Effect of continuous or intermittent feeding of ergot contaminated grain in a mash or pelleted form on the performance and health of feedlot beef steers

This study evaluated the effect of feeding ergot contaminated grain continuously or intermittently through backgrounding (BG) and finishing (FN) in a mash or pelleted supplement on the growth performance, health and welfare parameters, and carcass characteristics of feedlot beef steers. Sixty black Angus steers (300 ± 29.4 kg BW) were used in a complete randomized 238-d study. Steers were stratified by weight and randomly assigned to four different diets (15 steers/treatment) and individually housed. Treatments included: (1) control [CON; no added ergot alkaloids (EA)], (2) continuous ergot mash (CEM; fed continuously at 2 mg total EA/kg of DM), (3) intermittent ergot mash (IEM; fed at 2 mg total EA/kg of DM, during the first week of each 21-d period and CON for the remaining 2 wk, this feeding pattern was repeated in each period), and (4) intermittent ergot pellet (IEP; fed at 2 mg of total EA/kg of DM as a pellet during the first week of each 21-d period and CON for the remaining 2 wk as described for IEM). Steers were fed barley based BG diets containing 40% concentrate:60% silage (DM basis) for 84 d (four 21-d periods), transitioned over 28 d (no ergot fed) to an FN diet (90% concentrate:10% silage DM basis) and fed for 126 d (six 21-d periods) before slaughter. In the BG phase, steer DMI (P < 0.01, 7.45 vs. 8.05 kg/d) and ADG (P < 0.01) were reduced for all EA diets compared to CON. The CEM fed steers had lower ADG (P < 0.01, 0.735 vs. 0.980 kg) and shrunk final BW (P < 0.01, 350 vs. 366 kg) than CON. CEM had lower gain:feed (P < 0.07, 0.130 vs. 0.142) than CON. In the FN phase, steer DMI (P < 0.01, 9.95 vs. 11.05 kg/d) and ADG (P = 0.04) were also decreased for all EA fed steers compared to CON. Total shrunk BW gain (P = 0.03, 202.5 vs. 225.2 kg), final BW (P = 0.03, 617.9 vs. 662.2 kg), and carcass weight (P = 0.06) decreased for all EA fed steers compared to CON. The percentage of AAA carcasses decreased for all EA fed steers (P < 0.01, 46.7 vs. 93.3%) compared to CON. EA fed steers had increased rectal temperatures (P < 0.01, 39.8 vs. 39.4 °C) compared to CON. Pelleting ergot contaminated grain did not reduce the impact of ergot alkaloids on any of the measured parameters during BG or FN. Continuously or intermittently feeding ergot contaminated diets (2 mg total EA/kg of DM) significantly reduced intake, growth performance, and carcass weight, with minimal impact on blood parameters in feedlot steers. Pelleting was not an effective method of reducing ergot toxicity.

Risks for animal health related to the presence of ergot alkaloids in feed

The European Commission requested EFSA to provide an update of the 2012 Scientific Opinion of the Panel on Contaminants in the Food Chain (CONTAM) on the risks for animal health related to the presence of ergot alkaloids (EAs) in feed. EAs are produced by several fungi of the Claviceps and Epichloë genera. This Opinion focussed on the 14 EAs produced by C. purpurea (ergocristine, ergotamine, ergocornine, α- and β-ergocryptine, ergometrine, ergosine and their corresponding 'inine' epimers). Effects observed with EAs from C. africana (mainly dihydroergosine) and Epichloë (ergovaline/-inine) were also evaluated. There is limited information on toxicokinetics in food and non-food producing animals. However, transfer from feed to food of animal origin is negligible. The major effects of EAs are related to vasoconstriction and are exaggerated during extreme temperatures. In addition, EAs cause a decrease in prolactin, resulting in a reduced milk production. Based on the sum of the EAs, the Panel considered the following as Reference Points (RPs) in complete feed for adverse animal health effects: for pigs and piglets 0.6 mg/kg, for chickens for fattening and hens 2.1 and 3.7 mg/kg, respectively, for ducks 0.2 mg/kg, bovines 0.1 mg/kg and sheep 0.3 mg/kg. A total of 19,023 analytical results on EAs (only from C. purpurea) in feed materials and compound feeds were available for the exposure assessment (1580 samples). Dietary exposure was assessed using two feeding scenarios (model diets and compound feeds). Risk characterisation was done for the animals for which an RP could be identified. The CONTAM Panel considers that, based on exposure from model diets, the presence of EAs in feed raises a health concern in piglets, pigs for fattening, sows and bovines, while for chickens for fattening, laying hens, ducks, ovines and caprines, the health concern related to EAs in feed is low.

Effect of increasing concentration of ergot alkaloids in the diet of feedlot cattle: performance, welfare, and health parameters

This study was designed to evaluate the effects of feeding increasing dietary concentrations of ergot alkaloids from cereal grains (EA; 0, 0.75, 1.5, 3.0 mg/kg of dietary DM) to feedlot cattle over backgrounding (BG) and finishing (FS) phases on health, welfare, and growth performance. Two hundred and forty commercial steers (280 ± 32 kg BW) were stratified by weight and randomly allocated to 16 pens (15 steers/pen), 4 of which were equipped with the GrowSafe system (1 pen/treatment) to measure individual feed intake. Each pen was randomly assigned to a treatment (n = 4/treatment). Treatments included 1) control (CTRL), no added EA; 2) CTRL + 0.75 mg/kg EA (EA075); 3) CTRL + 1.5 mg/kg EA (EA150); and 4) CTRL + 3.0 mg/kg EA (EA300). Steers were fed barley-based BG diets containing 40% concentrate: 60% silage (DM basis) for 84 d. Steers were then transitioned over 28 d to an FS diet (90% concentrate: 10% silage DM basis) and fed for 119 d before slaughter. The diet fed to EA300 steers was replaced with the CTRL diet after 190 d on feed (DOF), due to EA-induced hyperthermia starting at 165 DOF. In the BG phase, average meal length (P = 0.01) and size (P = 0.02), daily feeding duration (P = 0.03), final body weight (BW; P = 0.03), and total BW gain (P = 0.02) linearly decreased with increasing EA levels, while gain to feed (G:F) responded quadratically (P = 0.04), with EA150 having the poorest value. Increasing concentrations of EA in the diet linearly increased rectal temperature (P < 0.01) throughout the trial. Over the full FS phase, a quadratic response was observed for ADG (P = 0.05), final BW (P = 0.05), total BW gain (P = 0.02), and carcass weight (P = 0.05) with steers fed EA150 having the lowest performance, as EA300 steers were transferred to CTRL diet after 190 DOF. Dressing percentage (P = 0.02) also responded quadratically, with the lowest values observed for EA300. Thus, EA reduced ADG during BG and FS phases, although more prominently in FS, likely due to increased ambient temperatures and high-energy diet in FS triggering hyperthermia. When EA300 steers were transferred to the CTRL diet, compensatory gain promoted higher hot carcass weight (HCW) when compared with steers fed EA150. In conclusion, feeding feedlot steers diets with > 0.75 mg/kg EA caused reductions in performance and welfare concerns, although this breakpoint may be affected by duration of feeding, environmental temperatures, and EA profiles in the feed.

Case-Control Study of Nodding Syndrome in Acholiland: Urinary Multi-Mycotoxin Screening

This case-control study adds to the growing body of knowledge on the medical, nutritional, and environmental factors associated with Nodding Syndrome (NS), a seizure disorder of children and adolescents in northern Uganda. Past research described a significant association between NS and prior history of measles infection, dependence on emergency food and, at head nodding onset, subsistence on moldy maize, which has the potential to harbor mycotoxins. We used LC-MS/MS to screen for current mycotoxin loads by evaluating nine analytes in urine samples from age-and-gender matched NS cases (n = 50) and Community Controls (CC, n = 50). The presence of the three mycotoxins identified in the screening was not significantly different between the two groups, so samples were combined to generate an overall view of exposure in this community during the study. Compared against subsequently run standards, α-zearalenol (43 ± 103 µg/L in 15 samples > limit of quantitation (LOQ); 0 (0/359) µg/L), T-2 toxin (39 ± 81 µg/L in 72 samples > LOQ; 0 (0/425) µg/L) and aflatoxin M1 (4 ± 10 µg/L in 15 samples > LOQ; 0 (0/45) µg/L) were detected and calculated as the average concentration ± SD; median (min/max). Ninety-five percent of the samples had at least one urinary mycotoxin; 87% were positive for two of the three compounds detected. While mycotoxin loads at NS onset years ago are and will remain unknown, this study showed that children with and without NS currently harbor foodborne mycotoxins, including those associated with maize.

The tolerance of steers (Bos taurus) to sorghum ergot (Claviceps africana) in a feedlot during the cooler months in subtropical Queensland

Two experiments tested the tolerance of steers (Bos taurus) to sorghum ergot (Claviceps africana) during cooler months in south-east Queensland. Sorghum grain containing 2.8% ergot and 28 mg/kg ergot alkaloids (84% dihydroergosine, 10% dihydroelymoclavine, 6% festuclavine) was incorporated into feedlot rations. In a previous study in summer–autumn, ergot (1.1–4.4 mg alkaloids/kg ration) severely reduced performance in steers when the temperature–humidity index (THI; dry bulb temperature °C + 0.36 dew-point temperature °C + 41.2) was ~70, whereas a THI of ~79 was tolerated by steers fed ergot-free rations. Experiment 1 was conducted in winter–spring, with rations containing 0, 2.8, 5.6, 8.2 or 11.2 mg ergot alkaloids/kg ration. All ergot inclusions depressed feed intake (14% average reduction) and growth rate (34% average reduction), even when the weekly average daily THI was less than 65. Rectal temperatures were occasionally elevated in ergot-fed steers (P < 0.05), primarily when the THI exceeded ~65. All ergot inclusions depressed plasma prolactin concentrations in steers. Experiment 2 was predominantly carried out in winter, with weekly average daily THI <65 throughout the experiment. Rations containing 0, 0.28, 0.55 or 1.1 mg ergot alkaloids/kg were fed for 4 weeks but produced no significant effect on feed intakes and growth rates of steers. Alkaloid concentrations were then changed to 0, 2.1, 4.3 and 1.1 mg/kg, respectively. Subsequently, feed intakes declined by 17.5% (P < 0.05), and growth rates by 28% (P > 0.05) in the group receiving 4.3 mg/kg alkaloid, compared with Controls. Plasma prolactin concentrations were depressed, relative to the Controls, by dietary alkaloid inclusion greater than 1.1 mg/kg, with alkaloid intake of 4.3 mg/kg causing the greatest reduction (P < 0.05). Cattle performance in these studies shows steers can tolerate up to ~2 mg ergot alkaloid/kg (0.2% ergot) in feedlot rations under low THI conditions (< ~60–65), but previous findings indicate a much lower threshold will apply at higher THI (>65).

Activities and Effects of Ergot Alkaloids on Livestock Physiology and Production

Consumption of feedstuffs contaminated with ergot alkaloids has a broad impact on many different physiological mechanisms that alters the homeostasis of livestock. This change in homeostasis causes an increased sensitivity in livestock to perturbations in the ambient environment, resulting in an increased sensitivity to such stressors. This ultimately results in large financial losses in the form of production losses to livestock producers around the world. This review will focus on the underlying physiological mechanisms that are affected by ergot alkaloids that lead to decreases in livestock production.

Techniques to reduce the temperature of beef muscle early in the post mortem period – a review

A review of the literature was conducted on the effects of high temperature and low pH (HTLP) on meat quality, with a focus on interventions that increase the rate of cooling post slaughter. HTLP can potentially change meat tenderness, water-holding capacity and colour due primarily to protein denaturation during the first 5 h post mortem. Deep muscles in large carcasses are susceptible to HTLP when cooled conventionally. Ante mortem and post mortem solutions that increase the rate of carcass cooling are discussed. Ante mortem solutions include access to feed and water, showering with water and provision of shade. Post mortem solutions included vascular flushing, hot fat trimming, opening seams, hot boning, spray chilling, blast chilling, immersion cooling, and very fast chilling. Accelerating rigor with electrical stimulation before HTLP remains controversial. Combinations of different techniques, that suit the specific requirements of a particular processing plant, is the likely best solution to HTLP, but further development of commercial solutions is suggested.