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PubMed1979

[Bean and rice mixtures of high protein value (author's transl)].

The optimum content of different rice (Oryza sativa) and bean (Vigna unguiculata L.) combinations was studied in Albino rats. The mixture containing 3 g of rice proteins, corresponding to 41g of rice "in natura", and 7 g of bean protein, corresponding to 59 g of bean "in natura", presented the highest protein efficiency ratio and the feed efficiency ratio. Since the limiting amino acid of this mixture was methionine, new assays using varying levels of this amino acid as a supplement were carried out. The PER of normal rats as well as the "plateau" value of previously protein depleted rats were highest when 0.2% methionine was added to the mixture. The net protein utilization (NPU) confirmed these findings. The values attained after the addition of other amino acids were not higher than those attained by the mixture containing 7 g of bean protein and 3 g of rice protein supplemented with 0.2% methionine. The PER and the NPU values came close to those of milk.

Amino Acids, Essential↗

PubMed1998

Comparison of egg-yolk protein hydrolysate and soyabean protein hydrolysate in terms of nitrogen utilization.

Egg-yolk protein hydrolysate (YPp) is an alternative protein source in formulas for infants with intolerance to cow's milk or soyabean protein, or for patients with intestinal disorders. However, the nutritional value of YPp has never been investigated. YPp was prepared by enzymic hydrolysis of delipidated yolk protein, which led to an average peptide length of 2.6 residues. Three experiments were performed. In Expt 1, we compared the intestinal absorption rate of YPp and soyabean protein hydrolysate (SPp) in rats. YPp and SPp solutions were injected into the duodenum of anaesthetized rats and blood samples were taken from the portal vein at 7, 15, 30, 60, and 120 min. A higher amino acid concentration in the serum of the YPp group demonstrated that YPp was absorbed faster than SPp. In Expt 2, the effects of dietary YPp and SPp on body-weight gain, protein efficiency ratio (PER) and feed efficiency ratio (FER) were determined. At the end of the experiment, body weight had increased in both groups, while PER and FER were significantly higher in rats fed on YPp. In Expt 3, to investigate the effects of dietary YPp and SPp on N metabolism, we determined the biological value and net protein utilization. Yolk protein was the reference protein. Biological value and net protein utilization values were very similar between animals fed on yolk protein and YPp diets, and significantly higher than in rats fed on the SPp diet. The present findings demonstrate that there is no adverse effect of hydrolysis of yolk protein on N utilization, and that the nutritive value of YPp is similar to that of yolk protein and superior to that of SPp.

Animals↗

PubMed1998

Microgravity and hypergravity effect on survival and reproduction of microinvertebrates.

Preliminary to carry out long-term experiments on the International Space Station (ISS) using living orgainisms, the capacity of the experimental organisms to cope with perturbations of gravity should be tested. Actually, animals have evolved under gravity, because on earth gravity force cannot be eluded, and several features that influence life-history traits may be affected by the presence of gravity. Among the other features, feeding efficiency may be affected by gravity if the animals feed by filtering suspended particles, creating currents that carry the particulate food to their mouth opening. In presence of gravity the food particles tend to sink to the bottom and filter-feeders must be able to suspend and collect the particles with some apparatus such as ciliary wreaths. It can be predicted that hypergravity, increasing the particle sedimentation rate, will reduce the animal filtering efficiency, while microgravity will increase filtering rate. Differently, some bacteriophagous animals do not possess structures to collect their food, but commonly live and move into sediment and feed on the bacteria upon encounter. Hypergravity will apply higher pressure on their bodies, and could force them to adhere to some surface and to reduce their displacement, and microgravity could impede adhesion to the surface and make food item encounters improbable. Thus, gravity perturbations may affect animal life-history traits, such as survival or fecundity, by influencing their feeding efficiency. In this study we exposed a filter-feeding organism (Macrotrachela quadricornifera, Rotifera Bdelloidea) and a bacteriophagous one (Panagrolaimus rigidus, Nematoda) to both microgravity and hypergravity to test their reproduction capacity under such stressful conditions, and their suitability as models for experiments on the ISS.

Animals↗

PubMed1980

Use of feed additives to reduce ruminal methane production and deaminase activity in steers.

Effects of feeding the methane inhibitor, amicloral, and the deaminase inhibitor (DAI), 4,4'-dimethyldiphenyliodonium chloride, at 1,500 and 25 mg/kg of diet, respectively, were investigated in finishing steers. Digestibility and ruminal VFA and ammonia concentrations were measured in six steers per treatment. Organic matter digestibility was increased significantly by amicloral, DAI and amicloral plus DAI. There were no treatment effects on molar proportions of acetic acid or propionic acid, but butyric acid was highest (P < .05) when both additives were fed. Ruminal ammonia concentrations were lower (P < .05) with all three treatment diets. Ninety-six steers were allotted to eight groups, two pens (replicates) per treatment, in a 112-day feedlot study. Neither amicloral nor DAI had any effect on intake or daily gain, although feed efficiency was increased (P > .05) by 9 and 4%, respectively. Feeding amicloral plus DAI lowered intake by 19% (P < .05) and gains by 8% (P > .05) but increased the efficiency of feed utilization by 12% (P < .05).

Animals↗

PubMed1990

Bromocriptine-induced reduction of body fat in pigs.

An experiment was conducted with 36 crossbred finishing pigs (18 male castrates and 18 females) to evaluate the effect of bromocriptine implants on growth, feed intake, feed efficiency, plasma urea nitrogen (PUN) and carcass characteristics. Three levels of bromocriptine (0, 5 and 10 mg/[pig.d]) were administered, via implants at the base of the ear, to six (two replicates of three) male castrates or to six (two replicates of three) intact female pigs (2 x 3 factorial arrangement of treatments). Average initial weight of pigs at the time of implantation was 89.7 kg, and the implants remained in the pigs for 28 (replicate 1) or 30 (replicate 2) d prior to slaughter. Gain, feed intake and efficiency of feed utilization were not affected (P greater than .10) by bromocriptine. Plasma urea nitrogen was lower in female pigs administered 10 mg bromocriptine; bromocriptine did not affect PUN of male pigs (gender x bromocriptine, P less than .08). Tenth rib fat thickness and average backfat thickness were lower (P less than .06) and percentage of muscling was higher (P less than .06) in pigs implanted with bromocriptine. Female pigs had less 10th rib fat but larger loin eye areas and a greater percentage of muscling than male pigs.

Adipose Tissue↗

PubMed2006

Energy partitioning and thyroid hormone levels during Salmonella enteritidis infections in pullets with high or low residual feed intake.

This experiment was conducted to investigate whether feed efficiency, as measured by residual feed intake as a phenotypic trait, affects energy partitioning in pullets that have received Salmonella inoculation as an immune challenge. In each of 8 trials, energy partitioning was measured during 5 wk in 15-wk-old efficient (R-) and nonefficient (R+) pullets, which were housed per efficiency group in 2 identical climate respiration chambers. After 1 wk of adaptation, the pullets in 4 trials were orally inoculated with 10(8) cfu of Salmonella enteritidis; pullets in the remaining trials were not inoculated and served as controls. Heat production was calculated from continuous recordings of O(2) consumption and CO(2) production. Energy and N partitioning were recorded on a weekly basis. Blood samples for analyses on thyroid hormones were taken at 16, 17, and 19 wk of age. There were no interactions between efficiency type and Salmonella treatment or Salmonella treatment effects in energy partitioning, except for a short-term increase in heat production in inoculated pullets. Nonefficient pullets had higher gross energy and ME intake, higher estimated ME for maintenance, lower ME:gross energy ratio, and higher total heat production and nonactivity-related heat production compared with R- pullets. Triiodothyronine levels in R+ pullets were higher at 16 and 17 wk but were lower at 19 wk of age compared with R- pullets. Thyroxine levels were higher in R- at 16 wk and showed interactions between efficiency type and Salmonella treatment at 17 and 19 wk of age. Body weights and spleen weights did not differ between efficiency groups. Nonefficient pullets had higher heart, liver, and ovary weights and more large yellow follicles than R- pullets. There were no Salmonella effects on body and organ weights. We conclude that R+ pullets have a faster running energy metabolism and that they put more resources into organ development than R- pullets. Inoculation with Salmonella has a short-term effect on nonactivity-related heat production but does not affect energy partitioning, regardless of efficiency type.

Aging↗

PubMedDate not supplied

The effect of zinc deficiency on the body composition of rats.

Body composition and the levels of some plasma metabolites were measured in zinc deficient and control rats with the aim of assessing the nature of the metabolic defects resulting from zinc deficiency. Two experiments, lasting 15 and 20 d, were carried out using 52 immature rats. Zinc deficient animals were fed a diet of 1-2 mg Zn/kg. Pair fed and ad libitum control rats received the same diet with 100 ppm zinc added to the drinking water. Feed intake and growth rate were measured, and the carcasses were analyzed for protein, fat, and ash. In each experiment, a group of rats were killed on d 1 to provide pretreatment values and to allow for estimates of net deposition of carcass components. Lactate, urea, and zinc were assayed in plasma, as well as zinc concentration in carcasses and liver. The main effect of zinc deficiency was to reduce feed intake and efficiency of feed conversion, resulting in a reduced proportion of carcass fat. However, when adjustments were made for difference in body wt because of the reduced feed efficiency, zinc deficiency per se resulted in an increase in the proportion of fat in the carcass. Plasma lactate concentration was unchanged, but urea concentration increased in both pair fed and zinc deficient rats relative to ad libitum fed control animals. The results indicate that a defect in protein synthesis and an increase in energy expenditure, perhaps resulting from increased protein turnover, underlies the reduced growth and efficiency of feed conversion of zinc deficiency.

Animals↗

PubMed2003

Crude protein and essential amino acid requirements in chicks during the first week posthatch.

1. This study examined optimal lysine and sulphur amino acid supply in the first week posthatch in broilers and the relationship between essential amino acids and dietary crude protein during the first week posthatch on performance at 7 d and through marketing. 2. The optimal supply during the 7 d posthatch using a 230 g/kg crude protein diet for sulphur amino acids was 9.1 and for lysine was 10.3-10.8 g/kg with maximal body weight (BW) or feed efficiency as the criteria. 3. Feeding diets with crude protein content ranging from 200 to 260 g/kg with either constant amounts of essential amino acids at different crude protein levels or constant ratios of essential amino acids to crude protein resulted in enhanced performance at 7 but not at 4 d with high protein intake and proportionally increased essential amino acids. 4. Performance on diets with crude protein ranging from 160 to 280 g/kg, with constant ratios of essential amino acid to crude protein, was much enhanced with the high crude protein diets at 7 d. All chicks were transferred to standard diets after 7 d and the BW advantage due to the balanced amino acid-high crude protein diet remained through marketing. 5. Thus increasing essential amino acids in a constant ratio to crude protein enhanced performance during the 7 d posthatch.

Amino Acids, Essential↗

PubMed1990

Effect of dose and frequency of administration of a potent analog of human growth hormone-releasing factor on hormone secretion and growth in pigs.

Ninety-six pigs (49.5 +/- .5 kg BW) were allotted to six treatments and were injected once (SID) or three times daily (TID) s.c. with a [desamino-Tyr1, D-Ala2, Ala15] human growth hormone-releasing factor (1-29) NH2 analog (GRF-AN). Treatments were T1, noninjected control; T2, saline-injected control (TID); T3, GRF-AN (1.66 micrograms/kg BW, TID); T4, GRF-AN (3.33 micrograms/kg BW, TID); T5, GRF-AN (6.66 micrograms/kg BW, TID) and T6, GRF-AN (10 micrograms/kg BW, SID). Feed protein levels were 14% for T1 and 18.8% for T2 through T6. The GRF-AN increased serum growth hormone (GH) concentration for the entire growing period (about 56 d) in a dose-related manner and did not induce desensitization of the somatotroph cells; in fact, an increase (P less than .05) in the GH response to GRF-AN was observed in T4 and T5 after 1 mo of treatment. This GRF-AN produced (P less than .05) a dose-dependent effect on several variables in animals grown to 110 kg BW: in comparison to T2, T5 increased meat in carcass (6%), carcass length (3%), loin eye area (13%), liver weight (19%), kidney weight (30%), improved feed efficiency (20%) and decreased total feed intake by 50 kg (26%). Compared to T2, average daily gain was increased (P less than .05) by 13% by the 3.33 micrograms/kg TID dose. Blood parameters were measured on d 1, 29 and 57. Increased serum glucose and insulin levels were observed. Triiodothyronine and thyroxine concentrations were increased and decreased, respectively after 28 d of treatment but were unchanged on d 57. This potent GRF analog maintained high GH concentration for at least 56 d and affected several growth parameters and carcass characteristics in a dose-related manner similar in magnitude to that reported in studies using porcine GH.

Animals↗

PubMed1994

Effect of early feed restriction and realimentation on heat production and changes in sizes of digestive organs of male broilers.

Two experiments were conducted with broilers to determine the effect of early feed restriction and realimentation on metabolic heat production and changes in sizes of digestive organs. An indirect open circuit calorimeter was used. Treatments were a full-fed control (FF) and a feed-restricted group (FR). Feed during the restriction period (6 to 12 d) for the FR birds was limited to 50% of voluntary feed intake of the FF birds. This was followed by realimentation period when all birds were provided feed for ad libitum consumption. The purpose of Experiment 1 was to measure basal metabolic rate (BMR), and Experiment 2 was designed to measure 36-h fasting metabolic rate (FMR), in both cases during time of restriction and realimentation. At the end of the 36-h unfed period, birds were killed and their digestive organs excised, blotted, and weighed. The FR birds showed significantly (P < .01) lower BMR compared with the FF birds during the restriction period. This lower BMR did not carry over into the refeeding period, when there was no difference between the two treatments. Thirty-six-hour FMR, like the BMR was also lower for FR compared with FF birds, but only during the period of restriction. Weights of digestive organs (expressed as a percentage of BW) during restriction were generally heavier for FR compared with FF birds. Measurements of organ weights taken during realimentation show significantly (P < .05) heavier liver and pancreas for FR compared with FF birds. Results of these experiments suggest that lower MR of "restricted-refed" birds does not play a role in the ability of the birds to show improved feed efficiency and growth compensation. Greater feed intake relative to BW and its associated digestive adaptations seem to be contributing factors to any growth compensation.

Animal Feed↗

PubMed1992

Interrelationships of heifer milk production and other biological traits with production efficiency to weaning.

Interrelationships among milk production, dam-calf feed efficiency to weaning, and other biological traits were evaluated on 411 first-calf heifers and their calves. Individual feed intakes were measured in a drylot environment for a 1-yr period until weaning of the first calf. Heifer breed types included crossbred Angus-Hereford, Simmental-Hereford, and Tarentaise-Hereford produced in two-breed rotational crossbreeding systems, F1 Salers-Hereford and straightbred Hereford. Production efficiency was defined as cumulative feed ME consumed by the dam-calf pair during the year divided by calf weaning weight. Milk production potential seemed to be unrelated to cow size, adjusted for breed-group effects. Lactational feed energy was increased for dams of increased milk production potential but not enough to offset the increased production of calf weaning weight in terms of production efficiency. Results indicated that increased levels of milk production of heifers were associated with improved production efficiency to weaning. However, the incremental improvement in efficiency per unit of increased milk was less for each additional unit of milk, within the range evaluated. These results are applicable to first-calf heifers that have not yet reached peak age for maximum milk production.

Animals↗

PubMed2001

Incorporation of dietary linoleic and conjugated linoleic acids and related effects on eggs of laying hens.

In the present study, laying hens received 29 g per kg diet of a preparation containing either 70% linoleic acid (LA) or approximately the same amount of conjugated linoleic acid (CLA) in the control and experimental treatments, respectively. The CLA preparation consisted predominantly of cis-9,trans-11 and trans-10,cis-12 fatty acid isomers as free fatty acids in a ratio of 1:1. The diets were fed for 8 wk to determine the effect of dietary CLA on quality characteristics of eggs. In addition, the fatty acid composition of liver and heart was analyzed. Performance parameters (egg weight, feed efficiency) were not significantly affected by feeding the diets supplemented with CLA. The overall amount of CLA that was incorporated into yolk was 7.95 g CLA/100 g total fatty acids, or approximately 400 mg CLA/egg. The transfer efficiency of the cis-9,trans-11 isomer was higher than that of the trans-10,cis-12 isomer; however, the transfer rate of CLA isomers into yolk and tissues was significantly lower than that of linoleic acid. Dietary CLA increased the concentration of saturated fatty acids in yolk and tissues at the expense of monounsaturated fatty acids. The proportions of myristic, palmitic, and stearic acids in yolk lipids were also changed by dietary CLA. Additionally, long-chain polyunsaturated fatty acids (arachidonic acid and docosahexaenoic acid) were decreased without changing the balance of the n-6/n-3 ratio in egg yolk. The inclusion of CLA in layer diets altered the shape of the yolk and various egg parameters (albumen height, foam index, and yolk index). The results of this study indicate that CLA induces various changes in lipid and fatty acid metabolism of laying hens and affects quality characteristics of eggs.

Animal Feed↗

PubMed1992

Effects of diets with graded levels of deoxynivalenol on performance in growing pigs.

Feeding trials were conducted to evaluate the effect of including deoxynivalenol (DON)-contaminated oats to provide approximately 0.5, 1.0, 2.0 and 4.0 mg/kg in the complete diets of growing pigs with initial weight of 25 kg. Performance was recorded as weight gain, feed intake, efficiency of feed utilization and carcass quality. Restricted feeding was compared to ad libitum feeding. For the groups fed diets containing 2 and 4 mg/kg of DON, a dose-related decrease in weight gain was observed during the first 8 weeks on experimental diets. With 4 mg/kg DON there were decreased feed intake, weight gain and efficiency of feed utilization throughout the experiment. No effect was observed in groups fed diets containing 0.5 or 1.0 mg/kg of DON. The carcass quality was not affected in any group.

Animal Feed↗

PubMed1988

Excess crude protein for nongravid gilts.

Twenty-five nongravid crossbred gilts (avg initial wt, 126 kg) were placed on either a high (38%) or a low (13%) crude protein (CP) diet and fed either at the rate of 1.82 kg/d or had ad libitum access to feed. In addition, a fifth group was pair-fed the 13% CP diet to the average intake of the gilts fed high CP ad libitum. The experimental period lasted 30 d. Corn-soybean meal diets were used and CP levels were varied by altering the corn:soybean meal ratio. Gain and gain/feed were reduced (P less than .01) in gilts fed 1.82 kg/d compared with the gilts fed ad libitum or pair-fed gilts. Gain (P less than .03) and feed intake (P less than .01) of gilts with ad libitum access to the 13% CP diet were higher than those of gilts with ad libitum access to the 38% CP diet. Gain/feed was not different (P greater than .10) between the two groups, however. Rate of gain and feed efficiency of gilts pair-fed the 13% CP diet were similar (P greater than .10) to those of gilts with ad libitum access to the 38% CP diet. Plasma total free amino acids, NH3 and total protein were not (P greater than .10) affected by treatment. Plasma urea-N and urinary total N, urea-N and orotic acid were increased (P less than .01) in gilts fed the high CP diet regardless of feed intake level. However, urinary NH3 was higher (P less than .01) in gilts fed the low-protein diet. These results indicate that excess dietary CP for nongravid gilts decreases gain and feed intake and has no effect on efficiency of feed utilization, but it increases plasma urea-N and urinary total N, urea-N and orotic acid.

Amino Acids↗

PubMed1997

Phytase supplementation of low-phosphorus growing-finishing pig diets improves performance, phosphorus digestibility, and bone mineralization and reduces phosphorus excretion.

Two experiments using 413 crossbred growing-finishing pigs were conducted to assess the use of a commercial microbial phytase (Natuphos) in corn-soybean meal diets to improve phytate P bioavailability and thus reduce inorganic P supplementation and fecal P excretion. In Exp. 1 (n = 189), the following diets were used: 1) .50/.40% total P, respectively, for grower and finisher phases, and no phytase; 2) .40/.35% P and no phytase; 3) diet 2 plus 250 U phytase/kg; and 4) diet 2 plus 500 U phytase/ kg. The total Ca level was .58/.48% for diet 1 and .53/.43% Ca for diets 2, 3, and 4 in the grower and finisher phases, respectively. Feeding the low-P diet without supplemental phytase resulted in an overall 18% reduction in ADG (P < .05), 15% reduction in ADFI (P < .05), and 3% poorer feed efficiency (P < .08). Adding 250 to 500 U phytase/kg to the low-P diet restored ADG, ADFI, and feed conversion to levels not significantly different from and within 96% of that observed for pigs fed the adequate-P diet. The overall apparent digestibility of P was linearly (P < .01) improved with addition of 250 and 500 U phytase/kg to the low-P diet, but Ca and DM digestibilities were not affected by phytase or P level. In Exp. 2 (n = 224) the following diets were used: 1) .38/.33% total P, respectively, for grower and finisher phases, and no phytase; 2) .42/.37% P and no phytase; 3) .46/.41% P and no phytase; 4) diet 1 plus 167 U/kg phytase; 5) diet 1 plus 333 U/kg phytase; and 6) diet 1 plus 500 U/kg phytase. All diets contained .41/.36% Ca for grower and finisher phases, respectively. Pigs fed the low-P control diet grew slower (P < .01) and less efficiently (P < .10) than pigs fed diets with added P or phytase. With increasing levels of supplemental phytase or P there was a linear increase (P < .01) in ADG, digestibility of P, and digested P and a quadratic improvement (P < .05) in feed efficiency. Tenth rib mineralization based on shear force and ash were linearly increased (P < .08 to .001) as phytase or P was added to the low-P diet. There were generally no effects of P or phytase level on carcass quality. Using prediction equations derived from the response traits of ADG and P digestibility in Exp. 1 and ADG, P digestibility, and bone shear force in Exp. 2 to added phytase or P, we estimated that 500 U phytase released an amount of phytate P that was approximately equivalent to .87 to .96 g of P from dicalcium-monocalcium phosphate supplements. Fecal P excretion was estimated to be reduced 21.5%.

6-Phytase↗

PubMed2002

Pancreatic and intestinal enzyme activities in rats in response to balanced and unbalanced plant diets.

To simulate the effects of nutritionally adequate and inadequate vegetarian diets, rats were fed, for 28 days, an isonitrogenous, isocaloric, amino acid unbalanced cereal diet (CD) deficient in lysine and tryptophan or a balanced cereal-legume diet (CLD). The impact of these diets on enzymes responsible for digestion of proteins and carbohydrates were measured. Neither experimental diet significantly affected the animal's final weight or feed consumption in comparison with controls fed a standard mixed diet from plant and animal sources. However, during the first three weeks, the weight gain of rats fed the CD was significantly lower (p < 0.01; p < 0.05) than that of the controls. CD fed rats also had a higher feed efficiency ratio (p < 0.05), demonstrating increased feed consumption per unit of body weight. They also had decreased pancreatic alpha-amylase activity (p < 0.05), serum phytolytic and zoolytic alpha-amylase activity (p < 0.05) and serum protein level (p < 0.05) than the controls. Activity of pancreatic trypsin and intestinal enzymes (sucrase, maltase, aminopeptidase N) were the same as in the controls. In rats fed CLD, growth, food consumption, and enzyme activities did not change, however serum protein and glucose levels were higher (p < 0.025; p < 0.005) than in the controls. It is hypothesized that decrease in alpha-amylase activity was mostly related to the tryptophan deficiency in the CD because this enzyme contains the highest amount of tryptophan units among all tested enzymes.

Animals↗

PubMed1997

Effects of plastic anti-pecking devices on food intake and behaviour of laying hens fed on pellets or mash.

1. This study investigated effects of plastic anti-pecking devices on food intake and behaviour to assess their applicability in commercial layer flocks. 2. In experiment 1, 72 individually caged ISA Brown pullets were fitted at 16 weeks of age (point of lay) with either 'ring' or 'bumper' beak devices or no device (control), half being fed on pellets and half on mash. The devices were held in place by lugs inserted in the nares. 3. There was evidence of discomfort immediately after fitting the devices, but not thereafter. In the first week, the devices reduced food intake, and were removed from 7 (15%) birds that lost weight consistently. Between 16 and 21 weeks, however, there were no significant effects of beak treatment or food form on either total food intake or egg production with the 65 remaining birds. 4. Beak treatment did not affect feeding efficiency (food intake per minute of feeding). The only behaviour affected was pecking at birds in adjacent cages, which was reduced with the ring device. 5. At 21 weeks, the birds were placed together in groups of 4 to 6 in 12 pens, each group consisting of birds from one of the 6 original treatments, and their behaviour was observed in experiment 2 between 21 and 23 weeks. 6. The only effects of beak treatment on behaviour were that pecking at pen walls was increased with the ring device, while pulling and eating feathers from group mates was seen mainly with control birds fed on pellets. Two birds were cannibalised in a control group on pellets. 7. Devices came off 3 (7%) birds in experiment 1 and were replaced, and rings slipped over lower mandibles of 2 (5%) birds in experiment 2 and were corrected. 8. At 23 weeks, beak lengths were increased with ring and bumper treatments, and pecking damage scores were low with all treatments. 9. It is concluded that these devices are not applicable commercially, but further trials would be justified with new improved designs.

Animal Feed↗

PubMed2004

Further evaluation of nonfeed removal methods for molting programs.

The objective of this study was to evaluate several nonfeed removal methods compared with feed removal for induced molting of laying hens. An experiment was conducted using 576 Dekalb White hens (69 wk of age) randomly assigned to 1 of 8 dietary treatments. Two of these treatments consisted of feed removal for 10 d followed by ad libitum access to a 16% CP, corn-soybean meal diet or a 94% corn diet for 18 d. The other 6 treatments provided ad libitum access for 28 d to diets containing 94% corn, 94% wheat middlings (WM), 71% WM: 23% corn, 47% WM: 47% corn, 95% corn gluten feed, and 94% distillers dried grains with solubles (DDGS). At 28 d, all hens were fed a laying hen diet (16% CP), and production performance was measured for 40 wk. The 2 feed removal treatments resulted in total cessation of egg production within 6 d. Egg production of hens fed the 94% WM, 71% WM: 23% corn, corn, corn gluten feed, and 47% WM: 47% corn diets all decreased to 6% or less by d 12, 16, 19, 20, and 28, respectively. Egg production of hens fed DDGS never decreased below 18%. Body weight loss ranged from 10% (DDGS) to 26% (10-d feed removal), with the other treatments being similar at 17%. No consistent differences were observed among treatments throughout the 40-wk postmolt period for egg production, egg specific gravity, egg weight, egg yield, or feed efficiency. No differences were observed among feed removal treatments versus several nonfeed removal treatments for ovary and oviduct weights and blood heterophil:lymphocyte ratios during the molt period. In addition, interactive social behaviors were not different throughout the molt period between hens fed the 94% WM and those deprived of feed for 10 d. Our results indicate feeding WM, corn, corn gluten feed, and WM:corn diets are effective nonfeed removal methods for molting laying hens.

Agriculture↗