Search PubMed⌕ Search

Biomedical subjects

J R Blackman

Publications and source records attributed to J R Blackman.

15 recordsLinked to original sources
PubMed1995

The use of feed restriction for improving reproductive traits in male-line white turkey hens. 2. Ovary morphology and laying traits.

The influence of feed restriction during rearing was investigated in male-line Large White breeder hens with regard to effects on ovarian morphology, egg production, laying patterns, and egg characteristics. Two hundred poults were reared from 4 to 28 wk of age under four treatments as follows: full-fed controls (FF), low-protein diet (12% CP from 12 to 28 wk; LP), and reduced BW (10 to 20% lower BW than FF; R10 and R20). At photostimulation (28 wk), all birds consumed a commercial breeder diet ad libitum for the remainder of the study (48 wk of age). Settable egg production (eggs per hen) to 48 wk for all hens, and those in lay was: FF, 39.4 (48.6); LP 42.7 (51.7); R10, 41.4 (52.8); R20, 40.7 (55.4). Inferior egg production per bird in R10 and R20 hens reflected a reduced persistency of lay. At first egg, hens of all treatments had a mean of 4.9 postovulatory follicles (POF) not accounted for by an egg. Number of unreconciled POF correlated with abdominal fat pad weight (P < or = .01). Ovary weight correlated with BW (P < .0001) and fat pad weight (P < .0004). Proportion of yolk and shell in the egg and egg specific gravity were improved with feed restriction. Sequence length was longest in R20 treatment hens and pause length shortest in R10 and R20 hens. Incidence of multiple-follicle sets was reduced in the R10 and R20 treatments. Feed restriction during rearing can potentially improve laying characteristics by altering ovarian morphology without limiting shell quality or yolk size. Quantitative feed restriction was most effective at improving egg quality, reducing average pause length, and reducing ovarian multiple-follicle sets. If problems with persistency of lay are addressed, the R10 and R20 treatments are the recommended rearing restriction treatments for male-line turkey breeder hen candidates.

Animals↗
PubMed1994

The use of feed restriction for improving reproductive traits in male-line large white turkey hens. 1. Growth and carcass characteristics.

The influence of feed allowance during rearing was investigated in male-line Large White breeder hens. A flock of 200 poults was reared from 4 to 28 wk of age under four treatments as follows: full-fed controls (FF), low-protein diet (12% CP from 12 to 28 wk; LP), and reduced BW (10 or 20% lower BW than FF; R10 and R20). At photostimulation (28 wk), all birds consumed a commercial breeder diet ad libitum for the remainder of the study (48 wk of age). Body weight differed among treatments during most of rearing. The LP birds were similar in BW to the R10 birds at 28 wk of age. By 40 wk of age, growth curves of all treatments became similar, with the R20 group having lower BW. Feed restriction reduced frame size during rearing. Flock uniformity in the R10 and R20 treatment hens was reduced during rearing, but improved early in the breeder period. Feed restriction reduced breast muscle and abdominal fat pad weight early in lay, except for the LP group. Liver lipid content increased throughout the breeder period. Changes in liver weight followed the pattern of BW changes. Total carcass protein content changes in time reflected breast muscle mass changes. In R20 hens, carcass lipid content was reduced and protein content increased. Sexual maturity was delayed in the R20 hens. Body weight at first egg was negatively correlated with settable egg production (r = -.37, P < or = .0015). The R20 treatment is recommended for male-line turkey breeder hen candidates during rearing.

Adipose Tissue↗
PubMed1986

Hematoporphyrin derivative fluorescence: photographic techniques for the localization of malignant tissue.

Three simple methods for the detection of malignancy by the photography of hematoporphyrin derivative (HPD) fluorescence are presented. Two methods employ a single lens reflex camera with macrolens and Kodak high-speed Ektachrome (EL 400) film. Both employ a Corning Glass #3482 filter as a barrier on the lens. In method I, a single Kodak Wratten #39 filter is placed over a fluorescent "black light" source (two General Electric F20T12BL 20-W bulbs). In method II, twin electronic flash units (5,500 BCPS unfiltered) with a double thickness of Kodak Wratten #39 filter over them provide the light of excitation. Method III employs an adapted Polaroid SLR 680E Sun camera with two electronic flash units (5,500 BCPS, total unfiltered) rigged with a slave trigger. A Corning Glass #3482 filter is placed on the lens to act as a barrier, and two filters of Kodak Wratten #39 glass are placed on each flash unit. Photographs are taken in a darkened room.

Animals↗
PubMed1985

Streamlined fluorescein photography.

A simple, accurate inexpensive method for obtaining Polaroid pictures after the intravenous injection of fluorescein is presented. The method relies on an interference filter system and modifications permitting the use of high speed film. The resultant photographic images are equivalent to the ultraviolet light fluorescence. The photographs may be used as either a diagnostic tool or for documentation purposes.

Fluorescein↗
PubMed1983

Influence of a low plane of nutrition during sexual development on subsequent reproductive performance of small white breeder toms.

Diamond White and Wrolstad breeder toms were reared to 10 weeks of age on a common nutritional regimen. Both strains were subsequently given high and low planes of nutrition to 30 weeks. Low nutrient feeds were ca. 200 kcal of metabolizable energy (ME)/kg less than high nutrient feeds, which paralleled commercial practice. Energy-protein ratio and essential amino acid profiles between nutrient levels were similar. Both planes were phased down ca. 200 kcal ME/kg between the feeds from 10 to 14 weeks to 14 to 30 weeks. All birds subsequently received the same breeder ration. Diamond Whites were heavier than Wrolstads from 2 through 10 weeks of age. Feeding the low plane of nutrition reduced body weight of both strains at 14 weeks. Growth during the 14- to 30-week-period was such that birds given the low plane feeds recovered earlier losses, and Wrolstads became heavier than Diamond Whites. Although no differences in body weight occurred throughout the breeder period that could be attributed to earlier nutrition, the low plane feeds led to significant improvements in semen and sperm yield during the early and late stages. Wrolstads accrued more fat and benefited more from the low plane of nutrition than did Diamond Whites. Results inferred that reducing fat accretion early in sexual maturity improves subsequent reproductive capacity apart from an alteration in body weight.

Animals↗
PubMed1983

Maintenance nitrogen requirement of the turkey breeder hen with an estimate of associated essential amino acid needs.

Nonproducing, small-type breeder hens in excess of 65 weeks of age were used to represent the maintenance state. All birds had been in laying cages since 30 weeks and accustomed to 16 hr of 70 lx lighting at 16 C. Nitrogen (N) balance was performed in metabolism cages under the same conditions. Ad libitum intake of a common breeder ration led to an intake of ca. 47 kcal metabolizable energy (ME)/kg body weight (BW)/day, which was considered to represent the maintenace energy requirement. Nitrogen retained while consuming this feed averaged 172 mg/kg BW/day. Force-feeding a N-free diet to satisfy the maintenance energy requirement resulted in an 85 mg N/kg BW/day endogenous loss. Total maintenance nitrogen requirement was considered to approximate 257 mg/kg BW/day. Nitrogen retention after force-feeding corn-soybean meal rations having a progressive protein content indicated that the associated amino acids were more efficient in satisfying the endogenous than the total N requirement. A model that estimated maintenance amino acid requirements was assembled by combining the relative concentrations found in muscle and feathers to represent endogenous and retained N, respectively. For the most part, model values agreed with published results for the rooster; however, verification in balance studies was less than successful and believed to be attributable to hen variation in feather cover and protein reserves.

Amino Acids, Essential↗
PubMed1983

A method for documentation of tissue perfusion using instant photography.

Two techniques for obtaining Polaroid pictures of tissue after the injection of fluorescein intravenously are presented. A rabbit small intestinal volvulus model was used to determine the accuracy of the techniques. Both methods are simple, accurate and relatively inexpensive, and immediate and permanent documentation is provided. While both methods provide results equivalent or superior to ultraviolet light fluorescence, the interference filter method produced brighter fluorescence and the results were more easily interpreted. Both methods can be performed by inexperienced personnel.

Animals↗
PubMed1981

Effectiveness of the free acid of methionine hydroxy analogue as a methionine supplement in broiler diets.

A liquid methionine supplement known as methionine hydroxy analogue-free acid (MHA-FA) was evaluated as a source of methionine in the diet of young broiler chicks. Diets calculated to be deficient in methionine were supplemented with MHA-FA and performance compared to that obtained when comparable diets were supplemented with molar equivalents of methionine from L-methionine, DL-methionine, or the calcium salt of methionine hydroxy analogue. Performance of chicks fed the test product was equal to that obtained on the other methionine products. The use of MHA-FA might allow for a more even distribution in the diet, easier handling, and a lower manufacturing cost with resultant savings in the cost of producing poultry and eggs.

Animal Feed↗
PubMedDate not supplied

Venomous snakebite: past, present, and future treatment options.

BACKGROUND: Venomous snakebites continue to cause great morbidity, and treatment options are confusing the attending physician. In the United States approximately 45,000 snakebites occur each year, of which some 8000 are by 20 species of venomous snakes. METHODS: Information on venomous snakes and snakebite treatment was gathered from the libraries of the Wilderness Medical Society and the Rocky Mountain Center for Wilderness Medicine in Boise, Idaho (co-supported by the Boise State University and the Family Practice Residency of Idaho), as well as from current literature files of physicians practicing wilderness medicine. RESULTS AND CONCLUSIONS: Three genera of venomous snakes account for the majority of poisonous snake envenomations in this country. Most hospitalized victims are bitten either by rattlesnakes or copperheads or by unidentified snakes. Most of these bites occur during the summer months and are found on the extremities. Field treatment focuses on the application of a vacuum extractor and transportation to the nearest medical facility. Although constriction band use can be helpful, tourniquets, incision and suction, and ice therapy are contraindicated. Electric shock therapy is of no use and could cause serious injury. Hospital management focuses on rapid clinical evaluation and laboratory tests to establish the degree of envenomation, looking for clotting abnormalities. If envenomation has occurred and is reactive, polyvalent antivenin should be administered according to the degree of envenomation. Errors in diagnosis and treatment result in increased morbidity and put attending physicians at risk for litigation. Prevention remains the most successful approach to snakebite management.

Antivenins↗
PubMedDate not supplied

Comparison of low dietary calcium and sodium sulfate for the potentiation of tetracycline antibiotics in broiler diets.

Three experiments were conducted to compare different methods of short-term potentiation of tetracycline antibiotics for broiler chicks. Reduction of dietary calcium and addition to sodium sulfate were compared in different combinations with various levels of chlortetracycline (CTC) and oxytetracycline (OTC). Reducing dietary calcium from 0.8 to 0.4% significantly increased serum levels of CTC and OTC. Adding sodium sulfate (1.25%) also increased serum levels; the majority of the response occurred at the higher calcium level. There was no benefit from adding sodium sulfate to the low-calcium diet. Neither body weight gain nor feed utilization were adversely affected during the 5-day test period.

Animals↗
PubMedDate not supplied

Spider bites.

BACKGROUND: This review provides the physician with a clinical approach to the diagnosis and management of spider bites. It examines the recent literature concerning management of bites causing dermonecrosis, secondary infection, neuromuscular damage, and allergic reactions. METHODS: Using the key words "spider bites," "brown recluse spider bites," "necrotic arachnidism," "black widow spider bites," "latrodectism," and "Tegenaria agrestis (Hobo spider)," the MEDLINE files were researched for articles pertinent to the practicing physician. Texts related to spiders and spider bites were also consulted. RESULTS AND CONCLUSIONS: At least 60 species of spiders have been implicated in human bites. Most cause bites of minimal medical importance, requiring little treatment. Some (brown recluse, Hobo spider) cause severe cutaneous and systemic reactions requiring intensive medical management. The black widow bite can cause severe neurologic problems requiring the use of antivenin. Spider bites are frequently difficult to diagnose because the spider is not seen at the time of the suspected bite. Such bites should be labeled arthropod bites, vector unknown.

Anti-Infective Agents↗
PubMedDate not supplied

Clinical approach to toxic mushroom ingestion.

BACKGROUND: This review provides the physician with a clinical approach to the diagnosis and management of toxic mushroom ingestion. It reviews the recent literature concerning proper management of seven clinical profiles. METHODS: Using the key words "mushroom poisoning," "mushroom toxicology," "mycetism," "hallucinogenic mushroom ingestion," and "Amanita poisoning," the MEDLINE files were searched for articles pertinent to the practicing physician. Much of the original data were gathered at the Aspen Mushroom Conference held each summer throughout the 1970s at Aspen, Colorado, sponsored by Beth Israel Hospital and the Rocky Mountain Poison Center. Texts related to poisonous plants and specific writings concerning mushroom poisoning were also consulted; many of these texts are now out of print. RESULTS AND CONCLUSIONS: The 100 or so toxic mushroom groups can be divided into seven clinical profiles, each of which requires a specific clinical approach. Two of the seven groups (amanitin and gyromitrin) have a delay in onset of symptoms of up to 6 hours following ingestion and provide essentially all the major mobility and mortality associated with toxic mushroom ingestion. These two groups are the major focus of this review. Treatment of the potential mushroom ingestion, as well as guidelines for asking clinical questions, are included. These questions serve as a form of algorithm to assist the clinician in arriving at the correct toxic group.

Algorithms↗