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PubMed1980

Efficiency of food utilization during body weight gain in dormice (Glis glis).

During spontaneous body weight gain in dormice, Glis glis, progressive increases in the efficiency of food utilization as defined by weight gain (g)/food intake (g), and parallel increases in mean daily food intake were observed. Towards the end of the weight gain period, there was an abrupt drop in feeding efficiency with no significant change in food intake even when the latter was expressed relative to an index of each animal's "metabolic mass" (body weightkg0.62). Animals whose body weight increases followed a return to ad lib feeding after prolonged food restriction showed marked decreases in feeding efficiency from initially high values which were independent of changes in food intake. These results are discussed in relation to the sliding set point concept of body weight regulation in hibernators.

Animals↗

PubMed1990

Supplemental fat source affects feedlot performance and carcass traits of finishing yearling steers and estimated diet net energy value.

Two trials that utilized 356 yearling steers were conducted to evaluate the effects of fat sources (3.5% of diet dry matter) in steam-flaked milo finishing diets. Fats differed in fatty acid composition and level of free fatty acids. In Trial 1, soybean oil, tallow and yellow grease were compared to a nonfat control. Feeding fat increased (P less than .05) daily gain, feed efficiency, estimated diet NE concentration, carcass weight and dressing percentage of steers. In Trial 2, fat treatments were control, acidulated soybean soapstock (SBSS), tallow, a blend of 70% SBSS:30% tallow, and yellow grease. Feeding tallow or the SBSS:tallow blend improved (P less than .05) feed efficiency and estimated dietary NE compared to control. Proportions of palmitic, stearic, oleic, linoleic and linolenic acid in longissimus muscle of steers were altered (P less than .05) by source of supplemental fat. Potential variability in animal response to fat blends was demonstrated by differences in animal response to yellow grease in the two trials. It was concluded that fats vary in feeding value and may alter carcass composition, contrary to putative thought. Further, potential associative effects of fat blends and interactions of fat with other dietary components in high-grain finishing diets require further investigation.

Animal Feed↗

PubMed1998

Effect of dietary energy level and oil source on broiler performance and response to an inflammatory challenge.

Broiler chicks were fed one of five diets from 3 d of age: a low energy diet containing 7% cellulose (ME 2,714 kcal/kg), or high energy diets containing approximately 7% of either tallow, corn oil, safflower oil, or fish oil (each 3,302 kcal/kg). Half of the chicks were injected intra-abdominally with Salmonella typhimurium lipopolysaccharide (LPS) on Day 11, sephadex on Day 13, and Freund's complete adjuvant on Day 15; samples were collected on Day 16. The uninjected chicks served as controls. In a second experiment, 3-d-old chicks were fed one of eight isocaloric diets containing tallow as the sole supplemental fat source, or tallow plus either 2% corn oil, 1, 1.5, or 2% fish oil, or fish meal at an amount to provide 1, 1.5 or 2% supplemental oil. Half of the chicks were injected intra-abdominally with S. typhimurium LPS on Days 10, 12 and 14; the uninjected chicks served as controls. Samples were taken on Day 15. In Experiment 1, the cellulose diet decreased performance to 10 d of age relative to the other diets, whereas immunogen injection decreased weight gain and feed efficiency and increased indices of inflammation among all dietary groups. Fish oil at approximately 7% of the diet did not improve weight gain. Fish oil diets improved weight gain and feed efficiency in Experiment 2 relative to the other diets, in spite of minimal effects on indices of inflammation. Injection of LPS decreased performance and increased inflammation across dietary treatment, although the second LPS injection was less potent in altering performance responses and inflammation compared to the first injection, indicating that repeated injections of LPS amy cause the chicks to become refractory to that stimulus. The fish meal diets resulted in poorer performance than similar levels of lipid provided as fish oil. Lower levels of dietary fish oil were more efficacious in improving broiler performance than higher levels, and fish oil provided from fish meal was not as efficacious as oil per se, possibly due to nonlipid components of the meal.

Animals↗

PubMed1984

Influence of colostrum preservation and sodium bicarbonate on performance of dairy calves.

Forty-eight Holstein calves were fed one of four liquid diets from 3 to 30 days of age to compare sodium benzoate, propionic acid, and formaldehyde as preservatives for colostrum. Colostrum batches were fermented at temperatures of 20 degrees C or higher. Diets were 2.73 kg of 1) naturally fermented colostrum, or colostrum treated with 2) sodium benzoate (.5% by weight), 3) propionic acid (1.0% by weight), or 4) formaldehyde (.05% by weight). Colostrum diets were diluted with .91 kg water. Prior to feeding, 25 g. sodium bicarbonate was added to liquid diets of one-half the calves on each treatment. Liquid diets were fed once daily. Water and a 15% crude protein complete starter were offered for ad libitum consumption. Calves were weaned abruptly at 30 days of age and received only water and starter from 31 to 44 days of age. Daily gain from 0 to 4 wk and 0 to 6 wk favored calves fed colostrum treated with sodium benzoate or propionic acid. Gains from 0 to 6 wk were .33, .44, .45, and .32 kg/day for the four diets, and feed efficiencies (kg dry matter intake/kg gain) were 3.23, 2.36, 2.76, and 2.89 during the same period. Addition of sodium bicarbonate to colostrum diets improved intake during the 1st wk of feeding. Gain and feed efficiency were similar during wk 0 to 4 but favored slightly calves not receiving sodium bicarbonate during the overall study, wk 0 to 6. Daily gain and efficiencies during wk 0 to 6 were .41 and 2.53 for calves without .36 and 3.01 with sodium bicarbonate added to colostrum diets.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

PubMed1983

Effects of population density on the growth, organ weights, and plasma corticosterone of young broiler chicks.

Two trials were conducted with broiler chicks to determine the effects of population density on the growth, feed efficiency, and several physiological parameters associated with stress in birds. Chicks were brooded in batteries at 116, 232, 348, and 697 cm2/chick. Chicks brooded at 348 cm2/chick grew and utilized feed significantly better than those brooded at 697 cm2/chick during the first week. For maximum growth and feed efficiency, 116 cm2/chick was adequate for the first week; 232 cm2/chick was adequate during the second and third weeks. Increasing cage density significantly decreased percentage heart and spleen weights (g/100 g body weight) and plasma corticosterone at 3 weeks.

Animals↗

PubMed1983

In vitro and in vivo evaluations of the antibiotic efrotomycin.

Experiments were conducted to determine the potential of the antibiotic efrotomycin as a growth permittant for poultry and to further elucidate the mode of action of antimicrobial agents for that purpose. Efrotomycin as the semipurified antibiotic and as fermentation solids demonstrated excellent activity against Clostridium perfringens at .1 to .2 ppm based on suppression of gas production in an anaerobic tube test. Supplementing a soybean protein and sucrose-based diet with levels of 2.2, 11, and 55 ppm of the antibiotic, from the two sources each with two different purities, improved weight gain of chicks an average of 23% and improved feed efficiency an average of 13% at the higher levels (all P less than .01). Computed indexes for each antibiotic treatment, which represent the combined effects of both weight gain and feed efficiency, showed that a maximum response was generally obtained at the 11 ppm level and that the antibiotic as fermentation solids was slightly more active than the semipurified material. Supplementing the soybean protein and sucrose-based diet with levels of 1.1, 5.5, 16.5, and 55 ppm of efrotomycin reduced the numbers of C. perfringens organisms in ileal contents of chicks (all P less than .01). The effects were dose-related. Control chicks in this experiment averaged greater than 7.7 log10 of C. perfringens counts per gram of contents. The results of these experiments show that efrotomycin has excellent growth-permittant activity and the activity correlates with the antibacterial activity against C. perfringens.

Animals↗

PubMed1991

A comparison of three continuous and four shuttle anticoccidial programs.

Continuous programs of a combination of narasin (40 ppm) and nicarbazin (40 ppm) (NaNi), narasin at levels of 60 and 70 ppm, and a 2 by 2 factorial shuttle design (NaNi or nicarbazin at 125 ppm, each for 27 or 28 days, followed by narasin at 60 or 70 ppm to termination), were compared with unmedicated controls for their anticoccidial efficacy and growth performance in nine broiler trials conducted in seven countries outside the United States. Cecal coccidial lesions were reduced only by treatments that incorporated nicarbazin either at the 40-ppm level in NaNi or at 125 ppm, whereas total intestinal lesion scores were reduced by all the anticoccidial programs tested. At Day 28, the three treatments containing NaNi and the treatment containing narasin at 60 ppm significantly improved weight gain and feed efficiencies over the two treatments containing nicarbazin at 125 ppm and the unmedicated controls. At termination all the anticoccidial programs significantly decreased the mortality rate and improved bird weights and feed efficiencies. Birds on the treatments containing NaNi either in the two shuttle programs or in the continuous program were significantly heavier than those on the two treatments containing nicarbazin at 125 ppm in shuttle programs.

Animals↗

PubMed1980

Economic value and course of infection after treatment of cattle having a low level of nematode parasitism.

To determine whether it is economically advantageous to treat calves having inapparent parasitism, we conducted experiments from 1971 to 1976, involving more than 1,800 calves from 30 pens or lots, using formulations of thiabendazole, levamisole, and crufomate (ruelene). Differential egg counts, cultured larvae, and cultured parasitic stages were used to estimate the kind and degree of nematode parasitism. Differentiation of infective larvae consistently established Cooperia as the predominating (%) genus in all fecal samplings. Bunostomum, when initially present, decreased or disappeared, whereas Trichostrongylus increased; other genera fluctuated less consistently. These qualitative generic fluctuations were not primarily the result of treatment, but more likely were seasonal variation. Judged by average daily gain (ADG), anthelmintic treatment was statistically advantageous at one or more points during the observation periods in 10 of 13 treated groups. In seven treated groups, the observation periods were concluded with statistical advantage in ADG, whereas in three groups, compensatory gain by corresponding controls had neutralized earlier advantages. The comparative influence of the various anthelmintics was not consistent from year to year. When total cost/kilogram gain was calculated from feed efficiency measuremnts and other costs, economic treatment advantage was evident in seven of 11 tests (7 of 10 treatment groups) from 1973 through 1976. This financial advantage, due primarily to feed efficiency and noted after 28 to 51 days, justified anthelmintic treatment. This advantage was not likely lost by the animals in subsequent periods (to 218 days) on pasture or in lots, since ADG indicated the treated calves performed either as well as, or better than, the nontreated controls. Considering all aspects of the study, the results indicate calves coming into Kansas from southern states and weighing 184 to 267 kg may possess a level of subclinical (symptomless) nematode parasitism that when treated will result in a response justifying expense for using anthelmintics.

Animals↗

PubMed1990

The nutritional properties of extruded and non-extruded corn fiber isolate.

The feed efficiency and selected organ weights of rats fed diets containing 3 or 7% corn fiber, extruded corn fiber or silica were compared to rats fed a fiber-free diet. No significant differences were found in feed efficiency, spleen, lung or liver weights for any of the treatments relative to the fiber-free control diet.

Animal Feed↗

PubMed1994

Interaction of forage level and monensin in diets for feedlot cattle on growth performance and digestive function.

A feedlot growth-performance trial and a metabolism trial were conducted to evaluate the interaction of forage level (10 vs 20%) and monensin (0 vs 28 mg/kg, air-dry basis) on utilization of a steam-flaked corn-based finishing diet. There were no treatment interactions (P > .10) on feedlot cattle growth performance or site and extent of digestion of OM, ADF, N, and starch. Monensin supplementation did not influence (P > .10) ADG, DM intake, feed efficiency, estimated NE value of the diet, or ruminal and total tract digestibility of OM, ADF, and starch. Monensin decreased (14.5%, P < .10) passage of microbial N to the small intestine and ruminal digestion of feed N (10.4%, P < .05). Ruminal pH tended to be slightly lower (1.9%, P < .10) with monensin supplementation. Monensin did not affect (P > .10) ruminal molar proportions of acetate and butyrate. There was an interaction between forage level and monensin on ruminal molar proportions of propionate. With the low-forage diet, molar proportions of propionate were 9.4% higher with monensin supplementation. In contrast, with the high-forage diet ruminal molar proportions of propionate were 5.5% lower with supplemental monensin. Monensin did not affect (P > .10) estimates of methane production. Decreasing the forage in the diet from 20 to 10% increased ADG (10.8%, P < .10), feed efficiency (11.6%, P < .01), and diet NEg (11.3%, P < .05). Ruminal digestibility of ADF, OM, and starch were not affected (P > .10) by forage level.(ABSTRACT TRUNCATED AT 250 WORDS)

Animal Feed↗

PubMed1998

Feedlot medicine and management. Implants.

Growth-promoting implants have been used extensively in beef production for over 30 years. Significant changes in implants and implanting strategies have occurred. Prior to 1987, available implants were estrogenic agents that metabolically enhanced nutrient use to enhance growth. These products tend to increase intake but significantly improved feed efficiency and daily gains. In 1987, an androgenic (tissue-building) agent, TBA, was approved for use in growth-promoting implants. The androgenic implant enhanced muscle growth without increasing intake, thereby adding an additional 3% to feed efficiency and 3% to 5% to daily gains. Today, implants have become almost "designer" products with varied doses and combinations of estrogenic and androgenic agents. Although implants tend to be most widely used in feedyards, numerous implant strategies are available for use in cattle from the suckling through finishing phases of production. Consistent responses to lifetime programs depend not only on product use but on timing and sequence as well. Lifetime implant programs should be designed to obtain an optimum growth and efficiency response while minimizing expression of live animal side effects and adverse effects on carcass traits. Recent studies suggest that using implants with increasing potency in succession allows for the greatest animal lifetime gain (up to 150 lb) while maintaining or slightly improving postweaning feed conversion when compared with that of nonimplanted cattle. Implant strategies that match implant dose or potency to animal age, weight, and production desired are recommended. Beginning in the preweaning period with low-potency products and ending in the postweaning period with high-potency androgenic-containing implant products which complement the estrogenic response, maintain the positive carry-over effects of previous implants. Implant programs should be designed to maintain hormone blood levels within an optimum response range. Hormone levels below or above this range should be avoided once implant programs are initiated.

Anabolic Agents↗

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↗

PubMed1984

[Influence of the environmental temperature on the metabolic use of dietary energy and nitrogen in the growing rat].

Sixty-seven male rats of the Wistar CF strain were used in two trials to study the effect of ambient temperature on nitrogen and energy balances (experiment 1) and on the variations of certain biochemical parameters of metabolism (experiment 2). In both cases, the rats, housed individually in metal cages and fed ad libitum, were kept under three different temperatures : 21 degrees C (control), 3 degrees C (cold), 31 degrees C (hot). Compared to the controls, the rats at 3 degrees C showed a significant increase (P less than 0.01) in food intake and a significant decrease (P less than 0.01) in daily growth rate and feed efficiency ratio; body fat content was unchanged. Compared to the controls, the rats at 31 degrees C showed a decrease (P less than 0.01) in food intake and growth rate, a better feed efficiency ratio (P less than 0.01) and a significant increase in carcass lipid content. When compared to rats at 21 degrees C, those at 3 degrees C had a much lower nitrogen retention; at 31 degrees C this retention was only slightly lower. The urinary nitrogen excretion, increased by the cold temperature, reflected higher nitrogen catabolism, while its increase at a high temperature was probably due to a decrease in protein synthesis, and a subsequent degradation of excess ingested nitrogen. Energy retention increased (P less than 0.01) as the ambient temperature increased from 3 to 31 degrees C, and wide variations in the amounts of fixed energy in the form of proteins or lipids were observed. The balance results obtained have been discussed in relation to the variations of some biochemical parameters of metabolism such as free fatty acids, free glycerol, lipoprotein-lipase activity and in vitro utilization of labelled glucose.

Animal Feed↗

PubMed1977

Metabolism of gamma-linolenic acid in essential fatty acid-deficient rats.

Female rats were weaned and fed a semipurified diet lacking in essential fatty acids. After 160 days, the deficient diet was supplemented with varying amounts of gamma-linolenic acid. Changes in body weight and feed efficiency were measured. Total liver phospholipid fatty acids were also analyzed. Supplementation with gamma-linolenic acid to the deficient diet for 7 days led to improvements in body weight and feed efficiency of the deficient rats. The liver phospholipid fatty acid composition returned to a normal pattern. There was a reduction of 5,8,11-eicosatrienoic acid and an increase in the arachidonic acid. Thus, there was a fall in the triene: tetraene ratio with increasing dietary supplementation of gamma-linolenic acid. The essential fatty acid potency, the minimum dietary requirement for this fatty acid, and the widely accepted levels of the minimum requirements of dietary essential fatty acids are discussed.

Animals↗

PubMed1983

Tiamulin feed medication for the maintenance of weight gains in the presence of mycoplasmal pneumonia in swine.

Tiamulin, a semisynthetic antibiotic, was fed to growing pigs and its value in maintaining weight gain and feed efficiency in the face of mycoplasmal pneumonia was determined. Four treatments divided among 64 growing pigs from a conventional pig farm were used to test the effects of tiamulin administered in feed at levels of 10, 20 and 30 ppm. All pigs were artificially infected with Mycoplasma hyopneumoniae. Medication was started on the 14th day after infection (d 0) and continued for 28 d (d 0 to 28). Pigs were continued on test for an additional 14-d period for further observation (d 28 to 42) after the medicated feed was withdrawn. Tiamulin fed at 10, 20 and 30 ppm for 28 d did not cure the mycoplasmal pneumonia. The effect of tiamulin on growth performance was not the same for all periods. During the medication period (d 0 to 28), both daily gain and feed conversion were not significantly affected by dietary tiamulin concentrations. For the post-treatment period (d 28 to 42), tiamulin improved daily gain (P less than .05) and feed conversion (P less than .05) over those of nonmedicated controls, and the responses of both daily gain and feed efficiency increased linearly (P less than .05) as dietary tiamulin levels increased.

Animals↗

PubMed1993

Effect of dietary T-2 toxin on biogenic monoamines in discrete areas of the rat brain.

Acute T-2 toxin treatments alter biogenic monoamine concentrations in the brain; however, these perturbations have not been well documented or demonstrated in feeding trials. In this study, the effect of dietary T-2 toxin on regional brain concentrations of biogenic monoamines and their metabolites was investigated in male rats fed a semi-synthetic diet containing 0, 2.5 or 10 ppm T-2 toxin for either 7 or 14 days. Reduction in feed consumption, feed efficiency and weight gain was observed in rats fed either 2.5 or 10 ppm T-2 toxin. This effect was transient in animals fed the 10 ppm T-2 toxin diet, with feed consumption, feed efficiency and weight gain improving significantly during wk 2. T-2 toxin affected brain biogenic monoamine concentrations. In the nucleus raphe magnus, serotonin, 5-hydroxy-3-indoleacetic acid and norepinephrine increased in a dose-dependent manner, and dopamine increased transiently. In the substantia nigra of rats fed 10 ppm T-2, epinephrine increased after 7 days and norepinephrine decreased after 14 days, when compared with controls. Dihydroxyphenylacetic acid concentrations in the paraventricular nucleus and medial forebrain bundle were lower in T-2 toxin-treated rats than in control animals. The observed effects of T-2 toxin on brain monoamines and the resulting neurochemical imbalance may account for the physiological manifestation of trichothecene intoxication.

Administration, Oral↗

PubMed1980

The amino acid requirements of chicks: experimental validation of model-calculated requirements.

The amino acid requirements of broiler chicks, on a weekly or biweekly basis, were calculated according to a model presented previously (Hurwitz et al., 1978). Based on the present results, the model has been somewhat modified. The model requirements provided the basis for computer-designed diets which were fed to chicks of different ages and were composed to others computed on the basis of NRC (1971, 1977) requirements. In all cases the model-based diets, which were considerably lower in protein, supported weight gains equivalent to those obtained on NRC-based diets. The relatively poorer feed efficiency observed in the first trial with chicks fed the model-based diets, could be alleviated by equalizing both energy and lipid concentrations in the experimental diets. Thus, equal growth and feed efficiency were obtained with the model and NRC (1971)-based diets, for 2- to 10-week-old chicks. The possible reasons for the slightly higher abdominal fat content of the chicks fed the model-based diets are discussed.

Amino Acids↗

PubMed1989

Effect of altering nutrient density (concentrate to roughage ratio) and restricting energy intake on rate, efficiency and composition of growing lambs.

Two hundred ninety-eight Rambouillet ewe and wether lambs approximately 9 mo old from Texas were allotted to pens (29 to 30 lambs/pen). Two replicate pens were fed each of five diets. Two methods of restricting energy intake were evaluated: altering nutrient density (55% vs 72.5% vs 90% concentrate levels) and restricting intake of the 90% concentrate pelleted diet (92.5% or 85% ad libitum intake). Daily gains were highest with the 72.5% concentrate level and feed efficiency was poorest with the 55% concentrate diet fed ad libitum. Altering nutrient density did not reduce energy intake because lambs compensated by increasing feed intake at the lower nutrient densities. Actual feed intake was 89.5% of ad libitum for the 92.5% of ad libitum intake level and 84% of ad libitum at the 85% of ad libitum intake level due to refusal to consume some fines from the 90% concentrate diet. Feed refusal was greatest for lambs with ad libitum access to feed. Average daily gain was depressed by 8% at the 85% intake level. However, feed efficiency was improved (P less than .01) by 20% when intake was restricted to 92.5% of the ad libitum intake level. Differences in carcass traits were small, but consistent; carcass fat content was reduced slightly by restricting feed intake at constant slaughter weight.

Animal Feed↗