Biomedical subjects

R H Harms

Publications and source records attributed to R H Harms.

At least 19 recordsLinked to original sources

PubMed1992

Abomasal dilatation and impaction in two Hampshire rams.

Two adult Hampshire rams, unrelated and from separate farms, were examined for the cause of intermittent bloat and, or anorexia which lasted for three to six weeks and caused depression and cachexia. The rumen of each ram was hypermotile and ballottement of the ventral abdomen of each animal revealed an enlarged doughy viscus. Mild prerenal azotaemia, hypokalaemia with metabolic alkalosis, and high rumen chloride concentrations were evident. One ram died during the induction of anaesthesia for an abomasotomy and the other was euthanased after unsuccessful medical therapy. The abomasum of each ram was four to six times larger than that of a normal adult ram and filled with coarse, semi-moist, impacted ingesta. This abnormality was clinically identical to the abomasal emptying syndrome which has been described only in the Suffolk breed.

Abomasum↗

PubMed1992

Research note: performance of single comb White Leghorn pullets as influenced by niacin supplementation from zero to six weeks of age and subsequent layer performance.

Two experiments were conducted using a total of 288 Hy-Line W-36 day-old Single Comb White Leghorn (SCWL) pullets in each experiment. The pullets were randomly assigned to one of the six dietary treatments that consisted of 0, 1.5, 3.0, 6.0, 12.0 or 36.0 mg supplemental niacin/kg in a corn and soybean meal basal diet that contained 25.1 mg niacin/kg. Six replicates of eight pullets per replicate were used per treatment in each experiment. Feed and water were provided for ad libitum consumption. The pullets were housed in battery brooder pens with raised wire floors. Total feed consumption (FC), BW, BW gain, and feed efficiency (FE) were measured at 3 and 6 wk of age. Birds were observed daily for any signs of niacin deficiency. At the end of a 6-wk experimental period, the pullets that previously received the diets containing either 0 of 36.0 mg supplemental niacin/kg of diet were raised to sexual maturity (SM) and their age at SM, BW at 24 wk, and number of eggs per pullet through 36 wk were measured in both experiments. No differences (P less than .05) in FC, BW, and FE were observed from 0 to 3 or 3 to 6 wk. None of the birds showed any signs of deficiency during the experimental period. No differences were observed in SM, number of eggs laid, and BW at 24 wk. It was concluded from these experiments that SCWL pullets do not require more than 25.1 mg/kg niacin furnished by the corn and soybean meal diet from 0 to 6 wk.

Animal Feed↗

PubMed1992

Research note: effect of removing salt from the diet of broiler breeder hens.

Two 28-day experiments were conducted utilizing 75-wk-old Arbor Acres broiler breeder hens to determine the effect of removing salt from the diet. Birds in Experiment 2 had been force-rested at 60 wk of age but were in production (65% hen-day) at experiment initiation. All hens received a corn-soybean meal diet either with or without added salt. Egg production was significantly reduced in both experiments by the end of the 4th wk for birds fed the diet with no added salt. However, egg production did not cease in hens receiving the diet with no added salt. Egg weights from hens receiving the diet with no added salt were significantly reduced by the end of Week 2 in Experiment 1 and Week 3 in Experiment 2. Specific gravity was only intermittently affected by dietary salt removal. Birds receiving no added salt lost 541 and 580 g in Experiments 1 and 2, respectively. Birds receiving added salt diets gained 55 and 23 g in Experiments 1 and 2, respectively. Removing salt from the diet was not an acceptable method of force-resting broiler breeder hens.

Animal Feed↗

PubMed1992

The effects of dietary protein level on the reproductive performance of bobwhite hens.

Two experiments were conducted to evaluate the protein requirement of adult bobwhite quail. Flight-type quail were used in one experiment and meat-type quail in the other. Corn and soybean meal diets containing 12, 15, 18, 21, and 24% protein were fed. Increasing the protein level of the diet from 12 to 15% significantly increased egg production with the flight-type bird. However, only a nonsignificant increase in egg production was obtained with the meat-type birds when the protein level was increased to 15%. Higher levels of protein did not result in further increases in egg production in either strain. Increasing the protein from 12 to 18% (flight) or 21% (meat) resulted in increased egg weight. Egg mass of flight-type hens receiving 18 and 21% protein was significantly greater than egg mass from hens receiving 12 and 15% protein. Hatch of fertile eggs, hatch of total eggs, chick weight, or weight of adult birds were not affected by protein level. Feeding the 12% protein diet resulted in significantly reduced fertility in the flight-type birds but not in the meat-type birds.

Animal Feed↗

PubMed1992

Research note: a lack of response to pantothenic acid supplementation to a corn and soybean meal broiler diet.

Two 21-day battery studies were conducted to determine whether a corn and soybean meal diet without pantothenic acid supplementation was adequate for growth and feed efficiency of broilers. In each experiment, 64 1-day-old broiler chicks (32 male and 32 female) were assigned to each of six dietary treatments. The basal diet was supplemented with 0, .3, .6, 2.4, 4.8, and 14.4 mg of supplemental pantothenic acid/kg of diet. Each diet in both experiments was fed to eight pens containing four females and four male day-old Arbor Acres broiler chicks. The basal diet contained 22.3% protein and 4.74 mg/kg pantothenic acid by analysis. No improvement in growth or feed efficiency was obtained from any level of pantothenic acid supplementation.

Animal Feed↗

PubMed1991

Response of broiler breeder females to feed restriction below recommended levels. 1. Growth and reproductive performance.

Arbor Acre broiler breeders were used to determine the effects on growth and reproductive performance of quantitative feed restriction below breeder recommended levels. Feed treatments were: 8% above standard (+8%); standard feeding program (STD); and 8 (-8%), 16 (-16%), and 24% (-24%) below standard. Proportional decreases in feed allocation resulted in corresponding decreases in body weight, frequency of double-yolked eggs, and number of days in production. Egg weight, fertility, hatchability, and female mortality to 64 wk of age were not significantly (P greater than or equal to .05) affected by the reduction in feed intake. Shell quality was significantly improved with the -16 and -24% feed treatments. A delay in sexual maturity caused a significant (P less than or equal to .05) decrease in average rate of lay (%hen-day) but not in total settable eggs for treatments -16 and -24% to 64 wk of age.

Animals↗

PubMed1991

Reassessment of pantothenic acid requirement for single comb White Leghorn pullets from 0 to 6 weeks of age and its subsequent effect on sexual maturity.

Two experiments were conducted using a total of 288 Hy-Line W-36 day-old pullets in each experiment. The pullets were randomly assigned to one of the six dietary treatments that consisted 0, .3, .6, .9, 1.8, or 3.6 mg supplemental pantothenic acid/kg of a corn and soybean meal basal diet (4.8 mg/kg). Six replicates of eight pullets per replicate were used per treatment in each experiment. Feed and water were provided for ad libitum access. The pullets were housed in battery brooder pens with raised wire floors. Body weight, body weight gain, average feed consumption per day, total feed consumption, and feed conversion were determined at 3 and 6 wk of age (WOA). The birds were observed for any signs of pantothenic acid deficiency. At the end of a 6-wk experimental period, the pullets previously receiving the diets containing either 0 or 3.6 mg supplemental pantothenic acid/kg of diet were raised to sexual maturity and their age at sexual maturity, body weight at 24 WOA, and average number of eggs per pullet through 32 WOA were measured in both of the experiments. No differences (P greater than .05) in total body weight, body weight gain, average feed consumption per day, total feed consumption, and feed conversion were observed in any of the supplemental pantothenic acid treatments from 0 to 3 and 3 to 6 WOA. None of birds during the experimental period showed any signs of deficiency.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

PubMed1991

Measurements of genetic variation in residual metabolizable energy intake of laying hens.

An experiment was conducted to determine heritability of the residual component of feed consumption. The effect of test period length was also examined to determine the shortest test period that would result in reliable data. Three hundred and thirty-five pedigreed White Leghorn hens were used. The experiment began when the hens were 26 wk of age and lasted for 28 wk. The residual component of energy intake was determined for each hen for time periods of 2, 4, and 8 wk in length. These values were used to determine heritability. Analyses of the data for each period were performed in two steps. A reduced model, without pedigree information, was used to develop a regression model. A complete model was used for analyses of data. The procedure of starting egg mass output measurements 2 days after body weight measurements was more effective than starting records on the same days that body weights were obtained. The partial regression coefficients of ME intake decreased with age. Also the partial regression coefficients of ME on body weight change increased with the length of the test period. The partial regression coefficients of ME on egg mass increased slightly with age. Heritability of ME intake adjusted for metabolic body weight, body weight change, and egg mass output was highest (.567 +/- .186) when the test was calculated by 8-wk periods. However, the range of estimates over time was lowest when made for 4-wk periods.

Animals↗

PubMed1991

Comparison of energy utilization efficiency among six lines of White Leghorns.

Individual records were used of feed consumption, BW, BW change, and egg mass (EM) output during a 4-wk period for 180 hens from six different lines of White Leghorn chickens (30 hens per line). The diet contained 16.45% protein and 2,825 kcal ME/kg. Feed consumption was used to calculate actual ME intake (AcME) for each hen. Multiple regression of AcME was performed with metabolic BW, BW change, and EM production as independent variables. The regression coefficients and the independent variables were then used to calculate the expected ME intake (ExME). The following values were calculated for each hen and were used to compare energy efficiency among the six lines: the residual component of energy intake (RES), defined as the difference between the AcME intake and ExME intake; the relative efficiency ratio (RER), defined as (ExME divided by AcME) X 100 (calculated using the partial regression coefficients of the overall equation); and feed conversion, the ratio of feed consumed to EM. Significant differences among the lines in efficiency of EM produced were observed regardless of the efficiency measurement used. Feed consumption did not indicate differences in RES or RER. A multiple regression equation was derived for each line. Significant differences were found among the six lines in their energy requirements for maintenance and for egg production. These results suggest the possible use of the partial regression coefficients as selection criteria for separately improving maintenance efficiency and egg production efficiency.

Analysis of Variance↗

PubMed1991

Effect of removing salt, sodium, or chloride from the diet of commercial layers.

Two experiments were conducted with Hy-Line W-36 hens. The hens were 45 and 65 wk old at the start of Experiments 1 and 2, respectively. A corn-soybean meal basal diet was used. Four diets were fed for 19 days: 1) control; 2) no added NaCl; 3) no added NaCl with Na supplied as NaHCO3; and 4) no added Na with Cl supplied as CaCl2. All hens were fed the control diet from Day 20 to Day 84. Hens fed a diet without NaCl reached zero production in 9.8 and 13.3 days in Experiments 1 and 2, respectively. Hens fed the diet without Na reached zero production in 10.3 and 13.1 days in Experiments 1 and 2, respectively. Only a few of the hens fed the diets with no Cl reached zero production. Time required for all hens to return to production after returning to control diets were 16.0, 15.7, and 6.0 days for hens receiving no added NaCl, Na, or Cl, respectively in Experiment 1, and 13.2, 15.0, and .6 days in Experiment 2. Molting occurred in 92.7, 77.8, and 24.2% of the hens receiving the no NaCl, Na or Cl, respectively, in Experiment 1, and 80.0, 72.5, 30% in Experiment 2. Mortality rates were 7.5, 12.5, 20.0, and 5.0% for the hens receiving diets with no NaCl, Na, Cl, or control, respectively, in Experiment 1, and 2.5, 10.0, 20.0, and 0% in Experiment 2.

Animals↗

PubMed1991

Specific gravity of eggs and eggshell weight from commercial layers and broiler breeders in relation to time of oviposition.

Eggs were collected from 1 day of production of Hy-Line W36 commercial egg production hens 55 wk old. Also, eggs were collected from 1 day of production of Arbor Acres broiler breeder hens when they were 40 and 55 wk of age. The eggs were immediately weighed (EW) after collection and specific gravity (ESG) determined. The eggs were then broken and the contents removed. Shells were washed, air dried, and weighed. The weights of shells (ESW) were calculated using the following formulas: Broiler breeder ESW = 1.9128 x EW - 1.9741 EW/ESG and layer ESW = 1.9140 EW - 1.9754 EW/ESG. Shell density (ESD) was calculated using a modification of this formula. Egg weights of both commercial layers and broiler breeders were heaviest in the early morning. There was a steady decline in EW until 1545 h; EW increased thereafter. Specific gravity of eggs was highest in the morning, declined until 1245 h, and then increased thereafter. Shell weight was also highest in the morning, declined until 1245 h, and then increased thereafter. The calculated and measured ESW were highly correlated. The ESD was 2.147 and 2.160 for the commercial layers and broiler breeders, respectively.

Animals↗

PubMed1990

Reassessment of riboflavin requirement for single comb White Leghorn pullets from 0 to 6 weeks of age fed on maize-soyabean meal diets and its subsequent effect on sexual maturity and egg production.

1. Two experiments were conducted using a total of 228 Hyline W-26 1-d-old pullets in each experiment. The purpose of the study was to reassess the riboflavin requirement from 0 to 6 weeks of age (WOA) and its subsequent effect on sexual maturity and egg production using a maize-soybean meal diet. 2. Approximately 10% incidence of curly toe paralysis was observed among birds fed on the diet with no added riboflavin (1.5 mg total riboflavin/kg diet). 3. Applying the non-linear regression model to the body weight gain data at 3 and 6 WOA in both the experiments, it was found that the minimum total riboflavin required to achieve maximum body weight gain for the two age periods was 2.3 and 2.0 mg/kg of the total diet. This is equivalent to 5.0 and 5.7 micrograms riboflavin/g of body weight gain from 0 to 3 and 3 to 6 WOA respectively. 4. Birds fed on the diet containing no added (1.5 mg total/kg) riboflavin laid fewer eggs and had lower body weights at 24 weeks. 5. We conclude that, from 0 to 6 WOA, at least 2.3 mg total riboflavin/kg should be present in the diet to prevent curly toe paralysis, obtain the maximum body weight gain and sustain the subsequent performance at sexual maturity.

Animal Feed↗

PubMed1990

Some observations on the influence of vitamin D metabolites when added to the diet of commercial laying hens.

Three experiments were conducted to study the influence of two vitamin D3 metabolites on the performance of commercial laying hens. In Experiment 1, adding of .75, 1.50, 3.00, and 4.50 micrograms of 1 alpha-hydroxycholecalciferol (1 alpha-OHD3) or of 1,25-dihydroxycholecalciferol [1,25-(OH)2D3] per kg to the diet containing 2,200 ICU of vitamin D3 from 55 micrograms of cholecalciferol per kg of diet resulted in increased plasma calcium (Ca) and phosphorus (P). The response was greater from the 1,25-(OH)2D3 metabolite than from the 1 alpha-OHD3 metabolite. Neither metabolite affected tibia breaking strength (TBS), egg production (EP), egg weight (EW), feed consumption (FC), feed conversion, eggshell quality (ESQ), fertility, or the hatchability of eggs or the tibia ash (TA) of the day-old chick. In Experiment 2, the EP, EW, FC, ESQ and TA of the hens were not affected when 1.5 micrograms of 1,25-(OH)2D3 were added to each kilogram of a corn-soybean meal diet containing either .38 or .43% P with adequate vitamin D3. Adding the 1,25(OH)2D3 metabolite to the low-P diet reduced plasma Ca and increased TBS. However, adding 1,25-(OH)2D3 to the high-P diet increased plasma Ca and P. In Experiment 3, the EP, ESQ, FC, and TA of the hens were significantly lower when the diet contained 2.04% Ca rather than 3.04% Ca. Plasma Ca and P, EW, or TBS were not affected by the dietary Ca. Neither the plasma Ca and P, EP, EW, ESQ nor the TBS and TA were influenced by adding the 1,25-(OH)2D3 metabolite to either diet.

Animal Feed↗

PubMed1990

Niacin requirement of broiler chickens fed a corn-soybean meal diet from 1 to 21 days of age.

Four experiments were conducted to determine the niacin requirement of broiler chicks fed a corn-soybean meal diet from 1 to 21 days of age. Day-old, feather-sexed, broiler chicks (1,408) were used. The unsupplemented basal diet of corn and soybean meal contained 21 mg of niacin per kg and .29% tryptophan, by calculation, and 25 mg of niacin per kg, by analysis. Eight pens and 6 pens, with 8 chicks per pen, were fed 0, 3, 6, 12, 33, and 66 mg of supplemental niacin per kg of diet in Experiments 1 and 2, respectively. Ten pens and 6 pens, with 8 chicks per pen, were fed 0, 3, 6, 12, and 15, and 0, 3, 12, 33, 66, and 132 mg of supplemental niacin per kg of diet in Experiments 3 and 4, respectively. The birds were weighed at 3 wk of age, and feed intake was determined. At the end of each experiment, each bird was evaluated for leg disorders. Using a two-phase regression analysis of the four experiments combined, a minimum requirement of total niacin (basal by analysis, plus supplemental) of 32 mg per kg of diet was found to be adequate in order to maximize broiler performance at 21 days of age.

Animal Feed↗

PubMed1990

Conversion of tryptophan into niacin in the turkey (Meleagris gallipavos).

Using Nicholas Large White turkey poults from 1 to 21 days of age, two experiments were conducted to measure the conversion of tryptophan into niacin. In Experiment 1, the dietary treatments were 0, 6, and 12 mg of supplemental niacin and 0, 150, 300, 450, and 1,000 mg of supplemental L-tryptophan per kg of diet, respectively. In Experiment 2, the niacin treatments were the same as in Experiment 1, but the L-tryptophan levels were 0, 150, 300, 450, 600, 800, 1,000, and 1,500 mg per kg, respectively. In both experiments, the diets used were based on corn and soybean meal. By analysis, the basal diet contained 29.6% crude protein, .35% tryptophan, 23 mg per kg of niacin, and 4.7 mg per kg of pyridoxine. Using Finney's slope ratio procedure, conversions were obtained of 103:1 (tryptophan:niacin) and 119:1 for Experiments 1 and 2, respectively. These results indicated the consistent, although inefficient, role of tryptophan as niacin precursor in turkeys fed a practical diet, compared with the reported conversion in other species.

Animal Feed↗

PubMed1990

An evaluation of a stepdown amino-acid feeding program for commercial pullets to 20 weeks of age.

Two experiments were conducted to study the use of a feeding program based on dietary amino-acid levels for commercial egg-production replacement pullets from 8 to 20 wk of age. HyLine W-36 pullets were used in Experiment 1; and HiSex White pullets were used in Experiment 2. All pullets were fed a starter diet calculated to contain 21% CP for the first 8 wk of age. From 8 to 20 wk of age, they were fed 10 series of diets calculated to provide various levels of TSAA, lysine (Lys), tryptophan (Trp), and arginine (Arg) at various ages. The levels of each of these amino acids were lowered every 2 weeks. The following levels of amino acids, based on calculated values suggested for corn and soybean meal, were found to be adequate from 8 to 20 wk, with linear reductions at biweekly intervals: .54 to .42% TSAA (.28 to .21% methionine), .64 to .48% lysine, .18 to .14% tryptophan, and .96 to .78% arginine.

Amino Acids↗

PubMed1990

Conditions necessary for a response by the commercial laying hen to supplemental choline and sulfate.

An experiment was conducted with commercial laying hens, 24 wk of age, to study the response from adding 440 mg of choline and sulfate as 2 g of K2SO4 per kg of a corn soybean-meal diet containing different levels of supplemental DL-Met. The basal diet was formulated to be deficient (.495%) in sulfur amino acids, and nonsulfate forms of trace minerals were used in all diets. The experiment was conducted for 22 wk; however, only the data from the last 12 wk were used as the measurement of response since the responses were greatest during this period. Egg production, egg weight, and feed efficiency were improved with each addition of Met from 0 to .2%. Choline supplementation of the diet containing added .033% Met significantly increased egg production. However, no response was obtained from choline supplementation of diets containing 0 or .067% added Met. Addition of sulfate improved egg production when it was added to the diet with choline but not when it was added to the diet with Met.

Animal Feed↗

PubMed1990

Influence of synthetic sodium aluminosilicate on laying hens fed different phosphorus levels.

Two 28-day experiments were conducted utilizing 360 and 180 Leghorn-type hens, 60 and 40 wk of age in Experiments 1 and 2, respectively. In both experiments, a corn-soybean meal basal diet containing no supplemental P was formulated. Dicalcium phosphate was added to the basal diet to supply 0, .05, and .13% supplemental P in Experiment 1 and 0, .13, and .35% supplemental P in Experiment 2. In both experiments, diets were fed with 0 and .75% synthetic sodium aluminosilicate (SAS). The basal diet was calculated to contain .30% P. In Experiment 1, egg production was significantly increased by the addition of .13% supplemental P. When SAS was added to each diet, a decline in egg production and feed consumption was observed. Egg specific gravity increased and egg weight decreased in the presence of SAS. In Experiment 2, egg production was significantly depressed by SAS in the absence of supplemental P and returned to normal with supplemental P. Feed consumption was significantly depressed by adding SAS to diets containing 0 to .13% supplemental P but not to diets containing .35% supplemental P. Egg weight decreased and specific gravity increased when SAS was supplemented to the diet. Data from these two experiments indicate that adequate P intake is advised when using SAS because feed consumption, egg production, and egg weight were decreased in the presence of SAS.

Aluminum Silicates↗