months on the winter feeding sites was 200 kg ha-1 of N, almost double what was measured in soil inorganic forms. Fourteen kg ha-1 of P was also recovered. This represented 34% of original feed N and 22% of original feed P that was imported into the field. Recovery of nutrients applied in the raw manure and compost sites was much lower, with only 7% recovery of N and 4% recovery of P in the forage. This was calculated to be 1% of original feed N and 3% of original feed P.<p>The system by which the cattle were overwintered had little influence on cattle weight and condition. All systems performed favorably in maintaining body weight and condition over the winter. Some slight advantages in cattle weight gain and condition were found on the winter feeding systems compared to the in-yard drylot that appeared to be related to slightly increased feed intake.<p>Economic calculations favored winter feeding directly on the pasture by 25% over the drylot systems when the feed value of additional pasture growth over 18 months was included and by 56% when the value of additional soil nutrients was factored in. Feed costs were similar between the systems but pasture feeding had savings in machinery use, fuel consumption and manure handling costs, and gains in pasture productivity.<p>Systems that winter fed cattle directly on pasture provided gains in nutrient cycling efficiencies, pasture growth, and economic savings compared to drylot feeding systems, while maintaining similar cattle growth and condition.
325

Cattle diets during spring and summer on desert shrub rangelands near Roosevelt Lake, Arizona

Aguirre de Luna, Raymundo January 1980 (has links)
No description available.
326

Seasonal utilization of Lehmann lovegrass and black grama in the desert grassland

Reese, Michael Edward January 1980 (has links)
No description available.
327

MICROBIAL PROTEIN FLOW TO THE SMALL INTESTINE OF COWS FED DIFFERENT PROTEIN SUPPLEMENTS

Sadik, Mohamad Shabir, 1959- January 1987 (has links)
Three duodenally cannulated lactating Holstein cows fed cotton-seed meal (CSM), corn gluten meal (CGM) or blood meal (BM) as protein supplement were used in a 3 x 3 Latin Square experiment to determine microbial crude protein (MCP) in duodenal digesta. Diets, formulated to contain 15% crude protein (CP) on a dry matter basis, consited of 60% concentrate, 31% corn silage and 9% alfalfa hay. Chromium oxide was employed as flow marker. Microbial protein fraction of digesta CP (MCP/DCP) was estimated by three microbial markers: ¹⁵N, diaminopimelic acid (DAP) and ribonucleic acid (RNA). The isotopic method gave the most reliable results. Variability was higher with DAP and RNA. Results from RNA were lower (P < .01) and unreasonable. Based on ¹⁵N, MCP/DCP differed among treatments (P < .10) with means of 61.5, 59.4, and 50.0% for CSM, CGM, and BM, respectively, but differences were not significant for absolute amounts of total CP and MCP in duodenal digesta.
328

Effect of type of nitrogen supplementation on digestibility and nitrogen balance by steers fed a reconstituted sorghum grain diet

Prouty, Frank Louis January 1978 (has links)
No description available.
329

The effect of gin trash on milk production

Halbach, Gerald David, 1951- January 1975 (has links)
No description available.
330

Effects of inoculation on alfalfa silage quality and its feeding on the performance of dairy cattle

Rizk, Charbel January 2004 (has links)
Five studies were conducted to determine the effect of inoculating (Pioneer Sila-Bac 11H50RTM) on the silage quality and the feeding value of high DM (55.3 %) alfalfa silage. The inoculant contained multi strains of Lactobacillus plantarum developed by Pioneer Hi-Bred Inc. In the first study, the effects of inoculation on ensiling characteristics of alfalfa were determined in a completely randomized design using 30 mini-silos. In the 2nd study, 9 containers were used in a completely randomized design to determine the effect of inoculation on the aerobic stability of alfalfa silage. In the 3d study, 2 ruminally fistulated cows were used in a randomized complete block design to determine the effects of inoculation on ruminal degradation of alfalfa silage. In the 4th study, 4 ruminally fistulated cows were used in a switch back experiment to determine the effects of feeding inoculated alfalfa on total tract nutrient utilization. In the last study, 27 Holstein cows in early lactation were used in a randomized complete block design to determine the effects of feeding inoculated alfalfa on intake, milk yield, and milk composition.

Page generated in 0.0755 seconds