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2.
J Vet Diagn Invest ; 34(6): 937-943, 2022 Nov.
Article in English | MEDLINE | ID: mdl-36184936

ABSTRACT

Cases of neglect in dogs are among the forensic cases submitted most commonly for postmortem examination. Starvation is a form of primary protein-energy malnutrition in which the availability of food is severely restricted or absent; cachexia is a form of protein-energy malnutrition secondary to progressive metabolic derangement during chronic diseases. Despite both conditions leading to an emaciated appearance of the cadaver, discrimination between the two is crucial in forensic cases. We hypothesized that among emaciated dogs, the degree of liver atrophy in starved animals is higher than in cachectic ones, and that this can be investigated microscopically, regardless of the degree of cadaver decomposition. We studied 46 animals: 23 starved, 11 cachectic, and 12 control dogs. Portal tracts were identified by the presence of a bile duct and associated vascular structures recognizable by a thin rim of collagen still visible regardless of the degree of cadaver decomposition. The number of portal tracts per lpf (10×) was used as an indirect measure of atrophy. The number of portal tracts in starved dogs was significantly higher (p < 0.01) compared to both cachectic and control dogs, indicating a higher degree of liver atrophy in starvation. Measuring the density of portal tracts offers a reliable additional tool for discrimination between starvation and cachexia.


Subject(s)
Dog Diseases , Liver Diseases , Protein-Energy Malnutrition , Starvation , Animals , Dogs , Cachexia/veterinary , Cachexia/metabolism , Cachexia/pathology , Protein-Energy Malnutrition/metabolism , Protein-Energy Malnutrition/pathology , Protein-Energy Malnutrition/veterinary , Liver Diseases/veterinary , Liver Diseases/pathology , Starvation/veterinary , Liver/pathology , Atrophy/veterinary , Atrophy/metabolism , Atrophy/pathology , Cadaver , Dog Diseases/pathology
3.
J Vet Diagn Invest ; 34(1): 160-163, 2022 Jan.
Article in English | MEDLINE | ID: mdl-34763579

ABSTRACT

A muskox neonate (Ovibos moschatus) that died of starvation was diagnosed with congenital lenticular anomalies that included spherophakia and hypermature cataract associated with probable lens-induced lymphocytic uveitis and neutrophilic keratitis. Impaired sight as a result of cataract and associated inflammation likely contributed to abandonment and starvation, although maternal death cannot be excluded definitively. Ocular lesions, such as congenital cataracts and spherophakia in neonates, may be important factors affecting survival in free-ranging animals.


Subject(s)
Cataract , Starvation , Animals , Canada , Cataract/veterinary , Northwest Territories , Ruminants , Starvation/veterinary
4.
J Vet Diagn Invest ; 33(6): 1183-1187, 2021 Nov.
Article in English | MEDLINE | ID: mdl-34250866

ABSTRACT

A 9-y-old, spayed female rabbit was presented for evaluation of hypoglycemia and lateral recumbency. The patient was hypothermic and had diffuse muscle wasting; weight loss since a previous visit was also noted. Hematologic abnormalities included progressive nonregenerative anemia and severe heteropenia. Evaluation of a bone marrow aspirate sample revealed active hematopoiesis with abundant pink matrix. The matrix material stained positively with periodic acid-Schiff and alcian blue, and a diagnosis of gelatinous transformation of the bone marrow (GTBM, serous atrophy of fat) was made. Although its precise prevalence remains to be determined, GTBM should be suspected in rabbits with persistent cytopenias following prolonged starvation or gastrointestinal disease.


Subject(s)
Bone Marrow , Starvation , Animals , Female , Gelatin , Rabbits , Starvation/veterinary
5.
Rev. bras. ciênc. vet ; 28(2): 69-74, abr./jun. 2021. il.
Article in Portuguese | LILACS, VETINDEX | ID: biblio-1366839

ABSTRACT

Este estudo teve por objetivo avaliar os efeitos da nutrição parenteral total ou enteral, associadas ou não à glutamina, sobre a motilidade gastrintestinal em equinos submetidos à inanição e realimentação. Foram utilizados 16 equinos adultos hígidos, sem raça definida, de ambos os sexos, quatro machos e 12 fêmeas, com idade variando entre quatro e 14 anos e peso corporal médio de 248,40 + 2,28 kg, divididos em quatro grupos, quatro animais por grupo: Grupo I (ENTGL): fluidoterapia enteral com eletrólitos associada a glutamina; Grupo II (PARGL): Nutrição parenteral total (NPT) associada a glutamina; Grupo III (ENTFL): fluidoterapia enteral com eletrólitos; Grupo IV (PARFL): fluidoterapia parenteral. O delineamento experimental foi inteiramente ao acaso, em um esquema fatorial 4x12 (grupos x tempo de colheita), para cada fase, e suas médias comparadas pelo teste de Duncan ao nível de 5% de significância. Independente do grupo experimental ocorreu redução da motilidade gastrintestinal durante a fase de inanição, mais pronunciada nos grupos PARGL e PARFL. Uma vez restabelecida a alimentação a motilidade gastrintestinal retornou à normalidade.


This study aimed to evaluate the effects of enteral or total parenteral nutrition, associated or not with glutamine, on gastrointestinal motility in horses subjected to starvation and refeeding. 16 healthy, mixed-breed adult horses of both sexes, four geldings and 12 mares, with ages ranging from four to 14 years and an average body weight of 248.40 + 2.28 kg, were divided into four groups, four animals per group: Group I (ENTGL): enteral fluid therapy with electrolytes associated with glutamine; Group II (PARGL): total parenteral nutrition (TPN) associated with glutamine; Group III (ENTFL): enteral fluid therapy with electrolytes; Group IV (PARFL): parenteral fluid therapy. The experimental design was entirely randomized, in a 4x12 factorial scheme (groups x harvest time), for each phase, and their means compared by the Duncan test at the level of 5% significance. Regardless of the experimental group, there was a reduction in gastrointestinal motility during the starvation phase, which was more pronounced in the PARGL and PARFL groups. Once the food was restored, gastrointestinal motility returned to normal.


Subject(s)
Animals , Enteral Nutrition/veterinary , Parenteral Nutrition, Total/veterinary , Gastrointestinal Motility , Horses , Starvation/veterinary , Glutamine/therapeutic use
6.
Int Immunopharmacol ; 95: 107584, 2021 Jun.
Article in English | MEDLINE | ID: mdl-33756224

ABSTRACT

The objective was to evaluate the effects of niacin on intestinal immunity, microbial community and intestinal barrier in weaned piglets during starvation. In this study, twelve weaned piglets with similar body weight were randomly divided into two groups, six for each group. These piglets were treated with starvation, one group was treated with10 ml normal saline (Control), and the other group was perfused with 10 ml niacin solution (Niacin, 40 mg niacin was dissolved in equal volume of normal saline) once daily for three consecutive days. The results showed that niacin effectively attenuated the weight loss and diarrhea index (P < 0.05) in weaned piglets; Niacin improved jejunal villous height and intestinal morphological score (P < 0.05); Additionally, niacin significantly increased the mRNA expression of antimicrobial peptide (pBD2 and PR39) in the jejunum (P < 0.05); Meanwhile, niacin significantly increased ZO-1 and Occludin expression in the jejunum (P < 0.05). Furthermore, niacin improved the microbiota and the concentrations of acetate (P < 0.05). Conversely, niacin decreased the ratios of propionate/acetate and butyrate/acetate in the colonic contents of weaned piglets (P < 0.05); Interestingly, niacin increased the protein expression of SIRT1 (P < 0.05) and inhibited the protein expression of HDAC7 (P < 0.05). In conclusion, niacin attenuated the weight loss and diarrhea, and improved the expression of antimicrobial peptides, and enhanced intestinal epithelial barrier function, and improved the microbiota in the colonic contents of weaned piglets, suggesting that niacin may be an effective way for weaned piglets to maintain the gut and overall health.


Subject(s)
Gastrointestinal Microbiome/drug effects , Intestinal Mucosa/drug effects , Niacin/pharmacology , Animals , Cells, Cultured , Colon/drug effects , Colon/microbiology , Diarrhea/immunology , Diarrhea/microbiology , Diarrhea/pathology , Diarrhea/veterinary , Female , Histone Deacetylases/metabolism , Intestinal Mucosa/immunology , Intestinal Mucosa/metabolism , Intestinal Mucosa/pathology , Male , Pore Forming Cytotoxic Proteins/genetics , Sirtuin 1/metabolism , Starvation/immunology , Starvation/microbiology , Starvation/pathology , Starvation/veterinary , Swine , Weaning , Weight Loss/drug effects
7.
Forensic Sci Int ; 316: 110522, 2020 Nov.
Article in English | MEDLINE | ID: mdl-33038828

ABSTRACT

Companion animal abuse is an issue that concerns not only veterinarians and law enforcement agencies but also society in general. Animals that die under suspicious or violent circumstances should be submitted to reference laboratories for a postmortem examination by veterinary forensic pathologists trained to recognize animal abuse. Nevertheless, the low notification rate of such cases in Spain may explain the country's lag in the development of veterinary forensics and the limited information available on animal abuse epidemiology in comparison with other countries. By sharing information among the entities involved in recognizing animal abuse, we can better address these issues, thus improving veterinary forensics in Spain (and elsewhere). In this study, we analysed the cause and manner of death of 96 dog and cat carcasses suspected of animal abuse. These cases were submitted to our diagnostic laboratory for forensic postmortem examination by public agencies and animal protection centres. To our knowledge, this is the first study to focus on the postmortem analysis of forensic cases of suspected dog and cat abuse in Spain. On the basis of gross and histopathological findings, we distinguished between natural and non-natural abuse-related deaths, classifying the latter. We confirmed that most of the dog deaths were related with abuse, though the suspected abuse and the cause of death did not always coincide. In contrast, cause of death was determined to be natural in many of the cat suspected abuse cases. The most frequent non-natural abuse-related cause of death in dogs was blunt force trauma (n=24, 43.64%), followed by firearm injuries (n=10, 18.18%), asphyxia (n=5, 9.09%), heatstroke (n=3, 5.45%), starvation (n=2, 3.64%), bite injury (n=1, 1.82%), and sharp force trauma (n=1, 1.82%). In cats, the most common cause of death was blunt force trauma (n=9, 21.95%), followed by firearm injuries (n=3, 7.32%) and bite injury (n=2, 4.88%). The main goal of our study is to share our results with the scientific community to advance the field of veterinary forensics in Spain, which will lead to more successful prosecutions by law enforcement agencies. Finally, we highlight that veterinarians who can accurately recognize signs of animal abuse may be able to better respond to cases of companion animal cruelty, which in turn, may prevent possible escalation to interpersonal violence.


Subject(s)
Animal Welfare/statistics & numerical data , Cause of Death , Animals , Cats , Dogs , Forensic Medicine , Heat Stroke/veterinary , Humans , Spain , Starvation/veterinary , Wounds and Injuries/veterinary
8.
J Vet Diagn Invest ; 32(2): 312-316, 2020 Mar.
Article in English | MEDLINE | ID: mdl-32081093

ABSTRACT

In February 2015, we conducted a field study of causes of mortality of northern elephant seal (Mirounga angustirostris) pups on San Miguel Island, California. Autopsies were performed on 18 freshly dead pups. Ages of pups ranged from stillborn to 6-8 wk. Gross and histologic lesions included trauma (9 of 18 pups), multifocal necrotizing myopathy (8 of 18), starvation with emaciation (7 of 18), congenital anomalies (3 of 18), bacterial infections (3 of 18), and perinatal mortality (stillbirths and neonates; 2 of 18). Trauma and emaciation or starvation were the most significant contributors to death. Bacterial infections included hemolytic Escherichia coli isolated from the lungs of 2 pups with pneumonia. Additionally, non-hemolytic Streptococcus sp. and hemolytic E. coli were isolated from the liver of an emaciated pup that had mild multifocal suppurative hepatitis. Other lesions, including a previously described necrotizing myopathy, congenital anomalies, and bacterial infections, were detected concurrently in cases with starvation and/or emaciation or trauma.


Subject(s)
Bacterial Infections/veterinary , Muscular Diseases/veterinary , Seals, Earless , Starvation/veterinary , Animals , Bacterial Infections/mortality , California/epidemiology , Female , Humans , Male , Muscular Diseases/mortality , Seals, Earless/injuries , Starvation/mortality
10.
J Vet Emerg Crit Care (San Antonio) ; 29(5): 542-548, 2019 Sep.
Article in English | MEDLINE | ID: mdl-31448525

ABSTRACT

OBJECTIVE: To describe the successful management of a dog following a period of prolonged food deprivation. CASE SUMMARY: A 7-year-old, intact male Labrador Retriever presented with profound weakness and loss of nearly 50% of his body weight due to severe prolonged starvation after being trapped in a well for 27 days. Electrolyte concentrations were managed with intensive intravenous supplementation during refeeding. The dog's electrolyte abnormalities resolved, wounds healed, and strength returned during the first 3 weeks of treatment. During the next 3 months, body condition score normalized and muscle mass improved. NEW OR UNIQUE INFORMATION PROVIDED: This report describes the management of a severely malnourished dog during refeeding, and highlights treatment considerations that may be important in the prevention of refeeding syndrome in such cases.


Subject(s)
Dog Diseases/diagnosis , Electrolytes/therapeutic use , Refeeding Syndrome/veterinary , Starvation/veterinary , Administration, Intravenous/veterinary , Animals , Dog Diseases/blood , Dog Diseases/therapy , Dogs , Electrolytes/administration & dosage , Male , Refeeding Syndrome/diagnosis , Refeeding Syndrome/therapy , Starvation/diagnosis , Starvation/therapy
11.
Vet J ; 243: 1-7, 2019 Jan.
Article in English | MEDLINE | ID: mdl-30606433

ABSTRACT

Veterinary diagnostic clinicians are increasingly presented with emaciated animals involved in suspected neglect cases. A rise in public awareness and media attention towards animal welfare, combined with changes in legislation and a demand for a higher standard of evidence be presented in animal neglect cases submitted for prosecutions, have created a need for an objective measurement of starvation, particularly given the lack of quantitative assessments at post-mortem examinations. Bone marrow fat (BMF) is the final fat reserve to be mobilised for energy by a calorie-deprived animal during a state of emaciation. Percentage of BMF has been used to study starvation in several species and may provide an objective measure of ante-mortem body condition. This paper reviews the literature on the use of BMF analysis as a post-mortem diagnostic test for ante-mortem starvation. Beginning with a general overview of starvation and usual methods of assessment to describe animals in poor condition, the analysis of BMF is then introduced. Various methods of BMF analysis are discussed, as well as factors that influence the amount of BMF. This review also discusses the limitations of BMF analysis and makes suggestions where future research should be primarily focused.


Subject(s)
Adipose Tissue/chemistry , Animal Husbandry/methods , Animal Welfare , Bone Marrow/chemistry , Livestock , Starvation/veterinary , Animals , Starvation/diagnosis
12.
Article in English | MEDLINE | ID: mdl-30315898

ABSTRACT

DNA methylation is susceptible to various environmental factors such as salinity, temperature and nutritional conditions, and can affect gene function, organ metabolism, body growth and development. In order to explore the effect of starvation on growth-related genes in large yellow croaker (Larimichthys crocea), we studied methylation of the global DNA and growth-related genes (MSTN1,MSTN2,IGF1,IGF2) and the corresponding mRNA expressions, using ELISA-based technique, bisulfite sequencing PCR (BSP) technique and quantitative Real-time PCR (qRT-PCR) respectively. The results showed that the global DNA methylation levels were significantly different (p <0.05) between the experimental group and the control group at starvation 14d, 21d in muscle and at starvation 7d, 14d, 28d, and re-feeding 7d in liver. The CpG islands of MSTN1, MSTN2, IGF1 and IGF2 were enriched in exons rather than promoters. The proximal promoter of MSTN1 and IGF1 and the exon1 of MSTN2 had almost no methylation at all treatment stages. The methylation status in MSTN1 exon 1 and IGF2 exon 2 varied from different starvation time, and started to have significant differences on starvation 7d (p <0.05) both in liver and muscle. In the liver there was a strong positive correlation between IGF2 exon 2 methylation and global DNA methylation (r = 0.7558). The mRNA expression levels of these growth-related genes were significantly different at starvation 14d (p <0.05), but did not have significant correlation with the methylation of these exons. The results implied that exon methylation of these growth-related genes might affect post-transcriptional process.


Subject(s)
DNA Methylation , Gene Expression Regulation, Developmental , Liver/metabolism , Muscle, Skeletal/metabolism , Perciformes/physiology , Starvation/veterinary , Animal Nutritional Physiological Phenomena , Animals , Aquaculture , China , CpG Islands , Exons , Fish Proteins/genetics , Fish Proteins/metabolism , Liver/growth & development , Muscle, Skeletal/growth & development , Myostatin/genetics , Myostatin/metabolism , Organ Specificity , Perciformes/growth & development , Protein Isoforms/genetics , Protein Isoforms/metabolism , RNA, Messenger/metabolism , Random Allocation , Somatomedins/genetics , Somatomedins/metabolism , Starvation/metabolism , Time Factors
14.
Vet Clin North Am Equine Pract ; 34(1): 169-180, 2018 Apr.
Article in English | MEDLINE | ID: mdl-29426711

ABSTRACT

Nutritional support is an important adjunct to medical therapy in the sick, injured, or debilitated equine patient. What is not clear is the optimal route, composition, or amounts of support. The enteral route should be chosen whenever possible to maximize the benefits to the gastrointestinal tract and the patient as a whole. Complete or partial parenteral nutrition is most useful as a bridge during recovery and transition to enteral feeding in the horse. The reader is encouraged to consider nutritional support whether enteral or parenteral in any anorexic, chronically debilitated, or sick equine patient.


Subject(s)
Enteral Nutrition/veterinary , Horse Diseases/metabolism , Horse Diseases/therapy , Parenteral Nutrition/veterinary , Starvation/diet therapy , Starvation/veterinary , Animals , Horses , Nutritional Requirements , Practice Guidelines as Topic , Veterinary Medicine
15.
Animal ; 12(1): 88-97, 2018 Jan.
Article in English | MEDLINE | ID: mdl-28689503

ABSTRACT

Domesticated horses are increasingly kept under semi-natural housing conditions, whereas their adaptation capacity is not fully investigated. In all, 10 Shetland pony mares were held under semi-extensive conditions for 1 year. In winter animals were allocated into two feeding groups (60% and 100% of maintenance energy requirement, respectively). Triiodothyronine, thyroxine, non-esterified fatty acids (NEFA), total bilirubin, total protein, triglyceride, glucose, insulin and hair length were measured at monthly intervals, whereas BW, body condition score, cresty neck score and resting heart rate were recorded every 2 weeks. From summer to winter all Ponies showed a reduction in resting heart rate (P0.05). Refeeding of restrictively fed ponies resulted in a rapid increase in resting heart rate and BW and a return of blood parameters to reference values. Adequately supplied animals adapted without difficulty to varying environmental conditions, whereas feed restriction in ponies during winter resulted in reduced resting heart rates suggesting a reduced basal metabolic rate. The energy restriction was compensated by mobilizing body fat reserves which led to changes in blood parameters. Refeeding in feed restricted animals revealed a remarkably quick recovery of physiological and blood parameters to reference values. We therefore suggest that year round-outdoor housing can be a suitable housing system for robust horse breeds provided that an adequate food supply is available.


Subject(s)
Adaptation, Physiological , Animal Feed/analysis , Eating/physiology , Horses/physiology , Insulin/blood , Animals , Blood Glucose/analysis , Climate Change , Diet/veterinary , Fatty Acids, Nonesterified/blood , Female , Germany , Health Status , Horses/blood , Seasons , Starvation/veterinary , Thyroxine/blood , Triiodothyronine/blood
16.
J Exp Biol ; 220(Pt 23): 4330-4338, 2017 12 01.
Article in English | MEDLINE | ID: mdl-29187615

ABSTRACT

Starvation is common among wild animal populations, and many individuals experience repeated bouts of starvation over the course of their lives. Although much information has been gained through laboratory studies of acute starvation, little is known about how starvation affects an animal once food is again available (i.e. during the refeeding and recovery phases). Many animals exhibit a curious phenomenon - some seem to 'get better' at starving following exposure to one or more starvation events - by this we mean that they exhibit potentially adaptive responses, including reduced rates of mass loss, reduced metabolic rates, and lower costs of digestion. During subsequent refeedings they may also exhibit improved digestive efficiency and more rapid mass gain. Importantly, these responses can last until the next starvation bout or even be inherited and expressed in the subsequent generation. Currently, however, little is known about the molecular regulation and physiological mechanisms underlying these changes. Here, we identify areas of research that can fill in the most pressing knowledge gaps. In particular, we highlight how recently refined techniques (e.g. stable isotope tracers, quantitative magnetic resonance and thermal measurement) as well as next-generation sequencing approaches (e.g. RNA-seq, proteomics and holobiome sequencing) can address specific starvation-focused questions. We also describe outstanding unknowns ripe for future research regarding the timing and severity of starvation, and concerning the persistence of these responses and their interactions with other ecological stressors.


Subject(s)
Diet/veterinary , Food Deprivation/physiology , Starvation/veterinary , Animals , Starvation/metabolism
17.
Article in English | MEDLINE | ID: mdl-28163184

ABSTRACT

Dietary regime modifications have been an integral part of health and healing practices throughout the animal kingdom. Thus, to assess the effects of periodic starvation and refeeding schedule on the physiological and immunological perturbations in Edwardsiella tarda infected red sea bream, we conducted a 20day experiment using 4 treatment groups, namely, pre-fed placebo (PFP); pre-starved placebo (PSP); pre-fed infected (PFI); and pre-starved infected (PSI), wherein a 5h E. tarda infection was done on the 11th day. In the present investigation, the pre-starved groups showed significant (P<0.05) alterations in the liver Hexokinase and Glucose-6-phosphatase activity. The pre-starved fish also exhibited significant (P<0.05) increment in the hepatosomatic index, along with increased hepatic glycogen content, in a time dependent fashion. The PPAR (peroxisome proliferator activated receptors)α transcription in the pre-starved group decreased significantly (P<0.05) by 10dai, while the PPARγ showcased a reverse pattern. The transcription of Hepcidin1 and Transferrin (iron homeostasis related genes), and Cathepsin D and Ubiquitin (programmed cell death related genes) portrayed a time responsive decrease and increase in PSI and PFI groups, respectively. Additionally, in comparison to the PFI group, the PSI fish demonstrated substantially reduced oxidative stress level. Fluorescent Immunohistochemistry showed significant (P<0.05) increase in p63 positive cells in the 10dai PFI fish in relation to the PSI group. Therefore, these findings provide new insight into the beneficial role of alternating starvation and refeeding schedule, preferably short-term starvation prior to an infection, in order to obtain better capability to battle against E. tarda infection in red sea bream.


Subject(s)
Edwardsiella tarda , Enterobacteriaceae Infections/veterinary , Feeding Methods/veterinary , Fish Diseases/prevention & control , Perciformes , Starvation/veterinary , Animals , Enterobacteriaceae Infections/prevention & control , Immunohistochemistry , Oxidative Stress/physiology
18.
Animal ; 11(2): 295-305, 2017 Feb.
Article in English | MEDLINE | ID: mdl-27452785

ABSTRACT

An investigation of stillbirth and early neonatal lamb mortality was conducted in sheep flocks in Norway. Knowledge of actual causes of death are important to aid the interpretation of results obtained during studies assessing the risk factors for lamb mortality, and when tailoring preventive measures at the flock, ewe and individual lamb level. This paper reports on the postmortem findings in 270 liveborn lambs that died during the first 5 days after birth. The lambs were from 17 flocks in six counties. A total of 27% died within 3 h after birth, 41% within 24 h and 80% within 2 days. Most lambs (62%) were from triplet or higher order litters. In 81% of twin and larger litters, only one lamb died. The most frequently identified cause of neonatal death was infectious disease (n=97, 36%); 48% (n=47) of these died from septicaemia, 25% (n=24) from pneumonia, 22% (n=21) from gastrointestinal infections and 5% (n=5) from other infections. Escherichia coli accounted for 65% of the septicaemic cases, and were the most common causal agent obtained from all cases of infection (41%). In total, 14% of neonatal deaths resulted from infection by this bacterium. Traumatic lesions were the primary cause of death in 20% (n=53) of the lambs. A total of 46% of these died within 3 h after birth and 66% within 24 h. Severe congenital malformations were found in 10% (n=27) of the lambs, whereas starvation with no concurrent lesions was the cause of death in 6% (n=17). In 16% (n=43) of the lambs, no specific cause of death was identified, lambs from triplet and higher order litters being overrepresented among these cases. In this study, the main causes of neonatal lamb mortality were infection and traumatic lesions. Most neonatal deaths occurred shortly after birth, suggesting that events related to lambing and the immediate post-lambing period are critical for lamb survival.


Subject(s)
Animals, Newborn , Sheep Diseases/pathology , Animals , Congenital Abnormalities/pathology , Congenital Abnormalities/veterinary , Female , Norway , Pregnancy , Risk Factors , Sheep , Sheep Diseases/mortality , Starvation/veterinary , Stillbirth/veterinary
19.
Nature ; 540(7631): 109-113, 2016 12 01.
Article in English | MEDLINE | ID: mdl-27880762

ABSTRACT

The behavioural rhythms of organisms are thought to be under strong selection, influenced by the rhythmicity of the environment. Such behavioural rhythms are well studied in isolated individuals under laboratory conditions, but free-living individuals have to temporally synchronize their activities with those of others, including potential mates, competitors, prey and predators. Individuals can temporally segregate their daily activities (for example, prey avoiding predators, subordinates avoiding dominants) or synchronize their activities (for example, group foraging, communal defence, pairs reproducing or caring for offspring). The behavioural rhythms that emerge from such social synchronization and the underlying evolutionary and ecological drivers that shape them remain poorly understood. Here we investigate these rhythms in the context of biparental care, a particularly sensitive phase of social synchronization where pair members potentially compromise their individual rhythms. Using data from 729 nests of 91 populations of 32 biparentally incubating shorebird species, where parents synchronize to achieve continuous coverage of developing eggs, we report remarkable within- and between-species diversity in incubation rhythms. Between species, the median length of one parent's incubation bout varied from 1-19 h, whereas period length-the time in which a parent's probability to incubate cycles once between its highest and lowest value-varied from 6-43 h. The length of incubation bouts was unrelated to variables reflecting energetic demands, but species relying on crypsis (the ability to avoid detection by other animals) had longer incubation bouts than those that are readily visible or who actively protect their nest against predators. Rhythms entrainable to the 24-h light-dark cycle were less prevalent at high latitudes and absent in 18 species. Our results indicate that even under similar environmental conditions and despite 24-h environmental cues, social synchronization can generate far more diverse behavioural rhythms than expected from studies of individuals in captivity. The risk of predation, not the risk of starvation, may be a key factor underlying the diversity in these rhythms.


Subject(s)
Charadriiformes/physiology , Nesting Behavior/physiology , Periodicity , Predatory Behavior , Animals , Biological Evolution , Charadriiformes/classification , Circadian Rhythm , Cues , Environment , Feeding Behavior , Female , Male , Photoperiod , Reproduction , Species Specificity , Starvation/veterinary , Time Factors , Zygote/growth & development
20.
Rapid Commun Mass Spectrom ; 30(13): 1461-8, 2016 07 15.
Article in English | MEDLINE | ID: mdl-27321833

ABSTRACT

RATIONALE: Nutritional bottlenecks often limit the abundance of animal populations and alter individual behaviours; however, establishing animal condition over extended periods of time using non-invasive techniques has been a major limitation in population ecology. We test if the sequential measurement of δ(15) N values in a continually growing tissue, such as hair, can be used as a natural bio-logger akin to tree rings or ice cores to provide insights into nutritional stress. METHODS: Nitrogen stable isotope ratios were measured by continuous-flow isotope-ratio mass spectrometry (IRMS) from 20 sequential segments along the tail hairs of 15 migratory wildebeest. Generalized Linear Models were used to test for variation between concurrent segments of hair from the same individual, and to compare the δ(15) N values of starved and non-starved animals. Correlations between δ(15) N values in the hair and periods of above-average energy demand during the annual cycle were tested using Generalized Additive Mixed Models. RESULTS: The time series of nitrogen isotope ratios in the tail hair are comparable between strands from the same individual. The most likely explanation for the pattern of (15) N enrichment between individuals is determined by life phase, and especially the energetic demands associated with reproduction. The mean δ(15) N value of starved animals was greater than that of non-starved animals, suggesting that higher δ(15) N values correlate with periods of nutritional stress. CONCLUSIONS: High δ(15) N values in the tail hair of wildebeest are correlated with periods of negative energy balance, suggesting they may be used as a reliable indicator of the animal's nutritional history. This technique might be applicable to other obligate grazers. Most importantly, the sequential isotopic analysis of hair offers a continuous record of the chronic condition of wildebeest (effectively converting point data into time series) and allows researchers to establish the animal's nutritional diary.


Subject(s)
Antelopes , Nitrogen Isotopes/analysis , Nitrogen Isotopes/chemistry , Starvation/veterinary , Animals , Carbon Isotopes , Hair , Humans , Mass Spectrometry , Nitrogen , Seasons
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