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PubMed2005

Temperature compensation of neuromuscular modulation in aplysia.

Physiological systems that must operate over a range of temperatures often incorporate temperature-compensatory mechanisms to maintain their output within a relatively narrow, functional range of values. We analyze here an example in the accessory radula closer (ARC) neuromuscular system, a representative part of the feeding neuromusculature of the sea slug Aplysia. The ARC muscle's two motor neurons, B15 and B16, release, in addition to ACh that contracts the muscle, modulatory peptide cotransmitters that, through a complex network of effects in the muscle, shape the ACh-induced contractions. It is believed that this modulation is critical in optimizing the performance of the muscle for successful, efficient feeding behavior. However, previous work has shown that the release of the modulatory peptides from the motor neurons decreases dramatically with increasing temperature. From 15 to 25 degrees C, for example, release decreases 20-fold. Yet Aplysia live and feed successfully not only at 15 degrees C, but at 25 degrees C and probably at higher temperatures. Here, working with reduced B15/B16-ARC preparations in vitro as well as a mathematical model of the system, we have found a resolution of this apparent paradox. Although modulator release decreases 20-fold when the temperature is raised from 15 to 25 degrees C, the observed modulation of contraction shape does not decrease at all. Two mechanisms are responsible. First, further downstream within the modulatory network, the modulatory effects themselves-experimentally dissected by exogenous modulator application-have temperature dependencies opposite to that of modulator release, increasing with temperature. Second, the saturating curvature of the dose-response relations within the network diminishes the downstream impact of the decrease of modulator release. Thus two quite distinct mechanisms, one depending on the characteristics of the individual components of the network and the other emerging from the network's structure, combine to compensate for temperature changes to maintain the output of this physiological system.

Animals↗

PubMed1986

Effect of lipids in milk replacers on calf performance and lipids in blood plasma, liver, and perirenal fat.

Various fats (20% of dry matter) were fed in milk replacer to calves, from 3 to 31 d of age, to compare their effect on calf performance, feed efficiency, and lipids in blood plasma, liver, and perirenal fat. Dietary fats tested were tallow (control), canola oil, canola soapstocks, corn oil, reclaimed restaurant cooking fat, and a high phospholipid waste product. Corn oil plus tallow (1:1) diet promoted scours and poor calf gains, but canola oil diet, despite a high content of unsaturated fatty acids, gave excellent calf performance and feed utilization and no scours. Canola soapstocks plus tallow (1:1) and restaurant waste cooking fat lowered gains by 25 and 15% and reduced diet intake. Calves effectively utilized high phospholipid (23%) in dietary lipids. Main lipid classes in blood plasma were cholesterol esters and phosphatidylcholine, and in liver phosphatidylethanolamine and phosphatidylcholine. Fatty acid composition of the major blood plasma and liver lipids, and of perirenal fat, tended to reflect dietary fatty acid concentrations.

Adipose Tissue↗

PubMed2006

Evaluation of dried and wet distillers grains included at two concentrations in the diets of lactating dairy cows.

The purpose of this study was to determine the lactation performance of dairy cows fed dried or wet distillers grains (DG) with solubles (DDGS or WDGS) at 2 dietary concentrations. A trial using 15 cows was designed as a replicated 5 x 5 Latin square with periods of 4 wk each and data collected during wk 3 and 4 of each period. Diets, on a dry matter basis, were: control, 10% DDGS, 20% DDGS, 10% WDGS, and 20% WDGS. All diets contained 25% corn silage, 25% alfalfa hay, and 50% of the respective concentrate mixes. Dry matter intake (DMI) tended to be greater for cows fed control than DG (23.4, 22.8, 22.5, 23.0, and 21.9 kg/d for control, 10% DDGS, 20% DDGS, 10% WDGS, and 20% WDGS). Milk yield (39.8, 40.9, 42.5, 42.5, and 43.5 kg/d) was greater for cows fed DG than control. Milk fat percentage (3.23, 3.16, 3.28, 3.55, and 3.40%) was similar for cows fed control and DG, but greater for cows fed WDGS than DDGS. Milk fat yield was greater for cows fed DG than control and tended to be greater for cows fed WDGS than DDGS. Milk fat from cows fed DG, especially 20% DG, was more unsaturated and contained more cis-9, trans-11 conjugated linoleic acid than when fed the control diet. Milk protein percentage (3.05, 3.01, 3.02, 3.11, and 3.06%) was similar for cows fed control and DG but greater for cows fed WDGS than DDGS. Milk protein yield was greater for cows fed DG than control, tended to be greater for cows fed WDGS than DDGS, and tended to be greater for cows fed 20% DG than 10% DG. Milk urea nitrogen was similar for cows fed control and DG but greater for cows fed WDGS than DDGS and tended to be higher for cows fed 20% DG than 10% DG. Ruminal ammonia concentrations were greater for cows fed WDGS than DDGS. Overall, feeding DG improved feed efficiency (1.70, 1.79, 1.87, 1.84, and 1.92 kg of energy-corrected milk/kg of DMI) by increasing yields of milk, protein, and fat while tending to decrease DMI.

Ammonia↗

PubMed1985

Development of a basal diet to study broiler chicken responses to the sulfur-containing amino acids and sodium sulfate.

Three experiments were conducted to develop a basal diet limiting in the sulfur-containing amino acids and with adequate sodium. Twelve hundred commercial male broiler chicks were grown to 3 weeks of age in battery brooders. Chicks were fed a diet of a corn-soybean meal-poultry oil containing .38% methionine, .74% total sulfur-containing amino acids, and .10% sodium. The first two experiments, pooled for statistical analyses, showed that supplementation with .25% L-methionine significantly increased chick growth over the basal (496 vs. 465 g; P = .034) as did sodium supplementation (518 vs. 465 g; P less than .001). The best growth rate occurred when L-methionine and sodium chloride (NaCl) were supplemented together at .25 and .33%, respectively (579 g gained). The response from NaCl was demonstrated to be due to the sodium and not the chlorine by comparison to responses from potassium chloride (KCl) and sodium carbonate (Na2CO3) supplementation. It is suggested that two "first-limiting" nutrients, methionine and sodium, exist for chicks fed this particular diet. In Experiment 3, a response surface was determined with supplemental sodium (as NaCl) and L-methionine each varying from 0 to .20% (.10 to .30% total sodium and .38 to .58% total methionine). It was concluded that .20% total sodium is adequate to maximize growth and feed efficiency (.20% better than .13%, no different from .27%). Similarly, .17% supplemental methionine (.55% total) appears to be adequate (.17% better than .10%; .20% not better than .17%) with no supplemental choline.

Amino Acids, Sulfur↗

PubMed1990

Response of male poults to high levels of dietary niacinamide.

The response was determined of male poults to high levels of dietary niacinamide, when maintained in a stressful environment of high stocking density and high litter moisture induced by excess dietary NaCl. The experiment was designed as a factorial (2 by 2 by 2) with 70 versus 140 mg of niacinamide per kg; .3 versus 1% NaCl; 7 versus 14 birds per m2. Each treatment was assigned to 6 pens, with either 20 or 40 males per pen depending on stocking density. The calculated niacin content of the basal diet was 22 mg per kg; the experimental diets contained 92 and 162 mg of total niacin per kg. Added niacinamide at 140 mg per kg increased the body weight at 8 wk of age (3,095 versus 3,198) at .3% dietary NaCl. The response to 140 mg per kg of niacinamide was 4.6% at .3% NaCl and only 1.9% at 1% NaCl. The high level of niacinamide was ineffective in terms of alleviating the growth depression induced by a high stocking density. Treatment effects were not detected in relation to feed efficiency. The incidence of leg abnormalities was not influenced by dietary niacinamide or by litter moisture, but was aggravated by a high stocking density. The treatments did not induce ascites or macroscopic lesions in the heart or kidney. These findings demonstrated that supplemental niacinamide at 140 mg per kg, in a basal diet calculated to contain 22 mg of niacin per kg of feed, will produce a significant increase in the weight gain of male poults at 8 wk of age under praxis conditions when dietary salt is at .3%, but not at 1%.

Animals↗

PubMed1991

Genetic correlations among growth, feed, and carcass traits of broiler sire and dam populations.

Genetic correlations based on sire variance and covariance components were estimated for broiler traits. Data were collected from various selected and control strains of sire and dam populations during five generations of selection. Results of analyses of variance for each of the strains within generations and populations were pooled across strains and generations. Correlations between body and carcass weights were all above .8. Weight gain (WG) had similar correlations with these traits with the exception of body weight at 28 days (.57 in site and .69 in dam populations). Body and carcass weights and WG had high correlations with feed consumption (FC) (greater than .7); however, values for feed efficiency (FE) varied: -.58, -.23 for 28-day body weight; -.17, .16 for 42-day body weight; .25, .43 for WG; and .53 in the dam population for carcass weight. Correlations of body and carcass weights and WG with abdominal fat weight (AFW) and percentage (AFP) were generally small to moderate with values being about half as large for AFP as for AFW. Feed consumption and FE were negatively correlated (-.51, -.22) in both populations. In the dam population, FC was positively correlated with AFW and AFP (.42, .55) but FE was negatively correlated with these traits (-.41, -.70). Abdominal fat weight and AFP were highly correlated (.99, .97). Values tended to be similar not only for these populations but also for this and other studies. Simultaneous genetic improvement of growth rate, FE and carcass leanness is feasible in broilers. Selection for WG, FE, and AFP should be effective.

Adipose Tissue↗

PubMed1986

Trends of performance in Arkansas cooperative beef-bull performance tests from 1962 through 1982.

Individual records of performance of 2787 bulls in cooperative beef-bull performance tests from 1962 through 1982 were analyzed to determine trends in final weight, average daily gain, daily feed consumption and gross feed efficiency. Data from Angus, Polled Hereford, Charolais, Hereford and Santa Gertrudis breeds were analyzed separately. Performance-test procedures and the ration fed remained the same in all tests. Least-squares means by year, adjusted for location of test, initial weight, initial age and initial condition score, were regressed on time to determine average yearly change in the traits. Yearly changes for Angus, Polled Hereford, Charolais, Hereford and Santa Gertrudis breeds in final weight were 3.3, 1.6, 3.3, 2.5, and 2.6 kg, respectively; in average daily gain and yearly changes were .02, .01, .02, .02, and .02 kg, respectively; in daily feed consumption the yearly changes were .08, .03, .09, and .04 kg, respectively; and in feed per kg gain the yearly changes were -.08, -.04, -.05, -.03, and -.07 kg, respectively. Because the test procedures were the same in all years, these trends represent genetic progress made by the Arkansas beef industry toward faster-gaining, more efficient cattle.

Animals↗

PubMed1986

Diurnal patterns in homecage behavior of rats after acute exposure to triethyltin.

Diurnal patterns of eating, drinking, locomotor activity, and rearing in male Fischer-344 rats were examined for 11 days after a single oral dose of triethyltin bromide (TET) at 0, 1.5, 3, or 5 mg/kg. The 5 mg/kg group exhibited a time-related drop in food consumption and body weight until 3 of 10 rats were sacrificed moribund 11 days after dosing. Doses of 1.5 and 3 mg/kg TET did not reduce body weight or consumption of food and water. In contrast, food consumption was significantly increased 7 and 11 days after 3 mg/kg TET, and diurnal patterns of eating and drinking were disrupted 7 days after 3 and 5 mg/kg TET. A phase shift in licking patterns was induced by the high dose. Unlike trimethyltin (TMT), TET did not affect efficiency of eating. Diurnal patterns of both horizontal and vertical activity were disrupted at all dose levels on Day 2 after dosing; by 16 days after dosing, recovery was evident in all rats including those surviving 5 mg/kg TET. These results show that a near-lethal dose of TET produced a reversible syndrome of hypoactivity, aphagia, and weight loss similar to that seen after acute TMT; in the absence of the above signs, diurnal patterns of behavior revealed effects of TET at doses as low as 1.5 mg/kg; the magnitude of the effect depended on the time of day at which the response was measured; and TET did not produce the same effects on ingestive behaviors (polydipsia and reduced feeding efficiency) that were previously observed after acute TMT.

Animals↗

PubMed1977

Effect of dietary restrictions and source of rats on growth rate and efficiency of conversion of food into muscles, bones and organs.

Differences in weight of the body, six different skeletal muscles, epididymal fat pads, three different bones, spleen, heart, kidneys, testes and liver were observed in 21-day-old male Sprague-Dawley rats from two different suppliers. All rats were pair-fed a 10% casein diet ad libitum, 10%, 20%, 30% restricted for 4 or 8 weeks. Original body and tissue weight differences between the two strains of rats were maintained in all diets during the 4 and 8 week feeding periods. Trends in body and tissue weight changes due to dietary restriction were similar in both strains of rats. Diet restrictions for 4 or 8 weeks caused similar patterns of weight decrease in most tissues. Feed efficiency ratio (FER) was reduced significantly at the 20% and 30% restriction for 4 weeks only in the lighter strain of rats. FER was higher in the heavier strain than in the lighter strain of rats at all levels of diet restriction. Food conversion efficiency with reduced food intake was constant or decreased depending on the skeletal muscle studied; decreased significantly for epididymal fat pad, bone weight (one strain only), kidneys and liver (one strain only) with the 30% reduced diet for 4 weeks; and increased for bone length and testes weight. Therefore, significant deviations from ad libitum controls were found only at 30% diet restriction, and the wide differences in body and tissue weight of two strains of Sprague-Dawley rats did not affect the interpretation of results when fed the same restricted diets.

Adipose Tissue↗

PubMed2002

Use of Tenebrio molitor (Coleoptera: Tenebrionidae) to recycle organic wastes and as feed for broiler chickens.

Several dried waste materials from different origins were used as a substrate to grow Tenebrio molitor L. Nutrient/amino acid values differed depending on both larval size/weight and substrate. These larvae were experimentally used as a broiler feedstuff. Seven-day-old chicks of a commercially available strain with an average weight of 126 g were randomly distributed into nine six-broiler groups. Three levels of Tenebrio molitor larvae (0, 5, and 10% dry weight) were used in a 19% protein content sorghum-soybean meal basal diet, to evaluate feed intake, weight gain, and feed efficiency. Results after 15 d showed no significant differences among treatments. These data indicate that Tenebrio molitor has the potential to be used as protein source for raising broilers.

Animal Feed↗

PubMed2000

The toxicity of purified fumonisin B1 in broiler chicks.

An investigation of the toxicity of fumonisin B1 (FB1), a toxic metabolite of Fusarium moniliforme, in broiler chicks was conducted. Purified FB1 (98.1% pure) was incorporated into the diets of broiler chicks at 0, 20, 40, and 80 mg/kg, and fed to chicks from 0 to 21 d of age. Dietary FB1, at concentrations of 80 mg/kg or less, did not adversely affect body weight, feed efficiency, or water consumption of broiler chicks. The relative weights of the liver, spleen, kidney, proventriculus, and bursa of Fabricius were also unaffected (P < 0.05) by any dietary concentration of FB1 compared with the control (0 mg/kg) group. Total liver lipids of chicks fed 40 or 80 mg FB1/kg were significantly lower than those of the chicks fed either 0 or 20 mg FB1/kg of feed. Liver sphinganine concentration and the sphinganine:sphingosine ratio were increased significantly in all treated groups. Chicks fed dietary FB1 at 80 mg/kg had significantly higher serum glutamate oxaloacetate aminotransaminase:aspartate aminotransferase ratios and levels of free sphinganine in the serum. The results of this investigation agree with the results previously described, in which FB1 was supplied to diets from the use of F. moniliforme-contaminated grain; therefore, the use of such material as the source of the mycotoxin in animal feeding studies is appropriate.

Alanine Transaminase↗

PubMed1975

Effect of drinking water temperature on broiler performance.

In the first experiment, higher body weight gain and feed comsumption were attained with water at a temperature of 23.9 degrees C. as compared with 35.0 degrees C. No significant differences in feed efficiency due to water temperature were evident. Livability was significantly reduced during brooding for the birds given warm water (35.0 degree C). A significant interaction for body weight gain was observed between the initial ambient air brooding temperatures and water temperatures during the growing period. In the second experiment six water temperatures during brooding to three weeks of age were studied. Body weight gain and feed comsumption were significantly depressed at a drinking water temperature of 40.6 degrees C. as compared with drinking water temperatures between 17.8 degrees C. and 35.0 degrees C. No differences in livability were noted which was in contrast to the results of the first experiment. A drinking water temperature below ambient air temperature is apparently beneficial to the growth of the broiler chick. The placement of the waterers in relation to the brooder stoves could influence water temperature which would affect the growth of broilers.

Acclimatization↗

PubMed2025

Nutrigenomics: A tool to unlock genetic potential of Nigerian indigenous goat breeds.

Nigerian indigenous goats represent a valuable genetic resource for meat and milk production. However, their productivity often falls below their genetic potential because of sub-optimal nutrition. Nutrigenomics offers a revolutionary approach to bridge this gap by exploring the interactions between nutrients and goat genes. This study explores how nutrigenomic tools can be used to identify gene variants associated with feed efficiency, meat quality, and milk production. Various technologies are designed to ensure the realization of genetic potential. Nutrigenomics is aimed at exploiting the noncoding section of an individual's genome, which is disregarded in traditional animal nutrient requirement assessment. Nutrigenomic technology has the potential to unlock the genetic potential of animals and essentially help to confront nutritional challenges and sub-optimal use of available feed resources, particularly in Nigerian indigenous goats, of which there is a dearth of information on their nutritional needs and requirements. This review discusses the potential of nutrigenomics to unlock the genetic potential of Nigerian indigenous goats. In addition, the review discusses the challenges and future directions of nutrigenomic research in Nigerian goats. By implementing nutrigenomic strategies, Nigerian goat production can be revolutionized, leading to increased productivity, improved product quality, and enhanced farmer livelihoods. It is hoped that this review will provide vital information to aid research into the nutrigenomics potential of unlocking the genetic potentials and reproductive performance of Nigerian indigenous goats through nutrition.

Animals↗

PubMed2003

Effects of microflora status, dietary bile salts and guar gum on lipid digestibility, intestinal bile salts, and histomorphology in broiler chickens.

The aim of the present study was to reexamine the effects of intestinal viscosity, microflora, and bile salts, and their interactions in order to clarify the mechanisms that explain the effect of intestinal viscosity on lipid digestibility, especially those that could involve microflora. Effects of intestinal viscosity, microflora status, and dietary bile salts on lipid digestibility, intestinal bile salts, and intestinal histomorphology were tested in a 2 x 2 x 2 factorial experiment. The effect of microflora status was examined by comparing conventional chickens to chickens with limited microflora obtained by rearing birds in sterilized conditions. Viscosity and dietary bile salts were tested with guar gum (0 or 0.5% in diets) and sodium taurocholate (0 or 0.3% in diets), respectively. Guar gum was autoclaved and added to the gamma-irradiated diets by mixing inside the sterile isolators. The intestinal concentration of lactic acid and cecal concentration of short-chain fatty acids were both very low in birds with limited microflora compared to conventional birds (P = 0.0001). Chickens with limited microflora had higher gain:feed ratios (P = 0.002), higher fecal lipid digestibility (P = 0.0001), more intestinal conjugated bile salts (P = 0.0001), less intestinal unconjugated bile salts (P = 0.0001), and their gastrointestinal compartments were smaller (P < 0.05) than those of conventional chickens. Addition of bile salts in diets increased the lipid digestibility (P = 0.0001) with a more pronounced effect in conventional birds (P = 0.0001) and in birds fed on guar gum diets (P = 0.002). Feeding the guar gum diets increased the intestinal supernatant viscosity (P = 0.0001) for both microflora status. Guar gum addition increased (P < 0.05) the lactic acid concentration in the small intestine of conventional chickens. Guar gum decreased the fecal lipid digestibility (P = 0.0001) and the intestinal conjugated bile salts (P = 0.0001) for both microflora status. However, the magnitude of lipid digestibility decrease due to guar gum was lower (P = 0.05) in birds with limited microflora than in conventional birds, and the negative effect of guar gum on intestinal conjugated bile salts was more pronounced (P = 0.02) in birds with limited microflora. Bile salt addition reduced the negative effect of guar gum on lipid digestibility (P = 0.02) for both microflora status. The mean lipid digestibilities were negatively correlated (P = 0.0001) with the ratio [Ln(viscosity)/total bile salt] measured in intestinal digesta. Except for gizzard, size of digestive compartments and villus heights increased (P < 0.05) with feed efficiency and digestibility decreased. In conclusion, the results provided evidences that the negative effect of guar gum on lipid digestibility was mainly mediated by its direct effect on intestinal bile salt concentration and efficiency. The small interaction between guar gum and microflora status effects on lipid digestibility had to be accounted for by the low basal level of intestinal bile salts in conventional chickens.

Animal Feed↗

PubMed2003

Efficacy of high available phosphorus corn in laying hen diets.

Our objective was to determine if high available phosphorus corn would provide sufficient available phosphorus (AP) to laying hens fed corn-soybean meal diets from 57 to 69 wk of age. Six replications of 12 Dekalb Sigma Leghorn hens were fed a normal yellow dent (YD) corn-soybean meal diet or high available phosphorus (HAP) corn-soybean meal diet without and with 0.04% supplemental inorganic P. The unsupplemented YD diet was calculated to contain 17% CP, 3.8% Ca, and 0.10% AP, and the unsupplemented HAP diet contained 17% CP, 3.8% Ca, and 0.16% AP. In addition, a positive control, YD diet (17% CP, 3.8% Ca, 0.45% AP) was also fed. The HAP corn was directly substituted for YD on a weight basis, and the amount of soybean meal was kept constant in all diets. Egg production, hen body weight, egg weight, egg mass, feed consumption, and feed efficiency were measured. The YD and the YD + 0.04% P treatments were terminated at 61 and 65 wk of age, respectively, due to severe depressions in egg production. Egg production and egg mass for hens fed HAP diets were not different (P > 0.05) from those of hens fed the 0.45% AP diet; however, hens fed the unsupplemented HAP diet did have lower hen body weights and feed intake (P < 0.05) compared to hens fed the positive control diet. Our results indicate that HAP corn contains more available P than normal YD corn and that hens can be fed HAP corn-soybean meal diets containing little or no P supplementation with only minimal effects on production performance.

Animal Feed↗

PubMed1984

Abdominal fat deposition and sudden death syndrome in broilers: the effects of restricted intake, early life caloric (fat) restriction, and calorie: protein ratio.

The effects of feed restriction, early life fat restriction, and calorie:protein ratio on abdominal fat pad development and sudden death syndrome (SDS) in the broiler chicken were studied in two experiments. In Experiment 1, restricting feed intake to 90% of ad libitum intake was found to reduce significantly (P less than .01) both 49-day body weights and abdominal fat pad size while feed efficiency was significantly (P less than .01) improved compared to groups fed a wheat diet ad libitum. Corn-fed birds tended to outperform wheat fed groups. Reduced growth rate or supplementation of the diet with additional vitamins and minerals did not effect the incidence of SDS. In Experiment 2, fat restriction in the diet from 0 to 7 days initially reduced growth rate and increased feed:gain ratios. By 49 days, no effect of fat restriction on these parameters was observed. Dietary fat restriction tended to increase abdominal fat measured at 49 days of age. Lowering the calorie: protein ratio of the finishing diet significantly (P less than .05) improved feed:gain ratios measured from 29 to 49 days and tended to reduce fat pad size. Incidence of SDS was significantly (P less than .05) lower from 29 to 56 days in groups fed the 24% protein finisher diet as compared to birds fed a 19% finisher diet.

Abdomen↗

PubMed2004

The effects of hen vocalizations on chick feeding behavior.

The purpose of this study was to determine if playing hen calls at the feeder affects broiler chick productivity and welfare. Hatched chicks (n = 832) were equally placed into 16 pens. Broilers in 8 treated pens received 3 min of hen-feeding calls once each hour during the first 9 d of age; broilers in the other 8 pens received no recorded hen vocalizations during the same period. After d 9, recorded hen vocalizations ceased and all birds were treated identically. Through 9 d of age, chicks receiving recorded hen vocalizations had improved (P < or = 0.05) feed conversion ratios, and these chicks weighed more (139.12+/-1.52 g vs. 133.17+/-1.59 g for control chicks; P < or = 0.01). The behavior data showed that on d 1, 4, and 7, more (P < or = 0.05) chicks receiving recorded hen vocalizations were found within 0.61 m of the speaker than control chicks. Following recorded hen vocalization cessation on d 9, birds and feed were weighed on 17, 24, 31, and 38 d of age, and carcass yield was measured on d 40. There were no differences in BW, feed efficiency, or carcass yield after recorded hen vocalization ceased. These data suggest that after d 9, differences became nonsignificant, corresponding to when recorded hen vocalization stopped. Behavior data demonstrated that chicks appear to be attracted when stimulated with recorded hen vocalizations, thus remaining in close proximity to the speaker. Evidence suggests that hen vocalization improves production and attraction to hen vocalization with known improvements in BW and feed conversion during the first 9 d posthatch.

Animal Husbandry↗

PubMed2006

A study on the interaction of xylanase and phytase enzymes in wheat-based diets fed to commercial white and brown egg laying hens.

A trial was conducted to investigate potential interactions between phytase and xylanase enzymes in wheat-based laying diets. Hens (480 ISA-White and 480 ISA-Brown) were distributed into 160 experimental units and fed one of 10 diets containing 75 to 77% wheat from 33 to 64 wk of age with a diet change at 49 wk. Two diets were adequate in P content (0.3 and 0.25% available P in the 2 phases) with or without xylanase (0 or 2,000 U/kg; Avizyme 2300, Danisco Animal Nutrition, Marlborough, Wiltshire, United Kingdom), and 8 diets had reduced P (0.2 and 0.15% available P) with or without xylanase and phytase (0, 300, 500, and 700 ppu/kg; Phyzyme 5000G, Danisco Animal Nutrition). Egg production was higher for ISA-Brown than for ISA-White hens, and ISA-Brown hens were larger. Eggs from ISA-Brown hens had lower albumen height; higher egg, shell, and albumen weights; and lower yolk weight than those from ISA-White hens. Egg production was not affected by the diet. In P-reduced diets without xylanase, phytase significantly increased BW gain in the first period with no change in feed intake or feed efficiency. In P-adequate diets, xylanase increased egg and albumen weight and albumen height. In P-reduced diets with xylanase, increasing levels of phytase increased egg and albumen weight. This trial demonstrated no negative interactions between these enzymes for production traits and no interactions between the diet and strain of hen. These data suggest that poultry producers can use these enzymes individually or together in feed for the Brown and White egg layers used in this study without concern for the strain of hen.

6-Phytase↗