Incidence Of Sudden Death Syndrome Research Articles

Effects of dietary supplementation of guanidinoacetic acid on physiological response of broiler chicken exposed to repeated lactic acid injection

Increased blood lactic acid is likely to be involved in the incidence of sudden death syndrome (SDS) in broiler chicken. Guanidinoacetic acid (GAA) with direct or indirect influence on the cardiovascular system may provide, to some degree, protection against lactic acidemia in birds. A total number of 144 male broiler chicks (Ross 308) were used in a complete randomised block design to investigate the effects of dietary supplementation of GAA at 0.6, 1.2, 1.8, 2.4 and 3 g/kg on the physiological response of broiler chicks to an acute lactic acidosis in an 8-days experiment. Birds receiving 1.8 and 3 g/kg GAA exhibited lesser mortality percentage compared with the control birds and those received dietary GAA at 0.6 and 1.2 g/kg (p < .03). Dietary inclusion of 1.2 g/kg GAA to broiler chicks increased serum concentration of uric acid compared to the control birds and those received 2.4 g/kg (p < .02). The mean serum concentration of creatinine was greater in the birds receiving different GAA levels compared with the control birds (p < .0001). The serum concentration of nitric oxide decreased in the birds receiving 1.2 g/kg GAA by 21.05 and 15.57% compared with the control birds and those received 1.8 g/kg of GAA, respectively (p < .04). A lesser frequency for liver colour score 5 was observed in the birds fed on the diet with 0.6 g/k GAA (p < .0001). It was concluded that dietary administration of GAA deteriorates the adaptive physiological responses to an acute lactic acidosis in broiler chicken possibly through liver and kidney dysfunction. HIGHLIGHTS Dietary guanidinoacetic acid decreased mortality but showed an adverse effect on growth performance in chickens exposed to acute lactic acidosis. The adverse effects of guanidinoacetic acid may happen through liver and kidney dysfunction. No firm evidence was found to suggest a significant effect of extra nutritional guanidinoacetic acid on the incidence of sudden death syndrome in chicken.

Ability of systemic acquired resistance-saponin and a bacterial metabolite to reduce the soybean cyst nematode (Heterodera glycines) and the incidence of the sudden death syndrome (Fusarium virguliforme)

Experiments were conducted to examine the ability of biological seed treatments to reduce the Soybean Cyst Nematode and the incidence of Sudden Death Syndrome. Biological seed treatments included systemic acquired resistance (SAR)-Saponin, Bacterial metabolite, Bacillus firmus, Burkholderia renojensis, B. subtilis, and untreated seeds as control treatments. These seed treatments were used in test that included seed with no treatment, H. glycines alone, Fusarium virguliforme alone, and H. glycines + F. virguliforme. Seed applied products were received from and treated by Albaugh, LLC. Seeds were planted in 500 cm3 of a steam sterilized sand: soil mix (1:1/ V: V) in 10 cm dia clay pots and placed in a 2.54 cm depression in each pot with 2500 eggs of H. glycines, and 1g of F. virguliforme. Tests included the standards Abamectin and Fluopyram. Treatments were arranged in a randomized complete block design with five replications. Parameter measured included effects on plant growth, nematode life stage development and the incidence of SDS. At 60 days, the biological seed treatments produced no negative plant growth effects. Treatments that included bacterial metabolite and SAR-Saponin significantly reduced SCN cyst, juveniles, and eggs compared to the control. SAR-Saponin, and bacterial metabolite were statistically similar to the standards abamectin and fluopyram. SDS foliar disease was more severe in the treatments that included H. glycines compared with F. virguliforme than F. virguliforme alone. SDS foliar disease index reduced in treatments with saponin product compared to control in the bacterial metabolite and SAR-Saponin treatments respectively. Saponin and bacterial metabolite have shown potential for Sudden Death Syndrome and soybean cyst nematode management.

ИНСТРУМЕНТАЛЬНАЯ ХАРАКТЕРИСТИКА НАРУШЕНИЙ СЕРДЕЧНОГО РИТМА И ПРОВОДИМОСТИ У ДЕТЕЙ С МАЛЫМИ АНОМАЛИЯМИ СЕРДЦА, ВОЗМОЖНОСТЬ ПРОГНОЗИРОВАНИЯ ОСЛОЖНЕНИЙ

The objective of our research was to establish specific features of cardiac rhythm and conduction disorders in&nbsp;children with minor heart anomalies (MHA) on electrocardiography and Holter monitoring, and to elaborate a&nbsp;predictive model of sudden death syndrome (SDS) in children.Material and methods. 168 children aged 2-17 years were examined. The incidence of sudden death syndrome in&nbsp;children was studied in Grodno from 2008 to 2017.Results. It was found that cardiac rhythm and conduction disorders in children with MHA were detected more often&nbsp;on Holter monitoring (HM) than on ECG compared to children without minor heart anomalies. A predictive model of&nbsp;SDS in children with left ventricular false tendons (LVFT) was elaborated (sensitivity 100%, specificity 100%).Conclusions. HM is necessary for children with MHA to monitor the presence of arrhythmias. The use of the&nbsp;discriminant equation will enable to perform targeted selection of children with LVFT to the high-risk group of the&nbsp;SDS.

Soybean fungal soil-borne diseases: a parameter for measuring the effect of agricultural intensification on soil health

The aim of this study was to investigate the influence of agricultural intensification on soil microbial diversity, chemical and physical parameters, and the decrease of the incidence of sudden death syndrome (Fusarium crassistipitatum) and charcoal rot (Macrophomina phaseolina) in soybean. Soils under different management systems were evaluated during 2 crop cycles: soybean monoculture for 24 and 11 years, soybean-maize rotation for 15 and 4 years, 1 year of soybean, and native vegetation. The incidence of both soil-borne diseases was higher under monoculture than under rotation. Increased populations of potential biocontrol agents (Trichoderma spp., Gliocladium spp., fluorescent pseudomonads) were associated with rotation treatments, especially in 2010-2011. The comparison of agricultural vs. native vegetation soil and the average of agricultural cycles showed that microbial biomass carbon and glomalin-related soil protein were higher in the rotation system than in monoculture (50% and 77%, respectively). Furthermore, from the community-level functional diversity (Biolog Eco plates), McIntosh index showed lower functional diversity in monoculture than in rotation and native vegetation plots. Agricultural intensification reduced microbial biomass carbon, glomalin-related soil protein, organic matter, total nitrogen, aggregate stability, and yield, and increased bulk density. Soil quality degradation was associated with the establishment of soil-borne pathogens and increased soybean plant susceptibility to disease.

Soybean Yield Response to Plant Distribution in Fusarium virguliforme Infested Soils

Sudden death syndrome (SDS), caused by the fungal pathogen Fusarium virguliforme, causes significant yield reductions in soybean [Glycine max (L.) Merr.] in the United States. Appropriate recommendations to manage SDS for growers in Iowa and the Upper Midwest are limited. The research objective was to determine the response of SDS foliar disease incidence, severity, and yield to row spacing and seeding rate. In 2008 and 2009, at two Iowa locations, in fields with histories of SDS, SDS‐susceptible and SDS‐resistant cultivars were planted at 38‐ and 76‐cm row spacing at seeding rates of 185,000, 309,000, and 432,000 seeds ha−1 in plots infested with and without the pathogen. Sudden death syndrome incidence and severity were very low; however, infested plots had greater SDS disease incidence and severity than uninfested plots. A row spacing × infestation interaction indicated 7% greater yield in narrow rows (38 cm) than wide rows (76 cm) in uninfested plots, with no yield advantage to narrow rows in infested plots. Soil infestation reduced soybean seed mass (7%) in narrow rows, explaining the yield reduction for narrow rows with greater SDS. The two highest seeding rates had increased SDS incidence but yielded 9% greater than the lowest seeding rate. The susceptible cultivar had greater SDS incidence and severity and yielded 7% less than the resistant cultivar. This study indicates that in infested plots with greater SDS symptom expression, the yield advantage of narrow rows may be negated; therefore, cultivar selection is crucial when planting in narrow rows to maximize yield.

Photoperiodic responses of broilers. I. Growth, feeding behaviour, breast meat yield, and testicular growth

1. A total of 7960 Cobb and Ross broiler males were reared in two trials to 35 d on various photoperiods between 2 and 21 h or under continuous illumination; a total of 444 birds were randomly selected at 35 d and retained for subsequent determination of breast meat yield and testicular weight at 40 or 54 d of age. 2. In both strains, feed intake and growth were positively correlated with photoperiod during the first 21 d, but afterwards feed intake was not significantly affected by photoperiods longer than 6 h and growth was negatively correlated with photoperiod beyond 12 h. Overall, to 35 d, there were no significant photoperiodic influences on either feed intake or growth for ≥6-h photoperiods, but significant depressions in feed intake and growth for photoperiods shorter than 6 h. Feed conversion efficiency was maximised by 12-h photoperiods, with decreases in efficiency above and below 12 h. Mortality was unaffected by photoperiod <12 h, but increased proportionately with photoperiod >12 h. The incidence of Sudden Death Syndrome (SDS) had an inverse relationship with photoperiod ≤10 h, but was positively correlated with photoperiod >10 h. The European Efficiency Factor was curvilinearly related to photoperiod, with the highest efficiency occurring at 12 h. Ross birds had significantly greater feed intakes but poorer feed conversion efficiencies than Cobb; differences in growth, overall mortality and the incidence of SDS between the strains were not significantly different. 3. By 5 d, birds given ≤15 h illumination had learned to eat in the dark, with the amount of feed consumed being inversely proportional to photoperiod; further increases in the amount of nocturnal feeding occurred between 5 and 20 d for ≤12-h photoperiods. The mean hourly rate of nocturnal feeding was consistently lower than diurnal feeding, irrespective of photoperiod. Nocturnal feeding patterns were similar for both genotypes. 4. Breast meat yield at 40 d was unaffected by photoperiod in Cobb birds, but significantly higher in continuously illuminated Ross birds than ≤21 h. At 54 d, breast meat yield was significantly higher in both genotypes given 21 h or continuous illumination and, overall, higher than at 40 d. 5. Testicular weights at 40 and 54 d of age increased with photoperiod in both genotypes to 12 or 15 h. Thereafter, weights plateaued for Cobb but decreased for Ross as the photoperiod was further extended to continuous illumination. 6. New EU welfare regulations come into effect on 30 June 2010 and these state that meat-chickens must have at least 6 h of darkness in each 24-h period, i.e. a maximum photoperiod of 18 h; compliance with the regulations should have no adverse effect on either performance or profitability.

Male broiler performance and nocturnal feeding under constant 8-h or 16-h photoperiods, and various increasing lighting regimens

This paper describes the responses of two genotypes of male broilers to constant 8- and 16-h photoperiods, and to an abrupt transfer from 8 to 16 h at 10, 15 or 20 d. Body weight, feed intake, and feed conversion efficiency were not significantly different at any stage during the 35 d study. Mortality and the incidence of Sudden Death Syndrome were similar for all lighting groups at 35 d. When these data were pooled with previously reported data for female broilers, growth and feed conversion efficiency post 21 d and through to depletion for constant 8-h and birds transferred from 8 to 16 h at 20 d were significantly superior to constant 16-h birds. Constant 8-h birds ate about half their feed during the dark period, whilst 16-h birds consumed no more than 10%. Birds which had been started on 8 h and transferred to 16 h at 10, 15 or 20 d reduced their rate of nocturnal feeding when changed to the longer photoperiod, however, they still consumed more feed in the 8-h dark period than birds that had always been given 16 h illumination. Cobb and Ross genotypes responded similarly to all lighting treatments. Keywords : Photoperiod, broiler growth, nocturnal feeding South African Journal of Animal Science Vol. 38 (3) 2008: pp. 159-165

The incidence of sudden death syndrome in a cohort of infants

To quantify the incidence of sudden infant death syndrome in the town of Passo Fundo, in Rio Grande do Sul, Brazil, and to describe the profile of the deaths observed. A population-based cohort study of the live births from February 2003 to January 2004 to parents resident in the urban area. Infants were excluded if they had been hospitalized since birth, were in the process of being adopted or had died before data collection. 2,411 children were included from the total of 2,634 live births and 2,285 (94.8%) of these were followed-up. Data were obtained from the Live Births Information System (Sistema de Informações Sobre Nascidos Vivos), death registers, records of the Committee on Infant Mortality and from interviews with the social mother during home visits. Data collection instruments were adapted from previously validated forms. Data were analyzed on Epi-Info with descriptive statistics. Ten deaths were registered (0.4%). Four deaths of unknown causes could be included in sudden infant death syndrome category III. These deaths took place at home, between 4 and 6 months of age. The children slept on their sides, sharing a bed with adults, and had soft mattresses, pillows and diapers on the surface. They were the children of young mothers, smokers, with incomplete prenatal care and previous births from underprivileged economic classes. The incidence of suspicion of this syndrome was 1.75/1,000. The incidence rate of suspected sudden infant death syndrome in Passo Fundo is comparable with the highest international coefficients, which suggests the need for vigilance and risk prevention measures.

Evaluation of lighting programs, diet density, and short term use of mash as compared to crumbled starter to reduce incidence of sudden death syndrome in broiler chicks to 35 d of age

Restricted lighting is used commercially to regulate early growth and limit losses associated with sudden death syndrome (SDS), ascites and leg problems. Standard lighting programs may not be suited for broilers marketed at 35 d of age, and promote injury (scratching, i.e., cellulitis) by creating peak feeding periods. This study evaluates four lighting programs, three phases of mash or crumble starter feeding and two diet densities on performance and mortality of broilers marketed at 35 d of age. Two trials each utilized 7200 male broiler (Cobb × Cobb) chicks randomly housed in six (2.75 × 4.90 m) floor pens in each of eight rearing rooms. Four lighting programs were replicated in each trial and consisted of: (a) 23C (23L:1D 0–35 d); (b) 16C (23L:1D 0–3 d, 16L:8D 4–35 d); (c) DDI (delayed decreasing increasing) (23L:1D 0–3 d; 20L:4D 4–6 d, 16L:8D 7–10 d; 8L:16D 11–15 d; 12L:12D 16–20 d; 16L:8 D 21–28 d; and 20L:4 D 29–35 d); and (d) IL (intermittent lighting, provided in four cycles of 6 h d-1 the same total daily hours of light as the DDI program). Two diet densities were applied for the starter and grower diets; high (ME 3170/3200 kcal; CP 251/210 g) or low (ME 3100/3060 kcal; CP 235/195 g kg-1 starter/grower diet, respectively). The two starter types were fed as combinations of mash (M) or crumble (C): (1) M 0–12 d followed by C 12–21 d; (2) C 0–12 d followed by M 12–21 d; and 3) C 0–21 d. The respective grower/finisher density diets were fed in a pelleted form. By 35 d of age the body weight (BW) of broilers maintained under the DDI lighting program was significantly lower than BW of broilers held under the other lighting programs (16Ca &gt; ILab &gt; 23Cb). Overall (0–35 d) feed conversion (corrected for mortality, but not market weight at 35 d) was highest for broilers reared under the 23Ca &gt; ILab &gt; DDIb &gt; 16Cc lighting programs, respectively. SDS (%) mortality was highest for IL (1.68a) = 23C (1.53a) ≥ 16C (1.02ab) ≥ DDI (0.80b) lighting programs. There were no significant differences in 35 d BW or feed conversion of broilers fed mash or crumble starter. Feeding mash diets did lower 21 d BW, but this decrease in early growth did not significantly reduce overall mortality. Broilers fed the low as compared to the high density diets weighed less at 21 d, but weighed significantly more at 35 d, and had a higher (P &lt; 0.05) 0–35 d feed conversion. Low as compared to high density diets did reduce SDS mortality significantly (0.72 vs. 1.81%, respectively). Lighting programs that do provide variable extended dark periods will alleviate broiler mortality as compared to constant (23 or 16 h) or intermittent lighting programs. However, these broilers had a significantly lower body weight when marketed at 35 or less days of age. Key words: Lighting, broilers, mash, diet density, sudden death, ascites

Influence of the stocking density and rearing season on incidence of sudden death syndrome in broiler chickens

Influences of the stocking density and rearing season on the incidence of sudden death syndrome (SDS) were investigated in commercial broiler chickens, which were reared until 63 d after birth. The SDS mortality and total mortality were measured at three different stocking densities of 12, 15, and 18 birds/m2 in rearing seasons of summer, autumn, and winter. At stocking densities of 15 and 12 birds/m2, neither SDS mortality nor total mortality was significantly different throughout the rearing season. However, at 18 birds/m2, SDS mortality significantly increased in summer and winter. The increased SDS mortality was accompanied by a significant increase in total mortality in summer but not in winter. Irrespective of the stocking density, body weight gain and feed intake were lower in summer with no significant change in feed efficiency. The data suggest that stocking density can act as a factor affecting the incidence of SDS in summer and winter, independent of feed efficiency.

Performance, incidence of metabolic disturbances and endocrine variables of food-restricted male broiler chickens

1. This experiment was carried out to evaluate the productive and physiological consequences of a slight but long term food restriction of male broiler chickens from 2 commercial strains. 2. Cobb-500 and Ross chickens were submitted to a 20% food restriction from 8 to 21 d of age. Strain, food programme and their interactive effects were analysed in terms of consequences upon performance, mortality, incidence of sudden death syndrome (SDS) and ascites syndrome (AS), index of right cardiac hypertrophy and plasma concentrations of hormones related to metabolism and growth (T3, T4, T3:T4 ratio, IGF-I and GH). 3. Although some catch-up growth was observed by refeeding previously restricted birds after 22 d of rearing, food restriction decreased (P ≤ 0.05) body weight at market age (42 d) irrespective of the strain, but improved (P ≤ 0.05) food conversion. 4. The incidence of mortality was not high in non-restricted birds but SDS and AS caused more than 50% of deaths. Hypertrophic cardiac index was observed in chickens of both strains after 4 weeks of age and was higher in ad libitum fed birds. 5. During the period of food restriction, plasma T3 and IGF-I concentrations decreased whereas plasma T4 and GH concentrations increased compared to those of the age-matched ad libitum fed counterparts. During the subsequent ad libitum feeding period, few differences in circulating hormone concentrations were observed, except for the higher mean GH litres in previously food-restricted chickens at 35 d of age. 6. These results indicate that even a non-severe food restriction negatively affects body weight of 42-d-old male broilers but these are benefits with improved food efficiency and diminished mortality from metabolic disturbances. The hormone results suggest that the degree of food restriction applied was not severe because there was a very fast adaptive response with small and transient alterations in T3, T4 and GH plasma concentrations during the period of compensatory growth.

A study of electrocardiographic patterns in a population of commercial broiler chickens.

A study was completed to characterize the electrocardiographic (ECG) patterns of male broiler chickens. Data were collected from 300 commercial broilers. ECG readings were collected from all birds between 12 and 15 days of age and then twice more at 10-day intervals. The measurements. included heart rate and rhythm, QRS complex duration, amplitude and mean electrical axis (MEA), incidence of ascites and incidence of sudden death syndrome (SDS). Eight birds died from SDS and 4 birds died from ascites. Twelve birds were condemned for ascites at the processing plant. The overall population heart rate declined with age. Birds that died of SDS had a higher heart rate, whereas those that developed ascites had a lower heart rate than the remainder of the population. The normal MEA was found to be between 0 degree and 180 degrees. On average 30% of birds showed left or right QRS axis deviation, and this pattern was observed in 14 of the 16 birds that developed ascites. Several types of cardiac arrhythmias were observed, the most common being premature ventricular contractions (PVC). The incidence of PVC increased with age, ranging from 1% at 12-15 days of age to 8.9% at 32-35 days of age. QRS axis deviation was present in 5 SDS birds. It is concluded that some 30% of the broiler flock tested was at risk of developing heart failure or heart-related disease.

Dietary Calcium and Phosphorus Effects on Broiler Performance and the Incidence of Sudden Death Syndrome Mortality

Three experiments were conducted with broiler chickens to determine the effect of dietary Ca and P on growth, feed conversion, bone ash, and the incidence of sudden death syndrome (SDS) mortality. Trial 1 tested three rations [100% NRC (1984) Ca and P; 140% NRC Ca and P; and 140% NRC Ca and P to 3 wk and 100% NRC from 4 to 7 wk] in Ross × Ross males to 7 wk of age. Dietary Ca and P had no effect on body weight, feed conversion, bone ash, or leg problems, but SDS mortality was significantly higher in the two groups fed 140% Ca and P for 3 or 7 wk (2.83 and 3.33% SDS mortality, respectively). Trial 2 tested three diets (85% NRC Ca and P, 100% NRC Ca and P, and 140% NRC Ca and P) in mixed sex Arbor Acres × Peterson chicks to 7 wk of age. The lower level of Ca and P (85% NRC) significantly improved feed conversion (7 wk) and decreased bone ash only at 3 wk and serum Ca (7 wk). There was no effect of diet on SDS in this trial. Trial 3 tested two diets (85% NRC Ca and P or 100% NRC Ca and 85% NRC P) in Ross × Ross males to 9 wk of age. Six-week body weight was significantly reduced in the 85% NRC Ca and P diet but body weight was equal by 9 wk of age. No effects were observed for feed conversion, leg disorders, bone ash, or serum Ca. The SDS mortality was significantly increased in the chicks fed the 100% NRC Ca and 85% P diet compared to the 85% NRC Ca treatment. The results of these trials indicate that even slight deviations in dietary Ca and P beyond the NRC recommendations can create a metabolic imbalance in certain strains of broilers (Ross × Ross), which possibly increases susceptibility to SDS mortality.

The Effects of Continuously or Diurnally Fed Melatonin on Broiler Performance and Health

An experiment was designed to investigate the effects of dietary melatonin (MEL) on me performance and health of broiler chicks. Chicks raised under constant lighting were fed practical broiler diets in mash form containing 0, 20, or 40 ppm MEL from 0 to 3 wk. A fourth treatment (0 ppm MEL: 6 h/d; 20 ppm MEL: 18 h/d) was used to mimic a diurnal light:dark cycle. Commercial broiler grower diets without MEL supplementation were fed from 3 to 6 wk of age. A small dose-related decrease was observed in weight gain (0 to 14 d) and feed consumption (0 to 21 d) due to continuous feeding of MEL. Continuously fed MEL also improved feed efficiency in the first 3 wk vs the control (0 ppm). Growth and feed consumption from 0 to 21 d were not affected by the diurnally fed diet when compared with the control treatment. No effects were found for mortality. However, the incidence of sudden death syndrome (SDS) was numerically less for the diurnal (3.56%) and 40 ppm (3.76%) diets from 0 to 42 d than for the control treatment (5.56%). Skeletal disease was generally unaffected, with the exception of the incidence of crooked toes at 42 d (0 ppm MEL: 8.67% vs diurnal: 4.89%). Dietary MEL fed either continuously or in a diurnal pattern had a minor effect on the performance and health of broiler chickens.

The Effect of β-Hydroxy-β-Methylbutyrate on Growth, Mortality, and Carcass Qualities of Broiler Chickens

Experiments were conducted to determine whether the leucine catabolite β-hydroxy-β-methylbutyrate (HMB) could influence protein metabolism in broilers. In Experiment 1, HMB was fed at either .01 or .05% of the diet. β-Hydroxy-β-methylbutyrate did not improve feed conversion or BW gain; however, broilers fed HMB at .01% in a diet formulated to meet NRC (1984) recommendations had no mortality (P < .03) from 0 to 21 d of age. In Experiment 2, HMB fed at .003, .01, .03, and .09% of the diet had no significant affect on growth or carcass yield of the broilers when compared with control-fed broilers. In Experiment 3, HMB fed at .001, .003, and .01% of the diet had no effect on broiler growth. In Experiment 4, HMB was fed at .01% of the diet in combination with an antibiotic and coccidiostat (GP). Use of GP increased (P < .01) BW, feed conversion, and carcass yield when compared with the control broilers. In Experiment 5, HMB was fed at .1% of the diet, and effects of sex and GP were examined. β-Hydroxy-β-methylbutyrate decreased (P < .01) mortality by 72% in the male broilers. In a combined analysis, HMB fed at .01% of the diet (Experiments 1, 2, and 3) increased breast yield (P < .05) and reduced mortality by 56% (P < .04) from 0 to 21 d of age. In a combined analysis, HMB fed at .003% of the diet (Experiments 2 and 3) increased 42-d BW (P < .02) and hot (P < .04) and chilled (P < .05) carcass yields. In conclusion, across all HMB dosages mortality of male broilers was decreased from 6.37 to 4.39% (−31%, P < .04) by feeding HMB, with the pattern of death suggesting that HMB decreased the incidence of sudden death syndrome in these broilers.

Effects of Dietary Fat Source on Sudden Death Syndrome and Cardiac Sarcoplasmic Reticular Calcium Transport in Broiler Chickens

Wheat and soybean diets supplemented with either tallow or sunflower oil (SFO) were fed to broiler chicks. Variables examined included performance, incidence of sudden death syndrome (SDS), and cardiac sarcoplasmic reticular (SR) calcium transport. The phospholipid content of heart tissues was also determined.Birds fed the SFO diet gained significantly (P < .05) more weight over the first 21 days of age and had a significantly better feed:gain ratio (P < .01). The incidence of SDS mortality up to 39 days of age was also lower (P < .05) for SFO-fed birds than for those fed the tallow diet. Calcium (45 Ca2+) uptake and calcium-magnesium 5′-adenosinetriphosphatase (Ca2+ + Mg2+-ATPase) activity in cardiac SR vesicles did not differ due to diet (P > .05). However, compared with similar weight pen-mates showing no disease signs, SDS birds had depressed 45 Ca2+ uptake (P < .01) and Ca2+ + Mg2+-ATPase activity (P < .05) of cardiac SR vesicles. The phosphatidylcholine concentration in the cell membranes of heart tissue of tallow-fed birds was significantly higher (P < .05) than in SFO-fed chicks. No differences were seen in other phospholipid constituents. The SDS birds, however, had significantly (P < .05) lower phosphatidylethanolamine plus phosphatidylglycerol, sphingomyelin, and total phospholipid concentrations in the heart tissues than the pen-mate controls. The results support the hypotheses that SDS in broilers is a cardiac dysfunction associated with defective cardiac SR membrane function and that dietary fat type is implicated with the syndrome.

The Effect of Taurine Transport Antagonists on Cardiac Taurine Concentration and the Incidence of Sudden Death Syndrome in Male Broiler Chickens

Two experiments were conducted in which 540 day-old male broiler chickens were raised in heated battery brooders to 4 wk of age. Diets contained taurine antagonists to test effects on cardiac taurine content and the incidence of Sudden Death Syndrome (SDS). In Experiment 1 treatments during Weeks 2 to 4 were A) basal diet; B) basal diet supplemented with .25% guanidinoethyl sulfonate (GES) in Week 2 and 1.5% GES in Weeks 3 and 4; and C) basal diet supplemented with .5% GES in Weeks 2 to 4. The taurine content of heart was significantly reduced (P<.05) with GES supplementation, but no effects on SDS mortality rates were noted. In Experiment 2 birds received diets containing 0.2.5, or 5% β-alanine. Supplementation with this compound decreased cardiac taurine concentration to extremely low levels (P<.05). No significant effects on SDS mortality rates were noted. The results are interpreted as suggesting that taurine does not play a major role in the etiology of SDS.

Lack of an Effect of Taurine Supplementation on the Incidence of Sudden Death Syndrome in Male Broiler Chicks

Two experiments were conducted to study the effect of taurine supplementation on growth and the incidence of Sudden Death Syndrome (SDS) in male broiler chickens. The 4,650 birds were day-old male broiler chickens raised in floor pens to 9 wk of age. In Experiment 1, the birds received diets containing 0,250, 500, or 1,000 mg taurine/kg. In Experiment 2, the treatments were no added taurine, 500 mg taurine/kg feed, 1,000 mg taurine/kg feed, 250 mg taurine/L water, and 500 mg taurine/L water. Taurine supplementation did not have any significant influence on growth performance although supplementation of the feed at 250 mg/kg reduced the feed:gain ratio from 1.67 to 1.63 in Experiment 1, which was significant (P<05). In general, mortality was unaffected by treatment with a few exceptions: in Experiment 2, SDS deaths were reduced significantly (P<.01) by supplementation of the feed with 500 mg taurine/kg, and at 3 and 6 wk of age, SDS deaths as a percentage of total deaths were reduced significantly with this treatment. The results are interpreted as suggesting that taurine does not play a major role in the etiology of SDS.

Effects of increasing photoperiod length on performance and health of broiler chickens

1. Broiler performance and health were compared from 0 to 42 d for lighting programmes consisting of near-continuous light 23L:1D (23L), a lighting programme where photoperiod gradually increased from 6 to 23 h between days 4 and 35 (INC) or an increasing-lighting programme with 1 h of light mid-way through the scotophase (INC + 1). 2. The increasing lighting programmes reduced growth rate and increased gain:food ratio from 0 to 21 d; INC + 1 growth rate was intermediate to the 23 L and INC treatments. From 0 to 42 d there were no differences in growth rate or gain:food ratio among lighting treatments. Males grew faster, ate more food and converted food more efficiently than females. 3. The increasing-lighting programmes (INC and INC + 1) resulted in less skeletal disease than the 23L control. The incidence of sudden death syndrome (SDS) and mortality other than SDS were numerically lower for the increasing lighting treatments. More males died as a result of SDS and were affected by skeletal defects than females. 4. In terms of health, increasing lighting programmes were superior to near-continuous light for broiler chickens.

Effect of Dietary Lactate and Glucose on the Incidence of Sudden Death Syndrome in Male Broiler Chickens

An experiment with a factorial arrangement of treatments using four levels of dietary lactate (0, 2.5, 5.0, 7.5% calcium lactate) and four levels of dietary glucose (0, 15, 30, and 45% cerelose) was conducted to determine the effect of these compounds on the incidence of sudden death syndrome (SDS) in 1,280 male broiler chickens reared in battery brooder cages to 4 wk of age. Overall mortality was 6.64% of which 32.9% (or 2.19% of broilers housed) was attributed to SDS. There were no significant differences between treatments in either total mortality or mortality due to SDS.