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PubMed2006

Tiamulin and semduramicin: effects of simultaneous administration on performance and health of growing broiler chickens.

The pleuromutilin antibiotic tiamulin (TIA) is known to produce a variety of negative interactive effects when it is administered in combination with several anticoccidial ionophores. A 35-d growth study was performed in cages to evaluate the compatibility of TIA when it was administered concurrently with the poly-ether ionophore anticoccidial semduramicin (SEM). Tiamulin and SEM, both alone and in combination, were administered to 10 replicates of female broilers arranged in a completely randomized block design. Tiamulin was administered in drinking water (250 mg of TIA/kg of water) from d 15 through 19 of the study, whereas SEM was incorporated in feed (25 mg/kg) from placement to the conclusion of the test. Water consumption was determined during the period of concurrent administration of the drugs and weekly measurements of feed intake and bird performance were recorded. In addition, hematocrit, blood cell counts, serum protein, albumin, glucose, uric acid, electrolytes, and activities of several enzymes were determined from blood samples taken at d 35. Results indicated that simultaneous administration of TIA and SEM during the third week of the trial reduced water and feed intake resulting in a temporary growth depression. Feed efficiency was transiently affected during the period of coadministration. However, during the fourth week of the test, negative effects in body weight were not observed for any treatment and feed conversion improved for birds concurrently receiving TIA + SEM. By the termination of the experiment, no adverse effects were observed in final performance for any treatment. Histopathological and hematological parameters were unaffected by treatment at d 35 of the test. These results demonstrated that simultaneous administration of TIA and SEM produced only temporary impairments of water and feed consumption that transiently influenced performance. Neither mortality nor long-term effects on performance variables occurred in broilers.

Animal Feed↗

PubMed2002

Effects of dietary protein and oathull fiber on nitrogen excretion patterns and postprandial plasma urea profiles in grower pigs.

The objectives of this study were: 1) to determine if dietary protein reduction or oathull fiber inclusion would reduce urinary N excretion in grower pigs, 2) to determine if plasma urea could predict urinary N excretion among diets differing in protein and fiber content with an expected range in N excretion patterns, and 3) to determine the postprandial time point to sample blood for the best prediction. Three dietary protein concentrations (high, 19.7; medium, 16.9; low, 13.8%) and two fiber levels (high, 5.0; low, 3.6% crude fiber) were tested in a 3 x 2 factorial arrangement. Diets (wheat, barley, soybean meal; oathulls as fiber source) were formulated to 3.25 Mcal of digestible energy (DE)/kg and 2.2 g of digestible lysine/Mcal DE for low- and medium-protein diets, and 2.4 g/Mcal of DE for high-protein diets, and supplemented with lysine, methionine, tryptophan, threonine, isoleucine, or valine to meet an ideal amino acid profile. Pigs (32 +/- 3.4 kg; n = 42) were housed in metabolism crates for 19 d. On d 10 or 11, catheters were installed by cranial vena cava venipuncture. Daily feeding allowance was adjusted to 3x maintenance (3 x 110 kcal DE/kg body weight(0.75)), and was fed in two equal meals. Feces and urine were collected from d 15 to 19. Five blood samples were collected in 2-h intervals on d 16 and 19. Fecal, urinary, and total N excretion was reduced linearly with a reduction of dietary protein (P < 0.001); the reduction was greater for urinary (48%) and total N excretion (40%) than for fecal N excretion (23%). Similarly, the ratio of urinary to fecal N was reduced linearly with a reduction of dietary protein (P < 0.001). Retention of N (g/d) was reduced linearly, but N retention as a percentage of N intake was increased linearly with a reduction of dietary protein (P < 0.001). The addition of oathulls did not affect N excretion patterns and plasma urea (P > 0.10). Dietary treatments did not affect average daily gain or feed efficiency (P > 0.10). A dietary protein x time interaction affected plasma urea (P < 0.001). For medium- and high-protein diets, plasma urea increased postprandially, peaking 4 h after feeding, and then decreased toward preprandial levels (P < 0.05). Plasma urea did not alter postprandially for the low-protein diet (P > 0.10). Urinary N excretion (g/d) was predicted by 3.03 + 2.14 x plasma urea concentration (mmol/L) at 4 h after feeding (R2 = 0.66). Plasma urea concentration is indicative of daily urinary N excretion and reduction of dietary protein is effective to reduce total and urinary N excretion.

Animals↗

PubMed1985

Effect of salinomycin level on nutrient digestibility and ruminal characteristics of sheep and feedlot performance of cattle.

A sheep digestion trial and two feedlot trials with cattle were conducted to study effects of an ionophore, salinomycin, on nutrient digestibility, ruminal metabolism and cattle performance. In trial 1, addition of salinomycin at 5.5, 11 or 22 ppm to 60% concentrate diets fed to ruminal-cannulated rams had no effect (P greater than .05) on apparent digestibility of dry matter (DM), organic matter (OM), neutral detergent fiber (NDF), acid detergent fiber (ADF) or starch in comparison with control diets. Apparent nitrogen (N) digestibility was increased (P less than .05) in animals fed salinomycin. Salinomycin did not affect total volatile fatty acid (VFA) concentrations in the rumen, but resulted in a linear (P less than .05) increase in molar proportion of propionate and a linear (P less than .05) decrease in molar proportions of acetate and butyrate and in acetate:propionate ratios. Shifts in VFA proportions were fully expressed within 4 d after salinomycin was added to the diet. In trial 2, salinomycin was added at 5.5, 11, 22 or 33 ppm to 85% concentrate diets fed to finishing steers. Salinomycin level had a quadratic effect (P less than .05) on daily weight gain and resulted in a quadratic (P less than .05) decrease in feed intake with a resultant average improvement of 10.3% in feed efficiency. Salinomycin (5.5, 11, 16.5 or 22 ppm) and monensin (22 ppm) were added to 90% concentrate diets in trial 3 and produced increased rates of gain without affecting feed intake.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

PubMed1981

Orotic aciduria caused by feeding excess lysine to growing rats.

Two 14-day factorial experiments were performed to assess changes in growth, feed intake and urinary orotic acid excretion of weanling male Sprague-Dawley rats. The dietary variables investigated included the percentage of dietary casein in the basal diet, its supplementation with 5% lysine-HCl or 1% arginine-HCl and sucrose or two parts dextrin and one part sucrose as the only form of carbohydrate. The response to 5% supplemental lysine was strikingly similar to that seen with arginine-free diets. With 5% lysine added to 15% casein diets, growth decreased 25% and feed efficiency 20% while orotic acid excretion increased significantly. When 5% lysine was added to diets with 7.5 or 30% casein, these responses were smaller and were prevented by the simultaneous feeding of 1% arginine. Growth depression by lysine was partially reversed by replacing two-thirds of the dietary sucrose with dextrin. When unsupplemented, the casein diets containing only sucrose as carbohydrate supported less growth than the same diets containing the dextrin sucrose mixture. This difference was abolished by supplementation with 1% arginine, suggesting that sucrose increases arginine requirements for optimal growth. The data are consistent with the conclusion that orotic acid excretion is a useful index for determining when lysine excess is producing a functional deficiency of arginine.

Ammonia↗

PubMed1985

Solid-state fermentation: an alternative to improve the nutritive value of coffee pulp.

Coffee pulp was subjected to a solid-state fermentation process, using Aspergillus niger. The initial moisture content of the pulp, as well as the fermentation time and temperature, had a significant effect on the increase in total amino acid content of the material. The increase in total amino acids showed a significant correlation with the dry matter recovered (r = -0.98) and the increase in pH during the process (r = 0.98). With a moisture content of 80%, a pH of 3.5, a temperature of 35 degrees C, and an aeration of 8 liters/min per kg as fermentation conditions, it was found that the maximum concentration of total amino acids was attained after 43 h. The fermented product had a higher total amino acid content and a lower cell wall constituent value (primarily cellulose and hemicellulose) than the original pulp. A growing chicken's ration containing 10% of the fermented product had a feed efficiency (2.14) similar to that of the standard ration (2.19) and was significantly better than that of the diet containing 10% of the original pulp (2.53). The difference observed in feed intake and weight gain between the standard diet and that with 10% of the fermented product is considered to be due to palatability factors which should be studied further.

Journal Article↗

PubMed1995

The effect of copper level on nutrient utilization of weanling pigs.

The effect of addition of 15 or 250 ppm of Cu (as CuSO4.5H2O) and 0 or 5% added animal fat on the utilization of nutrients by weanling pigs was evaluated. Two trials were conducted with four groups of four littermate barrows (6.8 kg, 26 d) in each trial. Dietary treatments were arranged in a 2 x 2 factorial. Data were collected at the beginning of the trial and at the end of each 3-d period. There were no treatment x period interactions (P > .15). There was a Cu level x fat level interaction for ADG (P < .01), feed efficiency (P < .01), N intake (P < .09), fat intake (P < .01), and ash intake (P < .09). Pigs fed 250 ppm of Cu and 5% fat had increased ADG and gain:feed, whereas pigs fed 5% fat and 15 ppm of Cu had decreased ADG and gain:feed compared to pigs fed the other treatments. Apparent digestibility of DM and ash and N retention were increased (P < .05) by the addition of 250 ppm of Cu, whereas the addition of 5% fat decreased (P < .05) DM and ash digestibility. Fat digestibility increased from 28.3% to 75.6% when 5% fat was added to the diet containing 15 ppm of Cu and from 60.8% to 85.1% when 5% fat was added to the diet containing 250 ppm of Cu (Cu level x fat level, P < .01). Pigs fed diets containing 5% fat and 15 ppm of Cu had decreased (P < .06) Na, Cu, Fe, and Zn retention compared to pigs fed the other diets.(ABSTRACT TRUNCATED AT 250 WORDS)

Aging↗

PubMed2004

Power of test considerations for beef cattle experiments: a review.

The use of power tests in the planning and design of beef cattle experiments provides critical information on sample sizes necessary to detect treatment differences at a predetermined significance (alpha) level. Retrospective power analysis provides additional information about previous experiments that may be helpful in designing subsequent investigations. However, in retrospective power analyses, power is inversely related to observed significance level. Benefits of prospective and retrospective power analyses in beef cattle experiments are similar to those for other species; however, because of differences in the methods and conditions involved, considerations for the use of power test procedures are specific for beef cattle research. Retrospective power analyses were conducted on 78 published experiments and on two unpublished experiments. Experiments were compiled into categories that represented group (or pen) feeding, individual feeding, and metabolism studies. Estimated power in pen feeding experiments using randomized block designs (RBD, n = 30) was less than 0.80 for ADG and feed efficiency (FE), but not different from 0.80 for completely random designs (CRD, n = 4). Furthermore, estimated power was less for ADG than for FE in both design types. For individual feeding experiments using RBD (n = 4), power was not different from 0.80 for either ADG or FE; however, for CRD (n = 18), power was less than 0.80 for both ADG and FE. Power was similar for ADG and FE for both RBD and CRD in individual feeding experiments. In metabolism experiments, estimated power for nitrogen retention was less than 0.80 for Latin square designs (n = 20) but not for CRD (n = 4). Comparisons of power between experimental design types were likely influenced by the number of experiments involved. These results indicate that retrospective power in beef cattle experiments is affected by design type, and response variable measured.

Animal Nutritional Physiological Phenomena↗

PubMed1989

Effects of monensin and bambermycins on the performance of market turkeys.

The effects were examined of monensin and the bambermycins in feed on growing turkeys. The drugs were used alone and in combination. A total of 1,600 hen and tom turkeys were divided into 32 pens. Four treatments were used, including 45 or 90 g/ton (907 kg) monensin either to 10 wk of age or to market age with and without adding of 2 g/ton of bambermycins. Evaluation parameters, including body weight, feed efficiency, and mortality, were done at 6, 10, and 13 wk of age for hens and 6, 10, and 18 wk of age for toms. Adding bambermycins increased body weights of hens at 10 wk of age and toms at 6 and 10 wk of age. No differences among treatments were noted at market weight within any of the parameters studied. No differences among treatments were noted in efficiency or mortality by the conclusion of the trial.

Aminoglycosides↗

PubMed1995

Effect of early nutrient restriction on broiler chickens. 2. Performance and digestive enzyme activities.

An experiment was conducted to determine the effect of two early nutrient restriction programs on performance, selected characteristics of the gastrointestinal tract (GIT), and activities of digestive enzymes of broiler chickens. Three hundred and sixty male broiler (Ross x Ross) chicks kept in floor pens were assigned to three groups. The control group (C) was given ad libitum access to feed from 1 to 48 d of age. Another group was restricted from 11 to 14 d (R4) of age to an energy intake of .74 x BW.67 kcal ME/d, and a third group was restricted from 7 to 14 d (R7) of age to an energy intake of 1.5 x BW.67 kcal ME/d. Then, both restricted groups were given ad libitum access to feed through 48 d. Body weight and feed intake were determined weekly and selected carcass characteristics were measured at 48 d of age. Broilers also were sampled at 7, 14, 21, and 42 d of age to obtain data on components of the GIT (proventriculus, gizzard, pancreas, and small intestine) and activities of selected digestive enzymes. Feed-restricted groups were lighter in body weight (P < .01) at 14 and 48 d of age than the C group but were superior in overall feed efficiency. No treatment effects were observed for percentage yields of breast meat and abdominal fat pad. Absolute weights of GIT components were significantly reduced at 14 d of age by feed restriction. However, GIT components increased in weight more quickly after refeeding than did the whole body. Restricted groups had reduced (P < .01) specific activities of jejunal alkaline phosphatase and pancreatic trypsin, amylase, and lipase as compared with the C group at 14 d of age but not at 21 and 42 d of age. Relative activities for jejunal maltase and sucrase were greater (P < .01) at 21 d of age in the R4 and R7 groups than in the C group. The present data show that feed restriction results in transient changes in organs and activities of digestive enzymes, suggesting a functional adaptation to feed restriction.

Age Factors↗

PubMed1991

Characterization of energetically efficient and inefficient beef cows.

Dry matter intake and BW data from 14 mature, nonpregnant, nonlactating Angus cows that were individually fed through two consecutive 70- to 80-d periods (maintenance and ad libitum) were used to predict ADG (ADG = -.512 + .213 DMI - .0017 BW, R2 = .95). This equation then was used to identify feed efficiency types among these cows. Cows were identified as average type (A) if ADG was within one SE of predicted ADG, and as efficient (E) or inefficient types (I) if ADG exceeded one SE above or below, respectively, its predicted ADG. Four, four, and six cows were identified and grouped as I, A, and E types, respectively. During the maintenance period, DM and ME intake and ADG were similar (P greater than .10) across all three efficiency types. But during the ad libitum period, voluntary DM and ME intakes of I cows were greater (P less than .05) than those of A or E cows. Average daily gains of I cows during ad libitum feeding were greater (P less than .10) than those of A cows. Daily ME required for maintenance of I cows was highest, that of A cows was intermediate, and that of E cows was lowest (180.2, 154.6, and 135.1 kcal/kg BW.75, respectively). Inefficient cows tended (P greater than .10) to have less fat and deposited more protein (P less than .05) than A and E cows (137.9 vs 77.2 and 46.2 protein g/d, respectively). Concurrent with higher protein accretion rates, liver weights of I cows were heavier (P less than .05) than those of A and E cows (8.58 vs 7.79 and 7.68 kg, respectively). Inefficient cows were characterized by higher energy requirements for maintenance. Their high protein accretion may partially explain their higher maintenance requirements.

Analysis of Variance↗

PubMed1987

Valorization of rapeseed meal. 2. Nutritive value of high or low-glucosinolate varieties and effect of dehulling.

Five groups of 12 growing rats each were fed a control diet or one of 4 experimental diets composed of either high glucosinolate (Jet Neuf) or low glucosinolate (Tandem) rapeseed meal. After a 3-day adaptation period, the rats were fed ad libitum for 15 days. Both meals were given dehulled or non-dehulled. The Tandem rapeseed meal provided all the protein and Jet Neuf half the protein of the corresponding diets. Dehulling the seeds significantly increased the energy and protein digestibility of the rapeseed meals (+ 16.5 and + 6.3 or 10.4 points, respectively), their digestible energy and digestible protein contents (+ 28 and + 30%) and metabolic utilization of digestible protein in the indirect nitrogen balance trial. Conversely, in the feeding trial, the feed efficiency of the dehulled meal diets was lower than that of the non-dehulled meal diets. However, dehulling the Tandem rape seeds did not seem to reduce lysine availability. Finally, feeding dehulled Tandem rapeseed meal as the sole protein source did not significantly increase the liver weight of the rats.

Animals↗

PubMed1997

Self-selection of dietary protein and energy by broilers grown under a tropical climate: effect of feed particle size on the feed choice.

Broilers, 2 wk of age, that had been previously adapted to energy: protein choice feeding, were offered corn (either ground, cracked, or presented as whole grains) and a protein concentrate (43.7% CP) in mash or pellet form. When corn was fed as whole grains, protein concentrate in the selected diet was significantly higher (35.1%) than with cracked corn (29.3%) or ground corn (29.1%). Presenting the concentrate as pellets resulted in a significantly higher concentration in the diet (32.7%) than when mash concentrate was fed (29.6%). Live BW at 4 and 6 wk of age were not significantly affected by feed texture. However, offering corn as whole grains or concentrate as pellets induced a significant improvement in feed efficiency. Total time to eat larger size particles (whole grains, pelleted concentrate) was significantly less than total time to eat ground corn or mash concentrate. Furthermore, the mean duration of the feeding bouts was two times shorter for whole grains (48 s) than for ground corn (98 s) and for pelleted concentrate (56 s) than for mash concentrate (114 s). Chickens ate whole grains or pellets at a significantly slower rate (number of pecks per second feeding time) than when eating ground corn or mash concentrate. There was a rejection during the first 24 h when the form of the concentrate (mash to pellets) was changed. Full adaptation to the new size of the concentrate required about 3 d.

Analysis of Variance↗

PubMed2003

Comparison of grass and legume silages for milk production. 2. In vivo and in sacco evaluations of rumen function.

Two experiments were conducted to investigate the basis for higher voluntary intakes and increased alpha-linolenic acid content in milk from cows offered clover silages. Six cows with rumen and duodenal cannulae were used in a four-period changeover-design experiment. Cows received 8 kg/d of dairy concentrate and had ad libitum access to one of six silage treatments: grass, red clover, white clover, alfalfa, and 50/50 (dry matter basis) mixtures of grass with red clover or white clover. The rumen fermentability of grass, red clover, white clover, and grass/red clover silages was also evaluated in a nylon bag study. Legume silages led to increased dry matter intake and milk production in comparison with grass silage. There was no significant effect of legume silages on rumen pH and volatile fatty acid concentrations, but a significant increase in rumen ammonia concentration with the legume silages, reflecting their higher protein content. The inclusion of white clover or alfalfa silage, but not red clover silage, in diets led to an increase in molar proportions of isobutyric, iso-valeric, and n-valeric acids in comparison with diets based on grass silage. Rumen fill was significantly lower, and rumen passage rates were significantly higher for cows offered alfalfa or white clover silages. However, the markedly different particle size distribution of rumen contents with these feeds suggests very different mechanisms for the high intake characteristics: high rates of particle breakdown and passage with alfalfa, and high rates of fermentation and passage with white clover. Microbial energetic efficiency (grams microbial N per kilogram organic matter apparently digested in the rumen) was highest for cows offered alfalfa silage, intermediate for clover silage, and lowest for cows offered grass silage. These differences reflect the higher rumen outflow rates for legume silages in comparison with grass silage. However, the effect of these differences on N-use efficiency (feed to milk) was probably quite small in comparison with effects of N intake. Although the biohydrogenation of alpha-linolenic acid was still high for red clover silage (86.1% compared with 94.3% for grass silage), there was a 240% increase in the proportion of alpha-linolenic acid passing through the rumen. This explains the increased recovery of alpha-linolenic acid from feed into milk with diets based on red clover silage.

Animal Feed↗

PubMed2000

The biology of somatotropin in adipose tissue growth and nutrient partitioning.

During the past 20 years, much has been learned about how porcine somatotropin (pST) affects growth and nutrient partitioning in growing pigs. The development of techniques to produce large quantities of recombinantly derived pST enabled numerous long-term studies to be conducted in which the effects of daily pST administration could be evaluated. Collectively, these studies established that treatment of growing pigs with pST markedly stimulated muscle growth and, concurrently, reduced fat deposition. In growing pigs, maximally effective doses of pST increase average daily gain as much as 10-20%, improve feed efficiency 15-30%, decrease adipose tissue mass and lipid accretion rates by as much as 50-80% and concurrently increase protein deposition by 50%. These effects are associated with a decrease in feed intake of approximately 10-15%. These responses occur because pST has a wide array of biological effects that modulate nutrient partitioning between adipose tissue and skeletal muscle. The decrease in adipose tissue growth is due to a reduction in lipogenesis that is the consequence of pST blunting the effects of many insulin-dependent events. With respect to fatty acid synthase (FAS), a pace-setting enzyme in the lipogenic pathway, enzyme activity is markedly reduced by pST. This is the result of a pST-mediated decrease in FAS mRNA levels that occurs because FAS gene transcription is decreased. The consequence of the decrease in lipid synthesis is that adipocyte hypertrophy is impaired and, hence, tissue growth. This review will provide an overview of some of the biological effects of pST in adipose tissue and will discuss what is known about the underlying mechanisms that account for these effects.

Adipose Tissue↗

PubMed1979

Response of hens to various dietary levels of tannic acid.

One-hundred-twenty Babcock B-300 ehns, 17 months of age, were placed one bird per cage with six replicates of five birds each per treatment. Four levels (0, 1, 2, and 4%) of technical grade tannic acid were added to a standard corn-soy layer diet. With the exception of feed comsumption during the second and third week, there were no significant differences for feed consumption, egg production, feed efficiency, fertility, or hatchability amond the control birds and those receiving tannic acid at the 1% level. The addition of tannic acid at levels of 2 and 4% resulted in significantly decreased feed consumption and egg production during the six-week experimental period. Fertility and hatchability were not significantly affected by dietary tannic acid.

Animals↗

PubMed1983

Finishing broiler toms using an estradiol 17 beta implant together with a high energy-low protein final feed.

Wrolstad Small White toms were implanted with 10 mg of estradiol 17 beta monopalmitate (EMP) at 8 weeks of age. Common corn-soybean meal feeds were given through to 12 weeks, then one-half the birds from control and EMP groups received either an adequate (16% protein, 3166 kcal ME/kg) or high energy-low protein (HE-LP, 12%, 3373 kcal) feed to 14 weeks. No differences in weight gain and feed conversion occurred between EMP and control treatments at 12 weeks but at 14 weeks when the HE-LP diet had been fed the implanted birds performed better than controls. The HE-LP feed led to body weights and feed efficiencies below that of toms given adequate diet. In all cases, EMP elicited male secondary sex characteristics rather than feminization. Processing losses were increased with EMP and when the HE-LP feed had been given. Both treatments also improved finish assessment and were additive to the extent that a substantial increase in grade occurred. Effects on carcass composition, yield of commercial cuts, and cooking loss were small. Implantation, reduced meat yield percentage of breast and thigh. The increase in grade advantage from combining EMP with a feed that forced fat deposition more than compensated for the adverse effects.

Animals↗

PubMed1985

Feed intake effects upon gain, carcass yield, and ration digestibility in broilers force fed five feed intakes.

Broiler chicks were force fed 75, 100, 125, 140 and 160% of the consumption observed by ad libitum-fed controls to examine feed intake effects upon productivity. Live body weight gain increased with feed intake up to the 140% consumption but was depressed above this point. Feed efficiency and fat, ash, ration (corrected for uric excretion mass), protein (corrected for uric acid excretion nitrogen), and starch digestibility estimates declined by 30, 56, 25, 16, 16, and 2%, respectively, as feed consumption increased from 75 to 160% of ad libitum consumption. Neutral detergent fiber digestibility was not affected by amount of feed consumption. Initial digesta passage rate, estimated by first appearance of ferric oxide in feces, averaged 215 min and was not correlated (P greater than .4) with feed intake. Gastrointestinal tract mass plus contents increased with feed intake and accounted for up to 67% of the increased live body weight gain. Birds apparently adjusted to feed intake level by varying gastrointestinal tract size (mass) and not passage rate. Dressing percentage declined from a high of 73% for birds fed at the lowest feed intake to a low of 63% at the highest feed intake. Carcass gain was 50% greater for the 160 vs 75% group, but most of this (41%) was reached at the ad libitum consumption level. Carcass gain-to-feed ratios were .42, .41, .32, .27, and .21 for the five intakes, respectively. Drumstick, breast, and thigh gains were not (P greater than .01) influenced by increased feed consumption above the ad libitum-fed controls but were depressed (P greater than .05) at the 75% feed intake.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

PubMed1991

Influence of dietary flaxseed oil on the performance, muscle protein deposition, and fatty acid composition of broiler chicks.

Experiments were conducted to assess the effect of feeding flaxseed oil on the performance, muscle protein deposition, and fatty acid composition of broiler chicks. Four levels of dietary flaxseed oil were fed in combination with animal tallow to give a total of 6% added fat in the diets. The diets were isonitrogenous and isocaloric. Mortality, weight gain, feed consumption, and feed efficiency were not significantly different among treatments. Dietary treatments had no significant effects on the relative weights of the Extensor digitorum communis and Sartorius muscles nor on their protein or lipid contents. Feeding flaxseed oil resulted in increased accumulation of omega 3 fatty acids in skeletal muscle lipids. Increased amounts of desaturation and elongation products (C20:3, C20:5, C22:5, and C22:6) of alpha-linolenate (C18:3 omega 3) were observed in the Sartorius muscle lipids of chicks fed flaxseed oil. Amounts of these omega 3 fatty acids increased with duration of feeding. The amounts of omega 6 fatty acids (C20:2, C20:3, C20:4) were significantly depressed in muscle lipids after 21 days of feeding flaxseed oil. The effects of flaxseed oil on tissue amounts of individual saturated fatty acids were minimal, but amounts of monounsaturated fatty acids, especially C18:1, were depressed.

Animals↗