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Biomedical subjects

K L Watkins

Publications and source records attributed to K L Watkins.

At least 37 records · Page 2Linked to original sources
PubMed1991

Interactive effects of sodium zeolite-A and copper in growing swine: growth, and bone and tissue mineral concentrations.

An experiment was conducted with 64 crossbred pigs to determine the effect of 0 or .50% dietary sodium zeolite-A (NZA) in combination with 0 or 250 ppm supplemental Cu (as CuSO4.5H2O). Pigs were assigned randomly to one of the following four treatments: 1) corn-soybean meal basal (B), 2) B + .50% NZA, 3) B + 250 ppm Cu, or 4) B + .50% NZA + 250 ppm Cu. Each treatment was replicated four times with four pigs per replicate. Average initial weight was 7.5 kg and the experimental period lasted 144 d. Overall rate and efficiency of gain, incidence of gastric ulcers, dressing percentage, carcass weight, percentage of muscling, 10th rib fat, loin eye area, blood urea N, and bone Ca, P, Mn, Fe, Ni, Na, and Al concentrations were not affected by treatment. The addition of 250 ppm Cu increased liver (P less than .01), serum (P less than .06), and bone (P less than .07) Cu concentrations but decreased mean backfat thickness (P less than .09), bone ash percentage (P less than .03) and serum (P less than .09) and bone (P less than .01) Zn concentrations. Sodium zeolite-A increased serum alkaline phosphatase (P less than .04), carcass length (P less than .06), and liver (P less than .02) and bone (P less than .01) Zn content but decreased (P less than .04) serum Ca and serum inorganic P concentrations. Sodium zeolite-A did not protect against liver Cu accumulation or gastric ulceration in growing swine fed 250 ppm supplemental Cu.

Adipose Tissue↗
PubMed1991

Effect of dietary sodium zeolite A and graded levels of calcium on growth, plasma, and tibia characteristics of chicks.

Sodium zeolite A (SZA), a synthetic sodium aluminosilicate having high ion-exchange capacity, has been shown to increase eggshell specific gravity in laying hens and to improve Ca utilization in chickens. A 4 x 2 factorial arrangement of treatments was used to investigate the effect of dietary Ca (.6, .8, 1.0, and 1.2%) and SZA (0 and .75%) on growth, plasma, and tibia characteristics of chicks from 5 to 15 days of age. Increasing dietary Ca linearly increased (P less than .05) Ca and alkaline phosphatase (AP) in plasma and increased tibia shearing force and percentage ash, Ca, and P in tibiae. However, dietary Ca linearly decreased (P less than .05) inorganic P and Mg in plasma and Mg and Mn in tibiae. Sodium zeolite A decreased (P less than .05) plasma P and AP and tibia Mg but increased (P less than .05) tibia Ca, Zn, Al, and Mn concentrations. Tibia ash and shearing force were increased in chicks fed SZA receiving inadequate dietary Ca, but they were decreased in chicks fed SZA and excess Ca (Ca by SZA interaction, P less than .05). Tibia density showed a similar trend, but the effect was not significant (Ca by SZA interaction, P less than .12). The addition of SZA enhanced tibia ash, density, and shearing force when dietary Ca was low; however, when added to diets containing 1.2% Ca, SZA reduced many bone mineralization indices with the exception of tibia Ca.

Aluminum↗
PubMed1990

Haematological measurements as an aid to early diagnosis and prognosis of respiratory viral infections in thoroughbred horses.

In late November 1988 large numbers of thoroughbred horses in training in Hong Kong developed a transient pyrexia with, in some cases, the clinical signs of viral respiratory disease. Serial blood samples for haematological examination were taken from 10 of the horses which were stabled in six different blocks. They had developed a high temperature within three days of each other and subsequently seroconverted to equine herpes virus 1 (EHV1). The absolute monocyte count was more than 0.5 x 10(9)/litre in all 10 within the first five days, and nine of them had a high neutrophil/lymphocyte ratio on the first day, which then decreased and reversed within four or five days. Five of the horses had a high plasma viscosity, and a large difference between the viscosity of plasma and serum which in three of them returned to normal within 10 days. In the two and a half months after the initial infection six of nine of the horses, including the five which had a large difference between the viscosity of plasma and serum, developed visible mucopus by endoscopic examination. These haematological and endoscopic changes can be used to detect horses in the acute stages of EHV1 infection and monitor the progress of the disease, before it can be confirmed by isolation of the virus and, or, serology.

Animals↗
PubMed1990

Bromocriptine-induced reduction of body fat in pigs.

An experiment was conducted with 36 crossbred finishing pigs (18 male castrates and 18 females) to evaluate the effect of bromocriptine implants on growth, feed intake, feed efficiency, plasma urea nitrogen (PUN) and carcass characteristics. Three levels of bromocriptine (0, 5 and 10 mg/[pig.d]) were administered, via implants at the base of the ear, to six (two replicates of three) male castrates or to six (two replicates of three) intact female pigs (2 x 3 factorial arrangement of treatments). Average initial weight of pigs at the time of implantation was 89.7 kg, and the implants remained in the pigs for 28 (replicate 1) or 30 (replicate 2) d prior to slaughter. Gain, feed intake and efficiency of feed utilization were not affected (P greater than .10) by bromocriptine. Plasma urea nitrogen was lower in female pigs administered 10 mg bromocriptine; bromocriptine did not affect PUN of male pigs (gender x bromocriptine, P less than .08). Tenth rib fat thickness and average backfat thickness were lower (P less than .06) and percentage of muscling was higher (P less than .06) in pigs implanted with bromocriptine. Female pigs had less 10th rib fat but larger loin eye areas and a greater percentage of muscling than male pigs.

Adipose Tissue↗
PubMed1990

Amino acid-supplemented raw soybean diets for finishing swine.

Growth and carcass traits of finishing swine fed amino acid-supplemented raw soybean (RSB) diets were examined. Experiments 1 and 2 were identical and included the following treatments: 1) corn-soybean meal (SBM), 2) corn-RSB (lysine equal to Diet 1), 3) Diet 2 + .15% L-lysine (LYS), 4) Diet 3 + .1% L-threonine (THR), 5) Diet 3 + .05% L-tryptophan (TRP), 6) Diet 3 + .15% DL-methionine (MET) and 7) Diet 3 + THR + TRP + MET equivalent to Diets 4 to 6. The unsupplemented corn-RSB diet reduced (P less than .05) gain, gain:feed, plasma urea N, loin eye area, and percentage of muscling compared with the corn-SBM diet. The addition of LYS or LYS + TRP generally improved these response variables, whereas the addition of LYS + THR or LYS + MET tended to reduce gain and gain:feed compared with the LYS addition alone. The LYS + THR + TRP + MET addition resulted in growth and carcass traits that were intermediate between those of pigs fed the corn-RSB and the corn-SBM diets but not different (P greater than .05) from either. Experiment 3 included Diets 1, 2 and 7 from Exp. 1 and 2, in addition to the following treatment: corn-RSB + LYS + THR + TRP. The LYS + THR + TRP addition improved (P less than .05) growth and carcass traits compared with the LYS + THR + TRP + MET addition.(ABSTRACT TRUNCATED AT 250 WORDS)

Amino Acids↗
PubMed1990

Interactive effects of sodium zeolite A (Ethacal) and monensin in uninfected and Eimeria acervulina-infected chicks.

An experiment was conducted with 5- to 18-day-old Arbor Acres broiler chicks to evaluate the interaction of sodium zeolite A (NZA) and monensin in uninfected and in coccidiosis-infected chicks. Sodium zeolite A (0 and .75%) or monensin (0 and 121 ppm), or both, were fed to uninfected chicks or to chicks infected with 4 x 10(5) sporulated, Eimeria acervulina oocysts, resulting in a 2-by-2-by-2 factorial arrangement of treatments. Coccidial infection reduced (P less than .01) weight gain, feed intake, feed efficiency, percentage of bone ash and of bone calcium; but the infection increased (P less than .05) bone Zn percentage. Monensin alleviated (or at least partially so) the adverse effects of the coccidial infection on weight gain, feed intake, feed efficiency and percentage of bone ash (coccidiosis by monensin, P less than .01). In addition, monensin increased the bone-calcium (P less than .06) and zinc content (P less than .02) in uninfected chicks and in those infected with coccidiosis. Sodium zeolite A tended to reduce feed intake by coccidiosis-infected chicks (coccidiosis by NZA, P less than .07), but increased (P less than .01) the bone zinc and decreased (P less than .01) serum inorganic phosphorus in uninfected chicks and in those infected with coccidiosis.

Aluminum Silicates↗
PubMed1990

Anticoccidial effect of monensin against Eimeria mitis and Eimeria dispersa.

Four chick and five poult trials were conducted in order to investigate the anticoccidial efficacy of monensin against Eimeria mitis in chickens and Eimeria dispersa in turkeys. The chicks were fed a basal diet with either 0 or 100 ppm of monensin. The poults were fed a basal diet with either 0 or 60 ppm of monensin. Two days after the initiation of each experiment, the chicks and poults were crop-intubated with oocysts of E. mitis and E. dispersa, respectively. A group was also included that was not infected and not medicated. Growth and feed intake were recorded. At 6 or 7 days postinoculation, the birds were killed by cervical dislocation and were scored for the incidence and severity of intestinal abnormalities. The Eimeria mitis infection reduced (P less than .01) gain and the feed:gain ratio, compared with uninfected birds; the E. dispersa infection only reduced (P less than .05) gain. Although well-defined, discrete lesions were not observed, marked intestinal abnormalities were noted in birds infected with either E. mitis or E. dispersa. Also, the infected, unmedicated birds had increased (P less than .01) intestinal scores compared with uninfected birds or those with infection but treated with monensin. Monensin eliminated the reduction in gain and feed efficiency seen in the infected birds. The infected birds fed monensin had intestinal scores, gain, and feed:gain ratios similar (P greater than .10) to those for the birds that were not infected and that did not receive medication.

Animals↗
PubMed1989

Haematological changes in two thoroughbred horses in training with confirmed equine herpesvirus 1 infections.

An outbreak of respiratory disease among thoroughbred horses in training in Hong Kong was caused by equine herpesvirus 1 (EHV-1) subtype 1 (abortion strain). Two of the horses affected by EHV-1 were serially blood sampled over a period of several weeks and their haematological values measured. There was an increase in monocyte count in the first few days which steadily decreased in one horse, but the other had a second monocyte peak after a period of exercise, thus demonstrating the importance of not working animals in the early stages of the disease.

Animals↗
PubMed1989

Effect of dietary sodium zeolite A and excess calcium on growth and tibia calcium and phosphorus concentration in uninfected and Eimeria acervulina-infected chicks.

Two identical trials were conducted with 5 to 14-day-old broiler chicks. Sodium zeolite A (NZA, 0 and .75%) and Ca (1.0 and 1.5%) were fed to both uninfected and Eimeria acervulina-infected chicks resulting in a 2 x 2 x 2 factorial arrangement of treatments. Coccidial infection reduced weight gain and gain:feed (P less than .01), and tibia ash, Ca, and Ca:P ratio (P less than .05). Excess dietary Ca reduced (P less than .05) weight gain and tibia ash in uninfected chicks but had no effect (P greater than .10) in coccidiosis-infected chicks (Ca x coccidiosis interaction, P less than .05). Addition of NZA to diets with excess Ca further decreased (P less than .05) weight gain and tibia ash in both uninfected and E. acervulina-infected chicks. Tibia Ca, as a percentage of dry fat-free tibia, was reduced (P less than .05) by the addition of NZA. This effect was not observed when tibia Ca was expressed as a percentage of ash. These results suggest that NZA may exacerbate the adverse effects of excess dietary Ca.

Aluminum Silicates↗
PubMed1988

Excess crude protein for nongravid gilts.

Twenty-five nongravid crossbred gilts (avg initial wt, 126 kg) were placed on either a high (38%) or a low (13%) crude protein (CP) diet and fed either at the rate of 1.82 kg/d or had ad libitum access to feed. In addition, a fifth group was pair-fed the 13% CP diet to the average intake of the gilts fed high CP ad libitum. The experimental period lasted 30 d. Corn-soybean meal diets were used and CP levels were varied by altering the corn:soybean meal ratio. Gain and gain/feed were reduced (P less than .01) in gilts fed 1.82 kg/d compared with the gilts fed ad libitum or pair-fed gilts. Gain (P less than .03) and feed intake (P less than .01) of gilts with ad libitum access to the 13% CP diet were higher than those of gilts with ad libitum access to the 38% CP diet. Gain/feed was not different (P greater than .10) between the two groups, however. Rate of gain and feed efficiency of gilts pair-fed the 13% CP diet were similar (P greater than .10) to those of gilts with ad libitum access to the 38% CP diet. Plasma total free amino acids, NH3 and total protein were not (P greater than .10) affected by treatment. Plasma urea-N and urinary total N, urea-N and orotic acid were increased (P less than .01) in gilts fed the high CP diet regardless of feed intake level. However, urinary NH3 was higher (P less than .01) in gilts fed the low-protein diet. These results indicate that excess dietary CP for nongravid gilts decreases gain and feed intake and has no effect on efficiency of feed utilization, but it increases plasma urea-N and urinary total N, urea-N and orotic acid.

Amino Acids↗
PubMed1987

Responses to excess dietary magnesium as affected by experimental Eimeria acervulina infection or by dietary ammonium chloride ingestion in the chick.

Three experiments were conducted to investigate the effect of experimental Eimeria acervulina infection on excess Mg ingestion in the chick and to investigate the effect of NH4Cl addition to the diet on the coccidiosis X Mg interaction. Two Mg sources were evaluated, MgO and MgSO4 X 7H2O. Gain, efficiency of feed utilization, bone ash percent (BAP), bone Ca and duodenal pH were lower in coccidiosis-infected chicks than in uninfected chicks. However, bone P and bone Mg levels were higher as a result of the coccidial infection. Bone Mg levels were higher and bone Ca levels and BAP were lower in chicks fed excess dietary Mg, either as the oxide or sulfate forms. Gain and feed efficiency of chicks fed excess Mg, as MgO but not as MgSO4 X 7H2O, were lower than in chicks fed the basal level of Mg. Coccidiosis X Mg interactions were observed in bone Mg and bone Ca concentration data; bone Mg uptake was greater when high dietary Mg and the coccidial infection were in combination. In some instances, a similar interactive effect was observed in bone Ca concentration data; bone Ca loss tended to be greater as a result of the combination of high dietary Mg and the coccidial infection.

Ammonium Chloride↗
PubMed1986

Gastric ulceration in mature thoroughbred horses.

Routine post mortem examination of 195 Thoroughbreds in Hong Kong revealed that 66 per cent suffered from gastric ulceration. Racehorses killed straight out of training suffered a significantly greater incidence of ulceration (80 per cent) than those having been retired for a month or more (52 per cent). The macroscopic findings post mortem enabled a classification of equine gastric ulceration to be suggested (Types 1, 2, 3), according to severity. Severe lesions (Types 2 and 3) were present in 45 per cent of horses put down from training and 5 per cent of retired horses. This difference was significant. Lesions appeared to be chronically progressive during training, but to regress during retirement. The observed difference of gastric ulceration between the two groups of horses was similar for different age groups.

Animals↗
PubMed1984

Effect of bedding on the incidence of exercise induced pulmonary haemorrhage in racehorses in Hong Kong.

An investigation into the incidence of exercise induced pulmonary haemorrhage (EIPH) in thoroughbreds in Hong Kong was carried out between the 1981 and 1983 racing seasons. A total of 1039 post race endoscopic examinations were performed in 1982-1983 and the results indicated that 46.8 per cent of runners had EIPH. This was not statistically different from the percentage of horses showing EIPH during 1981-82 (46.9 per cent). As it had been postulated that dust, especially from straw, could be implicated in lung haemorrhage a proportion of horses were bedded on paper in the 1982-83 season. No significant differences could be demonstrated in the incidence of EIPH resulting from the use of paper bedding in preference to straw.

Animals↗
PubMedDate not supplied

Turkey knockdown in successive flocks.

Turkey knockdown was diagnosed in three of five flocks of hen turkeys on a single farm within a 12-mo period. The age of birds in the flocks affected ranged from 6 wk 2 days to 7 wk 4 days. The attack rate ranged from 0.02% to 0.30% with a case fatality rate in affected birds ranging from 0 to 74%. The diagnosis was made on the basis of clinical signs and histopathologic lesions associated with knockdown. The feed in all flocks contained bacitracin methylene disalicylate and monensin (Coban). Affected birds were recumbent, demonstrated paresis, and were unable to vocalize. Postmortem examination revealed few significant lesions although pallor of the adductor muscles and petechiation in adductor and gastrocnemius muscles were noted. Birds that had been recumbent for extended periods were severely dehydrated. Consistent microscopic lesions included degeneration, necrosis, and regeneration of adductor, gastrocnemius, and abdominal muscles. No lesion in cardiac tissue was noted. Results of our investigation indicated that changes in water consumption, vitamin E status, and brooder to finisher movement correlated with the occurrence of knockdown. Turkey knockdown was defined in 1993 as any condition identified in a turkey flock that has affected the neuromuscular system to a degree that a turkey is unable to walk or stand. This definition was later modified to...neuromuscular or skeletal systems to a degree that a turkey is unable to walk or stand properly. Knockdown may be associated with numerous feed, management, or disease factors alone or in combination. Dosage of monensin, feed restriction/gorging, water restriction, heat stress, copper, mycotoxins, sodium chloride in feed, and sulfa drugs have all been suggested as contributing factors; however, laboratory studies to duplicate this have not been successful. This report presents observations from a single farm at which three of five hen flocks in a single year experienced knockdown. When a flock was reported as affected, a detailed investigation was initiated within 3 hr. The fifth flock was followed on a twice weekly basis from 0 to 8 wk of age to determine if initiating events were evident, but knockdown did not occur.

Animals↗
PubMedDate not supplied

Alterations in levels of various host antioxidant factors in turkey knockdown syndrome.

Five components (selenium, glutathione peroxidase, copper, superoxide dismutase, and vitamin E) of the antioxidant system of turkey poults were examined to determine if they play any role in the knockdown (KD) syndrome. All flocks were provided with feed formulated to contain monensin at 54-60 g/ton. Flock data were analyzed as a case-control study with three treatment groups (KD-affected and unaffected turkey poults from a KD flock and poults from an unaffected flock [control]). Affected turkey poults had lower (P < 0.001) serum vitamin E levels compared with unaffected poults from KD flocks or poults from unaffected flocks. No significant differences were observed for the other parameters evaluated but there was a trend towards lower copper and superoxide dismutase values in affected birds. It appears that serum vitamin E concentrations in turkey poults may play a significant role in susceptibility to or protection against KD syndrome. Other components of the antioxidant system may also be involved, and complex interactions among several body systems may be critical.

Animals↗