Utilizing fungus myceliated grain for molt induction and performance in commercial laying hens

Molting in poultry is used to rejuvenate hens for a second or third laying cycle. Feed withdrawal was once the most effective method used for molt induction; however, it has being phased out due to food safety and animal welfare concerns. This study evaluated the utilization of fungus myceliated grain as a safe and effective alternative for inducing molt, enhancing immunity, reducing Salmonella growth, and returning to egg production. Laying hens were subjected to 1 of 5 treatments: 1) nonfed (NF), 2) full-fed (FF), 3) fungus myceliated meal (FM), 4) 90% fungus myceliated meal+10% standard layer ration (FM-90), and 5) 90% alfalfa meal+10% fungus myceliated meal (AF-90). Each treatment condition was replicated 9 times during a 9-d molt period. The results revealed that egg production for treatments 1 and 3 ceased completely by d 5, whereas hens in treatments 4 and 5 ceased egg production by d 6. The percentage of BW loss decreased significantly (P<0.05) in treatments 1 (57%), 2 (8%), 3 (35%), 4 (37%), and 5 (44%). Ovary weights of hens fed all molting diets decreased significantly from the full-fed control but did not differ significantly (P<0.05) from each other. Salmonella population in the crop, ovary, and ceca from hens differed significantly (P<0.05) among treatments. Return to egg production differed between treatments with higher production beginning in treatment 3 and ending in treatment 5. Antibody titers did differ (P<0.05) among treatments. From these results, fungus myceliated meal appears to be a viable alternative to conventional feed withdrawal and other methods for the successful induction of molt and retention of postmolt performance.

The effect of mushroom and pokeweed extract on salmonella, egg production, and weight loss in molting hens

An experiment was conducted to evaluate the effects of mushroom and pokeweed extract alone or in combination with alfalfa meal on Salmonella spp. population, egg production, and weight loss in laying hens during a 10-d molting period. The trial used 54 active laying hens approximately 77 wk of age that were naturally infected with Salmonella spp. The layers were subjected to 1 of 9 treatment groups, replicated 3 times with 2 hens per replicate cage. The treatment conditions were as follows: 1) full-fed + H(2)0 (FFW), 2) full-fed + mushroom (FFM), 3) full-fed + pokeweed (FFP), 4) nonfed + H(2)0 (NFW), 5) nonfed + mushroom (NFM), 6) nonfed + pokeweed (NFP), 7) full-fed alfalfa meal + H(2)0 (FFAW), 8) full-fed alfalfa meal + mushroom (FFAM), and 9) full-fed alfalfa meal + poke-weed (FFAP). The results showed that the base-10 logarithm values of Salmonella from the ceca significantly increased (P <or= 0.05) in treatment NFW (3.48), NFM (3.22), and FFAW (3.33), whereas the greatest reduction was observed in treatment FFAM (2.72). The number of Salmonella bacteria recovered from the crop was significantly greater in the NFW treatment (3.43) and lowest in treatment FFAM (2.62). Treatment FFAM (30.0%) had the lowest BW loss and differed significantly from treatment NFW (42.3%), NFM (39.7%), and NFP (41.5%) but not from FFAW (38.0%) and FFAP (34.0%). Ovary weights for treatments NFW, NFP, FFAM, and FFAP did not differ significantly from each other but did so for NFM and FFAW (38.0%), which had the lowest weight. Return to egg production at 2 mo lagged behind in treatments FFAM, NFP, and FFM more than in any other treatments. At 3 mo, treatments FFAAM and NFW differed from the other treatments. Findings indicate that a greater decrease in the natural Salmonella population in the ceca and crop can be obtained with the combination of full-fed alfalfa plus mushroom extract in molting hens and induce a comparable molt with feed withdrawal.

Performance Assessment of Broiler Chickens Given Mushroom Extract Alone or in Combination with Probiotics

A study was conducted to evaluate the effect of combined Shiitake mushroom (Lentinus edodes) extract with probiotics (PrimaLac) on the growth and health of broiler chickens. In trial 1, 540 d-of-hatch chicks were randomly assigned to 6 treatment groups, replicated 3 times, with 15 males and 15 females per pen for 3 wk. Dietary probiotics and mushroom treatments were as follows: 1) control feed + ad libitum tap water; 2) control feed + skip-a-day mushroom water; 3) control feed + ad libitum mushroom water; 4) probiotic feed + ad libitum tap water; 5) probiotic feed + skip-a-day mushroom water; 6) probiotic feed + ad libitum mushroom water. Body weight gain, feed consumption and efficiency, mortality, bursa, liver, and spleen relative weights of chicks were taken. In trial 2, the performance of broilers 3 to 7 wk withdrawn from the mushroom extract was evaluated along with the comparative level of fecal biofidobacteria in the control and mushroom extract treatment (trt). Mortality, weight gain, feed consumption and efficiency, carcass yield, fat pads, bursa weights and fecal bifidobacteria were measured in trial 2. In trial 1, significant differences (P < 0.05) in female weight gain (trt 4-0.62 vs. trt 1-0.54 kg) and male spleen weights were observed. In trial 2, significant differences were observed in male weight gain (trt 2-2.40 vs. trt 4-1.12 kg), male and female fat pads, male bursa weights (trt 3-0.15 vs. trt 6-0.39), female carcass yield percentage (trt 1-77.8 vs. trt 4-66.4), and feed consumption and efficiency. Body weights were severely depressed in the male broilers receiving the probiotics feed in treatments 4, 5, and 6, but not in the female broilers. These results indicate that performance differences in gender occur with additives during different grow-out periods, and mushroom extract promotes bifidobacteria growth in broiler chickens after 4 wk of withdrawal. It appears that probiotics and mushroom extract offered no combination potential for weight gain, which was compromised in this study, but possible health-enhanced attributes.

Campylobacter isolation trends of cage versus floor broiler chickens: a one-year study

An experiment was carried out over a 1-yr period with broiler chickens to assess the influence of cage and floor rearing environments on the isolation trends of Campylobacter jejuni. The study used 36 7-wk-old broiler chickens that were raised in floor pens and naturally infected with or exposed to C. jejuni during the growout period. These broilers were then leg-banded and split into two groups with 18 per group. The groups were placed in wire cages or in a floor pen with unused litter in separate houses on the same farm. Each broiler was swabbed cloacally monthly to determine the presence of C. jejuni. The yearly average percentage isolation rates were significantly (P < 0.05) higher for the broilers held in the litter floor pen (130/185;66%) when compared to the broilers kept in wire cages (67/193;35%). There was a trend for higher isolation rates in the fall for caged and floor broilers and a decrease in rates near the end of the experimental year (summer) in the caged broilers. Isolation rates for both treatments reached their lowest level for the month of March. No caged broilers tested positive during the last 4 mo of the trial. The long-term cage isolation was linked to a reduced prevalence of C. jejuni. The results from this study suggest that housing environment and time spent in that environment play a major role in the continuing shedding and isolation of C. jejuni in broiler chickens.

Effect of delayed placement on the incidence of Campylobacter jejuni in broiler chickens

An experiment was conducted with broiler chickens to evaluate the effect of delayed placement on reused litter and the isolation of Campylobacter jejuni. The experiment also assessed the presence of C. jejuni in the crop following feed withdrawal periods in cages vs floor environments. Trial 1 utilized 320 female broiler chicks obtained from a commercial hatchery. The chicks were randomly placed into the following experimental groups that were replicated four times with 20 chicks per pen: 1) 0-h, 2) 24-h, 3) 48-h, and 4) 72-h delayed placement. Fecal samples were collected via the cloaca at 7, 14, 21, and 28 d of age; enriched in Bolton broth; and plated onto BBL agar. Campylobacter jejuni was isolated at 1 wk of age in the 48- and 72-h experimental groups but did not differ significantly from the others. Sampling results at 14 d of age showed that 63, 68, 73, and 80% of chicks were positive for the 0-, 24-, 48-, and 72-h treatments, respectively. At 28 d of age, 100% of all chicks sampled tested positive. In Trial 2, 60 market age broilers were evaluated for the presence of C. jejuni in the crop by subjecting them to 0-, 4-, 8-, 12-, and 16-h feed withdrawal times on litter or in wire cages. Crops were collected aseptically from the broilers, stomached, enriched in Bolton broth, and then plated on BBL agar. There were no significant (P < 0.05) differences between cage and floor withdrawal times for the presence of C. jejuni in the crop samples of broilers; however, there were significant differences in the length of withdrawal on the presence of C. jejuni. Collectively, these results suggested that the isolation of C. jejuni occurred earlier in broilers that were subjected to delayed placement on reused litter and that extended feed withdrawal times in cages or on litter may increase the possibility that the crop of broilers may contain a higher isolation rate of C. jejuni.

Evaluation of leaves as a litter material

The suitability of leaves for use as broiler litter was evaluated in four 49-d floor pen trials of 150 Avian x Avian female chickens each. In each trial, 25 broiler chicks were weighed and randomly assigned to one of six pens at a density of 1.2 m2 per bird. There were two replicates of each of the following three treatments: 1) pine wood shaving (control), 2) a mix of 50% pine wood shaving and 50% leaves, and 3) leaves. Litter materials had no significant (P > or = 0.05) influence on live weight, feed conversion, breast blisters, dressed carcass weight, carcass yield percentage, or mortality. Mortality of birds reared on leaves tended to be higher than the other treatments, but it was found to be nonsignificant at the P < 0.05 level. No significant differences were observed for percentage litter moisture among treatments. Body weight gain was significantly (P < or = 0.05) higher for the broilers reared on the leaf litter. Leaves alone or mixed with wood shavings have potential as an alternate litter material without compromising production or processing parameters at a low placement density.

Campylobacter jejuni seasonal recovery observations of retail market broilers

This study investigated possible seasonal trends in the Campylobacter jejuni carrier state of market broilers. In this study, broiler carcasses, 15 each of two major companies, were obtained from a local supermarket each month for an entire year to evaluate the presence of C. jejuni on the carcasses. Direct plating and the whole carcass rinse procedure were used for C. jejuni detection. Resuscitation of damaged cells and preenrichment of low numbers of micoorganisms were accomplished by Hunt's procedure. None of the carcasses tested positive from direct plating of skin flora in this study. After both Company A and Company B broiler samples were enriched, 69% (229/330) of the raw commercial broilers were, positive for C. jejuni. The highest recovery rates were obtained during the warmer months of the year, from May through October (93, 97, 97, 87, 87, and 93% respectively), and the lowest were obtained in December (7%) and January (33%). Storage time, due to slow movement of broilers, appeared to affect the detectability of C. jejuni during December and January. This study shows that seasons of the year influence C. jejuni detectability and the carrier state in market broilers at retail level.

Influence of exercise training on heart rate variability in post-menopausal women with elevated arterial blood pressure

Low heart rate variability (HRV) has been reported to be an independent risk factor for the development of coronary heart disease in women and has recently been identified as a risk factor for cardiac sudden death and all-cause mortality. We have recently demonstrated that endurance-trained post-menopausal women demonstrate higher levels of HRV than sedentary control subjects. The purpose of the present study was to test the hypothesis that 12 weeks of regular aerobic exercise would increase HRV in sedentary post-menopausal women with elevated arterial blood pressure (BP) (i.e. either high normal BP or stage I hypertension). A secondary aim was to test the hypothesis that the increase in HRV with exercise training, if observed, would be associated with an increase in spontaneous cardiac baroreflex sensitivity (SBRS), an important physiological determinant of HRV. To accomplish these aims, we studied eight sedentary post-menopausal women (age = 54.5 +/- 1.3 years) before and after 12 weeks of aerobic exercise training (3.3 +/- 0.3 days per week at 70% +/- 2% of maximal heart rate for 43 +/- 3 min per day). Maximal oxygen uptake and body weight did not change (P > 0.05) with training, but percentage fat (35.5 +/- 2.6% vs. 34.5 +/- 2.3%, P < 0.05) decreased and treadmill time to exhaustion increased (9.8 +/- 0.5 vs. 11.3 +/- 0.5 min, P < 0.05). Supine resting levels of heart rate, RR interval and the standard deviation of the RR interval (time domain measure of HRV) were unchanged (all P > 0.05) from baseline levels after 12 weeks of aerobic training. Similarly, the high-frequency, low-frequency and total power of HRV (frequency domain measures) were also unchanged from baseline (all P > 0.05). SBRS was also not different before and after aerobic exercise training (10 +/- 2 vs. 13 +/- 3 ms mmHg-1 respectively, P > 0.05). In contrast, systolic and diastolic BP were reduced approximately 8 and approximately 5 mmHg with training (both P < 0.05) respectively. These results indicate that 12 weeks of moderate-intensity aerobic exercise training does not increase HRV or SBRS, despite producing a clinically significant reduction in BP at rest in post-menopausal women with elevated BP. Considered together with our previous findings in female master endurance athletes, these findings suggest that more intense and prolonged exercise training may be required to produce increases in HRV and SBRS in sedentary post-menopausal women.

Retention of endothelium-dependent vasodilatory responses in canine coronary arteries following cryopreservation

In the present study, the cryoprotective effect of dimethyl sulfoxide (Me2SO) and fetal calf serum (FCS) on coronary endothelium and endothelium-dependent relaxation (EDR) responses was studied in isolated canine coronary arteries following cryostorage at -75 degrees C. Compared to the freshly isolated coronary arteries, the EDR responses to acetylcholine, thrombin, and calcium ionophore were not significantly altered following 1 day storage at -75 degrees C in the presence of 1.8 M Me2SO and 20% FCS. Prolonged cold storage to 7 days, however, resulted in a slight, but significant, rightward shift of the concentration-response curves of acetylcholine and thrombin, but not calcium ionophore. The maximum relaxant response after 7-day cryostorage was 80 to 85% of fresh controls. Omission of FCS from the cryostorage incubation medium further accentuated the loss of EDR responses to all three endothelium-dependent vasodilators tested. Scanning electron microscopic examinations of the intimal surface of the Me2SO and FCS cryostored canine coronary arteries confirmed the preservation of intimal endothelial cells following 1 or 7 days of storage at -75 degrees C, while significant patches of loss of endothelial cells were observed in the arteries cryostored only in the presence of Me2SO. No significant inhibitory effect of cryostorage was observed for the direct, endothelium-independent relaxation induced by isoproterenol, regardless of the presence or absence of FCS. These results demonstrate that slow freezing of canine coronary arteries to -75 degrees C in Krebs-Henseleit solution containing Me2SO and FCS provides good preservation of the vascular smooth muscle function and endothelium-dependent vasodilatory responses.

Effect of an evaporative cooling and dust control system on rearing environment and performance of male broiler chickens

An experiment was conducted to determine the effect of a micromist, high pressure, evaporative cooling and dust control system on rearing environment characteristics and performance of broiler chickens. Air of rearing chambers with the cooling and dust control system had significantly lower dust concentrations than that of chambers without the system. Birds reared with the cooling and dust control system were 45 and 165 g heavier at 4 and 7 wk of age, respectively, and had significantly higher 7-wk bursa weights than those reared without the system. Presence of the cooling and dust control system had no effect on mortality or lung weights.