Reduced Feed Consumption Research Articles

The Effects of Claw Removal on Growth Rate, Gonadal Steroids, and Stress Response in Cage Reared Pullets

The purpose of this study was to investigate the effects of claw removal on young pullets grown in wire cages. Body weight, feed consumption, stress response, and gonadal steroid data were collected to assess the effects of claw removal on growing pullets. Claw removal posed an initial physiological insult upon chicks that resulted in a reduction in body weight gain and reduced feed consumption during the early grow-out period. However, by 20 weeks of age there were no significant differences between the body weights of intact and declawed pullets. No significant differences in plasma corticosterone, progesterone, or estradiol were observed, nor were there any significant differences in mortality or antibody response during the course of the 20-week study. Nevertheless, several declawed pullets demonstrated relatively precocious egg laying, suggesting that claw removal enhanced sexual maturity.

Effects of Ochratoxin A on Egg Production, Body Weight, and Feed Intake in White Leghorn Hens

Two trials were conducted to determine whether ochratoxin A (OA) or reduced feed consumption was responsible for reduced body weight and egg production in hens. In an 8 week restricted feed intake trial two groups of White Leghorn hens received amounts of non-contaminated feed similar to that consumed in a previous trial by hens fed either noncontaminated diet or one containing 4 ppm OA. A significant (P<.05) loss of body weight was observed during the 5th and 6th weeks in the group receiving a similar amount of feed as the OA-treated group in the previous trial, indicating that reduced feed consumption might account for the loss in body weight. Since egg production was not affected, it was possible that OA may depress egg production through a mechanism that is separate from its influence on feed intake. In an organoleptic trial White Leghorn hens were offered a choice of layer feed either with or without OA added for a three week period. There was a significant (P<.05) reduction in the consumption of OA-contaminated feed.

Long-term and carry-over effect of dietary inorganic cyanide (KCN) in the life cycle performance and metabolism of rats

A long-term study was carried out to evaluate the cumulative effects of adding 500 ppm KCN to a cassava root flour-based diet. High dietary level of KCN did not have any marked effect in gestation and lactation performance of female rats. No carry-over effect of level of cyanide fed during gestation was observed on lactation performance. The high cyanide-containing diet, however, significantly reduced feed consumption and daily growth rate of the offspring when fed during postweaning growth. Protein efficiency ratio was not only reduced by the high cyanide diet during the postweaning growth phase but also there was a carry-over effect from gestation. Serum thiocyanate was significantly increased in lactating rats and their offspring during lactation and in the postweaning growth phase of the pups. No apparent carry-over effect was noticed on this parameter. Rhodanese activity in liver and kidney was unaffected by feeding the high cyanide diet during gestation, lactation, and/or during postweaning growth.

Fishmeal and oil from lantern fish (myctophidae) with special emphasis on protein quality.

AbstractFishmeal made from lantern fish (family: Myctophidae; genus: Benthosema pterotum) had proximate, mineral, amino acid and fatty acid composition within the range reported for fishmeal made from conventional fish. Similarly, the pressed‐out oil had a fatty acid composition and content of unsaponifiables as reported for conventional fish oil. The content of unsaponifiables in the body fat of the fish indicated that wax esters contributed a minor part of the lipids of this species of lantern fish. Determined in chicks, the true digestibility of the amino acids varied from 92% (arginine) to 73% (hydroxyproline) which for most of the amino acids was 1‐3% units lower than that found for a high‐quality capelin fishmeal. No differences in rate of mortality, growth rate and feed consumption and utilisation were found between lantern and capelin fishmeal when they replaced increasing amounts (0 to 100%) of soya bean meal as protein supplements (72% of total protein) to cereal diets, both fishmeals reducing feed consumption and causing a significant improvement in feed utilisation compared with soya bean meal. The data indicate that lantern fish may be used for the production of fishmeal.

Influence of Dietary Protein during the Pre-Breeder Period on Subsequent Reproductive Performance of Large White Turkeys: 2. Growth, Feed Consumption, and Male Sex-Limited Reproductive Traits

The effect of low dietary protein during the rearing and breeding periods on the reproductive performance of Large White turkey males was examined. At 12 weeks of age 251 males were randomly divided into two groups and fed either 12 or 17% protein through 56 weeks of age. Body weight gains from 12 to 20 weeks and 20 to 28 weeks of age were significantly reduced for the males receiving the 12% dietary protein. However, after 28 weeks of age, weight differences decreased and by 56 weeks of age body weights of both groups were approximately the same. In addition, a significant reduction in feed consumption was noted for the males fed 12% protein. Males on the high protein diet experienced a higher mortality than those on the low protein diet.Low dietary protein reduced semen volume and spermatozoa concentration at 33 weeks of age, but there were no significant differences thereafter. The percentages of normal, abnormal, or dead spermatozoa were unaffected by dietary protein levels. Feeding 12% protein from 12 to 56 weeks of age to Large White turkey breeder males was adequate for high quality semen production.

Safety of Feeding Aflatoxin-Inactivated Corn to White Leghorn Layer-Breeders

A two-year study was conducted to investigate the safety of feeding corn ammoniated to inactivate aflatoxins to White Leghorn layer-breeders. Four types of corn were used: 1) normal corn (control); 2) ammoniated control corn; 3) aflatoxin contaminated corn (754 ppb); and 4) ammoniated aflatoxin corn (resulting in an aflatoxin level of 3.5 ppb). Corn made up 66.3% of the total diet, resulting in an aflatoxin level in the feed of 500 ppb and 2.3 ppb for treatments 3 and 4, respectively. The study consisted of two trials each with a duration of ten 28-day periods. White Leghorn pullets used in the study were 26 weeks of age at the start of the first trial and 22 weeks of age at the start of the second trial.The birds receiving the ammoniated corn showed no deleterious effects on production, egg quality, reproduction, feed consumed per dozen eggs, or mortality rates. There was a trend for these birds, especially the aflatoxin-ammoniated group, to consume less feed and gain less body weight during the trial. However, as noted above, this did not cause any problems with other parameters. Therefore, these data indicate that corn treated by the ammoniation process used in this study would be safe in White Leghorn layer-breeder diets at levels up to 66.3% of the total diet.The presence of aflatoxin in the feed (500 ppb) did not cause any serious problems. Differences were observed for each of the following parameters but the differences were usually small and statistically significant in only one trial of the study: reduced egg weight (second trial), reduced total mass of eggs produced (second trial), increased percentage of blood spots (second trial), reduced feed consumption per bird per day (second trial), and reduced day-old chick weight (first trial).

Carbohydrate Metabolism in Chicks after Administration of Toxins from a Phomopsis sp.

Soybeans inoculated with Phomopis sp. were incubated for weeks and then extracted with methanol and ether, and the culture filtrates were intubated into crops of chicks. Activities of glucose-6-phosphatase and glucose-6-phosphate dehydrogenase in liver were increased, and glycogen stores and plasma glucose concentrations were reduced. Histologically, severe hepatocytic necrosis was found in chicks treated with the toxic culture filtrate. Significant clinical signs were loss of body weight and reduced feed consumption. The metabolic changes responsible for the findings are discussed.

Effects of Feeding High Magnesium to Young Dairy Calves

Holstein bull calves were fed 1, 2, and 4% supplemental magnesium as magnesium oxide. The control diet contained .3% magnesium and consisted of ground corn, soybean meal, cottonseed hulls plus mineral, vitamin, and antibiotic supplements. Diarrhea was the most obvious effect of high intake of magnesium. The extent and intensity of the diarrhea was related closely to the dietary magnesium content. High (2 and 4%) magnesium reduced feed consumption and weight gains. Although there were traces of blood in feces, no abnormalities were observed at autopsy. Large tubular sections of mucus were voided in the feces with a greater prevalance among calves fed 2 and 4% supplemental magnesium. Magnesium in plasma rose sharply in response to the increased intake of magnesium. In calves receiving the 4% added magnesium, the plasma values were triple those of controls. When high magnesium was fed, magnesium increased much more in urine than in plasma. Within 1 wk after calves were returned to control diet, magnesium in urine and plasma declined to control.

Added Fat, Ipropran, and Rofenaid in Diets of Breeder Turkeys

Using 216 Large White breeder female turkeys, a 24-week experiment was conducted to evaluate the effects of adding 6% fat, .05% Ipropran and .025% Rofenaid to their diets. The addition of 6% stabilized animal and vegetable fat to the diets reduced feed consumption 9.9%, decreased energy consumption 2.9%, slightly increased body weight gains, and did not significantly affect production, fertility or hatchability of eggs. The additions of Ipropran and Rofenaid were observed to be safe as indicated by their non-effect on any of the parameters measured.

Production, Quality and Hatchability of Eggs from Hens Fed Monensin

White Leghorn hens were fed a diet containing 0, 50, 100, or 200 p.p.m. of the anticoccidial drug monensin. A level of 200 p.p.m. reduced feed consumption, egg production, and egg weight, compared with birds receiving unmedicated feed. Weight loss was seen in hens receiving 100 and 200 p.p.m. monensin. Feed consumption decreased during the first week while the decrease in egg production was delayed until one week later. Levels of 50 and 100 p.p.m. monensin had no effect on egg production or feed consumption compared with unmedicated controls. No detectable effect was seen with any level of medication on Haugh units, egg shell thickness, or visible quality of eggs. A level of 100 p.p.m. monensin did not affect fertility and hatchability of eggs.

Emetic and refusal activity of deoxynivalenol to swine

The minimum emetic dose of deoxynivalenol to swine weighing 9 to 10 kg was 0.05 mg/kg of body weight intraperitoneally and 0.1 to 0.2 mg/kg orally. There was no emesis by undosed pigs consuming vomitus from pigs orally dosed with deoxynivalenol or penned with such pigs without access to vomitus. Analysis by gas-liquid chromatography of a sample of Gibberella zeae-infected corn containing about 25% visually damaged kernels indicated 12 ppm of deoxynivalenol. Deoxynivalenol added to feed reduced feed consumption of 20- to 45-kg pigs, ranging from a 20% decrease with 3.6 ppm to 90% reduction with 40 ppm. Loss in weight was associated with feed refusal. Feed refusal, however, was much greater for naturally infected corn samples than for feeds with equal concentrations of the pure compound added, indicating the involvement of an additional factor(s) in the swine refusal response.

The Effect of Marek’s Disease Vaccination and Day-Old Debeaking on the Performance of Growing Pullets and Laying Hens

In a 2 × 2 completely randomized factorial design, four hundred day-old Single Comb White Leghorn pullets were randomly assigned to four treatment combinations of vaccinated, non-vaccinated, debeaked and non-debeaked groups. Vaccination and debeaking were performed at day-old by administering 2,000 P.F.U. of HVT vaccine/chick and by removing approximately ⅔ of the upper beak, respectively. All the data were analyzed at 5% level of probability.Vaccination reduced feed consumption significantly only during the early growing period of the first 12 weeks, whereas debeaking caused a significant reduction in feed consumption throughout the experimental period of 80 weeks. Mortality during the 20-week growing period was not affected by either vaccination or debeaking. During the laying period (20–80 weeks of age), vaccination reduced the mortality numerically, while debeaking reduced the mortality significantly. Final body weight, hen-day egg production, egg weight, albumen height and egg shell thickness were not influenced by either vaccination, debeaking or a combination of the two. Debeaking had no effect on the incidence of blood-spotting in the eggs. Vaccination, however, significantly reduced percent blood spots in the eggs. Day-old debeaking effectively prevented the occurrence of cannibalism.

Performance of Red × Rock Sex-Linked Hens Subjected to Restricted Feeding During the Laying Period

Two trials were conducted to compare the influence of various levels of feed during the laying period on the performance of the layers. Four feeding levels were utilized in each trial. One group served as the full-fed control and the other three groups were limited to 95, 90 or 85 percent of the amount consumed by the control group the previous week. The restricted feeding treatments were initiated at 22 and 32 weeks of age in Trials 1 and 2, respectively. At 22 weeks the birds were just beginning to lay while at 32 weeks they had reached peak production.A linear and significant decrease in egg production occurred with the feed restriction practiced, but the reduced feed consumption of the groups was sufficient to compensate for the reduced egg production since the feed efficiency of these groups was numerically superior in Trial 1 and significantly superior to the full-fed group in the second trial.The feed restriction utilized in this study reduced average body and egg weights, but treatment differences were not detected in shell thickness or Haugh units.

Intermittent Watering and Feeding Programs for White Leghorn Layers

Three experiments were conducted to determine the effects of intermittent watering on White Leghorn layers. In addition in Exp. 2 the performance of layers subjected to intermittent feeding was also compared with the performance of control and intermittently watered layers. Providing hens two 1-hour or three 15-minute watering periods per day, after 5 months of lay on an ad lib. watering program, reduced egg production, feed per hen-day and weight gain, but had no effect on average egg weight (Exp. 1). When the three 15-minute watering periods were initiated prior to laying (Exp. 3), there was no effect on egg production, egg specific gravity or Haugh units; however, feed per hen-day, per egg, and per gram of egg, and average egg weight were reduced by 5.0, 11.0, 0.1, and 2.6 g., respectively. Providing five 15-minute watering periods per day had no effect on egg production, average egg weight or mortality. However, in two comparisons with controls (Exp. 2 & 3), feed per hen-day, per egg, and per gram of egg were reduced by 0.3 and 3.0, 7.7 and 9.0, and 0.14 and 0.17 g., respectively. Scheduling one 15-minute watering period each hour had no effect on egg production, feed intake or weight gain. Providing layers two 2-hour feeding periods per day significantly reduced feed consumption and weight gain, but had no significant effect on average egg weight or on egg production as compared to controls with feed and water ad lib. Haugh unit scores were higher when compared to the intermittent water treatments.

Egg production, shell thickness, and other physiological parameters of laying hens affected by T-2 toxin.

T-2 toxin has been reported to cause severe oral lesions and neural disturbances in young broiler chickens. T-2 toxin, when added at a level of 20 mug per g of feed, caused oral lesions but no abnormal neural disturbances in young broiler chickens. T-2 toxin, when added at a level of 20 mug per g of feed, caused oral lesions but no abnormal neural symptoms in laying hens. T-2 toxin had no effect on either hemoglobin, hematocrit values, erythrocyte count, plasma glucose, prothrombin times, or the sizes of the liver, spleen, pancreas, and heart. Lipid content of the liver was not altered. Feed consumption, however, was reduced, as were the total plasma protein and lipid concentrations and the total leukocyte count. Most important economically was the lowered egg production and a thinner egg shell. The timing and severity of the symptoms suggest that T-2 toxin causes primary oral lesions that reduce feed consumption with a consequent reduction in serum proteins and lipids, which culminate in decreased egg production. The leucopenia and thinner egg shell may be independent systemic effects of T-2 toxin in laying hens.

The Effect of Age at and Methods of Debeaking on Future Performance of White Leghorn Pullets

Debeaking S.C. White Leghorn pullets at 12 or 16 weeks of age produced carry-over effects into the egg production period of reduced egg size and body size which were considered undesirable. Debeaking at 6 days of age had no significant effect on egg production traits, but significantly reduced feed consumption through 20 weeks of age. Day-old debeaking had no significant effect on egg production traits other than a 5 day increase in sexual maturity. In the groups debeaked at day-old, feed consumed in the period to 20 weeks of age was reduced by 475 grams per pullet and a 118 gram reduction in body weight persisted through 35 weeks of age. Beak regrowth in the 1 and 6 day old and 12 and 16 week of age debeaked groups was not a problem. The two groups debeaked at 6 or 8 weeks of age showed a large number of pullets which required redebeaking at 20 weeks of age.

Egg Production, Shell Thickness, and Other Physiological Parameters of Laying Hens Affected by T-2 Toxin1

T-2 toxin has been reported to cause severe oral lesions and neural disturbances in young broiler chickens. T-2 toxin, when added at a level of 20 mug per g of feed, caused oral lesions but no abnormal neural disturbances in young broiler chickens. T-2 toxin, when added at a level of 20 mug per g of feed, caused oral lesions but no abnormal neural symptoms in laying hens. T-2 toxin had no effect on either hemoglobin, hematocrit values, erythrocyte count, plasma glucose, prothrombin times, or the sizes of the liver, spleen, pancreas, and heart. Lipid content of the liver was not altered. Feed consumption, however, was reduced, as were the total plasma protein and lipid concentrations and the total leukocyte count. Most important economically was the lowered egg production and a thinner egg shell. The timing and severity of the symptoms suggest that T-2 toxin causes primary oral lesions that reduce feed consumption with a consequent reduction in serum proteins and lipids, which culminate in decreased egg production. The leucopenia and thinner egg shell may be independent systemic effects of T-2 toxin in laying hens.

Environmental Heat and Partial Water Restriction Effects on Body Fluid Spaces, Water Loss, Body Temperature, and Metabolism of Holstein Cows

The effects of partial water restriction on metabolism, body fluid compartments, and water balance were measured in seven mature nonlactating Holstein cows at two constant environmental temperatures, 18 and 32C. For 7 days at each temperature, water was restricted to 50% of ad libitum consumption.Partial water restriction at 18C caused a 50% reduction in water loss with a reduction in total body fluid volume mainly from the extravascular fluid compartment. This was followed by a reduction in feed consumption and metabolism. At 32C partial water restriction caused a great reduction in water loss through urine and feces, allowing more of the water to be used for heat loss by vaporization.Partial water restriction, unlike total water withdrawal, did not change the volumes of vascular compartments at either normal or high temperatures. However, animals exposed to normal and high temperatures respond differently to water restriction. At 18C similar percentage reductions (approximately 50%) occur in urine, fecal water, and total vaporization to reduce water loss during water restriction. But at 32C water loss is reduced mainly by reduction of urine and fecal water, rather than vaporization.Comparison between ad libitum animals at the two temperatures showed that heat caused a 15.9% reduction in metabolism. Water restricted cows, compared to ad libitum cows at 32C, showed a 17.0% reduction in metabolism. Results suggest the reduced metabolism is a compensatory mechanism to reduce internal heat production in an environment of high external heat and low water availability. Also, insignificant reduction in blood and plasma volumes produced available fluids for heat loss through vaporization when water was restricted at a high temperature.

Intermittent Feeding and Lighting of Mature Leghorn Hens

Two experiments were conducted to determine the effects of limiting feed and light to adult female White Leghorn chickens. In both experiments, lighting treatments compared ten-minute periods of light every four hours with 17 hours of continuous light per 24-hour period; feeding treatments compared ten-minute periods every four hours (concurrent with the intermittent lighting periods) with ad libitum feeding. Two levels of dietary protein, 18 and 20 percent, were used in Experiment 1 and two levels of dietary energy, 2816 and 3028 Cal./Kg., were used in Experiment 2.In Experiment 1, no differences in egg production were observed. In Experiment 2, restricted feeding reduced egg production by 9.4 percent. Egg production was not affected by light restriction.Egg size was reduced by 0.4 gram per egg in both experiments when feeding time was limited; however, this difference was significant only in the first experiment. Intermittent light resulted in a significant increase in average egg weight of l.5 grams in Experiment 1 and 1.9 grams in Experiment 2 when compared with 17 hours of light.The limitation of feeding time resulted in a 20 percent reduction in feed consumption. Light restriction reduced feed consumption by ten percent in Experiment 1 and by 12 percent in Experiment 2.The efficiency of converting feed to eggs was significantly improved in the birds on restricted feeding by 10.0 percent in Experiment 1 and by 5.5 percent in Experiment 2. The improved efficiency of converting feed to eggs indicated a lowered maintenance requirement in birds on restricted feeding.

Interaction of Dietary Vanadium, Calcium and Phosphorus for the Growing Chicken

Various levels of dietary vanadium, phosphorus and calcium were fed to growing chickens in order to investigate the possible interaction of these three minerals. Vanadium significantly reduced feed consumption at 10 p.p.m.; however, there were no significant differences in blood phosphorus or bone ash levels with vanadium supplementation. There were no significant interactions noted between vanadium and calcium and/or phosphorus.