Agronomy and Crop Sciences Commons^™

Top Grazing High Protein Forages With Lactating Cows, H R. Conrad, R W. Van Keuren, B A. Dehority

IGC Proceedings (1977-2023)

Two grazing systems, top-grazing of alfalfa (Medicago sativa L.) and high-intensity grazing of orchardgrass (Dactylis glomerata L.), were investigated with three and four levels of concentrate, respectively. The concentrates consisted of corn, oats, and minerals. High dry-matter (DM) alfalfa silage fed in the barn with 40% concentrate by weight was used for a positive control ra­tion. Three- or 4-day grazing periods/paddock were used with 16- and 24-day rotation cycles for orchardgrass and alfalfa, respectively. Using alfalfa without concentrate resulted in mean daily yields of 20.2 kg of milk and 0.65 kg of protein. As amounts of concentrates were increased, daily …

Nutritive Value Of Cattle Diets On Fertilized And Unfertilized Blue Grama Rangeland, J D. Wallace, F J. Cordova, G B. Donart, R D. Pieper

IGC Proceedings (1977-2023)

Low levels of nitrogen (N) fertilization can substantia1ly increase forage production on native rangeland if adequate precipita­tion is available. The objective of this study was to_ compare nutritive value of diets selected by Hereford steers grazing unfer­tilized and N-fertilized (45 kg N/ha) rangeland in south central New Mexico. The study area consisted of two adjacent pastures of approximately 60 ha each, containing comparable areas ofbottomland, upland, and hillside sites. Stocking rates were 4.8 and 2.4 ha/yearling steer for control and N-fertilized pastures, respectively. Dietary samples were collected from esophageally fistulated steers (average weight 308 kg) during early, middle, and late …

Seasonal Changes In Botanical And Chemical Composition And Digestibility Of Diets Of Large Herbivores On Shortgrass Prairie, G M. Van Dyne, J D. Hanson, R C. Jump

IGC Proceedings (1977-2023)

Studies were conducted from 1969 through 1974 on northeastern Colorado shortgrass prairie during different grazing seasons and under different grazing intensities to evaluate bison, cattle, sheep, and pronghorn antelope diets. The purpose was to ex­amine seasonal changes in chemical and botanical composition and digestibility of diets of large herbivores. Bison, cattle, and sheep diets were obtained from esophageal fistula samples. Fistula samples were analyzed microscopically to determine botanical composition. Pronghorn antelope diets were obtained by bite-count methodology. Data, presented for im­portant plant species and species groups, were averaged for 28-day intervals to show typical seasonal trends in diets. During all …

Diet Selection By Cattle On Tropical Pastures In Northern Australia, B Walker, M T. Rutherford, P C. Whiteman

IGC Proceedings (1977-2023)

Diet selection by steers in northern Australia on a continuously grazed pasture of Setaria sphacelata var. sericea (Kazungula), Macroptilium atropurpureum (siratro), and Stylosanthes guianensis var. guianensis (Schofield) was studied. The pasture treatment that supported the highest annual weight gains (254 kg/steer) in a stocking-rate experiment had 1.7 steers/ha. Mean annual rain-fall was 1,490 mm, with 70 % falling from December to March. Monthly average temperatures are highest in December (30 .1 °C) and lowest in July (11. 9°C). Pastures were sampled in 1973 (seven 3-day periods) and 1975-1976 (six 3-day periods) with three esophageal fistulated steers. Extrusa samples were analyzed …

Relationship Between Botanical Composition Of Herbage On Offer And Herbage Eaten By Grazing Beef Cattle, R.D H. Cohen, D L. Garden

IGC Proceedings (1977-2023)

The relationship between botanical composition of the herbage ori offer and herbage eaten is a key link in the modeling and simulation of grazing systems, yet there appear to be no data describing this relationship for multispecific or nontemperate swards. This paper describes one such relationship for cattle grazing multispecific swards in the subtropics. Native or improved pastures were grazed by Hereford heifers fistulated at the esophagus. The native pasture, which had never received fertilizer, contained mixed grasses and no legumes. One of the improved pastures consisted of native pasture fertilized

with superphospbate, and the other improved pastures were fertilized …

Cattle Preference And Plant Selection Within A Hybrid Grass, P O. Currie, R S. White, K H. Asay

IGC Proceedings (1977-2023)

Recent development of hybrid forage grasses shows promise for advancing grassland agriculture. Previous selections within these hybrids have been based on morphological, reproductive, and adaptive attributes with only limited testing of animal ac• ceptability. Testing of animal preference and selectivity was the primary purpose of the present study. Yearling cattle were tamed and observed for their selectivity in grazing individual plants and genetic lines of F6 crosses between quackgrass (Agropyron repens) x bluebunch wheatgrass (Agropyron spicatum). Animals showed definite preference for individual plants within genetic lines and for different genetic lines. Different animals frequently preferred the same plant or lines …

Combination Range-Pasture Management In South Florida For A Low-Energy Grassland Program, L L. Yarlett

IGC Proceedings (1977-2023)

The semitropical environment of south Florida is favorable for coordinated management of a wide variety of native grass species and improved pasture forages. The decade of the 1980s will emphasize change from forage programs of high energy utilization to those with a low requirement of fossil fuels. For 4 decades, grassland management in south Florida has been primarily pasture establishment created from the rangeland resource. The establishment and management required substantial inputs of fossil fuel. Use and management of rangeland was largely neglected. Ecological concepts as a basis for managing semitropical ranges were not accepted. In recent years practical programs …

Forage Intake Of Cattle As Affected By Grazing Pressure, C D. Allison, M M. Kothmann, L R. Rittenhouse

IGC Proceedings (1977-2023)

A series of trials was conducted in 1977 to determine the effect of level of grazing pressure on organic-matter intake and the relationship between intake and forage disappearance. Levels of grazing pressure studied were 10, 20, 40, and 50 kg forage allowed/animal unit/day (kg/AU/day) for 14-day trials in April, July, and September. A standing crop of forage was measured before, in the middle of, and immediately after each trial. Organic-matter intake was estimated by the fecal output: indigestibility ratio technique. Organic-matter intake was highest in April; cattle also consumed Dlore forage in September than in July. The combination of forage …

Effect Of Herbage Mass And Allowance Upon Herbage Intake By Grazing Dairy Cows, J.A C. Meijs

IGC Proceedings (1977-2023)

An adequate supply of nutrients for grazing animals depends on the intake and nutritive value of herbage. Little information is available on factors affecting herbage intake of grazing cows, particularly for grazing systems that do not involve daily change of animals to a new pasture. Our objectives were to determine the effects of variation in herbage mass ( due to variation in stage of maturity) and of herbage allowance on herbage intake by grazing dairy cows and on efficiency of consumption (herbage con­sumed as a proportion of herbage accumulated). From 1976 to 1979 the herbage intake oflactating cows was determined …

Relation Of Animal Production To Stocking Rate On Cultivated Pastures In Cerrados Areas Of Brazil, C J. Escuder

IGC Proceedings (1977-2023)

The relationships among stocking rate, gain/animal, and gain/ha were compared on six grazed pastures. The experiment was established on an oxisol acrustox in Brazil. The pasture consisted of (1) jaraguagrass (J); (2) jaraguagrass plus legumes (J + L); (3) molassesgrass (M); (4) molassesgrass plus legumes (M + L); (5) pangolagrass (P); (6) Pangolagrass plus legumes (P + L); (7) mixture of grasses (jaragua, molasses, and pangola) plus legumes (JMP + L). Pasture of pangolagrass alone was discarded because of poor establishment. Four stocking rates were applied on each pasture, from 1.0 to 3.4 animals/ha. For all pastures, gains/animal decreased linearly …

Evaluation Of Forages Ensiled In Concrete Stave And Oxygen-Limiting Silos, J O'Leary, R W. Hemken, L S. Bull

IGC Proceedings (1977-2023)

This study evaluated corn silages stored in concrete stave and oxygen-limiting silos during 1978-1980. Factors considered in­cluded the effect of environmental conditions in each silo on silage stability and feeding value. Milk production was evaluated using Holstein cows, intake studies used Holstein heifers or steers. Weekly measurements of intake, milk production, silage temperature, pH, and yeast and mold content were made for each silage. Aerobic stability was determined monthly. Silo type had no effect on intake or milk production. Silage temperatures from the oxygen-limiting silo were higher, and the silage was less stable than that from concrete stave silos. No …

Round Baling From Field Practices Through Storage And Feeding, W L. Kjelgaard, P M. Anderson, L D. Hoffman, L L. Wilson, H W. Harpster

IGC Proceedings (1977-2023)

A model analysis compared labor and fuel requirements for round and rectangular bale systems. Round baling reduced harvesting, transport, and handling labor by one-half but increased fuel use by a factor of 1.6. When data from field studies of all dry matter (DM) losses were included, round baling required 80 % as much labor and 200 % as much fuel as did rectangular bal­ing. Baling losses for round balers and stackers averaged 10 % compared with 3 % for rectangular balers. ·Dry-matter losses from mowing through feeding of field-cured round bales, including 6 months of outdoor storage, totaled 41 % …

Harvesting And Processing Effects On Alfalfa Protein Utilization By Ruminants, R Britton, D Rock, T Klopfenstein, J Ward, J Merrill

IGC Proceedings (1977-2023)

Alfalfa (Medicago sativa) is an efficient and important means of producing supplemental protein for ruminants. This research was undertaken to characterize the value of alfalfa protein for ruminants and to show how the protein is affected by different harvesting or processing regimens. The effects of maturity (prebloom, one-tenth, one half, and full bloom) and processing method (freeze dried [FD], sun cured [SC], and oven heated [HJ), on percentage of nitrogen (N), acid detergent insoluble N (ADIN), in-vitro rumen ammonia release (NH3), and in-situ rumen protein degradation, using dacron bags (BAG), were studied on irrigated alfalfa harvested over 2 years. …

Comparison Of Conservation Methods Under Controlled Practical Conditions, H Honig, K Rohr, E Zimmer

IGC Proceedings (1977-2023)

The most common forage conservation methods (direct-cut and low-moisture silage, barn,dried hay, and dehydration) have been compared under practical, but strictly controlled, conditions to determine their relative value for meeting the increasing demands of high-yielding ruminants. A grass mixture was used as forage, at different stages of maturity in different ex­periments. Parameters determined were changes of nutrient content; losses of DM and net energy; and, in three experiments, forage intake by dairy cows. From the results of the experiments, the following conclusions could be drawn: (1) roughage quality is influenced more by cuttng time than by preservation methods; (2) low-moisture …

Wet Fractionation Of Alfalfa: A Direct Forage-Harvesting System, M Collins, R G. Koegel, N A. Jorgensen, H W. Ream

IGC Proceedings (1977-2023)

In this syst􀀇m, termed wet fractionation, fresh forage is macerated and pressed to remove approximately 50 % of the moisture. The result is a forage product containing 32 %-38 % dry matter (DM) that can be ensiled directly. In addition, the protein con­tained in the plant juice can be coagulated and removed. The remaining deproteinized juice contains large quantities of mineral nutrients that can be returned to the soil. This process has several potential advantages: (1) less weather-dependent harvesting, which minimizes harvest losses; (2) reduced harvesting time; (3) reduced fertilizer requirements; and (4) ability to harvest protein from land unsuited …

Hastening Hay Drying, J W. Thomas, T R. Johnson, M A. Wieghart, C M. Hansen, M B. Tesar, Z Helsel

IGC Proceedings (1977-2023)

The objectives of these studies were to increase the drying rate of cut alfalfa (Medicago sativa) by treating with chemical solu­tions and to examine factors that influence drying. Time to dry and drying rate of cut alfalfa were studied under laboratory and field conditions. Treatment consisted of spraying the cut alfalfa with methyl esters of long-chain fatty acids, an emulsifier alone, or a combination of an emulsifier and a potassium carbonate solution. Alfalfa sprayed with solutions of each chemical under specified conditions increased drying rate and decreased drying time to 60% or 75 % dry matter (DM) or …

Alternative Treatment Systems To Increase The Drying Rates Of Green Forage Crops, W E. Klinner, O D. Hale

IGC Proceedings (1977-2023)

Forms of conditioning treatment are being developed that aim to minimize the barrier effect of the crop cuticle without sacrificing too much of the structural strength of the herbage. Effective surface abrasion and favorable windrow structure can be achieved with steel-spoked rotors, which are now beginning to be offered commercially. More recently, plastic brushes have been developed because the higher population density and yielding ability of the crop-engaging elements, plus the absence of metal components, appeared to offer additional advantages. Four different brush conditioner systems have been evaluated in the laboratory and in replicated field experiments. Tufted brushes using trilobar …

Effects Of Microwave Treatment On Drying And Respiration In Cut Alfalfa, S A. Seif, D A. Holt, V L. Lechtenberg, R J. Vetter

IGC Proceedings (1977-2023)

After forage crops are cut mechanically, they usually undergo some degree of natural drying before being stored or further processed. During early stages of drying, plant respiration continues. Treatments or management practices that hasten drying and reduce postharvest respiration are desirable, because they minimize quantity and quality losses. Our objective was to determine the effects of brief microwave treatment on subsequent natural drying rate and respiration of alfalfa (Medicago sativa L. ). Duplicate samples of field grown Apollo alfalfa were subjected to focused microwave energy (2,450 MHz) generated at 0.25, 0.50, or 1.0 kilowatt of power for 3, 6, …

Effect Of Formic Acid- Formaldehyde Treatments On The Nitrogenous Constituents In Annual Ryegrass Silage, M L. Fishman, F Mchan, D Burdick

IGC Proceedings (1977-2023)

Prevention of proteolysis during ensiling is important in preserving the nutritive value of silage. Hence, the mechanism by which silage protein is protected against degradation was studied in wilted annual ryegrass (Lolium multiflorium Lam.) silage pretreated with formic acid, formaldehyde, and a formic acid-formaldehyde mixture. Raw-wilted ryegrass, control ryegrass silage, and treated ryegrass silage were extracted and fractionated under conditions previously found to maximize yield of nitrogenous constituents and minimize proteolysis during the extraction of fresh grass. Extractions were by boric acid-borate buffer at pH 8.0 with and without detergent (1 % sodium dodecyl sulfate). Sodium metabisulfite, an antioxidant, was …

Addition Of Lactobacillus Sp. To Aid The Fermentation Of Alfalfa, Corn, Sorghum, And Wheat Forages, N J. Moon, L O. Ely

IGC Proceedings (1977-2023)

As preservation of forage by ensiling has increased, so has the use of additives to enhance acid fermentation. Many of the fermentation aids currently on the market contain microflora to insure a lactic acid fermentation. The objectives of this study were to characterize the basic patterns of fermentation in a variety of crops and to evaluate the effects of adding selected microflora to forages to enhance the fermentation. Four crops were ensiled in each of three seasons. Alfalfa was harvested at 20 %-40 % bloom, second cut; wheat was cut in the early dough stage; corn was cut in the …

Interrelationships Between Pattern Of Fermentation During Ensilage And Initial Crop Composition, J M. Wilkinson, P F. Chapman, R J. Wilkins, R F. Wilson

IGC Proceedings (1977-2023)

Relationships between crop composition and silage composition were examined for 231 silages made at the Grassland Research Institute from 1968 to 1978 without additives. A test was made of the model of Weissbach et al. (1974) in which silage characteristics were related to the percentage of dry matter in the crop (OM) and the ratio of sugar (Z) to buffering capacity (PK). Although these factors accounted for significant variance, the percentage accounted for was low at 36 % for lactic acid (percentage of total acids), 26 % for Flieg's score, 22 % for ammonia N (percentage of total N), and …

Effect Of Delayed Sealing During Ensiling On Fermentation And Dry-Matter Loss, N Takano, Y Masaoka, T Manda

IGC Proceedings (1977-2023)

Two experiments were carried out from 1976 to 1980 to ascertain the effect of delayed sealing of silo on fermentation, dry· matter (DM) loss, digestibility, and silage intake. The effect of delayed sealing (up to 72 hours) of grass and corn silage was tested in laboratory silos on fermentation quality with storage temperatures at 15°C and 30°C, moisture content from 49% to 85 % , water-soluble carbohydrate (WSC) content ranging from 11.1 % to 17.5%, and with and without an addition of 0.25% formic acid. In all cases, delayed sealing resulted in poor-quality silage with high pH values and low …

Improving Hay Quality By Ammoniation, K J. Moore, V L. Lechtenberg, K S. Hendrix, J M. Hertel

IGC Proceedings (1977-2023)

Experiments were conducted to determine the effect of hay ammoniation on hay consumption and weight gain by steers when the hay was fed unsupplemented and supplemented with energy and protein. Mature orchardgrass (Dacrylis glomerata L.) hay was baled in early June 1979 and treated with anhydrous ammonia at 30 g/kg of hay. Seven weeks after treatment the hay was uncovered and allowed to aerate for 3 days. It was then fed to weanling steer calves weighing approximately 225 kg each. Similar hay baled from the same field but not ammoniated was fed to separate groups of steers. Both the treated …

Evaluations Of Low-Quality Roughages And Fibrous Cereal Grains Treated With Various Chemicals, G C. Fahey Jr, L L. Berger, M I. Mora, P J. Van Der Aar

IGC Proceedings (1977-2023)

Large improvements in the feeding value of low-quality roughages have resulted from treatment of them with various chemicals. Chemical treatment of grains may also be a potentially useful practice. The research reported here was designed (1) to determine how Chelating Metal Caustic Swelling (CMCS), a nontoxic, alkaline, aqueous reagent, compares with sodium hydroxide (NaOH) in enhancing in-vitro cellulose digestion (IVCD) of cornstalks (CS) (Zea mays) and soybean residues (SBR) (G!),cine max.), and (2) to evaluate the effects of NaOH and CMCS treatments of fibrous grains using in-situ techniques. CMCS or 7.5% NaOH solutions were added to CS or SBR at …

Effect Of Solvent Treatments On Intake And Digestibility Of Corn Stover, D M. Schaefer, M R. Ladisch, C H. Noller, V L. Lechtenberg

IGC Proceedings (1977-2023)

Treatment of crop residues with low levels of sodium hydroxide has been shown to improve organic-matter digestibility and animal performance. One objective of these experiments was to evaluate the effects of three treatments -water, sodium hydrox­ide, and chelating metal cellulose-swelling solution-on solubilization of cell-wall components in corn (Zea m£rys) stover. The two latter treatments were balanced for level of sodium hydroxide application, which was .3 .2 % of stover dry matter. The second objective was to determine the effects of these treatments on in-vitro and in-vivo digestibility as well as on consumption of corn stover. Twelve growing ram lambs were …

Factors Causing Greater In-Vitro Than In-Vivo Digestibility Of Sodium Hydroxide - Treated Roughages, L L. Berger, T J. Klopfenstein, R A. Britton

IGC Proceedings (1977-2023)

Research on sodium hydroxide (NaOH) treatment oflow-quality roughages generally indicates that in-vivo digestion is lower than in-vitro digestion. The purpose of this research was to identify factors that may cause less of the potentially digestible fiber to be digested in vivo than in vitro. Corn (Zea mays) cobs were raised to 60% moisture and treated to contain 0%, 2.5%, 5.0%, 7.5 % , and 10.0% NaOH. Lambs were fed diets containing 80% cobs and 20% supplement, giving a complete mixed diet con· taining 0%, 2.0%, 4.0%, 6.0%, and 8.0% NaOH. Five abomasally cannulated lambs were assigned to a 5 x …

Relationship Between Silage Quality And 15 N-Nitrate Reduction During Ensilage, K Ataku, M Horiguchi, T Matsumoto

IGC Proceedings (1977-2023)

Nitrate in forage has been proven to occasionally poison ruminants. Our recent studies, however, have shown that a high con­centration of nitrate inhibits butyric acid fermentation to the advantage of the silage quality. This work was undertaken to see the relationship between silage quality and the pattern of nitrate reduction during ensilage.

Exploring Regenerative Vegetable Systems On The Central Coast Of California, Una S. O'Connell

Master's Theses

As climate change and current agricultural practices place pressure on the long term sustainability and resilience of food production systems, there is growing interest in whether existing agricultural systems can adapt to maintain productivity while improving environmental outcomes.

This study evaluated the effects of regenerative versus standard organic vegetable production systems on yield, insect communities, and weed suppression across three field trials conducted on California's Central Coast. In addition, I collected baseline soil health data for all trials. Trials 1 and 2 were carried out at the Cal Poly San Luis Obispo Organic Farm using cabbage and broccoli as cash …

Evaluation Of Ultraviolet-C Light For Control Of Mites And Western Tarnished Plant Bug In Strawberry & Interactive Lethal Effects Of Common Strawberry Fungicides And Adjuvants On Phytoseiulus Persimilis, Colin T. Koubek

Master's Theses

California strawberry production relies heavily on chemical pesticides to manage arthropod pests and diseases, but pesticide resistance, regulatory pressure, and the need to conserve biological control agents have increased interest in alternative pest management tools. This thesis evaluated ultraviolet-C (UV-C) light as a nonchemical management tool for key strawberry arthropod pests and assessed the compatibility of common strawberry fungicides and adjuvants with the predatory mite Phytoseiulus persimilis Athias-Henriot. The first objective was to determine the ovicidal and lethal effects of UV-C light on Lygus hesperus Knight eggs and nymphs. Laboratory and field ovicide assays were conducted using UV-C doses relevant …

Effects Of Irrigation And Nitrogen Management On Yield And Leaching Risk In Organic And Conventional Broccoli Fields, Shane Egerstrom

Master's Theses

Under regulatory pressures to reduce groundwater contamination by nitrate from fertilizer, such as those posed by the Central Coast Regional Water Quality Control Board’s Agricultural Order 4.0, a need exists to better understand interactions between irrigation and nitrogen (N) management. To increase N use efficiency (NUE), growers are encouraged to account for additional sources of N in their management plans, such as irrigation water N and preplant soil N. The availability of these N sources for plant uptake and how it is affected by other management conditions is not yet well documented. We conducted 6 field trials, 3 organic and …