Biomedical subjects

N G Zimmermann

Publications and source records attributed to N G Zimmermann.

10 recordsLinked to original sources

PubMed1995

Mitigating the effects of halofuginone on skin strength by feeding L-proline to broiler chickens.

Two experiments were conducted to determine whether supplemental levels of L-proline in the diets of broiler chickens would mitigate the skin weakening effect caused by continuous feeding of the anticoccidial halofuginone. In Experiment 1, tensile strength and collagen levels in thigh apteria skin were determined at 21 and 42 d of age in male broilers fed 0, .5, and 1% L-proline with either halofuginone (3 mg/kg) or salinomycin (61 mg/kg). In Experiment 2, the same measurements were made on female broilers receiving diets containing halofuginone and supplemented with 0, .5, or 1% L-proline, 1% L-proline through 21 d of age, or 1% L-glutamic acid through 21 d of age, or a diet containing high L-proline feedstuffs (corn gluten meal and ring dried blood meal). In Experiment 1, dermis thickness of thigh apteria was measured in the males at Day 21. Skin strength was increased in male and female broilers fed halofuginone with addition of .5 and 1% L-proline, respectively, at 21 and 42 d of age. Continuous incorporation of synthetic L-proline into diets was shown to improve skin strength in females, whereas diets formulated to contain high levels of L-proline from feedstuffs, 21-d feeding of L-proline, or L-glutamic acid did not increase skin strength.

Animals↗

PubMed1994

Dietary and environmental factors affecting skin strength in broiler chickens.

Two experiments were conducted to evaluate dietary and environmental factors involved in skin tensile strength of commercial broilers. In Experiment 1 the effect of added dietary fat (4 or 7%), environmental temperature (25 or 20.5 C after 21 d), and anticoccidial drug (halofuginone or salinomycin fed continuously) were examined factorially using male and female chicks. Skin tensile strength was measured at 21, 35, and 40 d of age. Thickness of the dermal layers was measured from skin taken at Day 35. In Experiment 2, the effect of added dietary fat (0 or 7%), environmental temperature (25 or 18.5 C after 21 d), and anticoccidial drug (halofuginone or salinomycin) were examined factorially using female chicks. Skin strength and collagen content of the skin were measured at 21, 38, and 42 d of age. Skin tensile strength increased with age in both experiments, but female skin strength was subject to periodic decline. Males had significantly strong skin than females. Levels of added fat or environmental temperature did not affect skin strength in either experiment. Continuous feeding of halofuginone significantly (P < .0001) decreased skin strength compared with that of birds fed salinomycin in both experiments. Halofuginone reduced skin strength in females more than males (25 and 9%, respectively). Dermis thickness was correspondingly reduced in the birds consuming halofuginone. In Experiment 2, soluble collagen contents were reduced at all ages in birds consuming halofuginone; insoluble collagen was significantly decreased at 21 d of age. Birds with weakened skin exhibited increased incidence of skin tears during slaughter in a commercial processing plant (P < or = .0043). These results suggest that halofuginone interferes with collagen synthesis, causing decreased collagen formation and reduced skin strength. Neither added dietary fat nor ambient temperature were involved.

Age Factors↗

PubMed1994

Effect of halofuginone on broiler skin strength when used in a shuttle anticoccidial program.

Continuous feeding of the anticoccidial halofuginone to broilers is associated with reduced skin tensile strength and increased skin tearing during processing. The possible mitigating effect of shuttle administration of halofuginone and salinomycin to female broilers was evaluated. Halofuginone or salinomycin were included in the starter and grower diets in all four possible combinations, with anticoccidial omitted from the finisher diets. Starter, grower, and finisher diets were fed to broilers through 3, 6, and 7 wk of age, respectively. Skin strength of pullets fed a diet based on milo and corn (NW) vs a diet based on corn was also compared in a factorial arrangement. Two further treatments were also included: 1) halofuginone-only NW diet supplemented with 2,500 ppm ascorbic acid from 0 to 7 wk; and 2) NW diet reared on wire floor without anticoccidial treatment. Skin tensile strength was determined at 3, 6, and 7 wk of age. Dietary composition had no effect upon skin strength or BW of broilers. Addition of ascorbic acid to the diet containing halofuginone anticoccidial did not improve skin strength. Continuous feeding of halofuginone reduced skin strength whereas withholding anticoccidial and continuous feeding of salinomycin resulted in high skin strength. When halofuginone was used in shuttle feeding programs with salinomycin, there were no differences in skin strength at 7 wk of age compared to birds that were continuously treated with salinomycin. These results suggest halofuginone may be used in a shuttle program either during the starter or grower phase without adverse affect on skin tensile strength at slaughter.

Animal Feed↗

PubMed1991

Research note: effect of electronic treatment of drinking water on growth performance of broiler chickens.

Three electronic devices used to treat drinking water were compared with untreated city well water in a broiler growth performance trial. In each treatment feed conversion and BW were measured in 16 replicate pens of 60 female broilers at 29, 42, and 49 days of age. Two of the devices increased dissolved oxygen content of the water and reduced conductivity and microorganism count. One of these reduced broiler mortality (P = .065), decreased pH (P = .062), and increased Fe and Mn concentration in the water. The other increased water temperature, Ti, and Mn but reduced the concentration of Cl, Al, Ca, Cr, Mg, and Sr in the water. Neither the third device, an electrostatic water treatment, nor the other devices affected BW (P = .586) or feed conversion (P = .564) at 49 days of age. No significant treatment differences (P less than or equal to .05) in hematocrit, bursa of Fabricius weight, or tibial ash weight were observed at 21 days of age.

Animals↗

PubMed1988

Broiler performance when reared under various light sources.

Three trials were conducted to determine if modern energy-efficient light sources, which vary in wavelength emission, affect broiler growth performance. The effect of light source on growth performance was determined by measuring body weight, feed conversion, and livability at intervals throughout rearing and at market age in three flocks of approximately 3,600 broilers each. Illuminance within the light-proof experimental facility was approximately 5 1x and photoregimen was 1 h dark:23 h light. Trial 1 compared incandescent (IN), warm white fluorescent (WWF), and daylight fluorescent (DLF) light sources. The WWF source provided superior body weight compared to IN light but feed conversion ratios were similar. Both IN and WWF light sources resulted in better body weight and feed conversion than that of the DLF light source. Trial 2 used IN, WWF, DLF, PL-5 fluorescent (PLF), design white fluorescent (DWF), and high pressure sodium (HPS) light sources. The PLF source resulted in mean body weight significantly higher than those produced by IN, HPS, and DWF. No other significant differences were observed. Trial 3 used IN, WWF, DLF, PLF, HPS, and low pressure sodium (LPS) light sources. Feed conversion for the HPS treatment was superior to that of PLF and LPS treatments. No other significant differences were observed. Light source did not affect livability in any of the trials. These trials demonstrated that energy-efficient light sources varying in wavelength emission may affect broiler growth performance, but consistent differences were not observed. Generally, IN light sources may be replaced with more energy-efficient light sources without adverse effects on broiler growth performance.

Animals↗

PubMed1987

Comparison of several induced molting methods on subsequent performance of single comb White Leghorn hens.

Seventy-two-week-old Single Comb White Leghorn hens were induced to molt by 11 different methods 1) to determine the utility of molt-inducing procedures that employ full feeding, limited feeding, and fasting and 2) to determine the postmolt performance of hens induced to molt by fasting to varying degrees of body weight reduction (BWR) then fed postfast, prelay (PF-PL) diets varying in nutrient density. Induced molt treatments were full feeding of 10 and 15% guar meal diets to 30% BWR; limited feeding by withholding feed to 30% BWR, except for 6-hr feeding periods on every 3rd, 4th, and 5th recurring day; fasting to 25, 30, or 35% BWR then feeding either a pullet developer ration or a fortified molt ration (FR) for 21 days. Egg production, egg weight, shell quality, Haugh unit, feed consumption, and mortality were recorded for 33 weeks. Molt treatments produced few significant differences; nonmolted control hens had overall poor performance. Full feeding of the 15% guar meal diet caused a slow cessation and reinitiation of lay with acceptable lay performance. The 10% guar meal diet reduced livability. All recurring day, limited-feeding treatments conserved feed during the first 35 days of molt induction. The 3rd and 5th recurring day-feeding treatments were particularly effective and had acceptable lay performance and feed efficiency. Neither level of BWR nor type of PF-PL diet significantly affected postmolt performance. The 30% BWR-FR induced-molt method produced superior (but not significantly) postmolt lay performance.

Animals↗

PubMed1985

Blood sampling from the venous occipital sinus of birds.

Venous occipital sinus blood sampling was demonstrated to be an effective nonlethal method in all species tested including ducks, geese, Chukar partridge, Japanese quail, pea-fowl, pheasants, parakeets, turkeys, and chickens. Maximum blood volume obtained from the occipital sinus of 1-day-old chicks equalled the volume obtained by cardiac puncture and exceeded the volume collected by decapitation. Venous occipital sinus puncture was successfully used to rapidly collect several successive blood samples from individual birds, thus indicating the method's utility for serial blood sampling. Hematocrit values, as well as infectious bronchitis and Newcastle disease virus antibody titers measured in blood samples drawn from the occipital sinus and the brachial vein, were compared. Significant correlation coefficients between the two blood sources for each of the variables measured suggest that occipital sinus blood sampling may be substituted for venipuncture for many routine measurements.

Animals↗

PubMed1984

Catecholamine involvement in the control of growth hormone secretion in the domestic fowl.

A neuropharmacologic approach was utilized to investigate the catecholaminergic influence on the hypothalamic regulation of growth hormone (GH) secretion in young (6-week-old) male domestic fowl. The selective inhibition of norepinephrine (NE) and epinephrine (E) synthesis or activity by diethyldithiocarbamate (DDC), FLA63 (dopamine-beta-hydroxylase inhibitors), phenoxybenzamine (alpha 1 receptor blocker), and yohimbine (alpha 1 and alpha 2 receptor antagonist) was associated with a decline in circulating GH levels. Similarly inhibition of NE reuptake by imipramine or desmethylimipramine were followed by reduced GH secretion. In the presence of alpha-methyl-p-tyrosine (alpha Mpt, a tyrosine hydroxylase inhibitor), the administration of phenylephrine (alpha 1 agonist) was followed by increased plasma concentrations of GH. However, alone, it was without effect. Similarly plasma concentrations of GH were elevated by dihydroxyphenylserine (DOPS, a precursor of NE/E) in chicks pretreated with DDC or carbidopa. These data are consistent with the stimulatory hypothalamic control of GH involving NE/E which exert their effects via alpha (probably alpha 1) postsynaptic stimulatory receptors. Evidence that it is E rather than NE, which is the catecholamine involved or the hypothalamic control of GH, comes from the decrease in plasma GH concentration following the inhibition of central E synthesis by SKF64139 (an inhibitor of phenylethanolamine-N-methyltransferase). Some evidence for a limited inhibitory dopaminergic system was found. Inhibition of dopamine (DA) synthesis by alpha Mpt produced significant elevations in plasma GH concentration. In addition, apomorphine (DA agonist) consistently depressed GH release. However, blockade of DA receptors by pimozide had either no effect on plasma GH concentrations or at a very high dose decreased plasma GH concentrations. NE/E also appear to have a depressive effect on plasma concentrations of GH in young chicks, probably via a peripheral site of action. Plasma concentrations of GH were reduced by the peripheral administration of NE, which might be expected not to cross the blood-brain-barrier (BBB), alpha 1/alpha 2 agonists clonidine and p-amino clonidine (which does not cross BBB), NE/E precursors L-DOPA and DOPS, and the beta agonist, isoproterenol. Furthermore, the depression of peripheral E synthesis (by SKF29661 which inhibits phenylethanolamine-N-methyltransferase) elevated the plasma concentration of GH.

Animals↗

PubMed1984

Involvement of alpha 1- and alpha 2-adrenergic receptors in the hypothalamo-pituitary-ovarian axis of the domestic fowl, Gallus domesticus.

The alpha 1-adrenergic receptor ligand, 3H-WB4101, and the alpha 2-adrenergic receptor ligand, 3H-para-aminoclonidine, were utilized at a 1.0 nM incubation concentration to determine relative alpha 1-and alpha 2-adrenergic receptor binding by cell membranes from selected tissues within the brain, ovary and oviduct of the domestic fowl. Significant specific alpha 1-adrenergic binding was observed in the hypothalamus, anterior pituitary, pineal, cerebrum and cerebellum but only the cerebrum had significant alpha 2-receptor binding. Significant levels of alpha 1-adrenergic binding were observed in the granulosa cells of the three largest ovarian follicles and in the postovulatory follicle. Significant specific alpha 2-adrenergic binding was measured in the infundibulum, magnum, isthmus and shell gland of the oviduct. The physiological implications of alpha-adrenergic receptors in these tissues are discussed.

Animals↗

PubMed1983

Endocrine changes in the incubating and brooding turkey hen.

Turkey hens were allowed to incubate eggs and to hatch and rear young. Plasma prolactin (Prl) levels increased prior to the start of continuous incubation and rose sharply as incubation progressed to reach a peak of 1178.2 +/- 221.8 ng/ml (mean +/- SEM) just before hatching. Prl levels then fell precipitously before the hens left the nest, and returned to preincubation levels (36.8 +/- 3.4 ng/ml) by the time the poults were 2 weeks old. These results show that the high plasma concentrations of Prl found during incubation are not initiated or maintained only by the stimulus of nesting. We suggest that the decline in Prl levels at the end of incubation could be related to the pipping and hatching of eggs, and the consequent shift to maternal behavior. Plasma growth hormone (GH) levels were significantly increased in hens which were brooding poults, but not in hens incubating eggs. An elevenfold, 1-day increase in plasma GH was observed immediately after the hens left the nests. Mean plasma GH levels rose from 12.0 +/- 4.7 ng/ml on the day that the hens left the nests to 133.0 +/- 32.0 ng/ml on the following day, and then declined to 23.1 +/- 9.6 ng/ml after an additional day. There were no significant changes in plasma thyroxine levels during laying, incubation and brooding. Plasma glucose concentration was significantly depressed during incubation.

Animals↗