Showing papers in "Canadian Journal of Animal Science in 1967"
TL;DR: The effects of both days dry and days open on production were largely of an environmental nature, indicating that adjustment of milk yield for the number of days cows are open could lead to more accurate selection of dairy animals.
Abstract: The effect of days dry and days open on first, second and later lactation production was examined by intra-sire-herd-season regression. Neither variation in days dry nor days open accounted for more than 1% of the within-sire variance in fat test. Variation in preceding days dry accounted for 4.8% of the within-sire variance in milk production in second lactations but only 0.6% of the variance in later lactations. Differences in days open accounted for 4.5, 3.5, and 4.5% of the intra-sire variance in milk production in first, second, and later lactations, respectively. The effects of days dry and days open on fat production were, in all cases, slightly less than the effects on milk production. Heritabilities for both traits were low, indicating that the effects of both days dry and days open on production were largely of an environmental nature. Adjustment of milk yield for the number of days cows are open could lead to more accurate selection of dairy animals.
44 citations
TL;DR: Hydrogen balance was not significantly affected by treatment, but urinary ammonia excretion was significantly (P < 0.01) higher for the heifers fed high potassium, but water consumption and urine volume were significantly higher when the low potassium ration was fed.
Abstract: Balance studies were conducted with heifers weighing between 210–258 kg to determine effects of different dietary potassium levels, 156.6 (low), 439.4 (medium) and 1,086.8 (high) meq upon nutrient utilization. The low potassium ration produced an average negative potassium balance of 25.2 meq daily, while the other rations produced positive potassium balances. Urinary potassium excretion was markedly affected by potassium level while fecal potassium excretion was much less affected: in general, the higher the potassium intake, the higher the urinary and fecal potassium excretions. All heifers were in positive sodium balance and dietary level of potassium did not significantly influence either urinary or fecal excretion of sodium. Nitrogen balance was not significantly affected by treatment, but urinary ammonia excretion was significantly (P < 0.01) higher when the low potassium ration was fed. Water consumption and urine volume were significantly (P < 0.01) higher for the heifers fed high potassium, but w...
24 citations
TL;DR: The inhibitive effect of avidin was partially reversed by adding extra biotin, which suggests that the role of biotin in cellulose digestion and volatile fatty acid production by rumen microorganisms is underestimated.
Abstract: Four experiments, designed to study the role of biotin in cellulose digestion and volatile fatty acid production by rumen microorganisms, were conducted. These included trials to measure the effects of deletion of biotin from the fermentation medium, the addition of biotin antimetabolites to the medium, and the inclusion of metabolic intermediates on cellulose digestion and volatile fatty acid production.Omission of biotin from the medium markedly decreased cellulose digestion and volatile fatty acid production. Production of propionate was decreased approximately twice as much as was the production of acetate.Inclusion of the antimetabolite, desthiobiotin, at concentrations up to 0.47 mM had no effect, but 12 units of avidin per tube resulted in decreased cellulose digestion and reduced volatile fatty acid production. The latter effects were similar to those observed when biotin was omitted from the medium. The inhibitive effect of avidin was partially reversed by adding extra biotin. This suggests that ...
13 citations
TL;DR: It was concluded that digestible energy is the best practical measure of dietary energy utilization, due to the low degree of variability and ease of determination.
Abstract: Level of feed intake, ranging from a maintenance level to ad libitum had no effect on digestible, metabolizable or net energy for production values when a practical diet was fed to weanling pigs in two feeding trials. The relationship between energy retention and energy intake was linear above maintenance. It was concluded that digestible energy is the best practical measure of dietary energy utilization, due to the low degree of variability and ease of determination.A negative linear relationship between crude carcass fat and carcass moisture content was observed. At energy equilibrium, the pigs in both trials gained 0.09 kg per day. Pigs required 166.83 Wkg0.75 kcal and 137.41 Wkg0.75 kcal of metabolizable energy per day to maintain energy equilibrium m the two trials.
12 citations
TL;DR: A calorie-lysine ratio of 4000-kcal digestible energy per kg per unit percentage lysine was shown to be adequate for maximum efficiency of feed utilization, but a ratio of at least 3500:1 was needed for maximum gains.
Abstract: Three experiments, each of 6 weeks duration, were conducted with 23-day-old pigs averaging 5.9 kg initial weight. Three and four successive 0.2% additions of L-lysine to a 0.45% lysine, 14.2% protein basal diet improved feed consumption, gain, and the efficiency of feed and energy utilization. Adding 5% fat to the diets resulted in greater responses in gain and feed intake and conversion with male than with female pigs. No difference was observed between Yorkshire and Lacombe × Yorkshire pigs. A calorie-lysine ratio of 4000-kcal digestible energy per kg per unit percentage lysine was shown to be adequate for maximum efficiency of feed utilization, but a ratio of at least 3500:1 was needed for maximum gains.Metabolism trials were conducted when pigs were 5 and 9 weeks of age. Supplemental lysine increased the digestibility of lysine and the retention of nitrogen. The nitrogen digestibility improved with age of both sexes, but lysine digestibility improved with aging of the male pigs only. More energy and n...
11 citations
TL;DR: It was concluded that the most effective treatment for cattle suffering from "sweetclover disease" was the intravenous administration of vitamin K1 as a single massive dose of 2000 mg, which restored prothrombin times to near normal within 24 hours, with a minimum subsequent rebound.
Abstract: Oral vitamin K3 was found to be a moderately effective antagonist to dicoumarol in cattle. Given as single massive doses, however, vitamins K1 (intravenous) and K3 (oral) displayed high antidotal properties, although vitamin K3 was much less effective. It was concluded that the most effective treatment for cattle suffering from "sweetclover disease" was the intravenous administration of vitamin K1 as a single massive dose of 2000 mg. This restored prothrombin times to near normal within 24 hours, with a minimum subsequent rebound. A less effective but still useful antidote was a massive oral dose of 5000 mg of vitamin K3.
9 citations
TL;DR: Three Brahman (B) bulls were mated with Hereford (H), Angus (A) and Shorthorn (S) cows and the F1 progenies were evaluated for beef production in comparison with grade Hereford cattle under range conditions in southeastern Alberta.
Abstract: Three Brahman (B) bulls were mated with Hereford (H), Angus (A) and Shorthorn (S) cows and the F1 progenies were evaluated for beef production in comparison with grade Hereford cattle under range conditions in southeastern Alberta. The crossbred heifers were mated with Hereford bulls, as were their -Brahman female progenies. Calves were weaned on November 1 at 6 to 7 months of age.Each of the three Brahman-sire progeny groups, numbering 12, 6 and 146 calves born, averaged higher than contemporary Herefords in performance.B × A and B × S cows surpassed all other groups in weaned calf crop percentage. Hereford calves were lighter than F1 and heavier than -Brahman calves at birth. Breeding-group means and standard errors for weaning weight were (a) Generation 1: Hereford, 155 ± 2.2; B × H, 165 ± 2.4; B × A, 176 ± 2.9; and B × S, 175 ± 3.2 kg; (b) Generation 2: Hereford, 150 ± 2.7; H × (B × H), 184 ± 2.2; H × (B + A), 191 ± 2.4; and H × (B × S), 195 ± 2.6 kg; and (c) Generation 3: Hereford, 152 ± 3.8; H × [H ...
9 citations
8 citations
TL;DR: Uncooked crambe meal significantly depressed feed intakes and gains and heating by any method tested resulted in significant improvement, but feeding value remained below that of the casein-soybean protein control diet.
Abstract: Solvent-extracted crambe meal, uncooked, dry-heated, autoclaved or steam-stripped, was fed as 0, 5 or 10% of the diet to weanling mice. Ground rapeseed (1% of the diet) was fed in a cross-treatment as a source of myrosinase.Uncooked crambe meal significantly depressed (P < 0.05) feed intakes and gains. Heating by any method tested resulted in significant improvement, but feeding value remained below that of the casein-soybean protein control diet. The addition of the myrosinase source had little effect.In a second experiment, ground seed of crambe, rape and camelina (Crambe abyssinica Hochst., Brassica napus L. and Camelina sativa Crantz) were compared as myrosinase sources when incorporated 1:4 into cooked crambe meal and allowed to react overnight at room temperature with 0 or 30% moisture in the mixture. After this enzyme treatment, half of each mixture was autoclaved to destroy myrosinase prior to ration mixing and feeding.Appreciable hydrolysis of thioglucosides occurred in vitro at 30% moisture, res...
8 citations
TL;DR: Two trials involving a total of 120 Yorkshire SPF swine were conducted to evaluate the effect on live performance and carcass characteristics of replacing supplemental protein from 44% soybean meal with that from raw ground soybeans (RGS).
Abstract: Two trials involving a total of 120 Yorkshire SPF swine were conducted to evaluate the effect on live performance and carcass characteristics of replacing supplemental protein from 44% soybean meal (SM) with that from raw ground soybeans (RGS). Levels of 10.80, 16.45 and 22.15% RGS in the grower diets caused slower growth rates and reduced feed efficiency compared with those of pigs that did not receive RGS in their diets (P < 0.05). Although the results were not as consistent as in the grower phase, levels of 11.25 and 15.15% RGS in the finisher diets caused slower growth rate. Pelleting of a diet containing 3.65% RGS resulted in improved feed efficiency compared with that of the same diet unpelleted, when fed in the grower phase (P < 0.05). The area of the loin eye muscle tended to become smaller as the level of RGS in the diet increased. Treatment had no consistent effect on the other measures of carcass quality studied.
8 citations
TL;DR: In this article, 15 rations formulated by a factorial arrangement of 3 fat and 5 protein treatments were fed to non-castrate crossbred pigs from 3 to 9 weeks of age.
Abstract: Fifteen rations formulated by a factorial arrangement of 3 fat and 5 protein treatments were fed to non-castrate crossbred pigs from 3 to 9 weeks of age. Levels of 0, 4, and 8% fat and 12, 16, and 20% crude protein, and 12 and 16% crude protein with supplemental lysine and methionine to equal that present in the 20% protein diet were fed. Each increment of protein resulted in increased rate of gain. The amino acid supplemented 16% protein ration supported as rapid gain and as efficient utilization of feed as did the 20% ration. Feed intake and efficiency of feed utilization were improved as protein was raised from 12 to 16% and when lysine and methionine were added to the rations. Fat levels were not found to affect rate of gain, feed intake or efficiency of feed utilization. Apparent digestibility of nitrogen was higher in the 20% protein ration than the 12 or 16% protein rations and was also found to increase when amino acids were added to the low protein rations. More of the apparent digestible nitroge...
TL;DR: In this paper, the performance of breeder turkeys fed rations containing 10% of prepress-solvent rapeseed meal was compared with breeders fed an iso-caloric and iso-nitrogenous control ration without rapingeed meal.
Abstract: Two experiments were conducted in which the performance of breeder turkeys fed rations containing 10% of prepress-solvent rapeseed meal was compared with breeders fed an iso-caloric and iso-nitrogenous control ration without rapeseed meal. The results obtained indicated that substitution of 10% of rapeseed meal for other protein supplements in a turkey breeding ration had no adverse effects on mortality, rate of egg production, fertility, hatchability, or market quality of breeders at the end of the breeding season. The use of rape-seed meal resulted in an increase in the amount of feed required to produce a dozen eggs in the first experiment, but had no effect on feed efficiency in the second experiment. Amino acid distribution in the ration containing rapeseed meal was similar to that in the control ration.
TL;DR: Values of RSE increased with increasing values of the genetic correlation, but for any given value of the Genetic correlation, RSE was inversely related to the heritability of the basic trait.
Abstract: The relative selection efficiency (RSE) of direct selection for a trait of basic interest and indirect selection on an alternate trait was examined with consideration given to several population sizes, selection intensities and genetic parameters. Slaughter of litter samples resulting in a reduction of the population available for selection was associated with the direct but not the indirect selection procedure. Values of RSE increased with increasing values of the genetic correlation, but for any given value of the genetic correlation, RSE was inversely related to the heritability of the basic trait. Population size was important only for herds comprising fewer than 10 breeding females.Using predicted percent yield of lean cuts, (A), as the trait for direct selection with of 0.2, 0.3 and 0.4 and the live back fat probe, (B), as the trait for indirect selection, with and assuming a genetic correlaton between A and B of 0.6, it was demonstrated that, respectively 38, 19 and 9% faster genetic gains in the b...
TL;DR: Destruction of myrosinase by any method of heating resulted in significantly better feeding value of camelina meal, but steam stripping was superior to dry heating or autoclaving.
Abstract: Camelina seed was ground, solvent-extracted, and fed at levels of 0, 5, 10, 15, 20 and 25% of the diet to weanling mice. Licorice (0 and 0.025%) was tested as a cross-treatment to modify flavor. Levels up to 10% resulted in no adverse effects on growth of mice but each increase in level beyond 10% resulted m a significant (P <.05) reduction in gains and feed intakes. Licorice was ineffective.In a second experiment 20 to 22% of camelina meal was fed m all diets. Raw meal was compared with dry-heated meal (12 hours, 135 °C), autoclaved meal (15 min, 1.2 kg/cm2), steam-stripped (2 hours, 110 °C) and a casein–methionine–supplemented control diet. In each case, four myrosinase-source supplements were added: nil, crambe seed, rapeseed, and camelina seed (Crambe abyssinica Hochst., Brassica napus L., and Cameline sativa Crantz).Destruction of myrosinase by any method of heating resulted in significantly better feeding value of camelina meal, but steam stripping was superior to dry heating or autoclaving.It was c...
TL;DR: Fecal soap excretion was affected very little by dietary unsaturated fatty acids, but stearic acid proportion of fecal soaps increased as the level of dietary uns saturated fatty acids increased, suggesting that hydrogenation of C-18 polyethnoid fatty acids was occurring.
Abstract: Two metabolism experiments were conducted with rumen-fistulated sheep to study effects of increasing dietary levels of unsaturated fatty acids upon ration digestibility and rumen-fluid volatile fatty acids. Apparent digestibility of ration components was not significantly (P > 0.05) affected by diet. However, crude fat digestibility values, which include fecal soap excretion, were 11–19 digestion units lower than comparable ether extract values. When diets high in unsaturated fatty acids were fed, the rumen and fecal levels of these acids were lower than dietary levels, suggesting that hydrogenation of C-18 polyethnoid fatty acids was occurring. Fecal soap excretion was affected very little by dietary unsaturated fatty acids, but stearic acid proportion of fecal soaps increased as the level of dietary unsaturated fatty acids increased. The ratios of acetic to propionic acid gradually decreased as the unsaturated fatty acids of the ration increased in one experiment, but in the other experiment no consiste...
TL;DR: The fat-free moisture content of boneless beef from the rib, chuck, and round sections of Holstein-Friesian steer carcasses averaged 76.1% and was practically constant in specific carcass cuts from animals ranging from 9 to 22 months of age.
Abstract: The fat-free moisture content of boneless beef from the rib, chuck, and round sections of Holstein-Friesian steer carcasses averaged 76.1 ± 0.6%. This value was practically constant in specific carcass cuts from animals ranging from 9 to 22 months of age and in samples ranging from 2 to 50% fat. Therefore, the fat content of boneless beef was estimated with a high degree of precision from the equationwhen only the moisture and the fat-free moisture content of the sample were known. When this equation was used to estimate the fat content of boneless rib, chuck, and round cuts from 72 carcasses, average fat values of 33.8 ± 1.0, 20.8 ± 0.9, and 8.1 ± 0.4 respectively were obtained. These values were 33.8 ± 1.0, 21.0 ± 0.9, and 8.1 ± 0.4 respectively when fat was determined by the Soxhlet ether extract method.
TL;DR: In this paper, the effects of varying nitrogen fertilizer application rates to grass on the intake and digestibility of mature grass hays were investigated with wethers and showed that nitrogen fertilizer rates had little effect on dry matter intake.
Abstract: Conventional digestion experiments were conducted with wethers to determine the effects of varying nitrogen fertilizer application rates to grass on the intake and digestibility of mature grass hays.Nitrogen fertilizer rates had little effect on dry matter intake.The apparent digestibility of crude protein increased and that of dry matter and nitrogen-free extract decreased linearly (P < 0.01) with increasing nitrogen fertilizer rates.The mean dry matter intake was greater (P < 0.01) per unit body weight and less (P < 0.01) per unit metabolic body size (wt. 0.75) than that previously reported for concurrent digestion experiments with steer calves fed these forages. The apparent digestibility of the dry matter, crude protein, crude fiber, and nitrogen-free extract was less (P < 0.01) in wethers than in steers. There were no significant interactions of species × nitrogen rates for intake and nutrient digestibility.
TL;DR: Values of i for boars were larger than for sows and responded in greater degree to the changes in population size associated with variations in herd size and number of pigs surviving to breeding age in each litter, which decreased population size and reduced the opportunity for selection.
Abstract: Selection intensities appropriate to pig breeding operations were examined in relation to variations in structure and size of herd, level of testing, and generation interval. Values of i for boars were larger than for sows and responded in greater degree to the changes in population size associated with variations in herd size and number of pigs surviving to breeding age in each litter.In closed herds with a boar: sow ratio of 1: 5, relatively little improvement in resulted from increasing the size of breeding unit beyond four boars and 20 sows. However, increasing the number of sows bred to each boar resulted in a substantial improvement in selection intensity. The reduction in litter size associated with litter testing for carcass evaluation decreased population size and reduced the opportunity for selection.Application of these findings in relation to herd and breed improvement is discussed.
TL;DR: In this paper, the effects of shell fractures on the large end and equatorial areas of the shell were evaluated when stored for different periods under an atmosphere of air or nitrogen, and the results showed that the location of this type of crack did not appear to be important.
Abstract: Several experiment were conducted to study the effect of shell fractures on the hatchability of chicken eggs. The effects of patching "hairline" and "basket" shell fractures on the large end and equatorial areas of the shell were evaluated when stored for different periods under an atmosphere of air or nitrogen.Hatchability of eggs with "basket" cracks was enhanced by patching with plastic adhesive tape and storage in a nitrogen atmosphere. "Basket" cracks located in the equatorial area of the shell exhibited a more detrimental effect on hatchability than similar cracks in the large end of the egg.There was no apparent advantage in patching eggs with "hairline" cracks. The location of this type of crack in the shell did not appear to be important. Improved hatchability was obtained by storage of eggs with hairline cracks in a nitrogen atmosphere, compared with storage in air.A limited comparison of different patching materials was made; plastic adhesive tape, paraffin wax and a collodion material were use...
TL;DR: Bull calves fed a high-plane ration (two-thirds grain and one-third hay), for 168 days in a feedlot, compared with similar calves feeding a low- plane ration (hay only), had average daily gains (ADG) that were appoximately 2.1 times greater than when the rations were individually fed and 1.8 times greater when they were group-fed.
Abstract: Bull calves fed a high-plane ration (two-thirds grain and one-third hay), for 168 days in a feedlot, compared with similar calves fed a low-plane ration (hay only), had average daily gains (ADG) that were appoximately 2.1 times greater when the rations were individually fed and 1.8 times greater when they were group-fed. ADG of calves grazing for 168 days after they had been fed the low-plane ration in a feedlot surpassed that of calves that had been fed the high-plane ration by 1.7 times when individually fed and 1.9 times when group-fed. Animals group-fed the low-plane ration, however, did not compensate fully for their lower feedlot gains; their ADG to 18 months (685 g) remained significantly less than that (735 g) of those group-fed the high-plane ration. In the feedlot, gains of group-fed calves were significantly greater than those of calves individually fed the high- (998 vs. 830 g) and low- (567 vs. 494 g) plane rations.Calves on the individually-fed, high-plane ration consumed about 75% as many k...
TL;DR: Shorthorn heifers were bred to calve either at 24 months or at 36 months, and feeding meal during the second wintering period significantly increased the weights of the cows by 57 kg at the end of the treatment.
Abstract: Shorthorn heifers were bred to calve either at 24 months or at 36 months. During the wintering period when they were between 18 months and 2 years of age, they were fed either hay and grass silage or the same roughage with.5 kg of concentrate per 100 kg liveweight.Calving at 2 years of age significantly decreased the body weight of the cows by 88 kg at the age of 30 months, and by 54 kg at 42 months, as compared with calving for the first time at 3 years of age. By the time the cows were years old, the difference had diminished to a non-significant level of 28 kg. These differences in bodyweight were not explainable by different number of calvings under the various treatments, or by the culling of lighter cows in certain groups.Feeding meal during the second wintering period significantly increased the weights of the cows by 57 kg at the end of the treatment. The difference decreased to 38 kg 6 months later, and became negligible at subsequent weighings.
TL;DR: It was demonstrated that cell-free extracts of cells grown on acetate contained acetate kinase and phosphate acetyltransferase, plus, as demonstrated by spectrophotometric and isotopic methods, isocitrate lyase and malate synthase which are characteristic of the glyoxylate cycle.
Abstract: When cells of E. coli 64 were harvested in their exponential phase of growth in an acetate medium and incubated aerobically with sodium acetate-2-C14, about 33% of the label appeared in CO2 after 1 hr. Of the radioactivity in the cells, 72% was recovered in the protein hydrolysate, 8% in the nucleic acid, 6% in the lipid and 14% in the ethanol-soluble fractions. The radioactivity in the protein hydrolysate of cells incubated with sodium acetate-2-C14 was approximately 20 times that in the hydrolysate of cells incubated with C14O2 as the carbon source. By spectrophotometric methods, it was demonstrated that cell-free extracts of cells grown on acetate contained acetate kinase and phosphate acetyltransferase, plus, as demonstrated by spectrophotometric and isotopic methods, isocitrate lyase and malate synthase which are characteristic of the glyoxylate cycle. The enzymes of the glyoxylate cycle could not be demonstrated in cell-free extracts of E. coli 64 grown on glucose under either aerobic or anaerobic c...
TL;DR: Bacterial counts on the rumen fluid of two cows fed alfalfa hay revealed the presence of coliform organisms in a concentration in excess of 2% of the total microbial population; diurnal variations were observed in viable coliform counts.
Abstract: Bacterial counts on the rumen fluid of two cows fed alfalfa hay revealed the presence of coliform organisms in a concentration in excess of 2% of the total microbial population. When grain was included in the ration of one of the cows, the viable coliform count was of the order of 2.3 × 109 per ml as compared to a maximum of 4 × 108 per ml when hay alone was fed. However, total microscopic counts were also higher when grain was fed, so that the ratio of viable coliform counts to total microscopic counts was not changed. Diurnal variations were observed in viable coliform counts; the numbers increased immediately after feeding and fell off gradually to the prefeeding level after 10 hours. A culture of a coliform organism was isolated from a 10−8 dilution of rumen fluid from a cow fed alfalfa hay. Based on morphological, cultural, physiological and biochemical characteristics, the organism was identified as Escherichia coli type I, and designated E. coli 64. Under aerobic conditions, E. coli 64 entered the ...
TL;DR: Results indicated that the hatchability of eggs of specific strains was enhanced by storage in nitrogen gas, but the enhancement did not appear to be consistently related to the level of hatchability in a specific strain.
Abstract: Fertile turkey eggs, totalling 592 from two small strains over three bi-weekly hatch-storage periods in trial 1 and 666 from three large strains over one biweekly hatch-storage period in trial 2, were subdivided into two approximately equal groups and each group was subjected to either refrigerated storage or refrigerated storage plus nitrogen gas in a closed environment. Results indicated that the hatchability of eggs of specific strains was enhanced by storage in nitrogen gas. The enhancement in hatchability did not appear to be consistently related to the level of hatchability in a specific strain. The effect of nitrogen treatment in preserving embryonic viability was better in the second than in the first week of storage in one trial only. The interaction of nitrogen treatment with hatches in trial 1 suggested that the effect of nitrogen treatment may be most pronounced when other environmental factors deter embryonic viability.
TL;DR: Cap, at a dosage level of 2.5 mg, administered over a 10-day period to motivate first post-treatment estrus, was more effective when injected intramuscularly than when administered orally, and appeared to be more active in controlling breeding activity.
Abstract: Injected or orally-administered progestagens have been shown to synchronize estrus in mature ewes during their normal breeding season. Oral administration of 6–methyl-17-αα-acetoxyprogesterone (MAP) or 6-chloro-Δ6-dehydro-17-acetoxyprogesterone (CAP) for 10 days was more effective in synchronizing estrus than intramuscular injections of repositol progesterone. CAP appeared to be more active in controlling breeding activity than MAP (2.5 mg CAP per head vs. 60 mg MAP per head). The administration of 2.5 mg CAP per head per day for 18 days was as effective as the feeding of 3.5 mg per head per day for 10 days. CAP, at a dosage level of 2.5 mg, administered over a 10-day period to motivate first post-treatment estrus, was more effective when injected intramuscularly than when administered orally. The administration of Pregnant Mare Serum did not result in an increase of lambing percentage.
TL;DR: The prolonged use of diazoxide in the feed of 65-kg pigs at 40 mg/kg of body weight per day for 4 weeks was at first accompanied by a higher rate of gain, nitrogen retention and urine catecholamine excretion, but these gradually returned to control levels by the end of the experiment.
Abstract: The oral administration of single doses of 20 and 40 mg of diazoxide per kg of body weight to 22.5-kg pigs increased levels of blood glucose and urine catecholamines but had no appreciable effect on plasma-free fatty acid levels. The prolonged use of diazoxide in the feed of 65-kg pigs at 40 mg/kg of body weight per day for 4 weeks was at first accompanied by a higher rate of gain, nitrogen retention and urine catecholamine excretion, but these gradually returned to control levels by the end of the experiment. Diazoxide had a pronounced effect on water retention in the first 2 days of treatment. During this period pigs given the drug excreted 2.6 kg less urine and gained 3.1 kg more in body weight than controls. By the fourth day of treatment urine volume rose to just below control levels and remained there throughout the remainder of the experiment.
TL;DR: In general, half-carcass analysis was considered satisfactory although it was shown that the significance of treatment effects might be missed by sampling the single side in experiments of limited scope.
Abstract: The magnitude of various sources of variation and the effect of half-carcass analysis was studied in an experiment involving chemical analysis of 36 swine carcasses. Although systematic differences among sides were demonstrated, , for 16 of 32 traits studied, the analysis of single sides did not introduce serious bias into results. The efficiency of half-carcass analysis exceeded 90% for most chemical determinations except ash (54% for ham; 83% for carcass). Efficiencies were high also for specific gravities and the conventional carcass measurements, while the efficiency of area tissue measurements in the ham were lower (63–86%). In general, half-carcass analysis was considered satisfactory although it was shown that the significance of treatment effects might be missed by sampling the single side in experiments of limited scope.