Dynamics of energy utilization in male and female turkeys during growth

Determining energy utilization in growing animals enables to adjust the nutritional constraints to nutrient requirements while maximizing the ratio between lean retention and fat retention to improve feed efficiency. In turkey production, the important sexual dimorphism and differences between strains may contribute to differences in basal energy metabolism and the partitioning of energy retention between protein and lipid. The objective of this study was to determine the dynamics of energy utilization in males and females of a heavy strain of turkeys fed ad libitum from 1 to 23 weeks of age. Heat production (HP) was determined by indirect calorimetry and retained energy (RE) was calculated as the difference between metabolizable energy (ME) intake and HP. The RE as protein was determined by a nitrogen balance, while the remaining RE was assumed to be lipid. A modeling procedure allowed partitioning HP between fasting HP (FHP), activity-related HP and thermic effect of feeding. A multiple regression analysis was used to estimate the maintenance energy expenditure (ME(m)) and the energy efficiencies of protein and lipid retention (k(p) and k(f), respectively). Results were expressed either per day or per kg BW(0.75) per day. In comparison with females, males consumed more feed (440 v. 368 g/day), grew faster (163 v. 147 g/day) and retained more protein (38 v. 28 g/day) during the experimental period. Expressed per kg BW(0.75) per day, ME intake decreased linearly with increasing age and was not affected by gender. Similarly, RE as protein decreased with increasing age and tended to be greater in males than in females, whereas RE as lipid increased with increasing age and was lower in males than in females. In addition, HP decreased with increasing age and was greater in males than in females, because of greater activity-related HP and FHP (47% and 9% greater in males compared with females). The FHP averaged 417 kJ/(kg BW)(0.75) per day during the first 3 weeks of age and decreased to 317 and 277 kJ/(kg BW)(0.75) per day in males and females, respectively, from 20 weeks of age onwards. Similar to FHP, ME(m) was lower in females than in males ((586 to 12 × BW) and (586 to 5 × BW) kJ/(kg BW)(0.75) per day, respectively) and the k(p) and k(f) were estimated at 0.63 and 0.87, respectively. This study shows that the partitioning of RE and HP differs between genders in growing turkeys, which likely results in differences in nutrient requirements.     

Concentration of serum lipids and aortic lesion size in female and male apo E-deficient mice fed docosahexaenoic acid

Apolipoprotein (apo) E-deficient mice were fed an atherogenic diet with either 1% ethyl ester docosahexaenoic acid (DHA) or safflower oil (SO) as a source of linoleic acid for 8 week. Both genders fed DHA had higher proportions of eicosapentaenoic acid and DHA, and lower proportions of linoleic and arachidonic acids in the liver and serum phospholipids than those fed SO. Males fed DHA had greater liver weight and tended to have higher concentrations of serum lipids and liver cholesterol than those fed SO, and there were opposite trends in females. Dietary fats and gender led to no significant effect on lesion sizes in aortic arch and thoracic plus abdominal aorta. These results indicate that the interactive action of sex-related factor(s) with dietary polyunsaturated fatty acids is involved in metabolic changes of serum lipids in apoE-deficient mice, and addition of DHA, compared with addition of SO, is not effective to abolish the atherosclerosis in this animal model.     

Cartilaginous metaplasia of the thoracic aorta of control turkeys and exacerbation by beta-aminopropionitrile

Seventeen of sixty distal extremities of the thoracic aortas of 12-week-old control male turkeys and 37 of 40 distal extremities of the aortas of turkeys fed 0.07% beta-aminopropionitrile (BAPN) from 4 to 12 weeks of age contained areas of cartilaginous metaplasia when examined by light microscopy. The cartilaginous areas were generally elongated and located in the subendothelium of control turkeys, but a roundish area of cartilage was occasionally evident in the deep media. The magnitude of chondroplasia was enhanced by feeding BAPN; the extensive lesion usually extended from the subendothelium to deep in the media. Regardless of treatment, chondrocytes were pleomorphic, contained vacuoles, and had cytoplasmic processes. The cells were separated by pools of proteoglycans and connective tissue. The ultrastructure of chondrocytes in the aortas of both treatment groups was typical of this cell type. They had undulations or projections of the cell membranes. The cisternae of endoplasmic reticulum were dilated and contained electron-translucent material which was similar to extracellular proteoglycans. Golgi apparatus, free ribosomes, mitochondria, glycogen granules, filaments, and a centriole also were present in the cytoplasm. The extracellular matrix, which included collagenous and elastic fibers and also delicate fibrils and interconnecting matrix granules, separated adjacent chondrocytes by spaces of varying size.     

Mortality among male anaesthetists in the United Kingdom, 1957-83.

A cohort of 3769 male anaesthetists resident in the United Kingdom between 1957 and 1983 was followed up for a total of 51,431 person years of observation. All subjects were fellows of the Faculty of Anaesthetists and held full registration with the General Medical Council. With all men in social class I being taken as the standard, the standardised mortality ratio among anaesthetists for all causes of death was 68 (95% confidence interval 59 to 77) and the standardised mortality ratio for all cancers was 50 (95% confidence interval 36 to 67). There was no significant excess mortality from lymphomas or leukaemias, but 16 of the 221 deaths in anaesthetists were due to suicide, giving a standardised mortality ratio of 202 (95% confidence interval 115 to 328). When anaesthetists were compared with all doctors the standardised mortality ratio for suicide was only 114, a nonsignificant excess. These findings confirm that the risk of suicide among anaesthetists is twice as high as among other men in social class I but suggest that the risk does not differ significantly from that among doctors as a whole. There was no evidence of a significant excess risk of cancer, and, in particular, the small excess of cancer of the pancreas reported previously could not be confirmed.     

Comparisons of damaging feather pecking and time budgets in male and female turkeys of a traditional breed and a genetically selected male line

Feather and skin pecking leading to feather loss and tissue damage is a welfare problem in commercial turkeys. A factorial experiment was designed to compare a line of unselected turkeys that previously did not exhibit this behaviour with a genetically selected male line with a propensity for damaging pecking. We also compared the time budgets of male and female turkeys from the two lines at 3, 6 and 9 weeks of age and at different times of the day. Damaging feather pecking occurred in 32% of male and 15% of female male line turkeys but was not observed in the traditional line. Time budgets of males and females were similar. Preening increased and resting, feeding and general pecking declined with age. Resting was higher in the afternoon than in the morning and male line turkeys were observed resting more often than traditional turkeys at 3 and 6 weeks. Traditional turkeys displayed more gentle feather pecks than male line poults at 9 weeks. Male turkeys of both lines showed more strong feather pecks and pulls at 3 weeks whereas female turkeys showed more at 9 weeks of age. The frequency of strong feather pulls recorded electronically increased with age but was not related to mortality. It is suggested that damaging feather pecking in turkeys may be the result of vigorous investigative pecking.     

Aromatization and the induction of male sexual behavior in male, female, and androgenized female hamsters

Eight weeks after gonadectomy male, female, and androgenized [10 μg testosterone propionate (TP), 24 hr after birth] female hamsters were given daily treatment with: 150 μg dihydrotestosterone (DHT), 5 μg estradiol benzoate (EB), 150 μg DHT + 5 μg EB, 150 μg DHT + 1 μg EB, 30 μg DHT + 5 μg EB, 30 μg DHT + 1 μg EB, or the oil vehicle. Treatment of castrated male hamsters with 5 μg EB fully restored mounting but relatively few of these animals intromitted and none ejaculated. Treatment with 150 μg DHT restored all components of male sexual behavior but only in a small proportion of the males. Combined treatment with EB and DHT restored mounts, intromissions, and ejaculations in the majority of the males. Although as little as 30 μg DHT + 1 μg EB restored the full complement of male behavior, the males which received 150 μg DHT + 5 μg EB or 150 μg DHT + 1 μg EB required fewer intromissions to achieve ejaculation than the males which received 30 μg DHT + either dose of EB. The response of the androgenized females was similar to that of the males except that the androgenized females had lower intromission rates and none ejaculated. Relatively few of the nonandrogenized females responded to EB and DHT treatment and those that did mounted only a few times each test. These results demonstrate that both EB and DHT can stimulate male sexual behavior in the hamster and that the sensitivity to EB and DHT for copulatory behavior is determined by early postnatal androgen exposure.     

Adrenergic receptor properties of hepatocytes from male and female rats

alpha 1- and beta-adrenergic receptor properties of intact hepatocytes from adult male and female rats were evaluated in ligand binding studies using [3H]prazosin and [3H]CGP-12177 (4-(t-butylamino-2-hydroxypropoxy)-[5,7-3H]benzimidazole-2-one-HCl), a hydrophilic beta antagonist. Prior work had suggested that the response of hepatocytes from males to alpha 1-adrenergic stimulation was greater than that of cells from females. However, little sexual difference in prazosin affinity, number of binding sites or kinetics of association/dissociation with the cells was found. Epinephrine, [3H]prazosin competition for binding sites on intact cells was performed at 2 degrees C and 80-90% of agonist sites remained in a high affinity state with an epinephrine Kd comparable to that previously found in glucose release and phosphorylase alpha activation studies. Agonist Kd inferred from these competition experiments also showed no sexual dimorphism. These data suggest that the greater rise in the concentration of cytosolic free calcium and release of 45Ca from cells of males in response to epinephrine stimulation is not due to male/female alpha 1-receptor differences but, rather, may be a function of the previously observed sexual difference in cell calcium metabolism. [3H]CGP binding to hepatocytes from females was stereospecific, saturable and identified a single, high affinity site. Comparable sites were not found on cells from males, however, [3H]CGP binding to crude membrane preparations from both sexes was identical. This suggests that the loss of hepatic beta-receptor function in the adult male is due to an inaccessibility of beta-receptors at the external surface of the plasma membrane of the intact cell. Further studies with other beta-receptor ligands are being carried out to confirm these initial findings.     

Copper-silicon interaction studies in young, rapidly growing turkeys fed semipurified starter diets

A 3 × 3 factorial experiment was conducted to study the interactions between Cu and Si in growing turkeys fed a basal dextrosecasein semipurified diet supplemented at 0, 270, and 540 ppm Si, and 2, 8, and 75 ppm Cu levels of inclusion. There were no significant (p>0.05) Cu, Si, or Cu-Si interaction effects on turkey growth. However, there were significant (p<0.05) Si effects on hemoglobin concentrations, and Cu−Si interaction effects on hematocrit and plasma Mg levels (p<0.01). Plasma Ca, P, Zn, Cu, total cholesterol, and serum alkaline phosphatase activity were not affected (p>0.05) by Cu, Si, or Cu−Si interaction. Heart and liver weights were affected (p<0.05) by the Cu-Si interaction. In general, a 8-ppm Cu supplemental level prevented cardiac hypertrophy only in the presence of 270 or 540 ppm Si inclusion in the diets. There were significant (p<0.05) Cu effects on liver Cu and Mn and heart Zn concentrations, Si effects on liver Mn levels, and Cu-Si interaction on liver Zn concentrations. Within the 0- and 270-ppm Si groups, Cu-deficient turkeys (2 ppm Cu) had higher liver Zn levels but not within the 540-ppm Si group. The Cu-Si interaction did not affect (p>0.05) concentrations of Cu in the heart and liver tissues. It is postulated that the Cu-Si interactions demonstrated in this study could have profound implications on the cardiovascular and skeletal health of birds.     

Biomechanical bone strength and bone mass in young male and female rats fed a fish oil diet

The study objective was to determine if male and female rats fed a diet rich in fish oil had femurs and vertebrae that were stronger and more resistant to fracture than rats not fed omega-3 long chain polyunsaturated fatty acids. Weanling rats were randomized to a control or a fish oil diet for 5 weeks. Feeding fish oil to males had no effect on biomechanical strength properties of femurs and vertebrae as measured by three point bending and compression, respectively. In contrast, females fed fish oil had reduced length growth and a lower vertebral peak load. These effects may have been partly mediated by a lower food intake but were not associated with differences in serum IGF-I, estradiol or urinary calcium. The effect of consuming a fish oil diet into later adulthood should be investigated to determine if femur strength is also affected among females.     

Expression of adult female patterns of sexual behavior by male, female, and pseudohermaphroditic female rhesus monkeys

Gonadally intact pseudohermaphroditic female and normal female and neonatally castrated male rhesus monkeys were given estrogen treatment as adults and evaluated for attractivity, proceptivity, and receptivity during tests with a tethered stud male. Pseudohermaphrodites were produced by injecting their mothers during pregnancy with either testosterone propionate (TP) or dihydrotestosterone propionate (DHTP). Castrated males had reliably lower attractivity than normal females on all indicator responses shown by the tethered males. Additionally, castrated males showed reliably fewer proceptive responses on 4 of 5 measures than normal females. Receptivity could not be assessed in this situation for castrated males, because tethered males never contacted them unless the castrated males were displaying presentation. No reliable differences were observed between pseudohermaphrodites produced by prenatal treatments with TP or DHTP. Pseudohermaphrodites generally showed reliably less attractivity and proceptivity than normal females and reliably more of these traits than castrated males. Attractivity scores for pseudohermaphrodites were not different from those for normal females until proximity to the tethered male was established. Receptivity was not different in pseudohermaphrodites compared with normal females. Results indicate prenatal androgenization and its developmental sequelae lead to a defeminization in adulthood which, in this testing situation, was principally manifested by a deficiency in the performance of proceptive behaviors. Additionally, defeminization in rhesus monkeys, unlike that demonstrated in rodents, does not depend upon actions of an aromatizable androgen.     

Asymmetric male and female genetic histories among Native Americans from Eastern North America

Previous studies have investigated the human population history of eastern North America by examining mitochondrial DNA (mtDNA) variation among Native Americans, but these studies could only reconstruct maternal population history. To evaluate similarities and differences in the maternal and paternal population histories of this region, we obtained DNA samples from 605 individuals, representing 16 indigenous populations. After amplifying the amelogenin locus to identify males, we genotyped 8 binary polymorphisms and 10 microsatellites in the male-specific region of the Y chromosome. This analysis identified 6 haplogroups and 175 haplotypes. We found that sociocultural factors have played a more important role than language or geography in shaping the patterns of Y chromosome variation in eastern North America. Comparisons with previous mtDNA studies of the same samples demonstrate that male and female demographic histories differ substantially in this region. Postmarital residence patterns have strongly influenced genetic structure, with patrilocal and matrilocal populations showing different patterns of male and female gene flow. European contact also had a significant but sex-specific impact due to a high level of male-mediated European admixture. Finally, this study addresses long-standing questions about the history of Iroquoian populations by suggesting that the ancestral Iroquoian population lived in southeastern North America.     

Silicon bioavailability studies in young rapidly growing rats and turkeys fed semipurified diets

Two experiments were conducted using completely randomized designs to study the bioavailability of Si from three sources to growing rats and turkeys fed semipurified diets. The basal diets were dextrose-egg albumin for rats and dextrose-casein for turkeys. The Si sources were tetraethylorthosilicate (TES), sodium silicate (NaSil), and sodium zeolite A (NaZA). Rats and turkeys were supplemented at 500 and 270 ppm Si, respectively, from each source. A control group of unsupplemented rats and turkeys was included in each experiment. In general, irrespective of Si source, Si supplementation slowed (p < 0.05 orp < 0.01) growth rates in both rats and turkeys. Although dietary Si supplementation reduced (p < 0.05) plasma Mg levels and liver Zn concentrations in rats, it increased (p < 0.05) plasma P and reduced (p < 0.05) plasma Cu levels in turkeys. Rats on TES had significantly slower (p < 0.05 orp < 0.01) growth rates (5–10%) than those on NaSil or NaZA. In rats, NaZA and TES reduced (p < 0.05) hemoglobin concentrations and plasma Zn, respectively. However, plasma Mg levels were higher (p < 0.05) in TES than NaSil-or NaZA-fed rats. The source of the dietary Si did not affect (p < 0.05) the organ weights of rats and their mineral concentrations. Turkeys on TES diets grew at a significantly faster (p < 0.05) rate (15%) than those on NaSil or NaZA diets during the first 2 wk of experimentation. However, after 4 wk, there were no significant (p > 0.05) differences in growth between the Si sources. In turkeys, NaZA increased (p < 0.05) hematocrit levels and plasma Mg levels. Turkeys on NaZA diets had larger (p < 0.05) hearts and livers than those on NaSil but not TES. Liver Mn content was higher (p < 0.05) in turkeys on NaSil than TES or NaZA. Heart Zn was lower (p < 0.05) in turkeys on NaSil than TES, but not NaZA.     

Acute effects of 2-methoxyestradiol on endothelial aortic No release in male and ovariectomized female rats

The endogenous metabolites of 17β-estradiol are thought to have protective vascular effects, especially in males and estrogen-deprived females. The present study evaluated the acute in vitro effects of the active metabolite 2-methoxyestradiol on endothelial NO release from ovariectomized female and intact male and female rat aortas.NO was measured electrochemically by differential normal pulse amperometry using carbon fiber microsensors, and also by fluorescence microscopy using 4,5-diaminofluorescein diacetate.2-Methoxyestradiol alone induced a maintained increase in endothelial NO release in male and ovariectomized rats that was reduced by pretreatment with L-NAME. NO release induced by calcium ionophore alone (A23187) was lower in aortas from ovariectomized rats than from intact females, indicating that estrogen deprivation induces endothelial dysfunction. Pretreatment of aortas with 2-methoxyestradiol potentiated significantly the A23187-induced-NO release in ovariectomized as well as in males, but not in intact females. This potentiation was reduced or abolished by L-NAME. 2-Methoxyestradiol potentiated the vasodilatory effect of A23187 on intestinal arterioles, and also increased intestinal tissular laser-Doppler blood flow signal.These results demonstrate that 17β-estradiol and its active metabolite 2-methoxyestradiol increase basal aortic endothelial NO production and also cause a potentiation of the calcium ionophore-stimulated NO release in male and ovariectomized, while it has no effects on intact females. 2-Methoxyestradiol appears to be a promising pharmacological agent capable of improving endothelial function in men and postmenopausal women.     

Variation in spring harvest rates of male wild turkeys in New York,Ohio, and Pennsylvania

Spring harvest rates of male wild turkeys (Meleagris gallapavo) influence the number and proportion of adult males in the population and turkey population models have treated harvest as additive to other sources of mortality. Therefore, hunting regulations and their effect on spring harvest rates have direct implications for hunter satisfaction. We used tag recovery models to estimate survival rates, investigate spatial, temporal, and demographic variability in harvest rates, and assess how harvest rates may be related to management strategies and landscape characteristics. We banded 3,266 male wild turkeys throughout New York, Ohio, and Pennsylvania during 2006–2009. We found little evidence that harvest rates varied by year or management zone. The proportion of the landscape that was forested within 6.5 km of the capture location was negatively related to harvest rates; however, even though the proportion forested ranged from 0.008 to 0.96 across our study area, this corresponded to differences in harvest rates of only 2–5%. Annual survival was approximately twice as high for juveniles as adults . In turn, spring harvest rates for adult turkeys were greater for adults than juveniles . We estimated the population of male turkeys in New York and Pennsylvania ranged from 104,000 to 132,000 in all years and ranged from 63,000 to 75,000 in Ohio. Because of greater harvest rates for adult males, the proportion of adult males in the population was less than in the harvest and ranged from 0.40 to 0.81 among all states and years. The high harvest rates observed for adults may be offset by greater recruitment of juveniles into the adult age class the following year such that these states can sustain high harvest rates yet still maintain a relative high proportion of adult males in the harvest and population. © 2011 The Wildlife Society.     

Rift Valley fever knowledge,mitigation strategies and communication preferences among male and female livestock farmers in Eastern Province,Rwanda

The Government of Rwanda reported an outbreak of Rift Valley fever (RVF) in the Eastern Province in 2018. To respond to the outbreak, vaccination and education campaigns about the disease were carried out. Because RVF cases continue to be detected in Rwanda and the disease impacts livelihoods and health, accurate knowledge and communication are imperative. The objectives of this study were to evaluate knowledge and risk perceptions of RVF transmission among livestock farmers in Nyagatare District, Eastern Province, Rwanda, and to compare RVF knowledge, risk perceptions, and farming practices between male and female livestock farmers. This cross-sectional, quantitative study was conducted in selected sectors of Nyagatare District in the Eastern Province of Rwanda in June 2019. A 34-question survey was used to ask about demographics, livestock ownership, risk perceptions about zoonotic diseases and livestock management, RVF knowledge, preferred communication sources and information sharing strategies, and protective strategies for RVF mitigation while working with livestock. Livestock farmers were interviewed at three milk collection centers, two village meeting points, a farm cooperative meeting, and during door-to-door visits in villages. In total, 123 livestock farmers were interviewed. The survey found that most livestock farmers lacked knowledge about epizootic and zoonotic transmission of RVF, more male livestock farmers were familiar with RVF and risk mitigation strategies, and female livestock farmers are not viewed as reliable sources of information. Additionally, most livestock farmers had not vaccinated their animals against RVF despite past vaccination campaigns. Radio was the most popular communication channel. These findings show that RVF knowledge and information sharing are inadequate among livestock farmers in Eastern Province. Therefore, vaccination and education campaigns may need to be reevaluated within the context of these trends in order to prepare for future RVF outbreaks.