Agricultural Science Commons^™

An Experimental Center-Pivot Irrigation System For Reduced Energy Crop Production Studies, James R. Gilley, Lloyd N. Mielke, Wallace Wilhelm

United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications

An experimental 52.6 ha center-pivot irrigation system for studies of reduced energy crop production systems is described. The system consists of high pressure impact sprinklers, low pressure impact sprinklers, and low pressure spray nozzles that are automatically turned on or off at preselected locations in the field. The control procedures of the system operation are described. The system also has the capability of applying different depths of water per irrigation as a function of position radially outward from the pivot point. Four years of data indicate that the system controls function properly and the design irrigation depths are being met. …

Fate Of Turkey Spermatozoa After Intrainfundibular And Intramagnal Inseminations, M. R. Bakst

United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications

About 92% of the spermatozoa recovered after intrainfundibular inseminations of turkey hens were in the infundibulum and 6% in the magnal segments 24 h later. Of the spermatozoa recovered after intramagnal inseminations, about 67% were in the infundibulum, 26% in the magnal segments, and a total of about 8% in the isthmus, uterus, and vagina. It is suggested that spermatozoa in the infundibulum and magnum are not transported in significant numbers in an abovarian direction.

Physiology Of Male Reproduction, R. P. Amann, B. D. Schanbacher

United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications

The major advances over the past 25 yr in male reproductive physiology of cattle, sheep, swine and horses are reviewed. Those findings which have allowed efficient culling of subfertile males and exploitation of the reproductive capacity of genetically superior sires are emphasized.

Hormones secreted by the male gonad early in gestation induce regression of potentially female structures and development of the male reproductive tract. Compartmentalization of the testis and formation of the bloodtestis barrier during prepubertal development permit the steroidogenic and gametogenic activities of the adult testes to proceed normally. The role of the central nervous system, hypothalamus and anterior …

Pulsatile Luteinizing Hormone Secretion In The Castrate Male Bovine: Effects Of Testosterone Or Estradiol Replacement Therapy, B. D. Schanbacher, M. J. D'Occhio, T. W. Gettys

United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications

Luteinizing hormone (LH) secretory profiles have been determined for the male bovine following castration and steroid replacement therapy. Serum LH concentrations increased approximately threefold during the first week following castration and thereafter remained elevated (6.6 ± .7 ng/ml). Castrates not receiving steroid replacement showed a rhythmic pattern of LH release that was of high frequency (mean pulse interval; 85 ± 5 min) and high amplitude (mean peak concentration, 11.2 ± 1.4 ng/ml). Chronic administration of estradiol-17β via subdermal Silastic implants reduced mean serum LH concentrations (2.1 ± .3 ng/ml) and blocked the pulsatile pattern of LH release in all steers. …

Reproductive Effects Of Immunizing Heifers Against Androstenedione And Oestradiol-17Β, T. H. Wise, B. D. Schanbacher

United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications

Heifers were treated with saline (Group I, N = 10), keyhole limpet haemocyanin (KLH ; Group II, N = 10), androstenedione-KLH antigen (Group III, N = 14), or oestradiol-17β-KLH antigen (Group IV, N = 14). Booster injections were given to produce binding of > 10% at dilutions of 1:100 to 1:1000 (50% binding = 14·4pg androstenedione and 9·5pg oestradiol). The heifers were mated and killed at ~46days of gestation to establish ovulation rates, calf numbers, blood hormone relationships and ovarian morphology.

Ovulation rate in animals immunized against androstenedione (Group III) was significantly greater than in the other groups; 4 of the …

Semiautomated X-Y-Plotter-Based Method For Measuring Root Lengths, Wallace Wilhelm, J. M. Norman, R. L. Newell

United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications

Root-length measurements are an important aspect of many agronomic research programs. Several automated systems have been reported which use modifications of the line-intersect technique to estimate root length; however, most of these systems are very costly. This paper describes an inexpensive automated system using a modified line-intersect technique to estimate root length. An X-Y plotter was used to move a light sensor in a grid pattern through the projected photographic image of a root system, recording intersections with an event counter. Compared to manual counting using the Line-intersect technique, the system described accurately estimated root length of samples up to …

Semiautomated X-Y-Plotter-Based Method For Measuring Root Lengths, Wallace Wilhelm, J. M. Norman, R. L. Newell

United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications

Root-length measurements are an important aspect of many agronomic research programs. Several automated systems have been reported which use modifications of the line-intersect technique to estimate root length; however, most of these systems are very costly. This paper describes an inexpensive automated system using a modified line-intersect technique to estimate root length. An X-Y plotter was used to move a light sensor in a grid pattern through the projected photographic image of a root system, recording intersections with an event counter. Compared to manual counting using the Line-intersect technique, the system described accurately estimated root length of samples up to …

Proceedings Of The 9th Annual Meeting, Southern Soybean Disease Workers (April 14-15, 1982, Ft. Walton Beach, Florida): Better Yield, Higher Quality = Greater Profit, Walter J. Walla, Wayne Winner, H. Jack Walters, Jerry Berggren, J. Dan Smith

Southern Soybean Disease Workers: Conference Proceedings

Contents

1982 Southern Soybean Disease Workers Officers

1982 Southern Soybean Disease Workers Program Committee

Committee Chairmen

General session

Presidential address. Walter Walla

Role of American Soybean Association in Soybean Production. KL. Bader

Agricultural Chemistry World Wide. D Wolf

Soybean disease management. W Winner presiding

Soybean Disease Loss Estimate. E Koldenhoven

Disease Management Panel Discussion: The Consultant and Soybean Disease Control. R Carver

Disease Management: Chemical Industries' Point of View. HL McMenemy

Management Tactics for Soybean Diseases. DP Schmitt

Farmer and Soybean Disease Control. J Andries

Soybean nematodes. J Arnett presiding

Standardized Nematicide Research Report. A Wrather

Nematode Parasites …

Root Development Of Winter Wheat As Related To Tillage Practice In Western Nebraska, Wallace Wilhelm, L. N. Mielke, Charles R. Fenster

United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications

Tillage practices can influence crop root development. Root distributions were determined for wheat (Triticum aestivum L.) grown in a wheat-fallow rotation during the 1977-1978 winter wheat crop year on an Alliance silt loam (Aridic Argiustoll). The fallow tillage treatments were plow, subtillage, and chemical (no tillage). Each tillage treatment was split into subplots for N application of 0 or 45 kg/ha.

Rooting density was determined by washing the roots in soil cores 7.6 cm in diam by 15 cm long extracted to depths of 90, 105, and 120 cm on 28 Mar., 2 May, and 8 June 1978, respectively. …

Utilization Of The Intact Male For Red Meat Production: A Review, S. C. Seideman, H. R. Cross, R. R. Oltjen, B. D. Schanbacher

United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications

Castration has long been a traditional practice in the United States. Research studies indicate that intact males grow more rapidly, utilize feed more efficiently and produce a higher-yielding carcass with less fat and more edible product. The disadvantages of the intact male include aggressive behavior (bull and boar); undesirable odors and flavors (boar and ram); lower quality grade (bull); lower meat tenderness (bull and ram) and undesirable meat color (bull and ram). Research is needed to develop antemortem and(or) postmortem handling procedures that offset the disadvantages of the intact male so that the meat and livestock industry can take advantage …

Effects Of Contrasting Photoperiods And Temperatures On Performance Traits Of Confinement-Reared Ewe Lambs, B. D. Schanbacher, G. L. Hahn, J. A. Nienaber

United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications

The effects of contrasting photoperiods (16L:8D vs 8L: 16D) and ambient temperatures (5 C vs 18 C vs 31 C) on performance traits of ewe lambs have been evaluated. Seventy-two lambs were paired and allotted to one of six treatment groups in a 2 • 3 factorial experiment. The lambs were fed a pelleted diet ad libitum. throughout the 14-wk study (i.e., as Iambs progressed from 12 to 26 wk of age). "Analysis of performance and carcass data showed that both photoperiod and temperature affected growth rate (P.05) by treatment. Whereas serum prolactin concentrations were elevated in lambs exposed to …

Uterine Blood Flow And Uterine Arterial, Venous And Luminal Concentrations Of Oestrogens On Days 11, 13 And 15 After Oestrus In Pregnant And Non-Pregnant Sows, S. P. Ford, R. K. Christensen, J. J. Ford

United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications

Concentrations of oestradiol-17β and oestrone were measured in the uterine arterial and venous blood of anaesthetized sows on Days 11, 13 or 15 of the oestrous cycle or of pregnancy. Uterine arterial blood flow and the amounts of oestradiol-17β and oestrone in uterine flushings were determined in the same animals. In pregnant animals arterial and venous concentrations were significantly different (P < 0·05) for oestradiol-17β on Days 11 and 13 and for oestrone on Day 15. Uterine content of both steroids was consistently greater in pregnant than in non-pregnant animals with a peak on Day 13. Uterine arterial blood flow increased from Day 11 to 13 of pregnancy then declined (P < 0·08)by Day 15; no change in uterine blood flow occurred on the corresponding days of the oestrous cycle.

Androstenedione, Dehydroepiandrosterone And Testosterone In Ovarian Vein Plasma And Androstenedione In Peripheral Arterial Plasma During The Bovine Oestrous Cycle, T. H. Wise, D. Caton, W. W. Thatcher, A. Rami Lehrer, M. J. Fields

United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications

Catheters were placed in the carotid artery via a facial artery (n = 12) and in the ovarian vein (n = 12), and, in conjunction, electromagnetic flow meters were placed around the ovarian artery (n = 6) in cyclic beef cows. Androstenedione was quantitatively the highest and dehydroepiandrosterone the lowest of the ovarian androgens measured. Ovarian androgens were correlated positively with each other (P < 0·05)but not with ovarian blood flow or day of the cycle. There was a trend for spikes of androgen release (ovarian vein concentration × ovarian blood flow) from the ovary to be greatest during the period of decreasing progesterone and CL regression. However, only with testosterone were spikes of release different (Days -13 to -9 < Days -8 to -4;P < 0·05;Day 0 = oestrus). The dynamic changes in ovarian androgens noted in this study were compatible with the concept of continuous follicular development and atresia throughout the oestrous cycle.

Hormonal Interrelationships Between Hypothalamus, Pituitary And Testis Of Rams And Bulls, Bruce D. Schanbacher

United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications

This mini-review aims to summarize some of our recent findings relating to testicular function and feedback control of the hypothalamic-pituitary axis by testicular steroids in rams and bulls. Testosterone secretion in intact males is not tonic, but is characterized by episodic pulses. This pattern of secretion is dictated by inputs of the central nervous system via secretions of the hypothalamus (luteinizing hormone- releasing hormone; LHRH) and anterior pituitary (luteinizing hormone; LH). A temporal relationship exists between concentrations of LH and testosterone in serum and evidence is presented that strongly suggests that their episodic secretion is dependent on discrete episodes of …

Steroidal Control Of Gonadotrophin Secretion In The Orchidectomized Dog, M. Winter, J. Pirmann, R. E. Falvo, B. D. Schanbacher, J. Miller

United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications

The effects of s.c. administration of oil, testosterone, 5α-dihydrotestosterone, 5α-androstane-3α,17β-dioland oestradiol-17β on plasma concentrations of LH and FSH were determined in 5 orchidectomized dogs. The dosages for the androgens and oestradiol-17β were 500 and 50 μg/kg body weight, respectively. Testosterone and oestradiol-17β significantly reduced plasma gonadotrophin concentrations, although the onset and duration of their suppressive effects differed. Dihydrotestosterone and oil had no effect on either gonadotrophin. Administration of androstanediol had no effect on plasma concentrations of LH but did cause a temporary and significant reduction in FSH. It is concluded that testosterone and oestradiol-17β are major regulators of gonadotrophin secretion …

Root Development Of Winter Wheat As Related To Tillage Practice In Western Nebraska, Wallace Wilhelm, L. N. Mielke, C. R. Fenster

United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications

Tillage practices can influence crop root development. Root distributions were determined for wheat (Triticum aestivum L.) grown in a wheat-fallow rotation during the 1977-1978 winter wheat crop year on an Alliance silt loam (Aridic Argiustoll). The fallow tillage treatments were plow, subtillage, and chemical (no tillage). Each tillage treatment was split into subplots for N application of 0 or 45 kg/ha.

Rooting density was determined by washing the roots in soil cores 7.6 cm in diam by 15 cm long extracted to depths of 90, 105, and 120 cm on 28 Mar., 2 May, and 8 June 1978, respectively. …

An X-Y-Plotter-Based Technique For Measuring Root Length, Wallace Wilhelm, J. M. Norman, J. R. Ellis, R. L. Newell

United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications

Several automated systems have bee reported which use modifications of the line-intersect method to accurately estimate root length; however, most of these systems are relatively expensive to construct. The system described here employs an X-Y plotter, a 2 x 2 slide projector, and a fiber optic photodiode to determine intersections between projected images of a root system and grid pattern traced by the light sensor, which is mounted in the pen of the X-Y plotter. With adequate shielding to eliminate false counts, the system reproduced manual counts (r²=0.9999) for white sewing thread, carpet thread, and 0.14-mm-diam. wire. When …

Influence Of Crop Residue Removal On Yields Of Corn, Sorghum, And Soybeans With No Tillage, J. W. Doran

United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications

For 3 years, yields were significantly influenced by amount of crop residue on the soil surface. Where surface crop residues were completely removed, average yields of corn, sorghum, and soybeans were 24, 6, and 27% lower than where residues were not removed. Removal of 50% surface crop residues had little or no effect on yields. Yield reductions were directly related to higher soil and plant canopy temperatures and lower soil water contents where surface crop residues were removed.

Sperm Recovery From Oviducts Of Turkeys At Known Intervals After Insemination And Oviposition, M. R. Bakst

United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications

To determine whether there is a relationship between oviposition time and the release of spermatozoa from the uterovaginal junction-sperm-host glands (UVJ-SHG),oviducal segments from turkey hens were isolated and washed immediately or 8-12 and 18-22h after oviposition on Days 1, 2, 3 and 10-13 after artificial insemination. Spermatozoa were found in nearly all segments at all times examined, indicating that sperm release from the UVJ-SHG of the turkey is probably continuous or episodic and not exclusively associated with oviposition and ovulation. Alternatively, spermatozoa may be released at specific times of the daily ovulatory cycle and ascend variable distances between the UVJ …

Proceedings Of The 8th Annual Meeting, Southern Soybean Disease Workers (March 11-12, 1981, Memphis, Tennessee): Soybeans, The Crop Of The Future

Southern Soybean Disease Workers: Conference Proceedings

General Session

Presidential Address - Glen Whitney

The Influence of Plant Diseases on American Agriculture - Wiley Garrett

Integrated Pest Management: A National Prospective - B. Blair

Development in Brazil, the Future World Supplier of Food: Industry Overview - Ray Smith

Soybean Disease Loss Estimate - R. V. Sturgeon

Soybeans, Seed, Seedling, and Soil-Borne Disease, James Kantzes presiding

Standardized Seed Treatment Research Report - M. C. McDaniel

Soybean Seedling Disease Control and Plant Populations - Norman Horn

Metalaxyl: A New Seed Dressing and Soil Treatment Fungicide - H. V. Morton and D. Houseworth

Soybean Seed Treatment: U. S. Status …

Insecticides And Pheromones Used In The Midwest. A Short Review, Evelyn Osbourne, Paul Schwartz

United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications

The Midwest produces most of the food and feed grains and oilseeds grown in the US. as well as a substantial proportion of a variety of other crops, but corn accounts for at least 75% of insecticide use in the region. The total amount of insecticides used on crops could be greatly reduced if economic losses from insects could be predicted accurately. We will examine the current status of chemical controls for insects of economic importance to this region, indicating some areas where new developments are needed or are likely to occur.

Determination Of Selenium In Biological Materials By Stable Isotope Dilution Gas Chromatography-Mass Spectrometry, Donald C. Reamer, Claude Veillon

United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications

Selenium can be determined quantitatively in biological samples after digestion using nitric acid, orthophosphoric acid, and hydrogen peroxide and the formation of 5-nitropiazselenol. Samples are spiked with enriched ⁸²Se and lsotoplc ratio of ⁸⁰Se to ⁸²Se is measured by combined gas chromatographymass spectrometry using dual ion monitoring. Precise determination at the parts-per-billion level is possible. The accuracy of the method Is verlfied by using standard reference materials.

Housing And Management To Reduce Climactic Impacts On Livestock, G. Leroy Hahn

United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications

Weather is a constraint on efficient livestock production systems. Evaluation of the degree of constraint is a difficult, but necessary task before selection of appropriate modifications in management or environments can be made. The basis for rational selection from available alternatives for the limitation of climatic stress in livestock has continued to improve, particularly with the development of rudimentary functional relationships between animal performance and weather parameters. Such relationships, when combined with probabilistic knowledge of the weather parameters, permit prediction of the reduction in animal performance under natural conditions, or of the benefits to be derived from proposed housing or …

Blood Flow To The Corpus Luteum-Bearing Ovary And Ipsilateral Uterine Horn Of Cows During The Oestrous Cycle And Early Pregnancy, S. P. Ford, J. R. Chenault

United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications

Total ovarian blood flow of cows (sum of flows through the ovarian artery and uterine branch of the ovarian artery), measured by electromagnetic flow probes, followed a consistent cyclic pattern, being highest from Day 10 of the oestrous cycle (oestrus = Day 0) until 4 days before the subsequent oestrus. During this period of high ovarian blood flow, blood of uterine origin flowed to the ovary through the uterine branch of the ovarian artery and was found to comprise 20-40% of the ovarian blood flow. Between Days -4 and -3, ovarian blood flow dropped (P < 0·01)from 3·2 ± 0·5 to 1·0 ± 0·4 ml/min, coincident with a reversal of flow through this anastomosis. Uterine arterial blood flow was highest (P < 0·05)from 1 day before oestrus to the day of oestrus when compared to the remaining days of the oestrous cycle. Throughout the oestrous cycle, ovarian blood flow was positively correlated with systemic concentrations of progesterone (r = 0·55, P < 0·01)and negatively correlated with systemic concentrations of oestradiol-17β (r = -0·42, P < 0·01). In contrast, uterine arterial blood flow was negatively correlated with systemic progesterone (r =-0·25, P < 0·05) and positively correlated with systemic oestradiol (r = 0·45, P < 0·05). These data provide direct evidence in the cow that a portion of the blood flowing to the ovary containing a fully functional corpus luteum is contributed by the ipsilateral uterine artery.

Ratoon Stunting Disease Of Sugarcane: Isolation Of The Causal Bacterium, Michael J. Davis, A. Graves Gillaspie, Russell W. Harris, Roger H. Lawson

United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications

A small coryneform bacterium was consistently isolated from sugarcane with ratoon stunting disease and shown to be the causal agent. A similar bacterium was isolated from Bermuda grass. Both strains multiplied in sugarcane and Bermuda grass, but the Bermuda grass strain did not incite the symptoms of ratoon stunting disease in sugarcane. Shoot growth in Bermuda grass was retarded by both strains.

Dryland Corn Development Under Various Tillage Systems, Wallace Wilhelm

United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications

Corn (Zea mays L.) was grown under dryland conditions in eastern Nebraska to study the influence of tillage practice on plant development and leaf growth characteristics during 1977, 1978, and 1979. Tillage practices used in these experiments were plow, disk, chisel, and no-till. All tillage operations were applied during the spring of each cropping season. Green leaf area increased from emergence through tasseling and then decreased slowly until physiological maturity for all treatments. The maximum green leaf area indices (LAI) averaged 2.14, 2.56, and 1.89 for 1977, 1978, and 1979, respectively. There was no significant tillage treatment effect on …

Proceedings Of The 7th Annual Meeting, Southern Soybean Disease Workers (April 2-3, 1980, Fort Walton Beach, Florida)

Southern Soybean Disease Workers: Conference Proceedings

Contents

Schedule, Committees, Officers

History of the Southern Soybean Disease Workers, Glen Whitney

Presidential Address, H. Ray Smith

Global Agriculture Year 2000: A Strategic Analysis, Stuart Stearns

Attorneys Got Us Into This Mess, Attorneys Must Get Us Out, John Donley

Soybeans as a Protein Source, Kenneth Lepley

Soybeans in Human Nutrition, Ruth Patrick

Review of Plant Parasitic Nematode Problems on Soybeans, John Fulkerson

Efficacy of Nematicides for Nematode Control, Charles Baldwin

Breeding for Nematode Resistance, C. E. Caviness and R. D. Riggs

Effects of Fertility on Efficacy of Nematicides for Control of the Soybean Cyst Nematode, Al Chambers

Mississippi's Approach …

Growth And Performance Of Growing-Finishing Lambs Exposed To Long Or Short Photoperiods, B. D. Schanbacher, J. D. Crouse

United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications

The effects of photoperiod (8 hr light: 16 hr dark [8L:16D] or 16L:8D) on performance of growing-finishing lambs were evaluated in an experiment with 24 rams and 24 wethers. All lambs were caged in groups of two in a controlled environment and fed a pelleted diet ad libitum for the duration of the study (10 to 22 weeks of age). Performance and carcass data showed that both photoperiod and sex of lamb affected growth rate (P<.01) and feed efficiency (P<.05) but that only sex of lamb affected carcass quality (P<.05) and yield (P<.10). A sex by photoperiod interaction was not observed for any of the traits measured. Average daily gain (grams/per day) and feed efficiency (feed/gain) for lambs in the four treatment groups tested were: rams (16L:8D), 410 and 4.3; rams (8L:16D), 340 and 4.5; wethers (16L:8D), 345 and 4.6, and wethers (8L:16D), 300 and 4.8, respectively. Carcass weight, like slaughter weight, was affected by photoperiod (P<.01) and sex of lamb (P<.05); both rams and wethers exposed to long photoperiods had the heaviest carcasses. Ram carcasses were leaner, had better yield grades and were heavier than wether carcasses, yet both ram and wether carcasses graded Choice. Testosterone concentrations in serum were undetectable (<.2 ng/ml) at 22 weeks of age in wethers but were elevated (P<.O1) in ram lambs exposed to short (3.4 ± 1.4 ng/ml) or long (.8 ± .2 ng/ml) photoperiods. Prolactin concentrations, on the other hand, were not influenced by sex of lamb but were influenced (P<.01) by photoperiod; i.e., prolactin concentrations were high in rams (190 ± 34 ng/ml) and wethers (178 ± 28 ng/ml) exposed to long photoperiods and low in rams (43 ± 9 ng/ml) and wethers (27 ± 11 ng/ml) exposed to short photoperiods. These results suggest that testosterone and prolactin may independently affect growth and performance of growing-finishing lambs.

Fertilizing Capacity And Morphology Of Fowl And Turkey Spermatozoa In Hypotonic Extender, M. R. Bakst

United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications

The effects of graduated increments of hypotonic Beltsville Poultry Semen Extender (BPSE) on fowl and turkey sperm morphology, motility, percentage dead
and fertility were examined. The morphology of fowl and turkey spermatozoa was
adversely affected by decreases in BPSE osmolarity; a reduction of osmolarity of
BPSE to below 200 and 140 mosmol adversely affected the fertility of fowl and
turkey spermatozoa, respectively. The addition of Ficoll to the extender allowed
direct observation of the effects of hypotonic BPSE on the sperm plasmalemma.
Plasmalemmal swelling, due to the uptake of water, was noted initially at the
midpiece. Such plasmalemmal swelling may …

Testosterone Influences On Growth, Performance, Carcass Characteristics And Composition Of Young Market Lambs, B. D. Schanbacher, J. D. Crouse, C. L. Ferrell

United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications

Ram lambs, wethers and wethers implanted with Silastic capsules containing crystalline testerone were placed on test at 14.9 ± 1.1 kg and evaluated for differences in growth, performance, carcass characteristics and composition. Silastic implants that were able to maintain physiological concentrations of serum testosterone provided appropriate replacement therapy in wethers. Growth rate, efficiency of feed utilization and carcass yield of intact ram lambs and testosterone-implanted wethers were superior to the corresponding traits of wethers. Wethers had greater backfat thickness and percentage kidney and pelvic fat, and their carcasses graded higher than those of ram lambs or wethers implanted with a …