Lactation in mice fed endophyte-infected tall fescue seed

This study was conducted to assess the effects of endophyte-infected Acremonium coenophialum tall fescue (KY-31) seed (80% infected) on lactation in CD-1 dams and suckling performance of pups as measured by pup survival and growth rates. Twenty-four pairs of mature CD-1 mice were randomly allocated to four dietary treatments: 1) 100% mouse chow ad libitum; 2) 40% endophyte-infected tall fescue seed and 60% mouse chow (w/w); 3) reduced intake (100% chow), adjusted daily to the intake level of Treatment 2; and 4) 60% infected tall fescue seed and 40% chow. The mice were preconditioned on their respective diets for 100 d prior to 96 h of cohabitation between pairs of males and females. At parturition the litters were removed, and each dam was given a litter of six pups of equal weight, size and sex ratio to suckle for 15 days. All pups given to all the dams were born to other mice that were not part of the study and had not been exposed to endophyte-containing diets. Dams and litter weights were measured daily for 15 consecutive days. The combined body weight measurements of litters from dams fed the tall fescue containing diets (Treatments 2 and 4) were significantly lower (2.07 +/- 0.41 g/d) than that of litters from dams fed the chow containing diets (Treatments 1 and 3) during the suckling trial (P<0.05). Similarly, nine of ten (90%) dams fed the chow containing diets maintained five or more pups (5.5 +/- 0.2) throughout the study as compared to five of nine (55.6%) dams fed the tall fescue containing diets that maintained less than five pups (4.5 +/- 0.2).     

Effects of feeding endophyte infected tall fescue seed on reproductive performance of female CD-1 mice via competitive breeding

This study was conducted to determine the effects of feeding endophyte-infected (Acremonium coenophialum ) tall fescue (Festuca arundinacea ) seed on the growth and reproductive performance of female CD-1 mice via competitive breeding. One hundred sixty female mice were randomly allocated to groups of ten and fed one of two diets. Diet 1 consisted of 50% mouse chow and 50% noninfected Ky-31 tall fescue seed (w/w). Diet 2 contained 50% chow and 50% tall fescue seed that was 80% infected with A. coenophialum . After 50 d of preconditioning on their respective diets, a single male was introduced into each group of 10 females and allowed to cohabitate for 96 h. The males were removed after the cohabitation period and the females continued through gestation on their respective diets. Body weight of dams and litter weights were recorded at parturition. There were no differences (P>0.05) in pregnancy rates between dietary Treatments 1 and 2 (50% vs 48.8%, respectively). However, the average number of pups born per litter (11.10 pups) and average total litter weight (17.21 g) was greater for those females consuming Diet 1 than for females consuming Diet 2 (9.33 pups per litter and 13.97 g total litter weight). The incidence of dead and cannibalized pups was more frequent with Diet 2 than Diet 1 (0.13 vs 0.0 dead; 0.21 vs 0.03 cannibalized, respectively). The obtained data suggest that although the pregnancy rate was similar between the two dietary treatments, the reproductive capacity (litter size and litter weight) of female CD-1 mice was affected by the consumption of endophyte infected fescue seed.     

Effects of feeding endophyte-infected tall fescue seed on the reproductive performance in male and female CD-1 mice by combination crosses

The present study was undertaken to assess the effects of endophyte-infected Acremonium coenophialum tall fescue (KY 31) seed (80% infected) on the reproductive performance of male and female CD-1 mice by combination crosses. Forty-eight male and 48 female 30-d-old mice were randomly allocated to two diet treatments. Twenty-four males and 24 females were fed Diet 1, consisting of 50% non-infected fescue and 50% mouse chow; the remaining animals were fed Diet 2, containing 50% infected fescue. At the end of 50 d, the animals were paired in groups (n = 12) as follows: 1) Diet 1 males and females; 2) Diet 2 males and Diet 1 females; 3) Diet 1 males and Diet 2 females; and 4) Diet 2 males and females. The pairs were maintained on the diets of their female partners and were allowed to cohabitate for 96 h. After this period the males were removed and the females were carried to term. Pregnancy rates among the four treatment groups were 100, 83.3, 75.0 and 54.5%, respectively. Similarly, the average number of pups born per litter among the four groups were 11.5, 8.0, 9.7, and 7.5, respectively. Also, the weights (grams) of pups born per litter were 17.5, 12.6, 12.4, and 9.8, respectively. The results point out that the reproductive capacity of both male and female mice are affected (P < 0.05) by the ingestion of endophyte-infected fescue seeds. Such negative effects were more severe in the female than the male (P < 0.05).     

Effects of feeding endophyte-infected tall fescue seed on reproductive performance in male CD-1 mice by competitive breeding

The objective of this study was to assess the effects of endophyte-infected tall fescue (KY-31) seed (80% infected, containing Acremonium coenophialum ) on the reproductive performance of male CD-1 mice measured by competitive breeding. Sixteen mature CD-1 male mice were randomly allocated to one of two dietary treatments containing 50% mouse chow and either 1) 50% noninfected tall fescue seed, restricted to the daily feed intake of dietary treatment 2, or 2) 50% infected tall fescue seed (w/w) fed ad libitum. Mice were preconditioned on their respective diets for 50 d prior to 96 h of cohabitation with 10 mature CD-1 females. Following removal of males, the females were carried to full term. Males were sacrificed, and testicular, epididymal weights, sperm motility and progressive sperm motility were assessed. The results showed no differences (P>0.05) in average daily weight gain (ADG) and body weight changes during the course of the experiment between the two dietary treatments. There were significant reductions (P<0.05) in total testes weight (0.238 vs 0.214 g), epididymal weight (0.087 vs 0.073 g), sperm motility (82.5 vs 58.7%), and progressive motility (3.7 vs 2.6; scale 0 to 4) between dietary treatments 1 and 2, respectively. Similarly, significant differences in pregnancy rates were 53.8 and 45.0%, and the average numbers of pups born per litter were 10.67 and 9.84, respectively. These data suggest that 50% endophyte-infected fescue seed in the diet of male CD-1 mice can affect their reproductive capacity by influencing the testicular-epididymal weights, and subsequently, the quality of spermatozoa and overall fecundity.     

The effect of feeding tall fescue seed infected by Acremonium coenophialum on pregnancy and parturition in female rats

1. Female Sprague-Dawley rats (Rattus norvegicus) were randomly assigned to various dietary treatments containing: (1) 100% Purina rodent chow, ad libitum; (2) same as 1, but restricted to daily intake of 7; (3) 50% rodent chow (w/w) and 50% endophyte-free tall fescue (Festuca arundinacea) seed; (4) same as 3, but restricted to intake of 5; (5) 50% rodent chow, 25% endophyte-free tall fescue seed and 25% endophyte-infected (Acremonium coenophialum) tall fescue seed; (6) 50% rodent chow, 12.5% endophyte-free and 37.5% endophyte-infected tall fescue seed; and (7) 50% rodent chow and 50% endophyte infected tall fescue seed. 2. Average daily feed intakes and average daily weight gains decreased with higher levels of endophyte infected seed. 3. Frequency of litter production was affected by all endophyte-infected containing diets. 4. Conception was reduced only in dietary treatment (7). 5. Litter weights, number of pups per litter and weight per pup were proportionally reduced as higher levels of infected seed were incorporated in the ingested diets.     

Effects of feeding endophyte-infected fescue seed on reproductive traits of male mice divergently selected for resistance or susceptibility to fescue toxicosis

Our objective was to determine whether consumption of endophyte-infected fescue seed affected male reproduction differently in a mouse line previously selected for susceptibility (S) to fescue toxicosis than in a line previously selected for fescue toxicosis resistance (R). For 8 weeks following weaning, 48 males per line were provided diets containing 50% of either endophyte-infected (E+) or endophyte-free (E-) fescue seed. Each male was then paired with a female for 1 week, with litter size and weight recorded from subsequent births. Males were then killed, testes and seminal vesicles were weighed, cauda epididymal sperm were collected and testis cross-sections were fixed. The E+ diet reduced litter size by 0.5 in mates of S males but increased it by 1.0 in mates of R males (line by diet interaction P=0.05). Testis traits were not affected by diet or the line by diet interaction. Sperm integrity was adversely affected by the E+ diet (P<0.01) but did not differ significantly between lines, nor were line by diet interactions important. In earlier work, the E+ diet reduced long-term reproduction by a larger amount in S- than in R-line mated pairs. Because the E+ diet had similar effects on reproductive traits in R and S males in the current experiment, we infer that the differential impact previously reported acted primarily through traits expressed in females.     

Onset of puberty in CD-1 mouse pups exposed prenatally through weaning to endophyte-infected tall fescue seed

This study was undertaken to investigate the effects of feeding endophyte - infected (Acremonium coenophialum ) tall fescue seed to CD-1 mouse dams (P(1)) during gestation and lactation, and on the subsequent growth and sexual maturity (onset of puberty) of their male and female offspring (F(1)). Forty-eight 21 d old pups (24 male and 24 female F(1) mice) were weaned from dams fed one of two diets containing 50% rodent chow (w/w) and 50% KY-31 tall fescue (Festuca arundinacea ) seed. The seed in Diet 1 was noninfected, while the seed in Diet 2 was 80% endophyte-infected. At weaning (21 d), the F(1) pups were fed rodent chow, ad libitum throughout the remaining experimental period. At 24 d, they were paired with sexually mature non-treated virgin CD-1 mice (fed 100% rodent chow) for one parturition cycle. Male F(1) mice were sacrificed at 84 d to determine testicular development. The age at the birth of the first litter for Diet 2 F(1) male (76.8 +/- 2.2 d) and female (58.4 +/- 2.1 d) was significantly greater (P<0.05) than the age at parturition for Diet 1 male and female F(1) test mice (64.1 +/- 1.8 and 51.9 +/- 1.2 d, respectively). At parturition, the female F(1) mice showed no significant differences (P>0.05) in either mean parturition weight or number of F(2) pups born per litter. However, total F(2) litter wight (11.38 +/- 1.14 g) and mean weight per F(2) pup (1.40 +/- 0.04 g) for Diet 2 female F(1) mice litters were lower (P<0.05) when compared with Diet 1 females (14.53 +/- 0.57 g and 1.66 +/- 0.02 g, respectively). No significant differences were observed between the two male F(1) treatment groups, for total F(2) litter weight or the number of pups born per F(2) litter. Although Diet 2 F(1) males weighed significantly less (P<0.05) at weaning and at pairing, final body weights at sacrifice (84 d) were not different (P>0.05) from the Diet 1 males.     

Effect of feeding fungal endophyte (Acremonium coenophialum )-infected tall fescue seed on reproductive performance in CD-1 mice through continuous breeding

This study was designed to assess the effect of endophyte-infected (Acremonium coenophialum ) tall fescue (KY-31) seed (80% infected) on reproductive performance in CD-1 mice by continuous breeding. Twenty-four pairs of 70-d-old CD-1 mice were randomly allocated to four diets: 1) mouse chow ad libitum; 2) 40% infected fescue seed and 60% chow (w/w); 3) reduced intake (100% chow) similar to the intake, adjusted daily, in Diet 2; and 4) 60% infected fescue seed and 40% chow. Males and females were randomly paired (six pairs/treatment) and placed on the above diets. The mice were fed the corresponding diets for 80 d, although the pairs were separated on Day 60 (prior to the birth of the 3rd litter) and the females were monitored for one additional gestation period (20 d). The pregnancy data (litters produced) among the four treatments were 100.0 (18), 77.8 (14), 100.0 (18) and 80.0% (12) respectively. Similarly, the average number of pups born per litter among the four treatments was 11.8, 9.3, 10.1, and 9.8. When the chow treatment (1 and 3) and the fescue treatments (2 and 4) were pooled and compared, the percent pregnancy was 100.0 (n = 36) and 78.8 (n = 26), and the pups born per litter (means +/- SEM) were 11.0 +/- 0.5 and 9.5 +/- 0.6, respectively. Also the intervals between the three litters born during the 60-d cohabitation period were 21.6 +/- 1.1 and 24.5 +/- 0.9 d for the chow and fescue treatments, respectively. The results point out that 40 and 60% infected fescue seed in the diet of mice does influence (P < 0.05) their reproductive capacity as measured by percent pregnancy and litter size.     

Adaptive responses to fescue toxicosis under thermoneutral and heat stress conditions

This study determined the potential for short-term adaptation to fescue toxicosis and heat stress in rats. Male CD outbred rats (n=24) were implanted with temperature transmitters (Respironics, Bend, OR) to measure core temperature (Tc) and general activity. All rats were initially fed diets with ground, uninfected tall fescue seed (E−) and exposed to 21 °C (thermoneutral, TN) to establish baseline values. In Period 1, all groups were maintained at TN for 7 days, with one group fed a diet containing ground, endophyte-infected tall fescue seed (E+, approximately 165 μg ergovaline/kg BW/d) and two groups fed E− diet. Ergovaline is thought to be the primary toxin responsible for many symptoms associated with fescue toxicosis. Period 1 was followed by 7 days at 31 °C (heat stress, HS, Period 2) on the same diets. All animals were fed E− diet during the second 7 day of HS (Period 3). In the final 7 day (Period 4), E+ diet was returned to the original group and fed to one of the previously E− groups, with the third group remaining on E− diet. A 40% decrease in FI occurred with E+ treatment at TN (P<0.05), with a comparable BW reduction (P<0.05) after 4 day. Both responses worsened during HS. Treatment with E+ in Period 4 indicated that FI and BW had not adapted to fescue toxicosis. A reduction in daily Tc occurred with E+ treatment at TN (P<0.05) followed by hyperthermia during the initial stage of HS (P<0.05). Although feed intake and growth rate showed no change over time, there was a reduction in fescue toxicosis-induced hyperthermia in the heat with repeat treatment. Conditioning animals to fescue toxicosis and heat stress prior to exposure may be beneficial in reducing impacts on thermal status of the animal.     

Short- and long-term responses to fescue toxicosis at different ambient temperatures

Intake of endophyte-infected tall fescue by cattle results in fescue toxicosis, which is characterized by increased hyperthermia during heat stress and concomitant reductions in feed intake and growth. Rats were monitored at 21 or 31 °C for short- or long-term periods to determine temporal changes associated with the intake of endophyte-infected (E+) or uninfected (E−) fescue seed diets. Core temperature only changed in rats fed E+ diet at 31 °C. Intake of E+ diet reduced feed intake, daily gain, and serum prolactin. There were temporal and thermal differences in the response to endophytic toxins, with short-term changes diminishing over time at 21 °C, but increasing for certain parameters at 31 °C.     

Effects of grazing endophyte-infected tall fescue on eCG and progestogen concentrations from gestation days 21 to 300 in the mare

The influence of grazing endophyte-infected tall fescue on endometrial cup formation and function, progestogen production, and embryonic and fetal development were examined in pregnant mares between Day 21 and Day 300 of gestation. Total immunoreactive progestogens and equine chorionic gonadotropin (eCG) concentrations were compared between untreated controls (endophyte-free, n = 12) and treated mares (endophyte-infected, n = 12). There were no differences in endometrial cup formation or function, as determined by eCG concentrations at Days 45, 60, 75, 90 and 120 (P > 0.05) between mares grazing endophyte-infected and endophyte-free tall fescue. Mares grazing the endophyte-infected tall fescue had lower total progestogen concentrations (P < 0.01) from Days 90 to 120 than the mares grazing endophyte-free tall fescue. Embryonic development based on mean vesicle height was not affected by endophyte exposure. No pregnancies were lost by mares in either treatment group during the trial period. The results of this study indicate that grazing endophyte-infected tall fescue between Day 21 and Day 300 does not alter endometrial cup formation and function, or result in increased pregnancy losses during this period. Lower progestogen concentrations between Days 90 and 120 with exposure to endophyte-infected tall fescue could reflect decreased luteal progesterone production.     

Preference by sheep for endophyte-infected tall fescue grown adjacent to or at a distance from alfalfa

Two experiments were conducted to assess preference by sheep for endophyte-infected tall fescue growing in monoculture at least 5 m away from alfalfa (fescue-middle (FM)) over endophyte-infected tall fescue growing adjacent (0.2 to 1 m; fescue–alfalfa (FA)) to alfalfa (FA), and the effect of legume scent on preference for endophyte-infected tall fescue. In Experiment 1, 10 six-month-old lambs were offered for 12 days a choice of freshly harvested FA and FM. On days 13 and 14, lambs were offered the same choice, except cages (to allow access only to scent) containing freshly harvested alfalfa were put in the feeders containing FA, whereas cages containing freshly harvested FM were included with the feeders containing FM. Forage intake was measured 1 h after feeding and at three consecutive 2-h intervals thereafter. FA contained greater (P<0.002) concentrations of the alkaloid ergovaline (360±27 ppm) and CP (8±0.4%) than FM (219±27 ppm and 6±0.4%, respectively). Lambs preferred (P<0.05) FA to FM during the 1^st hour of feeding, but the differences became smaller and disappeared in later feeding periods (P<0.005). Lambs offered FA with alfalfa scent or FM with FM scent preferred (P<0.05) FA but only on the 2^nd day. In Experiment 2, 10 six-month-old lambs were offered a choice of FM with cages (to allow access only to scent) containing freshly harvested alfalfa or FM for 8 days. During the following 4 days, FM in the cages was replaced with freshly harvested sainfoin. Preference was greater (P<0.05) for FM offered with alfalfa scent than for FM offered with FM scent only on days 4 and 8. When lambs were offered FM with alfalfa or sainfoin in cages, they preferred (P<0.05) tall fescue with sainfoin scent over fescue with alfalfa scent, but intake was variable across hours and days (P<0.001). It is concluded that (1) lambs adjusted their intake of and preference for FA and FM over successive feeding bouts within each day, likely owing to an attempt to balance intakes of nutrients and alkaloids and (2) olfactory cues influenced preference, but to a lesser extent than nutrients and alkaloids in endophyte-infected tall fescue.     

Influence of endophyte-infected tall fescue on cyclicity, pregnancy rate and early embryonic loss in the mare

The effects of grazing endophyte-infected tall fescue on luteal function, pregnancy rates, and embryonic loss rates were compared between treated mares (n=18) and untreated controls (endophyte-free, n=12). Mares grazing endophyte-infected fescue demonstrated significantly (P<0.01) prolonged luteal function (22.9 vs 15.8 d) than those grazing endophyte-free fescue. Continuous grazing of endophyte-infected fescue resulted in a decreased (P=0.30) per cycle 14-d viable pregnancy rate (14 31 , 45.2%) compared with that of endophyte-free grazing (12 16 , 75.0%). Early embryonic death rates were higher (P=0.20) in the endophyte-infected group (6 20 , 30.0%) than the endophyte-free group (1 13 , 7.7%). Cumulative pregnancy rates after a 60-d breeding period did not differ between the 2 groups. Embryonic development based on mean vesicle height at 14-d was not significantly different between treatment groups for embryos that maintained viability. Embryos that underwent early embryonic death were smaller (P<0.10) at Day-14 than embryos that maintained viability. Mean plasma progesterone concentrations were significantly (P< 0.01) greater at Day-21 postovulation in endophyte-infected mares in which the embryo remained viable (15.8 ng/ml) than in endophyte-free mares that experienced early embryonic death (9.8 ng/ml) or that demonstrated prolongation of luteal function (11.2 ng/ml). The results of this study suggest that grazing endophyte-infected tall fescue can have a detrimental effect on reproductive efficiency in the mare due to an increase in cycles bred per pregnancy rate, increased early embryonic death rate and prolongation of luteal function.     

Effect of feeding tall fescue seed infected by endophytic fungus (Acremonium coenophialum ) on reproductive performance in male rats

An experiment was conducted to determine the effect of feeding tall fescue seed infected by an endophytic fungus Acremonium coenophialum on the reproductive performance of male rats. Thirty 70-day-old rats were randomly allocated to four treatments: (I) fed 50% rat chow and 50% healthy fescue seed ad libitum (control; N=9; (II) same as I but restricted to the daily feed intake of III (N=7; (III) 50% fungal-infected fescue seed and 50% chow (N=7); and (IV) a mixture of 50% laboratory chow, 25% healthy fescue seed and 25% fungal-infected fescue seed (N=7). The rats were fed these diets for 42 days. During this time, body weights were taken weekly and feed intake was taken daily. At the end of the experiment, the rats were sacrificed and the testes and epididymides were excised and measured. Sperm parameters were assessed (concentration, percentage of motility and progressive motility) at the site of the cauda epididymis; the testes were homogenized and assessed for daily sperm production potential (DSP). Concentrations of spermatozoa (x 10(6)) among the various treatments were 645.6, 486.5, 387.4 and 457.1; motility and progressive motility measurements ranged from 48 to 50% and 2.3 to 2.4 (0-4), respectively. DSP values (per gram) and testicular weight were reduced (P<0.05) in Diet III. The data suggests that 50% fungal-infected fescue seed in the diet of rats does influence the DSP, testicular parechyma and epididymal weight in the rat.     

Prevalence of Escherichia coli O157:H7 and Salmonella in beef steers consuming different forage diets

AIMS: To compare the prevalence of faecal shedding of Escherichia coli O157:H7 and Salmonella in growing beef cattle consuming various forages. METHODS AND RESULTS: In Experiment I, faecal samples were collected from steers grazing either endophyte-infected (E+) tall fescue or common bermudagrass (CB). Steers grazing E+ tall fescue were confined to a dry-lot pen and fed CB hay ad libitum for 10 days. In Exp. II, faecal samples were collected from steers grazing either E+ or novel endophyte-infected (NE) tall fescue and treated with one of two anthelmintics: ivermectin (I) or fenbendazole (F). In Exp. I, prevalence of E. coli O157:H7 was less in E+ tall fescue steers fed CB hay than steers grazing CB. More I-treated steers shed Salmonella than F-treated steers at 42-day postanthelmintic treatment but shedding of Salmonella was similar between anthelmintics at day 63 in Exp. II. CONCLUSIONS: Faecal shedding of pathogenic bacteria was not affected by grazing E+ tall fescue. Alterations of forage diets may influence the prevalence of E. coli O157:H7, and anthelmintic treatment could affect faecal shedding of Salmonella. SIGNIFICANCE AND IMPACT OF THE STUDY: Knowledge of factors that influence shedding of pathogenic bacteria in cattle is necessary to develop on-farm intervention strategies aimed at reducing pathogen shedding.     

Fertilization rates and embryonic development in CD-1 mice fed fungal endophyte-infected tall fescue seed

The objective of this study was to assess the effects of endophyte-infected tall fescue (KY-31) seed (80% infected, containing Acremonium coenophialum ) on the fertilization rates and embryonic development of CD-1 mice. Twenty-four pairs of mature CD-1 mice were randomly allocated to two dietary treatments containing 40% mouse chow and 1) 60% noninfected tall fescue seed or 2) 60% infected tall fescue seed (w/w). The mice were preconditioned on their respective diets for 60 d prior to 96 h of cohabitation between pairs of males and females. Following the removal of the males, equal numbers of females (n = 4) from each dietary treatment were sacrificed at 80 h, 6 and 10 d after vaginal plug establishment. The female reproductive tracts were excised and flushed to recover eggs and embryos or dissected to identify the number and status of the implanted fetuses. The number of eggs-embryos and/or fetuses per mouse present at the time of sacrifice were 9.8, 8.8 and 11.5 vs 8.2, 5.3 and 4.8 for the mice fed the noninfected and infected fescue seeds, respectively. Similarly, the conception rates (%) were 100, 100 and 100 vs 73, 50 and 50 for the two treatments. The mice sacrificed at 80 h and fed the noninfected fescue had 9.8 expanded blastocysts per animal, whereas those fed the infected fescue had only 4.0 expanded blastocysts. The results suggest that the infected fescue seed consumed by these mice had a significant effect on fertilization rates. More importantly, the infected fescue seed influenced negatively the development of these embryos during the embryonic-preimplantation period.     

EFFECTS OF N-METHYLAMINOETHANOL, AND N,N-DIMETHYL-AMINOETHANOL IN THE DIET OF PREGNANT RATS ON NEONATAL RAT BRAIN CHOLINERGIC AND PHOSPHOLIPID PROFILE

Abstract— Pregnant rats were fed for 15 days predelivery until 15 days postpartum a choline (Ch)-deficient diet (CD diet) or a CD diet supplemented with 0.8% Ch-CI (CS), 1% N -methylaminoethanol (MME) or 1% N,N -dimethylaminoethanol (DME). Gestation and parturition of the pregnant rats proceeded normally. However, all the pups born of dams fed the MME diet, and most of those born of dams fed the DME diet, died within 36 h of birth. No histological or cytological alterations were detected in the brain of the pups. Levels of Ch and acetylcholine (ACh) were elevated in the brain of pups born of dams fed the MME and DME diets, but not the CS diet. The content of total phospholipids in the brain of the pups was not altered by the diet fed to the dams. However, the phosphatidyl-Ch and phosphatidylaminoethanol (PAE) contents in the brain of the MME- and DME-exposed pups were markedly reduced. At the same time, significant amounts of DME, phosphatidyl-N-monomethylaminoethanol (PMME) and of phosphatidyl- N,N -dimethylaminoethanol (PDME) were present in the same brain areas. These results are evaluated and discussed in terms of providing a cause for the death of the MME- and DME-exposed neonatal rats.     

A preliminary study of growth, serum prolactin and reproductive performance of beef heifers grazing Acremonium coenophialum -infected tall fescue

In an experiment with a 2x2 factorial arrangement of treatments, 32 virgin Angus heifers were used to study effects of tall fescue endophyte Acremonium coenophialum and energy supplementation on reproductive performance. Treatments were feeding of endophyte-free (EF) or endophyte-infected (EI) tall fescue without (0%) and with energy supplementation at one percent group mean body weight (1%). Blood samples were collected at 28-day intervals for prolactin (PRL). Starting 21 days before the breeding season, blood was also collected weekly for progesterone (P(4)) and PRL. After 99 days of grazing, heifers received Syncro-Mate-B (SMB) and were then artificially inseminated over a 30-day period. Heifers on EI-0% had a lower (P<0.05) average final body weight. Highest average daily gain was observed in heifers fed EF-1% (0.98 kg/day), whereas, heifers fed EI-0% had lowest average daily gain (0.53 kg/day; P<0.05). Endophyte-infected fescue depressed serum PRL concentrations (171 and 143 ng/ml vs 70 and 85 ng/ml; EF-0% and EF-1% vs EI-0% and EI-1%, respectively; P<0.05). No differences were observed among treatments in luteal activity before or after SMB, in pregnancy rates after a synchronized estrus or in overall pregnancy rates during the 30-day breeding season. Endophyte-infected fescue decreased average daily gain and depressed serum concentrations of prolactin, but had no effect on reproductive performance as measured in this study.     

Genotypic and chemotypic diversity of Neotyphodium endophytes in tall fescue from Greece

Epichloid endophytes provide protection from a variety of biotic and abiotic stresses for cool-season grasses, including tall fescue. A collection of 85 tall fescue lines from 15 locations in Greece, including both Continental and Mediterranean germplasm, was screened for the presence of native endophytes. A total of 37 endophyte-infected lines from 10 locations were identified, and the endophytes were classified into five distinct groups (G1 to G5) based on physical characteristics such as colony morphology, growth rate, and conidial morphology. These classifications were supported by phylogenetic analyses of housekeeping genes tefA and tubB, and the endophytes were further categorized as Neotyphodium coenophialum isolates (G1, G4, and G5) or Neotyphodium sp. FaTG-2 (Festuca arundinacea taxonomic group 2 isolates (G2 and G3). Analyses of the tall fescue matK chloroplast genes indicated a population-wide, host-specific association between N. coenophialum and Continental tall fescue and between FaTG-2 and Mediterranean tall fescue that was also reflected by differences in colonization of host tillers by the native endophytes. Genotypic analyses of alkaloid gene loci combined with chemotypic (chemical phenotype) profiles provided insight into the genetic basis of chemotype diversity. Variation in alkaloid gene content, specifically the presence and absence of genes, and copy number of gene clusters explained the alkaloid diversity observed in the endophyte-infected tall fescue, with one exception. The results from this study provide insight into endophyte germplasm diversity present in living tall fescue populations.     

Endophyte-infected tall fescue diet alters gene expression in heifer luteal tissue as revealed by interspecies microarray analysis

Cattle consuming endophyte-infected tall fescue grass have an associated reduction in circulating progesterone and reduced reproductive rates. In this study, commercially available rat microarrays were used to analyze the gene expression in luteal tissues from heifers fed endophyte-free fescue, endophyte-infected fescue, or endophyte-infected fescue supplemented with the dopamine (DA) antagonist, domperidone. The number of hybridized spots represented approximately 40% of the total 10,000 rat genes/ESTs evaluated. Each luteal sample was analyzed in triplicate, resulting in within treatment correlation coefficients of >/=0.98. Median values of mRNA abundance from luteal tissue taken from the endophyte-infected fed heifers revealed 598 genes and ESTs that were down regulated and 56 genes and ESTs that were upregulated compared with luteal mRNA values from the endophyte-free treatment. There were fewer comparative differences between median values from luteal mRNA from the endophyte-free versus feeding endophyte-infected plus domperidone treated heifers. Only 19 genes and ESTs were upregulated and two were down-regulated.