[Drug control of eelworm in the domestic chicken, using piperazine adipate, with special reference to laying performance].
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Animals↗
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The effect of choline supplementation in growing pullet and laying hen diets.
Two experiments were conducted to determine the effect of choline supplementation on corn-soy-meat-based grower and laying hen diets. Diets contained 2.5% and 3% meat and bone meal in the growing and laying diets, respectively, and on chemical analysis contained 1005 and 1041 ppm of choline respectively. In the first experiment, 1000 ppm of choline were added to the basal growing and laying diets, and in the second experiment the laying diet was supplemented with 550 ppm or 1000 ppm of choline. In both trials, choline supplementation did not increase gains or feed efficiency for pullets from 8 to 20 weeks. However, choline supplementation during the laying period resulted in a statistically significant improvement of egg production and egg size. Supplementation of choline in the growing phase did not affect the laying performance. Laying performance was not improved by 2 micrograms/kg of supplementary vitamin B12 in a 1000 ppm choline supplement diet (78% vs. 76% hen-day production). In the second trial, added levels of choline (0, 500, and 1000 ppm) resulted in egg production from 24 to 64 weeks of 73, 76, and 76% hen-day production, respectively. Egg weights were 59, 61, and 61 g, respectively. This suggests that the total choline requirement of laying hens on a corn-soy-meat diet, and in absence of supplementary methionine, is greater than 1000 ppm but no more than 1500 ppm.
Animals↗
Effects of high concentrations of dietary vitamin E and ethoxyquin on the performance of laying hens.
1. Three experiments were carried out with light strain laying hens to evaluate the effects of relatively high doses of dietary vitamin E (125 mg/kg food) or ethoxyquin (EQ) (250 mg/kg food) on their laying performance. The control diet contained 5 and 125 mg/kg vitamin E and EQ, respectively. The experimental diets were fed either from one or 32 weeks until 88 or 89 weeks of age. 2. The two antioxidants did not affect the growth of the pullets, age at first egg, final body weight, average egg weight or relative abdominal fat pad size and liver weight at the termination of the experiments. In two out of three experiments, vitamin E and EQ did not affect egg production, food efficiency or mortality; in the third experiment vitamin E significantly (P less than 0.05) improved egg production and food efficiency after an outbreak of Newcastle disease which occurred at 34 weeks of age. EQ significantly reduced mortality during the course of this experiment, but did affect the variables of performance. In two experiments vitamin E consistently improved shell density, although a significant effect was observed in only one of the eight determinations carried out. EQ did not affect this variable. 3. The uterine muscle was more susceptible to oxidation than the drumstick meat, as evaluated by TBA values. In both tissues, vitamin E significantly and consistently decreased TBA values and restricted their increase during incubation, while EQ was less effective, particularly in the drumstick meat. 4. It is concluded that increasing vitamin E and EQ concentrations in diets of laying hens have no effect on the decrease in egg production due to aging. However, vitamin E may minimize the decline in egg production and food efficiency following the outbreaks of some diseases and slightly improve--under certain yet undefined conditions--shell density.
Adipose Tissue↗
The effects of low dietary concentrations of saponin on liver lipid accumulation and performance in laying hens.
1. Feeding 4 or 5 saponin/kg diet depressed food consumption, egg and body weights and liver lipid concentrations. Rate of egg production decreased initially but later returned to normal. 2. At 1 g/kg diet saponin had no effect on food consumption or laying performance but decreased the high liver lipid concentration in two experiments on a heavy (Warren) strain of bird. There was no effect on liver lipid concentration in another experiment using a light (White Leghorn) strain in which liver lipid concentration was low. 3. Excreta lipid, liver cholesterol and plasma high density lipoprotein-cholesterol concentrations were unaffected by saponin but plasma triglyceride concentrations were decreased.
Animal Feed↗
Dietary interaction of 1,4-diaminobutane (putrescine) and calcium on eggshell quality and performance in laying hens.
An experiment was conducted to evaluate the potential dietary interaction between 1,4-diaminobutane (putrescine) and calcium on eggshell quality and overall laying performance. One hundred ninety-two 30-wk-old White Leghorn hens were fed a corn-and soybean-meal-based diet supplemented with 0.00, 0.05, 0.10, or 0.15% putrescine and 2.5, 3.0, 3.5, or 4.0% calcium in a factorial design (12 birds per diet) for 4 wk. The percentage of egg production increased linearly (P < 0.05) with increasing levels of dietary calcium. Significant interactions (P < 0.05) were observed between dietary putrescine and calcium for eggshell thickness, eggshell deformation, percentage of eggshell, calcium intake, total calcium retention, total eggshell calcium, and percentage of eggshell calcium. Interactions were due to quadratic effects of putrescine or calcium on these parameters. Eggshell thickness and percent eggshell increased when hens were fed 3.5% calcium in combination with 0.1% putrescine; however, calcium intake and calcium retention were significantly lower (P < 0.05). Eggshell quality improved with increasing dietary levels of calcium due to increased calcium retention and calcium balance. Increasing levels of dietary putrescine did not have a negative effect on eggshell quality; however, calcium intake was lower at higher-supplemented levels of putrescine. It was observed that dietary calcium in excess of requirements resulted in increased egg production and eggshell quality. Eggshell quality improved when hens were fed 3.5% calcium diet in combination with 0.10% putrescine. It was concluded that small supplements of dietary putrescine may improve eggshell quality, depending on dietary calcium concentration.
Animal Feed↗
Performance of laying hens fed on practical diets containing different levels of supplemental biotin during the rearing and laying stages.
1. The effect of biotin supplementation of low-biotin practical diets during rearing and laying stages on performance was studied in White Leghorn-type laying hens. 2. Biotin supplementation during rearing did not have any apparent effect on the condition of the bird at point-of-lay or on subsequent laying performance. 3. Biotin supplementation during lay did not have any beneficial effect upon egg number, egg size or food intake or food conversion efficiency. 4. Internal egg quality, as reflected by albumen height, was slightly improved by biotin supplementation of layer's diet. 5. Input-output relationships were calculated for the incorporation of biotin in egg yolk. 6. Metabolic measurements suggested that biotin concentration in egg yolk was the best criterion of biotin status in the hen. 7. It is concluded that practical diets contain sufficient biotin to support optimum egg-laying performance in hens.
Animals↗
The use of low-protein, low-phosphorus, amino acid- and phytase-supplemented diets on laying hen performance and nitrogen and phosphorus excretion.
Two experiments were conducted to determine whether, by using a low-protein, amino acid-supplemented diet or a low-protein, amino acid-supplemented diet in conjunction with low-P, phytase-supplemented diet, the excretion of N and P could be reduced without affecting the productive performance of laying hens. Eight dietary treatments were assigned to Babcock B300 hens in each of 2 experiments that involved a positive control (16 to 16.5% CP) and a negative control (13% CP) with and without supplementation with the limiting essential amino acids. In experiment 1, supplementing the negative control with lysine, methionine, and tryptophan resulted in performance comparable to that obtained with the positive control, with the exception that egg weight was heavier for the negative control supplemented with amino acids. Supplementing the negative control with additional essential amino acids improved the performance higher than the positive control indicating that the positive control was deficient in one or more essential amino acids. In experiment 2, supplementing the negative control containing 0.2% nonphytate P (NPP) with all the limiting amino acids plus phytase resulted in performance comparable to the positive control group, which was fed 0.4% NPP without phytase. The results of a digestibility assay indicated that daily total P and N excretions of the negative control containing 0.2% NPP and supplemented with limiting amino acids and phytase were reduced by 48 and 45% of the positive control group, respectively, without compromising laying performance.
6-Phytase↗
Effect of enzyme addition to wheat-, barley- and rye-based diets on nutrient digestibility and performance of laying hens.
1. Laying hen performance, egg quality, intestinal viscosity and nutrient apparent digestibility were evaluated with respect to the main cereal used in the diet and dosage rate of a fungal beta-glucanase/xylanase enzyme complex. 2. Twelve diets were arranged factorially, with three soluble fibre cereals (SFC); 500 g/kg of wheat or barley or 350 g/kg of rye, and 4 enzyme concentrations (0, 250, 1250 and 2500 mg/kg). An additional control diet based on maize was also included. 3. The use of SFC in the diet instead of maize did not affect egg production or food efficiency, but hens fed on SFC diets exhibited a higher incidence of dirty eggs than hens fed on the maize diet (8-6 vs 4.6%; P<0.01). 4. Laying hens fed on enzyme-supplemented diets produced more eggs (2.1%; P<0.05) and had better food efficiency per dozen eggs (2.5%; P<005) than hens fed on non-supplemented diets. An excess of enzymes in the diet (10 times the recommended dose) did not produce any deleterious effect on laying hen productivity. 5. Enzyme supplementation (ES) reduced intestinal viscosity (P<0.001) and the incidence of dirty eggs (P<0.01). The reduction in viscosity was more pronounced in barley than in wheat or rye diets (P<0.05). 6. Apparent nutrient digestibility in SFC diets was higher with ES, including dry matter (3.1%; P=0.08), fat (4.4%; P<0.001), non-starch polysaccharides (83.3%; P<0.01) and AMEn (2.5%, P<0.01). 7. It is concluded that substitution of maize by SFC is facilitated by ES, especially with respect to egg production, food conversion efficiency and egg shell cleanliness. An excess of enzymes did not produce any deleterious effect on nutrient digestibility or performance of laying hens.
Animal Feed↗
Effect of early feed withdrawal on subsequent laying hen performance.
Two experiments evaluated the effects of short periods of feed withdrawal early in production on subsequent performance of laying hens. Laying hens of the H&N strain (22 or 20 wk of age) were full fed (control) or deprived of feed for 4 or 7 days when they reached 10% production. Egg production was evaluated for 45 wk, but other performance data were collected for 32 wk because no treatment differences existed beyond that point. Feed withdrawal for 4 and 7 days caused BW losses of 14 and 20%, respectively. In Experiment 1 (winter), BW at 2-wk postwithdrawal for hens that did not eat for 7 days were reduced (P < or = .05) compared with controls or hens that did not eat for 4 days. However, in Experiment 2 (summer), BW of hens deprived of feed for 4 or 7 days were lower (P < or = .05) than those of controls. Average early egg weight (Weeks 1 to 6) was not different among treatments in both experiments. The only observed effect of treatment on long-term egg weight was that egg weight for 7-day hens was greater (P < or = .05) than for controls in Experiment 2. Early hen-day egg production was depressed by 4- or 7-day feed withdrawal, but long-term production was not different between control and 4-day hens in both experiments. However, hen-housed production was lower (P < or = .05) for 4-day hens compared with controls in Experiment 2. Fewer (P < or = .05) eggs were produced by 7-day hens versus controls in both experiments.(ABSTRACT TRUNCATED AT 250 WORDS)
Animal Feed↗
The effects of sorghum tannin and methionine level on the performance of laying hens maintained in two temperature environments.
At the conclusion of a 31-day recovery period following a previous sorghum feeding trial (Sell et al., 1983), 128 White Leghorn hens were used in a subsequent 44-day study to investigate the effects of methionine supplementation of sorghum-soybean meal diets on laying hen performance. The hens were arrayed into four nutritional treatments in each of two constant environments (22 and 28 C) based on their egg production during the last 10 days of the recovery period within a previous treatment and environment so that equal numbers of hens from the previous treatments were represented in the new treatments. Nutritional treatments consisted of either low (RS610) or high (savanna) tannin sorghum-soybean meal diets containing 13% protein and supplemented with either .2% DL-methionine (Met) or an isonitrogenous level of L-glutamic acid (Glu). With both high (HTS) and low tannin sorghum (LTS) diets, Met supplementation resulted in greater egg production, egg weight, feed intake, and less hen weight loss as compared with Glu addition, but with the exception of hen weight loss, the magnitude of the response was much greater with HTS. Hens fed the HTS diet supplemented with Glu showed greatly reduced egg production and feed efficiency as compared with those fed LTS similarly supplemented. In contrast, little difference in egg production and feed efficiency was observed between hens fed HTS and LTS diets supplemented with Met. All parameters studied except hen weight appeared to be reduced slightly by the higher temperature.
Animals↗
Effect of atmospheric ammonia on laying hen performance.
In periods of extremely cold weather, energy conservation in a pit-type laying house usually results in a restricted ventilation rate and an increase in air pollutants particularly ammonia. Results show that 200 ppm ammonia for 17 days causes a significant loss in percent egg production and the hens lose a significant amount of weight with a reduced feed intake. Although not satisfactory, it appears that lesser amounts of ammonia (100 ppm) can be tolerated for short periods without an immediate drastic loss in laying performance if a choice has to be made between frozen waterers and cold stress versus atmospheric ammonia in the laying house.
Ammonia↗
Performance of laying hens as affected by split time and split composition dietary regiments using ground and unground cereals.
A factorial experiment was conducted to study the effects on the performance of White Leghorn X Australorp laying hens of diets based on unground cereal grains, small morning and large afternoon meals, and morning and afternoon meals of different composition. From 10 to 21 weeks of age the pullets' food intake was restricted, using either a diet in which the wheat fraction (600 g/kg) was unground or a fully ground diet of similar composition. In the laying period the birds received either a diet (U) in which the limestone was granulated and most of the cereal fraction (wheat and oats or wheat and sorghum) was unground or a fully ground diet (G) of similar composition. Both laying diets were offered ad libitum (A), with 25% issued in the morning and 75% in the late afternoon (T) or as a protein concentrate (250 g/kg of total diet) in the morning and cereal/limestone fraction (750 g/kg) in the late afternoon (C). Rearing and laying performance were unaffected by rearing diet. Laying diet U resulted in a 5.2% increase in food intake and a 0.9 g increase in average egg weight compared with diet G. From 21 to 56 weeks of age, when the cereal/limestone fraction of the diet included oats (240 g/kg of total diet), diet U resulted in fewer (4.8/bird) eggs and a lower financial margin than diet G. From 56 to 80 weeks of age, when oats were replaced by sorghum, this trend was reversed (-3.5 eggs). Birds on diet C produced fewer (16.9) eggs of lower (1.5 g) average weight than birds on diet A, ate less (1.39 kg) food and had a lower financial margin.(ABSTRACT TRUNCATED AT 250 WORDS)
Age Factors↗
Effect of duration of fasting on postmolt laying hen performance.
Two experiments were conducted to examine the effects of varying length of feed withdrawal on postmolt laying hen performance. Commercial laying hens (65 wk of age) were fed continuously or fasted for 4 or 10 days in Experiment 1 and fed continuously or fasted for 4, 7, or 14 days in Experiment 2. Egg production performance was evaluated for 35 wk of production following initiation of fasting. Hen-day egg production (Weeks 1 to 35) and egg weight (Weeks 5 to 35) did not differ between treatments in Experiment 1; however, in Experiment 2, egg production was depressed for the 14-day fasted hens compared with the fed hens. Lower egg weight also occurred for the 14-day fasted hens compared with the fed, 4-, or 7-day fasted hens in Experiment 2. Egg yield (grams of egg per hen per day) for Weeks 5 to 35 was lower for fed hens versus the 4- or 10-day fasted groups in Experiment 1, but no treatment differences occurred in Experiment 2. Feed efficiency (grams of egg per gram of feed) for Weeks 5 to 13 was not affected by length of fasting in Experiment 1, but feed efficiency of hens fasted for 14 days was lower (P less than .05) than that of hens on other treatments in Experiment 2. Egg specific gravity was highest for hens fasted for 10 or 14 days and was lowest for fed hens, with egg specific gravity for hens fasted for 4 or 7 days being intermediate (P less than or equal to .05). The results indicated that fasting periods of less than 10 days may yield satisfactory egg production and egg weight but that eggshell quality may be enhanced by using fasting periods of 10 days or longer.
Animals↗
Effect of protein and methionine levels in molt diets on postmolt performance of laying hens.
Three experiments were conducted to evaluate the effects of feeding molt diets varying in protein content and supplemental Met on postmolt layer performance. Laying hens (70, 65, or 96 wk of age) were induced to molt by fasting (feed only) until 26 to 28% body weight loss occurred. Six molt diets consisting of 16, 13, or 10% CP with or without .15% supplemental Met were then fed until egg production reached approximately 10%, at which time all hens received a 16% CP layer diet for 30 wk in Experiments 1 and 2 and for 4 wk in Experiment 3. In Experiment 1 (summer), hens regained body weight more rapidly, returned to production faster, and had larger egg weights (Weeks 1 to 4) when fed the 16 or 13% CP molt diets than when fed the 10% CP molt diet. Long-term egg production, egg yield (grams of egg per hen per day) (Weeks 1 to 30), and feed efficiency (Weeks 1 to 8) were greater for hens fed the 16 or 13% CP molt diets compared with those fed the 10% CP molt diet. The Met supplementation had no effect on postmolt performance. In Experiment 2 (winter), the only significant treatment effect was that Met supplementation increased egg weight (Weeks 1 to 30). Molt diet treatments had no consistent effect on egg specific gravity during the last 4 wk of the postmolt production period in Experiments 1 or 2. The effects of the dietary treatments on early postmolt performance in Experiment 3 (early fall) were similar to those observed in Experiment 1. The present study indicated that protein content, but not Met supplementation, in molt diets influenced postmolt performance of hens during the summer and early fall experiments, but not in the winter experiment.
Animals↗
Effect of dietary fluoride and aluminum on laying hen performance and fluoride concentration in blood, soft tissue, bone, and egg.
Changes in laying-hen performance due to the effect of graded levels of dietary fluoride (F) have been documented earlier. The present study examined the effect of dietary F and aluminum (Al) on laying hen performance, and F levels in plasma, soft tissues, muscle, bone, and eggs. Two hundred and seventy Single Comb White Leghorn (SCWL) layers were fed a basal diet containing the following F and Al levels: control; 100 ppm F; 80 ppm Al; 100 ppm F/80 ppm Al; 100 ppm F/40 ppm Al; 1300 ppm F; 1040 ppm Al; 1300 ppm F/1040 ppm Al, and 1300 ppm F/520 ppm Al. After 112 days of feeding, the blood, tissue, bone, and egg samples were collected for analysis. High F intake significantly depressed feed intake and hen-day production and elevated serum, tissue, bone, and egg F levels. Dietary Al minimized the effect of high fluoride feeding. The mean fluoride concentration for low (80 ppm Al diet) vs. high F (1300 ppm) intake was, respectively: plasma, .2 vs. 10.1 ppm; liver, 4.5 vs. 19.2 ppm; kidney, 2.9 vs. 31.8 ppm; pectoralis muscle, 3.6 vs. 6.7; tibia muscle homogenate, 3.9 vs. 21.1 ppm, and bone, 611 vs. 2600 ppm. The majority of the F transferred to the egg was incorporated into the shell (2.8 to 307.1 ppm). Low F levels were found in albumen (fresh, .4 to 1.0 ppm) and yolk (dry fat free, 3.1 to 18.4 ppm). The data suggested that dietary F is readily accumulated in bone and kidney; however, liver and muscle are less responsive.(ABSTRACT TRUNCATED AT 250 WORDS)
Alum Compounds↗
Effect of watering systems for floor-reared pullets on subsequent caged laying hen performance.
Two watering system trials were conducted with floor-reared pullets. Trial 1 showed that pullets raised on trigger cups (STC) compared to pullets raised on dome waterers (DW) had significantly better feed conversion and lower mortality. A significant difference was shown between 4 and 5 hens per cage for hen-day egg production and feed per dozen eggs. There were no differences in production responses according to cage waterer availability or for main effect interactions. Trial 2 showed that raising pullets on STC, DW, or a DW to STC change during the rearing phase had no effect on cage laying performance. Mortality trends were shown according to waterer system. Trial differences were hypothesized to be associated with the laying cage waterer type used in each trial; fount cups were used in Trial 1 and TC in Trial 2.
Animals↗
Effect of inorganic phosphate source and dietary phosphorus level on laying hen performance and eggshell quality.
Two experiments were conducted to evaluate laying hen performance when fed two sources of inorganic phosphorus. In Experiment 1, a regular and a coarse form of defluorinated phosphate and one source of dicalcium phosphate were used in diets calculated to contain either .4 or .5% total phosphorus (.2 or .3% nonphytate phosphorus). In Experiment 2, either the regular form of defluorinated phosphate or the dicalcium phosphate source was fed in diets calculated to contain either .4, .5, .6, or .7% total phosphorus (.2, .3, .4, or .5% nonphytate phosphorus). In Experiment 1, hens fed .5% total dietary phosphorus consumed more feed and produced heavier eggs (P less than or equal to .05). Hens fed the .4% dietary phosphorus level lost more weight during the experiment (P less than or equal to .05). No differences among dietary treatments existed for egg specific gravity. A significant source by level interaction occurred for the farm classification of thin-shelled, cracked, or broken eggs and for the total of these classifications. In Experiment 2, egg production, feed consumption, egg weight, and egg mass were depressed (P less than or equal to .05) at the .4% total dietary phosphorus level. Hens fed the .4 and .7% total dietary phosphorus level laid eggs with the highest and lowest egg specific gravity, respectively. This trend was inverse to the effect of these phosphorus levels on egg weights. A significant source by level interaction occurred for the farm classification of thin shell and for the total percentage of eggs with exterior defects. At the .4% total phosphorus level, the regular form of defluorinated phosphate produced eggs with a significantly greater thin shell classification than the dicalcium phosphate source. Hens fed the dicalcium phosphate source produced a higher percentage of compressed-sided and misshapen eggs.
Animals↗
Effects of genotype and feed allowance on plasma luteinizing hormones, follicle-stimulating hormones, progesterone, estradiol levels, follicle differentiation, and egg production rates of broiler breeder hens.
The aim of this study was to compare and relate plasma hormone levels of luteinizing hormone (LH), follicle-stimulating hormone (FSH), progesterone (P4), estradiol (E2), and the in vitro P4 production capacity of the largest yellow (F1) follicle granulosa cells with the laying performance of 2 genotypes (a standard S line and a dwarf cross-experimental E line) maintained under ad libitum (SA, EA) or restricted (SR, ER) feeding regimens. Age-related hormone changes were determined from 4 to 50 wk, hormone changes during the ovulatory cycle were determined during lay, and changes in follicle granulosa cell P4-producing capacity in response to LH with or without growth factors were measured in vitro at different ages. The mean laying rate was similar for SR, EA, and ER but were lower for the SA. Plasma LH and FSH concentrations increased with age in all groups and peaked at puberty. Restricted feeding delayed puberty in both genotypes. Concentrations of E2 and P4 increased after puberty in all groups but delayed in restricted hens. Plasma levels of LH, FSH, P4, and E2 before and after puberty were not correlated with egg-laying performance, but peak E2 levels were. Luteinizing hormone and P4 concentrations during the ovulatory cycle showed differences that may be associated with the different laying performances of the 2 genotypes under ad libitum and restricted feeding. The increase in plasma LH concentration (from basal) during the preovulatory surge was higher in the SR than in the SA but was similar for EA, ER, and SA. The increase in P4 was also higher in SR than in the SA with no difference between EA and ER. In vitro P4 production by granulosa cells in response to LH with insulin-like growth factors, and bone morphogenetic protein-7 was different among the SA, SR, EA, and ER; the EA, SR, and ER had greater responses, and the SA had less response. The presence of insulin-like growth factors and bone morphogenetic protein-7 enhanced LH effects depending on the feeding regimen and age of hen. This finding suggests that differences in laying performances among genotypes fed at different nutritional levels may be partly due to differences in processes associated with follicular maturation modulated by gonadotropins and growth factors. It is concluded that the age at puberty is determined mainly by feed allowance, irrespective of genotype, and that differences in laying performance may be due to a combination of factors that include changes in the levels of gonadotropins or ovarian hormones and growth factors, BW, and the condition of the different genotypes under different feeding allowances.
Aging↗