Iodine deficiency, iodine requirement and iodine excess of farm animals--experiments on growing pigs

Since insufficient iodine intake is widespread among the German population, farm animals should if possible receive iodine above requirement, thus concentrating the trace element in milk, eggs and possibly meat. Experiments with a total of 29 fattening pigs with grain soy-bean meal diets without iodine supplementation or with increasing supplements up to 1000 micrograms iodine/kg diet did not show any effect on growth intensity (gain) and feed efficiency. At and above 125 micrograms supplementary iodine/kg diet the thyroid was not or only little hypertrophied and iodine incorporation into thyroglobulin sufficed to sustain serum T4 concentration. The glucosinolates of rape feeds increase iodine requirement. In an experiment with a total of 36 fattening pigs the thyroid iodine depot was decreased due to rapeseed meal feeding, this in agreement with antithyroid drugs which had been also tested. A thyroid with emptied iodine depot is hardly able to synthesize and release hormone, the serum thyroxine concentration showed a drastic decrease. More iodine may compensate for effects of glucosinolates, however, only with not too much of these compounds in the feed. Excessive iodine dosages (10 mg/kg diet) were compared with supplements in the range of recommendations (100 and 1000 micrograms/kg diet) with a total of 120 pigs in three groups of 40 animals each. The dosage of 10 mg iodine/kg diet decreased serum T3 concentration. The enlarged thyroid with double weight had a very high iodine concentration. In comparison with physiological application (100 or 1000 micrograms iodine/kg diet) the thyroid deposited only little iodine in the group with the excessive iodine intake related to consumed iodine quantity. In case of sufficient and excessive iodine supply--industry of compounds feed applies up to 2.5 mg supplementary iodine/kg diet--T4 and iodine of serum but also thyroid weight cannot serve as markers. This range of usual iodine supply is better characterized by the iodine depot of the thyroid. As a rule, thyroid weight increase indicates glucosinolate effects, generally those of dietary antithyroid compounds, more seldom it shows extreme and longterm iodine undersupply or iodine excess.     

Testing in swine of meal extracted from winter rapeseed with different glucosinolate content with regard to iodine supply. 1. Characterization of rapeseed extraction particles and fattening results

In a feeding experiment with 48 growing pigs 16% high glucosinolate rapeseed meal (HGRSM) (136 mumol glucosinolates + aglucones/kg dry matter, DM) or low glucosinolate (LG) RSM (48 mumol glucosinolates + aglucones/kg DM) in the feed were compared with 14% soya-bean meal (SBM) in each case. It were established 24 pairs of animals, which received the same quantity of the isonitrogenous but not isocaloric diets with SBM and the both RSM (pair fed). Four of the 2.12 animal pairs were not given supplementary I, four received 0.25 mg supplementary I/kg feed. Further four animals which were fed on LGRSM or HGRSM were provided with 0.0625 or 1 mg supplementary I/kg feed. In case of high glucosinolate intake (HGRSM) the lacking I supplementation decreased feed intake and growth and led to remarkable I deficiency symptoms from the fifth week onwards. The 2/3 lower glucosinolate dosage of the LGRSM diet also decreased performance and provoked I deficiency, however significantly later. The investigated I dosages (greater than 0.0625 mg/kg feed) did not effect the performance. In the experiment the eight animals which received LGRSM with supplementary I consumed 13% more feed than animals fed on HGRSM (P less than 0.05). The additional weight gain was 20% (P less than 0.05). Comparing the live weight gain of the SBM and RSM fed animals (pair fed) there was a significant increase of 9% versus the HGRSM groups and 5% versus the LGRSM groups.     

Effects of rapeseed-press cake glucosinolates and iodine on the performance, the thyroid gland and the liver vitamin A status of pigs.

Rapeseed press cake (per kg DM 181 g EE, 341 g CP and 23.3 mmol glucosinolates) was tested in a long-term experiment with a total of sixty pigs (live weight range 24 to 104 kg). The 3 x 2 factorial design consisted of three rapeseed press cake levels (no rapeseed press cake--control, 75 g or 150 g rapeseed press cake per kg diet) each with two iodine dosages (125 or 250 micrograms supplementary iodine per kg diet). Reduced feed intake and depressed weight gain were found in groups receiving 150 g rapeseed press cake per kg diet, which correspond to 3.2 mmol glucosinolates per kg diet. At an inclusion level of 75 g rapeseed-press cake per kg diet no differences in feed intake and growth intensity were recorded in comparison to the rape feed free control. The rapeseed-press cake diet increased the weight of thyroid gland and liver and decreased the serum thyroxine (T4) concentration. Higher iodine dosage increased the serum T4 concentration of pigs receiving 75 g rapeseed press cake per kg diet (= 1.6 mmol glucosinolates per kg diet) to the level of the control group and retarded the enlargement of the thyroid gland. Intake of rapeseed products lowered the iodine content of the thyroid gland, however, there was no significant difference between groups given 1.6 and 3.2 mmol glucosinolates per kg diet. The vitamin A content of the whole liver and the vitamin A serum concentration were not influenced by the diets tested. However, rapeseed press cake and the glucosinolates, respectively, decreased the vitamin A concentration per gram liver due to the organ enlargement and the resulting dilution effect.     

The extraction particles from winter rapeseed with different glucosinolate fractions in swine with regard to the iodine supply. 3. Apparent digestibility of crude nutrients with special regard to the carbohydrate and nitrogen balance]

In two digestibility and N-balance experiments the following solvent extracted meals were examined in a grain (barley and wheat in equal parts) or in a starch diet with four female pigs/group fitted with urethra catheters during the 5 days sampling period: 48% soyabean meal (SBM) (1), 24% conventional rapeseed meal (RSM) (2), 24 (3) or 48% (4) RSM from a newly bred low glucosinolate variety, groups 1 to 4 with grain, 48% low glucosinolate RSM (5) or 48% SBM (6) both with starch. In numeric order of the groups 88, 85, 86, 84, 79 and 89% N were digested. Pigs responded to the additional faecal N excretion from RSM diets by a lower urinary N excretion and thus they reached the N-balance of the animals fed on SBM. In numeric order of the groups 86, 79, 80, 73, 73 and 92% of the organic matter of the solvent extracted meals were digested. In comparison with SBM even 48% RSM in the feed significantly lowered the digestibility of organic matter. Using detergents the additional faecal organic matter excretion of RSM versus SBM could quantified as two third lignin. In the case of 24% RSM in the diet--i.e. 15% of the carbohydrates given--the carbohydrate digestibility is estimated with a high error, that an energetic feed value should not calculated. Investigating 48% SBM or RSM respectively in a grain diet the net energy content was 9.8 MJ (666 Energetic Feed Units, EFU pig) or 8.3 MJ (569 EFU pig)/kg dry matter (DM). Based on the starch diet, however, little relevant for estimation of normal pig diets, there were evaluated 10.6 MJ (720 EFU pig) for SBM and 8.3 MJ (567 EFU pig) net energy/kg DM for RSM.     

Effect of various iodine supplementations, rapeseed meal application and two different iodine species on the iodine status and iodine excretion of dairy cows

The aim of the present study was to investigate the impact of various feed iodine supplementations up to the permitted maximum level in the EU, the effect of applying rapeseed meal (RSM) compared to a glucosinolate (GSL) free ration and the impact of two different iodine species (iodide, iodate) on milk, urinary, faecal and blood serum iodine as well as on T₃ and T₄ levels of blood. The results of the milk iodine are not completely shown but partly discussed in this paper. The study was conducted with 32 dairy cows, divided into 4 groups with 8 animals each. In two groups the cows were fed distillers dried grains with solubles (DDGS) as main protein source (16.5% of ration DM), in the other groups rapeseed meal (3.5 mmol GSL/kg) was applied. In each case half of the animals received feed with iodine in the form of potassium iodide, the other half as calcium iodate. Iodine supplementations of 0, 0.5, 1, 2, 3, 4 and 5 mg/kg DM were tested in consecutive periods of 21 days each. The supplementary iodine increased iodine contents of serum, urine and faeces. RSM application resulted in consistently higher iodine contents in the mentioned matrices just displaying significant differences at high supplementation levels. When feeding DDGS, at high iodine supplementations iodide caused higher serum and faecal iodine than iodate. Besides, the iodine species showed no consistent impact on the tested parameters. At the highest tested iodine supplementation (5 mg/kg DM) in the experimental groups (DDGS/iodide, DDGS/iodate, RSM/iodide, RSM/iodate) the iodine concentration of serum amounted to 234, 157, 334 and 361 µg/l, of urine to 1134, 1020, 2341 and 2513 µg/l and of faeces to 673, 354, 715 and 790 µg/kg fresh matter. At the same supplementation level T₄ was significantly lowered. No impact was shown for the RSM application and the iodine species on T₃ and T₄. The results of the present study indicate that high iodine intakes not only cause strong increases in milk and urinary iodine but also lead to a considerable rise of iodine excretion via faeces. RSM in feed causes a shift of iodine normally excreted via milk to an excretion via urine and faeces accompanied by higher serum iodine.     

Supplementation of algae to the diet of pigs: a new possibility to improve the iodine content in the meat

Meat products with a higher iodine content can be produced through feeding animals with a diet supplemented with inorganic iodine salts or with algae containing high iodine. This may help to improve daily iodine intake and to control iodine deficiency disorders (IDD) in man. In the present study a total of 40 crossbred pigs (Deutsche Landrasse × Piétrain) with an average body weight of 17 kg were allotted to either a control group, to two groups receiving potassium iodide (KI) at different concentrations (5 or 8 mg iodine per kg of feed) or to two groups receiving the algae Laminaria digitata containing the same amount of iodine. After pigs were fed with iodine-supplemented diets for 3 months, it was found that compared to the control group the iodine content increased by up to 45% in fresh muscle, by 213% in adipose tissue, by 124% in the heart, by 207% in the liver and by 127% in the kidneys. There was a significant (p < 0.01) higher concentration of serum thyroxine (T₄) and a lower concentration of serum triiodothyronine (T₃) in those iodine-supplemented groups. The iodine content of urine from all iodine-supplemented groups was also greatly increased. Furthermore, it was shown that the supplementation of algae into feed could increase daily body weight gain by 10% (p > 0.05). It is suggested that the carry-over of iodine through feeding pigs with an algae-supplemented feed could be beneficial to both the control of IDD and the improvement of pig production.     

Effect of iodine, copper and zinc supplements to rations with a high quota of rapeseed extract meal on the growth and thyroid function of fattening swine. 3. The effect on weight and the histomorphometric findings in the thyroid and on the serum T3 and T4 concentrations

Studies were made with a total of 272 fattening pigs. Iodine deficiency both in rations of soya bean meal and rape seed meal increased the weight of the thyroid gland and the height of the epithelium cells and significantly reduced the T4 and T3 level in the serum. Iodine supplements to the rape seed meal rations distinctly diminished the goitrogenic effect, did not, however, cancel it out. Stage of goiter and depression of consumption were--different shown by the T3 and T4 level in the serum. Highly significant relations were calculated between live weight gain, weight and the height of the epithelium cells on the one hand and the T4 level in the serum on the other. Iodine supplementations of rations without thyrostatic components should amount to greater than or equal to 0.1 mg/kg. Iodine supplementations of 0.5 mg/kg feed are at present recommended to rations with rape seed meal quotas of less than 8%.     

Recent information on iodine deficiency in New Zealand sheep flocks

AIMS: To determine the value of pasture iodine, serum thyroxine (T4) and tri-iodothyronine (T3) concentrations and thyroid (g) to body weight (kg) ratios in lambs as criteria to predict and diagnose increased litter size and decreased perinatal mortality in response to iodine supplementation. METHODS: Results from ten iodine response trials in ewes using an oil-based intramuscular iodine preparation were reviewed along with results from investigations into goitre on five farms in the Manawatu. RESULTS: In two trials, litter size was increased by 14% and 21% in iodine-treated ewes. In only three of the 10 trials was there a significant reduction in perinatal mortality in iodine-treated ewes. CONCLUSIONS: Pasture iodine and serum thyroxine (T4) and tri-iodothyronine (T3) concentrations appeared to be unhelpful in predicting the occurrence of increased litter size and reduced perinatal mortality in response to iodine supplementation. New-born lambs from ewes not supplemented with iodine, that had a mean thyroid weight (g) to body weight (kg) ratio of 0.40 g/kg or greater, generally had a significant increase in perinatal mortality compared to lambs from iodine-supplemented ewes.     

Hyperplastic goitre and mortality in captive-reared black stilts ( Himantopus novaezelandiae )

AIM: To study the gross, histopathological and clinico-pathological findings in cases of hyperplastic goitre in sub-adult captive- reared black stilts following their release on riverbeds in the south Canterbury region of New Zealand. METHODS: Necropsies were undertaken on the recovered carcasses of 48 black stilts over a 3-year period (1997-1999). The cause of death was determined, and thyroid glands were examined histopathologically and compared with those of free-living pied stilts. Concentrations of triiodothyronine (T3) and thyroxine (T4) in the serum of sub-adult and adult stilts were measured before and after iodine supplementation. RESULTS: The main causes of death of captive-reared black stilts following release were trauma, predation and starvation. An increase in size of the thyroid gland due to follicular hyperplasia and dilation was seen in all birds with intact thyroid glands (n=27). Dysplastic follicular changes such as epithelial desquamation, lipid deposition and haemorrhage were common in a large proportion of individuals with goitre. Dietary supplementation with iodine greatly improved survival rates in sub-adults following release, and significantly increased concentrations of T3 and T4 in serum. CONCLUSIONS: Subclinical goitre due to thyroid hyperplasia and dysplasia was the cause of hypothyroidism and this contributed to the poor survival of released sub-adult black stilts raised in captivity. Iodine supplementation of the diet of captive adults and sub-adults resulted in increased concentrations of T3 and T4 in serum and improved survivability.     

Effects of low and high glucosinolate rapeseed meals on productive performance,egg quality,composition of liver and incidence of haemorrhagic liver syndrome in laying birds

1. Two experiments were done with low and high glucosinolate rapeseed meals (RSM) fed to layers at various concentrations in the diets.

2. The inclusion of low glucosinolate RSM (100g/kg) in the diet did not affect egg production adversely. Inclusion at a rate of 125 or 150 g ‘ of this type of meal per kilogram resulted in non‐significant reductions in egg production when compared with that of the birds fed on the control diet.

3. Egg weight, specific gravity and Haugh unit values were unaffected when low glucosinolate RSM was included at rates of up to 150 g/kg whereas inclusion of high glucosinolate RSM at the rate of 100 or 150 g/kg decreased egg production and Haugh unit values when compared with the results obtained from a control diet based on soyabean meal.

4. Thyroid glands were slightly enlarged when low glucosinolate RSM was included in the diet at concentrations up to 150 g/kg, while 100 or 150 g high glucosinolate RSM/kg caused marked enlargement in thyroid glands.

5. None of the treatments affected liver weight, spleen weight, composition of liver, liver fat score or the incidence of haemorrhagic liver syndrome.     

Effect of dietary iodine on growth and iodine status of growing fattening bulls

The aim of the present study was to assess the influence of different levels of iodine supplementation on animal growth and the iodine content of food from beef cattle. In a dose–response experiment with 34 growing fattening bulls of the “German Holstein” breed, in the range from 223 to 550 kg body weight, three iodine dosages were tested. The animals were fed a corn silage/concentrate ration. Iodine concentration in the diet amounted to 0.79 (Group 1), 3.52 (Group 2) and 8.31(Group 3) mg I per kg dry matter (DM). After slaughtering, I was determined in blood, serum, plasma, thyroid, liver, kidneys and meat (M. longissimus dorsi, M. glutaeus medius) by ICP-MS. I-supplementation did not significantly influence DM intake, daily weight gain (1453 (1), 1419 (2) and 1343 (3) g; p > 0.05) or slaughtering performance, but the weight of the thyroid gland increased significantly with the highest I dosage (32 (1), 26 (2) and 42 (3) g animal^− 1, p < 0.05). I-supplementation significantly increased I-concentration in muscle, liver, kidney and thyroid gland (p < 0.05). The contribution of beef food to I-intake of humans is relatively low, therefore there is no need to reduce the EU-upper limit (10 mg kg^− 1 feed) for growing fattening cattle from the view of consumer safety. In view of animal health and performance more dose–response studies seem to be necessary.     

Effects of dietary supplementation of selenium and iodine on growth performance,carcass characteristics and histology of thyroid gland in goats

This study assessed the effects of dietary selenium (Se), iodine (I) and a combination of both on growth performance, thyroid gland activity, carcass characteristics and the concentration of iodine and selenium in Longissimus lumborum (LL) muscle in goats. Twenty‐four bucks were randomly assigned to four dietary treatments: control (CON), basal diet without supplementation, basal diet + 0.6 mg Se/kg dry matter (DM) (SS), 0.6 mg I/kg DM (IP), or combination of 0.6 mg/kg DM Se and 0.6 mg/kg DM I (SSIP) and fed for 100 days. Animals fed diet SSIP exhibited higher (P < 0.05) body weight and better feed conversion ratio (FCR) than those fed other diets. Dressing percentage of goats fed the supplemented diets was higher (P < 0.05) than that of the control. Carcasses from the IP group had higher (P < 0.05) total fat proportion than the SSIP group. The levels of both elements were significantly elevated (P < 0.05) in LL muscle in supplemented goats. Thyroid follicular epithelial cells of IP and SSIP animals were significantly higher than those of CON and SS groups. The study demonstrated that the combined Se and I dietary supplementation improves growth performance, carcass dressing percentage and increases the retention of Se and I in goat meat.     

Utilisation of iodine from different sources in pigs.

Balance experiments have demonstrated that growing pigs fed a ration consisting of wheat, barley, extracted soya meal, dicalciumphosphate, and iodine-free feeding salt utilised 48.8% of the received iodine. The tested supplementary iodine sources included potassium iodide (KI), ethylenediamine dihydroiodide (EDDI), iodine humate (HUI) prepared from iodine acid (HIO3), and the product P containing 0.004% iodine in an oil base (P). The amount of the supplemented iodine was in all cases 1 mg per 1 kg feed. The utilisation of iodine from the supplements reached 93.6, 92.6, 90.7, and 67.9% for KI, EDDI, P, and HUI, respectively. The values were significantly higher compared with controls (P < 0.01). Compared with KI and EDDI, the utilisation of iodine from HUI was significantly lower (P < 0.01). The lower availability of iodine from HUI was probably due to the high binding capacity of humate. The amount of urinary iodine excreted by control pigs receiving in the non-supplemented ration 147.5 micrograms iodine per day, was 40.3 micrograms per day (27.3%). In the pigs receiving in the supplemented ration 1647.5 micrograms iodine per day, the amount of urinary iodine reached 734.9 to 805.0 micrograms per day (44.6 to 48.9%). The corresponding values of faecal excretion were 75.6 micrograms iodine per day (51.2%) for the control pigs and 106.2 to 121.1 micrograms iodine per day (6.45 to 7.35%) for the pigs fed the supplemented rations. A high amount of 528.6 micrograms iodine per day (32.1%) was excreted in the faeces by pigs of the group HUI.     

The feline iodine requirement is lower than the 2006 NRC recommended allowance*,†,‡

The purpose of this study was to determine the iodine (I) requirement in adult cats. Forty‐two healthy euthyroid cats (1.6–13.6 years old) were utilized in a randomized complete block design. Cats were fed a dry basal diet (0.23 mg/kg I) for a minimum of 1 month (pre‐test) then switched to a different basal diet supplemented with seven levels of KI for 1 year (experimental period). Analysed I concentrations were 0.17, 0.23, 0.47, 1.1, 3.1, 6.9 and 8.8 mg I/kg diet [dry matter (DM) basis] and used to construct a response curve. Response variables included I concentrations in serum, urine and faeces, urinary I:creatinine ratio, I balance, technetium^99m pertechnetate (Tc^99m) thyroid:salivary ratio, complete blood count and serum chemistries as well as serum thyroid hormone profiles. No significant changes in food intake, weight gain or clinical signs were noted. Serum I, daily urinary I, daily faecal I and urinary I:creatinine ratio were linear functions of iodine intake. An estimate of the I requirement (i.e. breakpoint) was determined from regression of Tc^99m thyroid:salivary ratio (scintigraphy) on I intake at 12 months [0.46 mg I/kg diet (DM basis) as well as 9 months I balance (0.44 mg I/kg diet (DM)]. The I requirement estimate determined in our study at 12 months for adult cats (0.46 mg I/kg) was higher than current Association of American Feed Control Officials (AAFCO) recommendations (e.g. 0.35 mg I/kg), but was lower than the 2006 National Research Council (NRC) I recommended allowance (e.g. 1.4 mg I/kg).     

Effects of using locally produced protein feed ingredients in low protein diets to single-phase-fed growing-finishing pigs

ABSTRACT

In two trials, 358 female and entire male pigs vaccinated against boar taint (YxH) were single-phase-fed with diets that were planned to contain 0.78?g standardized ileal digestible (SID) lysine/MJ net energy and 14.5?g SID CP/g SID lysine. A reference diet with soya bean meal (SBM) as the protein feed ingredient, was replaced with either cereal by-products (CBP), rapeseed meal (RSM), faba beans (FB) or mixtures of 50% CBP and 50% RSM (CBP?+?RSM) or 50% FB and 50% RSM (FB?+?RSM) in the experimental diets. Treatments had no effect (P?>?0.05) on daily weight gain, feed efficiency, carcass weight, lean meat content or dressing percentage and carcass value. Single-phase-fed pigs on diets with local protein ingredients can perform as well as single-phase-fed pigs on diets with soya bean meal, and CBP, RSM, FB have the potential to replace soya bean meal in nutritionally well-balanced diets to growing-finishing pigs.     

Effect of iodine supplementation on thyroid and testicular morphology and function in euthyroid rats

Seventy-five male weaner euthyroid rats, randomly divided into three equal groups were used to evaluate the effect of iodine supplementation in the diet on growth and spermatogenesis. From the age of six weeks, the rat groups were fed normal diet containing 0.05 mg iodine/Kg diet (A); normal diet supplemented with 0.5 mg/Kg iodine (B) and normal diet supplemented with 3.0 mg/Kg iodine for a period of 90 days. Thereafter, all three groups were fed the normal diet for another 60 days. Body weight and feed consumption were determined; morphomeric studies of thyroid glands, testes and epididymes were carried out. Spermatogenesis was evaluated with epididymal (ESC) and testicular sperm counts (TSC). Increasing iodine intake significantly (p < 0.05) decreased mean body weight from day 30 of supplementation. Iodine supplementation influenced feed conversion ratio and efficiency in feed utilization in an inconsistent pattern. Supplementation did not significantly (p > 0.05) alter the size of thyroid glands, but increased the mean weights of the testes and epididymes to levels significantly (p < 0.05) higher than values for non-supplemented rats at specific stages of the study, especially at the highest (3 ppm) level of iodine supplementation. However, supplementation resulted generally in lower sperm counts, which was significant (p < 0.05) in the case of the epididymes. The results of the study show that iodine supplementation to weaner, non-iodine deficient euthyroid rats at 3ppm not only retard weight gain but could also reduce fertility by lowering epididymal sperm counts.     

The effects of different maternal dietary iodine concentrations on Japanese quail I. Thyroid status of hens

Japanese quail Coturnix japonica were used as a model system for studying the effects of different levels of dietary iodine (I) supplementation (0–1200 μg I/kg of purified diet) on thyroid function and egg-laying in adult galliform birds. Quail have the ability to adapt their thyroid function to a wide range of dietary I intakes.We measured thyroidal ¹²⁵I uptakes, stable I concentrations in serum and thyroid glands, and triiodothyronine (T₃) and thyroxine (T₄) concentrations in thyroid glands and serum. Body weights of the hens as well as egg production, egg hatchability, and yolk I content were monitored regularly throughout the 56 week study.With low dietary I (0–50 μg I/kg) and consequent low serum I, there is marked stimulation of thyroidal I uptake. Thyroidal stores of I and T₄ are reduced, but thyroidal T₃ and serum concentrations of both T₃ and T₄ are maintained.On dietary I regimes of 150–1200 gg I/kg, thyroidal I stores are regulated at essentially the same level despite a linear relationship between dietary I and serum I concentrations. Thyroidal hormone content and serum hormone concentrations also do not differ between dietary I regimes with >I50 μg I/kg.Egg production and egg hatchability are maintained on all dietary I intakes, a result consistent with the maintenance of serum T₃ and T₄ concentrations independent of dietary and serum I. In contrast to the thyroid, the ovaries do not appear able to regulate I in relation to I availability, and egg yolk I is proportional to serum I concentrations.These studies suggest that feed supplementation of 150 μg I/kg is sufficient to meet the needs of Japanese quail hens without requiring alterations in thyroid function. Quail adapt effectively to dietary I from 0–1200 μg I/kg; maintenance of thyroid status and egg production are favored while egg I stores vary with I availability.     

Effect of feeding Sarsaponin in cattle and swine diets

In four trials, steer calves were received in the feedlot, processed and fed diets supplemented with soybean meal (SBM), 1% urea (UR) or 1% urea plus sarsaponin (S) over a 28-d period. In trials 1 and 2, the feeding period was extended to approximately 62 d, in which steers were fed a common (SBM) diet the last 34 d. In trials 3 and 4, a SBM plus S diet treatment was included. During the first 28 d (four trial summary) daily gains of steers fed urea plus S (.74 kg) were intermediate to and significantly different from gains of steers fed SBM (.84 kg) or UR (.66 kg) diets. However, at the end of the 62-d feeding period (two trial summary) daily gains, feed intakes and feed efficiency did not differ (P greater than .05) among treatments. No significant improvements in performance were found in steers fed SBM diets supplemented with S. In swine trials, pigs were fed diets containing no additive, 63 mg S X kg-1, 55 mg chlortetracycline (C) X kg-1 or S plus C in a grower-finisher (GF) and grower (G) trial. In the GF trial, overall efficiency of feed conversion was improved (P less than .05) by feeding S or S plus C. In the G trial, daily gains and intakes were greatest for pigs fed S plus C and differed (P less than .1) from those of pigs fed S or C in the diet. Compared with feeding S or C alone, gain and intake of growing pigs were stimulated to a greater extent when S was fed in combination with C. Feeding S with or without C improved efficiency of feed conversion in finishing pigs.     

Clinical and subclinical colloid goitre in adult camels (Camelus dromedarius) at Kordofan region of Sudan

Colloid goitre was diagnosed in adult camels in the Kordofan region of the Sudan. The disease is characterized by gross enlargement of the thyroid, histopathological follicular changes, reproductive disorders, low concentrations of circulating thyroid hormones (T3, T4) and normocytic normochromic anaemia. The possible cause of the condition is discussed and iodine supplementation is recommended.     

The effect of various iodine supplementations and two different iodine sources on performance and iodine concentrations in different tissues of broilers

1. The objective of this study was to determine the influence of iodine (I) supplementation of feed, within the range of the European guidelines, on the performance of broiler chickens and I transfer into different organs and tissues, especially meat. The main emphasis was to assess whether broiler meat could be enriched and used as an I source in human nutrition. 2. Two experiments were performed, one with KI and the other with Ca(IO(3))(2). For each experiment, 288 d-old broiler chicks were divided into 4 groups (72 birds/group) and fed on diets with supplementations between 0 and 5 mg I/kg feed. The birds were reared to 35 d of age under standard conditions. Six birds per group were slaughtered at 35 d and samples of blood, thyroid gland, liver, pectoral and thigh meat taken. 3. Iodine treatment did not significantly affect the growth and slaughter performance of the broiler chickens. In all investigated parameters, I concentrations increased significantly with increasing I intake of the animals. The lowest I concentrations were measured in the meat, but they were considerably higher in blood serum, liver and thyroid gland. Since the I content of meat was still low in the highest supplemented group (highest median concentration: 67·8 μg I/kg thigh meat), there is no evidence that this could substantially improve I supply in human nutrition.