Interactive effects of sodium zeolite A (Ethacal) and monensin in uninfected and Eimeria acervulina-infected chicks

Effects of monensin sodium and live attenuated oocyst vaccine as coccidiosis management programs on productive performance, bone quality and mineral utilisation in broiler chickens

1. The following study was conducted to evaluate the influence of coccidiosis vaccine-induced metabolic stress on the utilisation of minerals in broilers. The starter, grower and finisher phase diets, including macro- and micro minerals at the recommended levels for the breed standards, were fed to chickens between 1 and 39 d of age.2. A total of 486, one-d-old male broilers were randomly distributed into three coccidiosis management programs (CMP) with six replications each. The CMP comprised: monensin sodium (MON), coccidiosis vaccine (VAC), not treated with MON or VAC (CNT).3. No significant differences between CMP were observed for body weight and weight gain among treatments. When compared to the CNT, the VAC program increased feed intake (P < 0.05) between d 1 to 13 and 14 to 26, while FCR worsened in the latter (P < 0.05) and the former (P = 0.05) periods.4. For birds in the MON and VAC programs, tibia bone length at d 13 and bone diameter at d 39 were both enhanced (P < 0.05). Meat yield characteristics were comparable among the CMP.5. Faeces of VAC birds had a lower (P < 0.05) dry matter and ash content than those in CNT program. CMP had no effect on serum or bone mineral concentrations at any point in time. For minerals, Mg, Na, and K faecal excretion was reduced (P < 0.01) as a result of the VAC program at d 13 with a trend at d 26.6. Compared to the CNT, the VAC program decreased the percentage ratio of drip loss (P = 0.08), water holding capacity (P < 0.01) and cooking loss (P < 0.01) in breast meat.7. Overall, the results showed that current broiler industry practices are capable of meeting the mineral needs of broilers vaccinated against coccidiosis.

Dietary vitamin D improves performance and bone mineralisation, but increases parasite replication and compromises gut health in Eimeria-infected broilers

Coccidial infections reduce fat-soluble vitamin status and bone mineralisation in broiler chickens. We hypothesised that broilers infected with Eimeria maxima would benefit from increased dietary supplementation with vitamin D (vitD) or with 25-hydroxycholecalciferol (25(OH)D3 or 25D3). Broilers were assigned to diets with low (L) or commercial (M) vitD levels (25 v. 100 μg/kg) supplemented as cholecalciferol (D3) or 25D3. At day 11 of age, birds were inoculated with water or 7000 E. maxima oocysts. Pen performance was calculated over the early (days 1-6), acute (days 7-10) and recovery periods (days 11-14) post-infection (pi). At the end of each period, six birds per treatment were dissected to assess long bone mineralisation, plasma levels of 25D3, Ca and P, and intestinal histomorphometry. Parasite replication and transcription of cytokines IL-10 and interferon-γ (IFN-γ) were assessed at day 6 pi using quantitative PCR. Performance, bone mineralisation and plasma 25D3 levels were significantly reduced during infection (P < 0·05). M diets or diets with 25D3 raised plasma 25D3, improved performance and mineralisation (P < 0·05). Offering L diets compromised feed efficiency pi, reduced femur breaking strength and plasma P levels at day 10 pi in infected birds (P < 0·05). Contrastingly, offering M diets or diets with 25D3 resulted in higher parasite loads (P < 0·001) and reduced jejunal villi length at day 10 pi (P < 0·01), with no effect on IL-10 or IFN-γ transcription. Diets with M levels or 25D3 improved performance and mineralisation, irrespective of infection, while M levels further improved feed efficiency and mineralisation in the presence of coccidiosis.

Eimeria challenge adversely affected long bone attributes linked to increased resorption in 14-day-old broiler chickens

There is limited information on the effects of enteric pathogen on bone quality in rapidly growing broiler chicks. We examined tibia and femur attributes (length, diameter, relative weight of ash content [AC] to the BW, ash concentration [AP]) and serum bone-turnover markers including receptor activator of nuclear factor kappa-B ligand (RANKL) for resorption, alkaline phosphatase (ALP) for mineralization, and selected serum metabolites in 14-day-old broilers challenged with Eimeria. A total of 160 (80 males and 80 females) 1-day-old Ross × Ross 708 chicks were used. Based on BW, birds were placed within sex in cages (5 birds per cage) and fed chick starter diets to day 9 of age. On day 9, half of the cages were orally gavaged with 1 mL of Eimeria culture (100,000 oocysts of E. acervulina and 25,000 oocysts of E. maxima) and the other half (unchallenged control) received 1 mL 0.9% saline in distilled water. On day 14, 2 birds were randomly selected and necropsied for intestinal lesion score, blood, tibia, and femur samples. Data were analyzed in a 2 (challenged vs. unchallenged) × 2 (males vs. females) factorial arrangement. There was no interaction (P > 0.05) between Eimeria and sex on any measurement. Whereas there were no intestinal lesions in unchallenged birds, Eimeria resulted in lesion score (0 to 4) of 3.35, 2.59 and 0.11 in duodenum, jejunum and ileum, respectively. Eimeria challenge decreased (P < 0.05) tibia AC and AP by 10 and 8.2%, respectively but had no (P > 0.10) effect on femur attributes. Generally, males showed (P < 0.05) longer and wider bones with more AC compared with the female. Circulating serum RANKL concentration increased (P = 0.017) in response to Eimeria challenge and was negatively correlated with tibia AC (-0.731; P = 0.021). Our findings showed that Eimeria damage to the intestinal physiology had adverse effects on long bone attributes linked to increased resorption.

Does selection for growth rate in broilers affect their resistance and tolerance to Eimeria maxima?

Chickens exhibit varied responses to infection with Eimeria parasites. We hypothesise that broilers selected for increased growth rate will show lower resistance and tolerance to a coccidian challenge. 288 chickens of fast (F) or slow (S) growing lines were inoculated with 0 (control), 2500 (low-dose), or 7000 (high-dose) sporulated E. maxima oocysts at 13 days of age in two consecutive rounds. Gain and Intake were measured daily and their values relative to BW at the point of infection were calculated over the pre-patent (days 1-4 post-infection), acute (d5-8 pi), and recovery (d9-12 pi) phases of infection to assess the impact of infection. Levels of plasma carotenoids, vitamins E and A, long bone mineralisation, caecal microbiota diversity indices, and histological measurements were assessed at the acute (d6 pi) and recovery stage (d13 pi). In addition, we measured the levels of nitric oxide metabolites and the number of parasite genome copies in the jejunumat d6pi. In absolute terms F birds grew 1.42 times faster than S birds when not infected. Infection significantly reduced relative daily gain and intake (P < 0.001), with the effects being most pronounced during the acute phase (P < 0.001). Levels of all metabolites were significantly decreased, apart from NO which increased (P < 0.001) in response to infection on d6pi, and were accompanied by changes in histomorphometric features and the presence of E. maxima genome copies in infected birds, which persisted to d13pi. Furthermore, infection reduced tibia and femur mineralisation, which also persisted to d13pi. Reductions in measured variables were mostly independent of dose size, as was the level of parasite replication. The impact of infection was similar for S and F-line birds for all measured parameters, and there were no significant interactions between line x dose size on any of these parameters. In conclusion, our results suggest that line differences in productive performance do not influence host responses to coccidiosis when offered nutrient adequate diets.

The physiological response of broiler chickens to the dietary supplementation of the bacteriocin nisin and ionophore coccidiostats

The aim of this study was to investigate the effect of dietary supplementation with nisin alone or in combination with salinomycin or monensin on broiler chickens in terms of growth performance, selected blood parameters, digestive enzyme activity, apparent nutrient digestibility, and tibiotarsus mineralization, as well as selected gastrointestinal tract (GIT) organ weights, intestinal length, and central immune organ weights. Two independent experiments, each including 400 one-day-old female Ross 308 chicks differing in ionophore coccidiostats, i.e., salinomycin and monensin supplementation, were conducted. The following treatments were applied: experiment 1: NA-no additives, SAL-salinomycin (60 mg/kg diet), NIS-nisin (2,700 IU/kg diet), SAL+NIS-salinomycin (60 mg/kg diet) and nisin (2,700 IU/kg diet); experiment 2: NA-no additives, MON-monensin (100 mg/kg diet), NIS-nisin (2,700 IU/kg diet) and MON+NIS-monensin (100 mg/kg diet) and nisin (2,700 IU/kg diet). The addition of nisin with or without ionophores to the birds' diet improved broiler growth performance in terms of BWG and FCR (days 1 to 14) and BWG and FI (15 to 35 d; 1 to 35 d). Salinomycin showed effects similar to those of nisin influence on growth performance (1 to 35 d), while monensin supplementation resulted in lower BWG. Moreover, no additive effect between nisin and ionophores was observed. Nisin and salinomycin had no influence on the serum concentration of selected hormones and other blood biochemical parameters except glucose, which was reduced by nisin. A decrease in lipase activity was observed during nisin and salinomycin supplementation, while the apparent ileal digestibility of fat was not affected. However, the digestibility of crude protein increased with nisin administration. Additionally, the effects of nisin on decreasing the weight and length of GIT segments were observed. Supplementation with nisin and monensin was not associated with a negative impact on tibiotarsus mineralization and the immune organ index. This study suggests that nisin may be used in broiler nutrition as a growth promotor, with no negative influence on the bird's metabolism or immune status.

Bone formation controlled by biologically relevant inorganic ions: role and controlled delivery from phosphate-based glasses

The role of metal ions in the body and particularly in the formation, regulation and maintenance of bone is only just starting to be unravelled. The role of some ions, such as zinc, is more clearly understood due to its central importance in proteins. However, a whole spectrum of other ions is known to affect bone formation but the exact mechanism is unclear as the effects can be complex, multifactorial and also subtle. Furthermore, a significant number of studies utilise single doses in cell culture medium, whereas the continual, sustained release of an ion may initiate and mediate a completely different response. We have reviewed the role of the most significant ions that are known to play a role in bone formation, namely calcium, zinc, strontium, magnesium, boron, titanium and also phosphate anions as well as copper and its role in angiogenesis, an important process interlinked with osteogenesis. This review will also examine how delivery systems may offer an alternative way of providing sustained release of these ions which may effect and potentiate a more appropriate and rapid tissue response.

Effects of phytase supplementation in broiler diets on a natural Eimeria challenge in naive and vaccinated birds

Our study was conducted to determine the effects of dietary phytase on a natural Eimeria challenge in naive and vaccinated broilers. Prior to the experiment the litter was seeded with Eimeria by orally infecting 10-d-old chicks with a cocktail containing 100,000 and 5,000 sporulated Eimeria acervulina and Eimeria tenella oocysts, respectively. Straight-run broiler chicks were placed across 48 floor pens on fresh or seeded litter. Eight treatment combinations were created to include 2 dietary Ca-nonphytate P (npP) levels [0.9% Ca, 0.45% npP; 0.7% Ca, 0.35% npP, 500 phytase units of Optiphos phytase (JBS United, Sheridan, IN)], unchallenged versus challenged, and unvaccinated versus vaccinated groups of chicks. Body weights and feed consumption (FC) were recorded on d 10, 18, and 21. A total of 10 birds/treatment were killed on d 10 and 18 to obtain tissue samples from the duodena and ceca for lesion scoring and cytokine response measurement. At 21 d of age, the left tibia was removed from 18 birds/treatment to assess bone strength. Body weight, FC, and bone strength were unaffected (P > 0.05) by diet or vaccination. By d 21, birds exposed to coccidia had lower FC (P < 0.01), higher feed conversion (P < 0.001), and decreased bone strength (P < 0.01) compared with those not challenged. Regardless of treatment, gross and microscopic scoring of the intestines showed few differences (P > 0.05). Expression of interferon-γ did not differ (P > 0.05) in the duodena or ceca at either time point. The IL-17 gene expression was increased (P < 0.05) in phytase-supplemented, vaccinated, or challenged birds by 18 d of age, with significant interactions (P < 0.05) occurring between birds challenged and fed the marginal diet or vaccinated. Phytase supplementation was unable to provide additional benefits to performance or P utilization in birds vaccinated, subjected to a coccidiosis infection, or both. Based on cytokine production in the intestinal tract on d 10 and 18 postchallenge, the response to the Eimeria challenge was characterized by a T-helper type (Th) 17-like immune response and to a lesser extent a Th1-like immune response, whereas no Th2 cytokine was detected.

Parasitism and production in farm animals

The impact of internal and external parasitism on productivity of farm animals is considered for cattle, sheep, pigs and poultry. The parasitic challenge experienced and the outcome of that challenge is a dynamic one in which environment, management practices, including housing or grazing management, nutritional status, the host's ability to develop effective immunity and the speed with which this can occur, play a significant role. Much of our assessment of the impact of infection comes from pathophysiological and nutritional studies with contrived infestations. A common feature of all infestations is reduced efficiency of food utilization through reduction in food intake, though in some cases increases in nutrient requirement are induced as a result of damage to or loss of host tissue. Assessment of the impact on productivity in the field is technically very difficult and must take account of fluctuating challenge, determined by environmental and management decisions, and the manager's objectives for the performance of a particular category of livestock. This review attempts to integrate the assessment of losses in productivity based on pathophysiological studies with those based on protection of groups of livestock in production systems by regular pesticide use. Throughout the review the limitations inherent in both approaches and in our knowledge of how parasites impair productivity of the host are emphasised.

The interactive effects of Eimeria acervulina infection and phytase for broiler chicks

An experiment was conducted to determine the interactive effects of Eimeria acervulina infection and phytase in male broiler chicks. Chicks were standardized from 0 to 4 d posthatching, and the assay period was 5 to 15 d. Treatments were replicated with 6 pens of 5 chicks each. The initial and final BW were 67 and 363 g. A corn-soybean meal diet formulated to provide 1.26% total Lys and 3,200 kcal of ME/kg was used, and it was adequate in all other nutrients except Ca and nonphytate P (NPP) when appropriate. The treatments were in a 2 x 2 x 2 factorial arrangement: adequate Ca and NPP (1.0% Ca and 0.45% NPP) or inadequate Ca and NPP (0.80% Ca and 0.25% NPP), 0 or 600 phytase units/kg of diet, and uninfected or infected with 400,000 E. acervulina oocysts on d 0, 3, and 6 of the experiment. Daily gain, average daily feed intake, and gain:feed (GF) were reduced (P < 0.01) by the coccidial infection and the reduction in Ca and NPP. Phytase addition increased (P < 0.02) average daily gain and average daily feed intake, regardless of the Ca and NPP contents of the diet or the presence of coccidiosis. The GF was increased by phytase but only in uninfected chicks (phytase x coccidiosis, P < 0.02). Toe and tibia ash percentages were decreased (P < 0.01) in chicks fed diets deficient in Ca and NPP, but tibia ash was decreased more by Ca and NPP in healthy chicks than in infected chicks (coccidiosis x Ca and NPP, P < 0.02). Phytase increased (P < 0.02) toe and tibia ash but only in diets deficient in Ca and NPP (phytase x Ca and NPP, P < 0.01). Phytase increased toe ash percentage of healthy chicks fed diets deficient in Ca and NPP, but it had less of an effect in infected chicks fed diets deficient in Ca and NPP (coccidiosis x Ca and NPP x phytase, P < 0.08). Also, phytase was less effective in increasing tibia ash percentage in coccidiosis-infected chicks than in uninfected chicks (phytase x coccidiosis, P < 0.02). These data indicate that phytase is effective in the presence of a coccidial infection, but based on GF and tibia ash percentage, it may not be as effective as in uninfected chicks. Also, phytase increased average daily gain and average daily feed intake in uninfected chicks fed diets formulated to be adequate (or in excess) in all nutrients for male broiler chicks.

Interactive effects of betaine and monensin in uninfected and Eimeria acervulina-infected chicks

Three experiments (Exp.) were conducted to evaluate the interactive effects of dietary betaine (BET) and monensin (MON) in uninfected or Eimeria acervulina-infected chicks. The treatments were replicated with six (Exp. 1) or five (Exp. 2 and 3) pens of five chicks each. The experimental periods lasted 9 (Exp. 1 and 2) or 10 (Exp. 3) d each and the coccidiosis infections were established on Day 2 (Exp. 1 and 2) or Day 3 (Exp. 3) of the experiment. Average initial weight of the chicks was 101, 73, and 68 g in Exp. 1 to 3, respectively, and the initial age of the chicks was 5 (Exp. 1) or 4 (Exp. 2 and 3) d. A corn-soybean meal basal diet was used in each experiment. In Exp. 1, the effect of dietary BET (0, 0.1, or 0.5%) in uninfected or coccidiosis-infected (COC; 5 x 10(5) sporulated E. acervulina oocysts) chicks was investigated. In Exp. 2, the interactive effects of BET (0 or 0.1%) and MON (0 or 55 ppm) in uninfected or COC chicks were investigated in a 2 x 2 x 2 factorial arrangement of treatments. Experiment 3 was identical to Exp. 2, except the level of MON was 110 rather than 55 ppm. In Exp. 1, 2, and 3, COC reduced (P < 0.01) gain, feed intake (FI), feed efficiency (GF), and plasma carotenoid concentration (CAR) and increased (P < 0.01) lesion score (LS). In Exp. 1, gain and FI were decreased in uninfected chicks fed 0.1% BET but gain and FI were increased in COC chicks fed 0.1% BET (COC x BET quadratic, P < 0.01). Dietary BET linearly increased (P < 0.05) GF. In Exp. 2 and 3, MON increased (P < 0.01) gain, FI, GF, and CAR and decreased (P < 0.01) LS of COC chicks, but MON had no effect in uninfected chicks (COC x MON, P < 0.01). In Exp. 2, GF was increased more in chicks fed both MON and BET than in chicks fed MON (BET x MON, P < 0.06). In Exp. 3, BET increased GF of uninfected chicks fed MON and of COC chicks not fed MON (COC x BET x MON, P < 0.02). Betaine may have an effect on E. acervulina-infected chicks, but there is no conclusive evidence to indicate that the efficacy of MON is improved when fed in combination with BET.

Interactive effects of dietary copper, water copper, and Eimeria spp. infection on growth, water intake, and plasma and liver copper concentrations of poults

The effects of dietary Cu, water Cu, and coccidial infection on poult growth performance and selected tissue mineral concentrations were investigated in a 10-d experiment using 200 5-d-old Nicholas toms (five replicates of 5 poults each; initial weight = 85 g). Uninfected and coccidiosis-infected (Eimeria meleagrimitis, Eimeria dispersa, Eimeria adenoeides, and Eimeria gallopavonis; cocci) poults were assigned to two levels of dietary Cu [Basal (B) and B + 204 mg Cu/kg diet on Days 1 to 10] and two levels of water Cu (0 and 103 mg Cu/kg water on Days 6 to 10). Dietary Cu and water Cu (main effects) did not affect (P > .10) gain, feed intake, gain:feed, water intake, hemoglobin, hematocrit, or liver Fe and Zn concentrations. Dietary Cu and water Cu increased (P < .03) liver and plasma Cu concentrations. The combination of dietary Cu and water Cu increased plasma Cu more than the sum of the Cu additions (dietary Cu by water Cu, P < .08). Coccidial infection reduced (P < .07) gain, feed intake, gain:feed, water intake, and hemoglobin, and increased (P < .02) liver Zn. Water Cu reduced water intake in uninfected poults but increased water intake in coccidiosis-infected poults (water Cu by cocci, P < .07). Water Cu increased hemoglobin in uninfected poults but decreased hemoglobin in coccidiosis-infected poults (water Cu by cocci, P < .07). Water Cu increased plasma Cu and liver Cu more in coccidiosis-infected poults than in uninfected poults (water Cu by cocci, P < .02).(ABSTRACT TRUNCATED AT 250 WORDS)

Research note: interactive effects of sodium zeolite A and Eimeria acervulina infection on growth and tissue minerals in chicks

Two experiments were conducted to assess the interactive effects of dietary sodium zeolite A (SZA) and experimental Eimeria acervulina infection on growth and tissue mineral concentrations in chicks. The average initial weight of the chicks was 71.8 g, and the experimental periods were from 5 to 15 days posthatching. In both experiments, the corn-soybean meal basal diet was supplemented with 0 or .75% SZA and fed to uninfected chicks or to chicks infected with 4 x 10(5) sporulated E. acervulina oocysts on Days 0, 3, and 6 of the experiments. Both coccidial infection and SZA reduced (P < .05) gain and feed intake; however, feed efficiency was reduced (P < .01) only in the coccidiosis-infected chicks. Neither SZA nor the coccidial infection affected (P > .10) plasma Ca or P, tibia P, liver Ca, Zn, Fe, or Mn, or pancreas Cu. Sodium zeolite A increased (P < .05) plasma Zn but only in uninfected chicks (SZA by coccidiosis, P < .10). The coccidial infection decreased (P < .02) tibia ash percentage. Sodium zeolite A decreased tibia Ca in uninfected chicks but increased tibia Ca in coccidiosis-infected chicks (SZA by coccidiosis, P < .10). The coccidial infection increased (P < .05) tibia Mg, Cu, Fe, Pb, Mn, and Al concentrations. Dietary SZA also increased (P < .02) tibia Zn, Mn, and Al concentrations. The coccidial infection decreased (P < .02) tibia Zn concentration, and SZA decreased (P < .05) tibia Mg and Fe. Sodium zeolite A by coccidiosis interactions (P < .10) were evident in tibia Zn, Fe, Mn, and Al concentrations.(ABSTRACT TRUNCATED AT 250 WORDS)

Effect of dietary sodium zeolite A on zinc utilization by chicks

Two experiments were conducted with chicks from 5 to 15 days posthatching to study the effect of sodium zeolite A (SZA) on Zn utilization. The corn-soybean meal basal diet was supplemented with ZnCO3 to provide three levels of dietary Zn (35, 40, and 85 ppm) in Experiment 1, and two levels of dietary Zn (85 and 4,000 ppm) in Experiment 2. Experimental diets also contained either 0 or .75% SZA, resulting in a 3 x 2 and a 2 x 2 factorial arrangement of treatments in Experiments 1 and 2, respectively. The tendency for increased growth, feed intake, and hematocrit in chicks fed Zn-supplemented diets in Experiment 1 suggests that the 35-ppm level of Zn in the basal diet was marginal for chicks. Both supplemental Zn and SZA increased (P < .02) hematocrit and plasma, pancreas, and tibia Zn and decreased (P < .02) tibia Cu. Sodium zeolite A increased (SZA by Zn, P < .03) tibia Al and tended to increase (SZA by Zn, P < .09) liver Fe in chicks fed either 35 or 85 ppm Zn, but SZA had no effect on tibia Al and liver Fe in chicks fed 40 ppm Zn. In Experiment 2, both SZA and excess dietary Zn decreased gain, feed intake, gain: feed, hematocrit, hemoglobin, and plasma alkaline phosphatase (AP) activity, and increased tibia, liver, and pancreas Zn, and tibia Al. In addition, excess Zn increased (P < .05) plasma Zn and liver Al but decreased (P < .01) plasma, liver, and pancreas Cu and percentage of tibia ash. The addition of SZA enhanced the adverse effects of excess Zn by further decreasing feed intake, hematocrit, hemoglobin, and plasma AP and Cu and by increasing tibia Al and liver Zn. Sodium zeolite A increased pancreas (P < .09) and tibia (P < .03) Zn regardless of dietary Zn concentration; however, SZA increased plasma Zn only in chicks fed 85 ppm Zn (SZA by Zn, P < .03). Sodium zeolite A tended to improve Zn utilization in chicks fed inadequate Zn but exacerbated the adverse effects of feeding excess Zn. The addition of SZA to the diet of chicks fed inadequate, adequate, or toxic levels of Zn resulted in increased tissue Zn concentration.

Effect of dietary sodium zeolite A and graded levels of calcium and phosphorus on growth, plasma, and tibia characteristics of chicks

Sodium zeolite A (SZA), a synthetic sodium aluminosilicate having a high ion exchange capacity, has been shown to influence Ca and P utilization in chickens. A 3 x 2 x 2 factorial arrangement of treatments was used to investigate the effect of dietary P (.41, .55, and .69% total P), Ca (.6 and 1%), and SZA (0 and .75%) on growth, plasma, and tibia characteristics of chicks from 5 to 15 days of age. Growth, feed intake, gain:feed ratio, and tibia characteristics were influenced by dietary Ca and P in a manner consistent with dietary recommendations for these macro minerals. The addition of Ca, SZA, or both exacerbated the adverse effects of feeding low-P diets, yet alleviated the adverse effects of feeding a low-Ca, high-P diet. Dietary SZA had no effect (P greater than .5) on plasma Ca or alkaline phosphatase; however, SZA reduced (P less than .01) plasma P. Dietary SZA increased (P less than .02) tibia Mn, Zn, Cu, and Al. The SZA-induced increase in tibia Al was most evident in chicks fed low levels of P (SZA by P interaction, P less than .02). The overall response to dietary SZA addition paralleled the response observed from Ca supplementation, indicating that SZA increased Ca utilization, reduced P utilization, or contributed to both of these effects. These data demonstrate that the effects of SZA are influenced by the dietary concentration of Ca and P and that the addition of SZA to diets low in P results in bone Al accumulation.

Effect of dietary sodium zeolite A and graded levels of calcium on growth, plasma, and tibia characteristics of chicks

Sodium zeolite A (SZA), a synthetic sodium aluminosilicate having high ion-exchange capacity, has been shown to increase eggshell specific gravity in laying hens and to improve Ca utilization in chickens. A 4 x 2 factorial arrangement of treatments was used to investigate the effect of dietary Ca (.6, .8, 1.0, and 1.2%) and SZA (0 and .75%) on growth, plasma, and tibia characteristics of chicks from 5 to 15 days of age. Increasing dietary Ca linearly increased (P less than .05) Ca and alkaline phosphatase (AP) in plasma and increased tibia shearing force and percentage ash, Ca, and P in tibiae. However, dietary Ca linearly decreased (P less than .05) inorganic P and Mg in plasma and Mg and Mn in tibiae. Sodium zeolite A decreased (P less than .05) plasma P and AP and tibia Mg but increased (P less than .05) tibia Ca, Zn, Al, and Mn concentrations. Tibia ash and shearing force were increased in chicks fed SZA receiving inadequate dietary Ca, but they were decreased in chicks fed SZA and excess Ca (Ca by SZA interaction, P less than .05). Tibia density showed a similar trend, but the effect was not significant (Ca by SZA interaction, P less than .12). The addition of SZA enhanced tibia ash, density, and shearing force when dietary Ca was low; however, when added to diets containing 1.2% Ca, SZA reduced many bone mineralization indices with the exception of tibia Ca.

Comparison of the effects of synthetic and natural zeolite on laying hen and broiler chicken performance

Three experiments were conducted to investigate the effect of zeolites on laying hens (Experiments 1 and 2) and broiler chickens (Experiment 3). Each experiment used corn and soybean meal-based practical diets. Experiment 1 was a 90-day trial and used 200 40-wk-old laying hens. The basal diet contained 2.75% calcium and .7% total phosphorus. The dietary treatments were the basal diet and the basal diet plus 1.5% synthetic zeolite (SZ; Ethacal). Experiment 2 was a 56-day trial and used 360 36-wk-old laying hens. The dietary treatments were .12, .22, .32, and .42% nonphytin phosphorus with and without 1.0% SZ and 1.0% natural zeolite (NZ; Zar-Min). All diets contained 3.5% calcium. Experiment 3 utilized 240 broiler cockerels from 1 to 16 days. The dietary treatments were two calcium levels (.65 and 1.0%) with and without 1.0% supplementary SZ and NZ. In Experiment 1, egg specific gravity was significantly increased with SZ supplementation. Egg weight and egg production were unaffected. Phytin phosphorus retention and plasma dialyzable phosphorus were significantly reduced by SZ. In Experiment 2, egg specific gravity was not affected by SZ or NZ. Egg weight, egg production, plasma dialyzable phosphorus, and the retention of phosphorus and phytin phosphorus were significantly reduced by SZ with the effect on egg weight and egg production being the most severe at the lower levels of dietary nonphytin phosphorus. Natural zeolite had no effect on egg weight, egg production, plasma calcium, plasma phosphorus, or on the retention of calcium, phosphorus, and phytin phosphorus. In Experiment 3, weight gain and percentage tibia bone ash were significantly reduced by SZ. The SZ had no effect on the incidence and severity of tibial dyschondroplasia. Weight gain, feed efficiency, and the incidence and severity of tibial dyschondroplasia were significantly reduced and the percentage bone ash significantly increased by 1.0% calcium. Natural zeolite significantly improved feed efficiency and had no effect on any other parameter measured.