Ergot alkaloid transport across ruminant gastric tissues

Ergot alkaloids cause fescue toxicosis when livestock graze endophyte-infected tall fescue. It is generally accepted that ergovaline is the toxic component of endophyte-infected tall fescue, but there is no direct evidence to support this hypothesis. The objective of this study was to examine relative and potential transport of ergoline and ergopeptine alkaloids across isolated gastric tissues in vitro. Sheep ruminal and omasal tissues were surgically removed and placed in parabiotic chambers. Equimolar concentrations of lysergic acid, lysergol, ergonovine, ergotamine, and ergocryptine were added to a Kreb's Ringer phosphate (KRP) solution on the mucosal side of the tissue. Tissue was incubated in near-physiological conditions for 240 min. Samples were taken from KRP on the serosal side of the chambers at times 0, 30, 60, 120, 180, and 240 min and analyzed for ergot alkaloids by competitive ELISA. The serosal KRP remaining after incubation was freeze-dried and the alkaloid species quantified by HPLC. The area of ruminal and omasal tissues was measured and the potential transportable alkaloids calculated by multiplying the moles of transported alkaloids per square centimeter of each tissue type by the surface area of the tissue. Studies were conducted to compare alkaloid transport in reticular, ruminal, and omasal tissues and to determine whether transport was active or passive. Ruminal tissue had greater ergot alkaloid transport potential than omasal tissue (85 vs 60 mmol) because of a larger surface area. The ruminal posterior dorsal sac had the greatest potential for alkaloid transport, but the other ruminal tissues were not different from one another. Alkaloid transport was less among reticular tissues than among ruminal tissues. Transport of alkaloids seemed to be an active process. The alkaloids with greatest transport potential were lysergic acid and lysergol. Ergopeptine alkaloids tended to pass across omasal tissues in greater quantities than across ruminal tissues, but their transport was minimal compared to lysergic acid and lysergol.     

Protein metabolism in growing pigs fed corn or cassava peel based diets containing graded protein levels

Sixty-four Large White cross Landrace weanling pigs were randomly allotted to eight treatments in a two by four factorial arrangement. The two dietary variables were cassava peel (0 and 40 per cent) and crude protein (20, 15, 10 and 5 per cent). Total serum protein concentration was significantly (P less than 0.01) reduced by protein deficiency and by its interaction with cassava peel. The multiple coefficient of determination (R2) showed that protein intake was the primary factor determining changes in serum protein. R2 values for cyanide intake (independent variable) on serum protein (dependent variable) increased from day 30 to 90 of the trial. Serum urea was increased on the 5 per cent protein diets on days 60 and 90 of the trial. The R2 values for cyanide and protein intake on serum urea concentration increased from day 30 to day 90 of the trial. Serum creatinine increased (P less than 0.05) on the 5 per cent protein diet on day 90 of the trial. The R2 value for the effects of protein intake on serum creatinine was higher than for cyanide intake on days 30 and 90. The results confirm the progressive and pronounced effects of long term cyanide intake on serum nitrogenous metabolites in pigs consuming between 110 and 120 ppm hydrocyanic acid, especially in diets containing 10 per cent or less protein.     

Claviceps cyperi, a new cause of severe ergotism in dairy cattle consuming maize silage and teff hay contaminated with ergotised Cyperus esculentus (nut sedge) on the Highveld of South Africa

During December/January 1996/97 typical summer syndrome (hyperthermia and a 30% drop in milk yield) occurred in succession in two Holstein dairy herds (n=240 and n=150 milking cows, respectively) on the South African Highveld. These farms are situated in the midst of the prime maize and dairy farming areas of South Africa where this condition had never been diagnosed before. The individual components of the concentrate on both farms were negative for ergot alkaloids. Endophytic fungi and/or ergot infestation of teff and other grasses fed to the cows were then suspected of being involved, but neither endophytes nor ergot alkaloids could be implicated from these sources. By measuring the serum prolactin levels of groups of sheep (n=5) fed the first farm's total mixed ration (TMR) or its three individual fibre components for a period of 11 days, the source of the ergot alkaloids was identified. A statistically significant decrease in the level of this hormone occurred only in the group on maize silage (which constituted 28% on dry matter base of the TMR). The involvement of the maize silage was further chemically confirmed by the high levels of total ergot alkaloids, predominantly ergocryptine, found by LC-MS in the silage as well as in the TMR (115-975 ppb and 65-300 ppb, respectively). The ergot alkaloid content (mainly ergocryptine) of the maize silage on the second affected farm was 875 ppb. Withdrawal of contaminated silage resulted in gradual recovery of stock on both farms. Nut sedge (Cyperus esculentus and Cyperus rotundus of the family Cyperaceae) has a world-wide distribution and is a common weed in annual crops, and can be parasitized by Claviceps cyperi. Careful examination of the maize silage from both farms revealed that it was heavily contaminated with nut sedge and that it contained minute sclerotia, identified as those of Claviceps cyperi, originating from the latter. Nut sedge was abundant on both farms and it is believed that late seasonal rain had resulted in mature, heavily ergotised nut sedge being cut with the silage. Claviceps cyperi sclerotia, collected on the affected fields in the following autumn contained 3600-4000 ppm ergocryptine. That the dominant alkaloid produced by this particular fungus was indeed ergocryptine, was confirmed by negative ion chemical ionization MS/MS. In one further outbreak in another Holstein herd, teff hay contaminated with ergotised nut sedge and containing 1200 ppb alkaloids, was incriminated as the cause of the condition. This is the first report of bovine ergotism not associated with the Poaceae infected with Claviceps purpureum or endophytes but with the family Cyperaceae and this particular fungal phytopathogen.     

Induction of heat stress in beef cattle by feeding the ergots of Claviceps purpurea

Two groups of 4 Hereford steers were housed in a controlled environment room and exposed to simulated high summer temperatures. Both groups were fed a barley grain and hay diet ad libitum. The barley in one diet contained 0.5% w/w ergots of Claviceps purpurea. Within one week of feeding the ergot diet mean rectal temperature was significantly elevated (P less than 0.05) each afternoon (up to 41 degrees C) but returned to normal overnight. Elevated rectal temperature was accompanied by other signs of heat stress, reduced feed intake, body weight loss and depression or serum prolactin concentration. Symptoms disappeared within 1 week of ceasing to feed the ergot diet.     

Control of salmonella infections in broiler chickens by the acid treatment of their feed

In three experiments a solution of formic acid (Bioadd) was added to feed 'naturally' contaminated with salmonellas. In two of them no salmonella infections were demonstrated in broiler chickens given feed containing 0.6 per cent (w/w) of the formic acid solution for seven weeks and in the third the infection rate was reduced considerably. In four other experiments the feed was contaminated artificially with between 1 and 47 Salmonella kedougou/g and a second product (BPO12), consisting of a mixture of formic acid and propionic acid, was evaluated. When it was added at 0.5 to 0.68 per cent (w/w) only one of 30 groups of 10 to 12 birds became infected with S kedougou by two weeks of age, compared with 22 of 27 control groups. The treatment of the feed with BPO12 one week before the addition of the salmonellas prevented the establishment of infection in chicks given the treated feed, indicating that acid treatment will provide protection against subsequent recontamination of the feed with the organisms. The isolation rate of S kedougou from artificially contaminated feed treated with BPO12 was reduced only slightly but the feed was apparently 'safe' for the birds which consumed it.     

Compensatory growth after under-nutrition in market turkeys: effect of low protein feeding and realimentation on body composition

Turkey poults were fed starter diets containing either 29 or 20 per cent crude protein. Live‐weight at 6 weeks was depressed by about 30 per cent in poults fed the low protein diet. From 6 to 10 weeks of age four protein levels were fed but carcass studies were restricted to the groups which received adequate amounts of protein at this stage. Sixty poults from each treatment were slaughtered for carcass studies at 6 weeks of age, and also at 7 weeks when the undernourished poults had reached the body weight attained by fully fed groups at 6 weeks. Further samples were taken for carcass analysis at 20 weeks of age.

Percentage body fat was increased and percentage protein in the fat‐free dry matter was decreased by feeding a low protein starter diet from o to 6 weeks. Poults fed the low protein starter diet retained nitrogen more efficiently during the period of undernutrition and in the first stages of recuperation. Following a return to full feeding at six weeks, body protein content was quickly restored, but a longer period was required before their body fat percentage was reduced to the level of fully fed controls.

The organs which were weighed were little affected, except in the case of the gizzard and liver which became proportionately heavier in retarded turkeys at 6 weeks of age. Only spleen weight appeared to have been reduced in relation to total body weight but it occupied a similar proportion in high and low groups when compared on a fat‐free basis. Some, but not all, of the organs weighed were restored to normal proportions by 20 weeks of age. However, dressing percentage and economic value of carcasses at market weight were not materially affected by early nutritional treatment.     

Effect of protein and lysine levels in the diet on body gain composition and energy utilization in growing pigs

Eight replicates of four Large White littermate female pigs were used to evaluate the effect of protein and lysine levels in the diet on the efficiency of protein and energy utilization. In each replicate, one pig was slaughtered at about 20 kg live weight and the others received three diets that contained (per Mcal digestible energy) 37.5 and 2.00 g (diet pl), 37.5 and 2.35 g (diet pL) or 45.0 and 2.35 g (diet PL) of digestible protein and lysine, respectively. Pigs were slaughtered after a 7-wk period. Tissue and chemical composition of the gain and energy and nitrogen gain were determined by using the comparative slaughter technique. Metabolizable energy (ME) intakes were similar in the treatments. Pigs fed the pl diet had a smaller body weight and muscle gain and retained less nitrogen and more lipids than pigs fed pL and PL diets. The decrease in the level of nonessential nitrogen in the diet (pL vs PL) did not affect body weight and muscle gain and the amount of nitrogen retained in muscle tissues. However, pigs given the PL diet had a higher total nitrogen retention and a lower fat deposition and exhibited a higher heat production. For each gram of additional protein catabolized for energy purposes (PL vs pL), heat production was increased by 1.8 kcal. The amount of lysine per unit of muscle gain (38 g/kg) or protein deposited (120 g/kg) was independent of protein and lysine levels in the diet. Estimates of energy (indirect calorimetry) and nitrogen (balance technique) retention were also obtained on the same animals; results were comparable with data obtained by direct measurements.     

Adverse effects of soluble non-starch polysaccharide (guar gum) on piglet growth and experimental colibacillosis immediately after weaning

This study evaluated the effects of adding soluble fibre to the diet of healthy weaner pigs and weaner pigs experimentally infected with enterotoxigenic Escherichia coli (ETEC) in a model of post-weaning colibacillosis. Bodyweight gain, intestinal changes and proliferation of ETEC were measured 7 days following weaning. The basal diet consisted of pregelatinised rice fortified with animal protein. Addition of guar gum to this diet elevated the soluble fibre content from 1 to 6 per cent, and was associated with reduced bodyweight gains, increased large intestinal weights and fermentation, and increased proliferation of ETEC in the small intestine. The optimal levels and type of dietary fibre used for weaner pig diets require further evaluation.     

The protein requirements of two strains of laying pullets

Diets with 16.5, 14.5, 12.5 and 10.5 per cent protein and 2765 k cal. metabolisable energy per kg. and a fifth diet containing 10.5 per cent protein and 2165 k cal. M.E./kg. were fed to Rhode Island Red x Light Sussex pullets and to “hybrid” pullets which weighed 33 per cent less and produced 20 per cent more eggs. Both strains had protein requirements of the order of 20 g./bird/day. It is possible that the assumed higher requirement of the “hybrid” pullets for productive purposes was offset by a smaller requirement for maintenance and growth. Expressed as a percentage of a 2765 k cal. diet, the small strain required at least 16.5 per cent protein and the large strain no more than 12.5 per cent protein for maximum performance. Both strains performed well on the 2165 k cal., 10.5 per cent protein diet, illustrating that high energy diets are not essential for small strains of pullets.

Egg size was reduced by protein restriction in the heavy strain but not in the light strain. On isocaloric diets the light strain consumed more food only at the lowest protein level whereas the heavy strain tended to eat progressively more as the protein was reduced from 16.5 to 12.5 per cent. When offered the low energy diet both strains ate more food, but substantially fewer calories, than when given diets of 2765 k cal. M.E./kg. Protein restriction had a marked effect in reducing live‐weight gains. Energy level of the diet had a large effect on weight gain and also on fat deposition in the carcass.

The greatest differences in performance due to diet did not occur at the time of maximum egg output. The evidence indicates that a diet which is too low in protein to support peak egg production will also fail to support normal egg production at any later stage of the laying year.     

Growth of broilers given diets containing field beans (vicia faba l.) during period the 0 to 4 week

In the first experiment 32 groups, each of about 30 male or female Ross 1 chicks, were given mash diets containing 0, 15, 30 or 45 per cent field beans from one day of age for 4 weeks. From 4 to 8 weeks they were given pelleted diets containing 30 or 45 per cent field beans, the treatments being imposed in a 2 (sexes) x 4x2 factorial design. Increasing the proportion of beans in the diet gave a significant worsening in food conversion ratio and in live‐weight gain to 4 and 8 weeks.

In the second experiment 30 groups, each of about 32 male Ross 1 chicks, were given diets containing o, 30, 45, 30 or 45 per cent beans from one day of age to 4 weeks. In the second and third diets the digestibility of bean protein was assumed to be 100 per cent; in the fourth and fifth diets the digestibility was assumed to be 80 per cent and higher concentrations of other protein supplements were therefore included. All diets were prepared as mash, pellets and ground pellets. From 4 to 8 weeks all groups were given a standard diet, the experiment having a 5 x 3 factorial design. Birds fed the control diet ate significantly less, had a significantly poorer food conversion ratio and weighed significantly less than birds fed the diets containing beans. Growth was similar on all diets containing beans, but food conversion ratio was significantly worsened when the concentration of beans in the diet was increased to 45 per cent. Birds grew best on pellets and grew worst on ground pellets.     

Effects of feeding a blend of grains naturally contaminated with Fusarium mycotoxins on growth and immunological measurements of starter pigs, and the efficacy of a polymeric glucomannan mycotoxin adsorbent

An experiment was conducted to investigate the effects of feeding a blend of grains naturally contaminated with Fusarium mycotoxins on growth and immunological parameters of starter pigs. A polymeric glucomannan mycotoxin adsorbent (GM polymer, Alltech Inc., Nicholasville, KY) was also tested for its efficacy in preventing Fusarium mycotoxicoses. A total of 150 starter pigs (initial weight of 9.3 +/- 1.1 kg) were fed one of five treatment diets (six pens of five pigs per diet) for 21 d. Diets included control, low level of contaminated grains, high level of contaminated grains, high level of contaminated grains + 0.20% GM polymer, and pair-fed control for comparison with pigs receiving the high level of contaminated grains. Feed intake and cumulative weight gain of pigs decreased linearly with the inclusion of contaminated grains in the diet throughout the experiment (P < 0.0001). Weight gains recovered, however, during wk 3 (P > 0.05). There was no difference between the pair-fed group and the pigs fed the diet containing the high level of contaminated grains in terms of weight gain or feed efficiency (P > 0.05). Feeding contaminated grains linearly increased the serum albumin:globulin ratio (P = 0.01), whereas serum urea concentrations and gamma-glutamyltransferase activities responded in a quadratic fashion (P = 0.02). When compared with the pair-fed pigs, serum concentrations of total protein (P = 0.01) and globulin (P = 0.02) were decreased in pigs fed the diet containing the high level of contaminated grains. The feeding of contaminated diets did not significantly alter organ weights expressed as a percentage of BW, serum immunoglobulin concentrations, percentages of peripheral blood lymphocyte subsets, contact hypersensitivity to dinitrochlorobenzene, or primary antibody response to sheep red blood cells (P > 0.05). It was concluded that most of the adverse effects of feeding Fusarium mycotoxin-contaminated grains to starter pigs were caused by reduced feed intake. Although supplementation of GM polymer to the contaminated diet prevented some toxin-induced changes in metabolism, it did not prevent the mycotoxin-induced growth depression under the current experimental conditions.     

Growth, carcass characteristics, and lipid composition of adipose tissue and muscle of pigs fed canola

Sixty-one finishing pigs (53.4 kg) were fed a control diet (containing soybean meal) or diets containing 20% intact canola (IC) or 20% ground canola (GC) for 8 wk. Diets were not isocaloric. Daily gain and feed efficiency were not affected by dietary treatment, but pigs fed GC ate less than pigs fed either IC or the control diet. Carcass measurements, obtained on 43 of the pigs, were not affected by diet. For 27 pigs, fatty acid composition of perirenal adipose tissue (PRF), subcutaneous adipose tissue (SCF), and longissimus muscle (LDM) was analyzed. Nine pigs (three per treatment) were randomly selected for fatty acid composition analysis of intramuscular adipose tissue (IMF) and for cholesterol analysis of several tissues. Pigs fed canola had greater (P less than .05) proportions of mono- and polyunsaturated fatty acids and less (P less than .05) saturated fatty acids in PRF and SCF. The differences were more pronounced for PRF than for SCF. In the LDM, pigs fed canola tended to have elevated levels of unsaturated fatty acids at the expense of the saturated fatty acids, but this effect was significant for linolenic acid only. The fatty acid composition of IMF was not affected by diet (P greater than .05). Diet did not alter the cholesterol content of the tissues, but cholesterol in IMF was higher (P less than .05) than in PRF, SCF, and LDM. In conclusion, 20% IC or GC did not alter growth performance or carcass characteristics of pigs. Feeding of canola increased the degree of unsaturation of PRF and SCF, but it had less effect on IMF and LDM.     

D'Mello JP,+DMELLO JP: Utilisation of ammonium nitrogen by the adult hen

Colostomised hens were given one of 3 diets: A, basal diet containing 10.8 per cent crude protein; B, diet A supplemented with the equivalent of 1.8 per cent crude protein as diammonium phosphate; C, diet A supplemented with the equivalent of 1.7 per cent crude protein as diammonium citrate. The mean percentages of dietary nitrogen absorbed were 82.9, 85.2 and 85.2 for the three diets, respectively, the percentages of the nitrogen of diammonium phosphate and diammonium citrate absorbed being 97.8 and 99.0, respectively. Retention of nitrogen was variable but was lower with diet A than with diet C but higher with diet A than with diet B.     

A study of digestibility and biological value of protein in diets fed to colostomised laying pullets to determine their protein requirement

Hybrid pullets were colostomised just after the commencement of laying. A nitrogen‐free diet was used to determine metabolic faecal nitrogen (MFN) and endogenous urinary nitrogen (EUN). The mean figure obtained for MFN/kg. wt./100 g. dry matter/day was 67.2 mg. and for EUN/kg. body weight 3/4/day was 83.3 mg.

High energy diets of about 1350 k cal./lb. containing 13, 15 and 17 per cent protein and medium energy diets of 13 and 17 per cent protein were fed to colostomised pullets to determine their digestibility, biological value and net protein value. In a further experiment a maize‐fishmeal diet of 1370 k cal. ME/lb. and 17 per cent protein, a soyabean‐maize diet of 1330 k cal. ME/lb. and 14 per cent protein and the latter diet supplemented with methionine and/or lysine were also examined. The mean BV and NPV values of the diets considered in Experiment 1 were 60 and 52 respectively.

Addition of methionine to the maize‐soyabean diet increased the BV from 43.9 to 61.6, the addition of lysine to 43.0 and the addition of both to 67.1.

A factorial method of calculating the daily protein requirement of the pullet based on the data for MFN and EUN and the NPV of each diet is presented. The estimate of 13.3 g. protein per day for the hybrid pullet is compared with other estimates in the literature.     

Survey for transmissible spongiform encephalopathies in Irish pigs fed meat and bone meal

Samples of brain and lymphoid tissues from 1107 meat and bone meal-fed, culled adult pigs from 24 Irish farms were examined for evidence of transmissible spongiform encephalopathy (TSE) by histopathological, immunohistochemical and Western blotting techniques. No evidence of deposits of abnormal prion protein suggesting the presence of TSE was found. Neuropil vacuolation was apparent in the rostral colliculus in 64 per cent of the brains examined and neuronal vacuolation was present in the dorsal vagal nucleus in 15.4 per cent of the brains. However, similar lesions have been described in pigs used as controls in a bovine spongiform encephalopathy challenge experiment. Age-related changes were also observed, including spheroids in the funicular nucleus of 24.5 per cent of the pigs, deposits of lipofuscin in the trigeminal neurons of 13.75 per cent, and mineral deposits in the walls of vessels in the dorsal vagal nucleus of 0.6 per cent. Low-grade non-suppurative inflammatory changes of uncertain origin were observed in 4 per cent of the animals.     

Effect of Rye Ergot on Growth and N-retention in Growing pigs

An experiment with five litter-mate barrows showed that severe reduction in feed intake and growth rate accompanied the inclusion of either 1.0 or 2.0% ergot in the ration. Levels of 0.10 and 0.05% ergot allowed moderate feed intake and weight gain but not equal to the pig fed the ergot-free ration. A subsequent experiment involving five lots of four litter-mate barrows each, indicated the possibility of reduced feed intake and growth performance by growing-finishing pigs fed rations containing 0.05 — 0.10% ergot. This was substantiated by a N-balance experiment in which control pigs retained 1.54 gm more N daily than pigs fed 0.10% ergot. The total alkaloid content of the ergot used in these experiments was 0.292%; the predominant alkaloid (71%) being ergocristine.     

Compensatory growth in turkeys: effect of undernutrition on subsequent protein requirements

An adequate and a low protein starter diet (29 and 20 per cent crude protein respectively) were fed from o to 6 weeks of age. The poults receiving only 20 per cent protein were 17 per cent lighter at 6 weeks than the fully fed group. Turkeys from each treatment were then fed one of five levels of protein from 6 to 10 weeks of age. After 10 weeks all groups were fed adequate levels of protein to allow undernourished poults to exhibit compensatory growth.

The percentage protein required for maximum growth in the 6 to 10‐week stage was similar whether turkeys had been fully fed or undernourished from 0 to 6 weeks. But the “ effective “ percentage of protein required in the 6 to 10‐week stage, defined as the level which subsequently allowed maximum body weight at 20 weeks of age, was less for initially fully fed birds. This was because they had smaller growth deficits at 10 weeks and consequently made faster recovery in the limited time allowed.

Turkeys fed 29 and 17 per cent protein or 20 and 22 per cent protein in starter and grower diets respectively reached the same live‐weight at 20 weeks as fully fed turkeys which received 29 per cent protein from o to 6 weeks and 24 per cent protein from 6 to 10 weeks. The compensating turkeys ate about the same total weight of food as fully fed groups, but had a 10 per cent lower total protein intake.     

Feed preferences of ponies

Preference trials were conducted with mature ponies. In Trial 1, oats were compared with oats plus sucrose. Four of six pony geldings selected oats plus sucrose, but one pony demonstrated a dislike for sucrose and one selected from the bucket on the right side regardless of content. Oats, maize, barley, rye and wheat were compared in Trial 2 using six mature pony mares. Oats were the preferred grain, with maize and barley ranking second and third respectively. Wheat and rye were the least preferred. Even though the ponies demonstrated preference, the total intake at a given meal was not greatly depressed when only the less palatable grains were fed. In Trial 3, pony mares selected a diet containing 20 per cent dried distillers' grain and 80 per cent of a basal mixed diet of maize, oats, wheat bran, soybean meal, limestone and molasses over 100 per cent basal mixed diet, but selected the basal diet over diets containing 20 per cent blood meal, beet pulp or meat and bone meal and 80 per cent basal diet. They did not differentiate against diets containing 20 per cent alfalfa meal or 10 or 5 per cent meat and bone meal when the diets were compared to the basal mixed diet.     

Use of low protein grower diets to delay sexual maturity of broiler breeding males 1

Two experiments were conducted to determine the effects of delaying sexual maturity of broiler breeder males on subsequent reproductive performance. Four dietary protein levels (16.0, 12.4, 8.9 and 5.1 per cent) were fed during the growing period. Thereafter, all males were fed a diet containing 17.0 per cent protein.

Sexual maturity was delayed 4 and 8 weeks, respectively, by feeding the 8.9 and 5.1 per cent protein diets, but was not affected by feeding the 12.4 per cent protein diet. Viability was superior for males receiving the diets containing 8.9 or 5.1 per cent protein. The low protein diets had no adverse effects on semen production, fertility or hatchability following recovery from the protein restriction.     

Effect of Feeding Fescue Seed Containing Ergot Alkaloid Toxins on Stallion Spermatogenesis and Sperm Cells

The cellular effects of tall fescue grass–associated toxic ergot alkaloids on stallion sperm and colt testicular tissue were evaluated. This was a continuation of an initial experiment where the effects of toxic ergot alkaloids on the stallion spermiogram were investigated. The only spermiogram parameter in exposed stallions that was affected by the toxic ergot alkaloids was a decreased gel‐free volume of the ejaculate. This study examined the effect of toxic ergot alkaloids on chilling and freezing of the stallion sperm cells. The effect of toxic ergot alkaloids on chilled extended sperm cells for 48 h at 5°C was to make the sperm cells less likely to undergo a calcium ionophore–induced acrosome reaction. The toxic ergot alkaloids had no effect on the freezability of sperm cells. However, if yearling colts were fed toxic ergot alkaloids, then the cytological analysis of meiotic chromosome synapsis revealed a significant increase in the proportion of pachytene spermatocytes showing unpaired sex chromosomes compared to control spermatocytes. There was little effect of ergot alkaloids on adult stallions, but there might be a significant effect on yearling colts.