Search

An acute outbreak of Taenia hydatigena cysticercosis, causing mortality in 5 of 21 (23.8%) female lambs, is reported. Gross post-mortem examinations and histology showed Cysticercus tenuicollis as the cause of death. Biochemical parameters in infected lambs confirmed severe hepatitis. Praziquantel, given once at 15 mg/kg body weight (bw), was administered and a dramatic improvement in the clinical condition and biochemical parameters was observed up to 30 days following treatment. [ABSTRACT FROM AUTHOR]

CASE HISTORY: As part of a production study of ewe lambs on a large farm in the Waikato region of New Zealand in 2011, pregnancy diagnosis was undertaken twice by trans-abdominal ultrasonography at 68–103 and 97–132 days of gestation. At the second pregnancy diagnosis 257/3,790 (6.8%) ewe lambs had evidence of non-viable fetuses or absence of a pregnancy that was present at the previous pregnancy diagnosis (fetal loss). LABORATORY FINDINGS: Serum antibody titres forLeptospira interrogansserovar Pomona appeared generally higher in 10 ewe lambs with fetal loss compared with 10 that were still pregnant. Histopathological investigation was not able to confirm that fetal loss was associated with leptospial infection. EPIDEMIOLOGICAL INVESTIGATION: In the 2012-born cohort of ewe lambs 443 were vaccinated with a bivalent leptospirosis vaccine and 882 unvaccinated. Serum was collected from 124 non-vaccinated ewe lambs between January and December 2013 for measurement of antibodies toLeptospiraserovar Pomona andL. borgpeterseniiserovar Hardjo-bovis using a microscopic agglutination test (MAT). Less than 5% of these ewe lambs were seropositive until May, but by August 85% and 48% of animals were seropositive toLeptospiraserovars Hardjo-bovis and Pomona, respectively. Fetal loss in non-vaccinated ewe lambs was 78/882 (9%) compared with 23/443 (5%) in vaccinated ewe lambs. Combined data from the 2011- and 2012-born ewe lambs (n=5,115) were analysed using a logistic regression model and fetal loss as the dependent variable. In the final model fetal loss was associated with pre-mating bodyweight (p=0.003), weight change from pre-mating to initial pregnancy diagnosis (p<0.001), year born and leptospirosis vaccination status (p=0.013). Amongst the serologically monitored ewe lambs, there were associations between fetal loss and being seropositive toLeptospiraserovar Pomona using titre cut-points of 1:48 and 1:768 (p<0.001). CLINICAL RELEVANCE: Low pre-mating weight and/or low weight gain from mating to pregnancy diagnosis was associated with increased fetal loss, emphasising the importance of ewe lambs achieving target pre-mating weights and liveweight gains during pregnancy. Infection withLeptospiraserovar Pomona was associated with fetal loss in the 2012-born cohort and the possibility of infection with this serovar should be considered when investigating cases of fetal loss. [ABSTRACT FROM AUTHOR]

Background: Perinatal mortality is a major cause of loss in the sheep industry. Our aim was to explore time trends in crude population stillbirth and neonatal mortality rates in Norway. We used data on 6,435,715 lambs from flocks enrolled in the Norwegian Sheep Recording System (NSRS) from 2000 through 2010 for descriptive analysis of trends. Longitudinal patterns of mortality rates were compared for lambs within different levels of variables suspected to be associated with perinatal loss. Results: There was an approximately linear increase in the annual proportion of stillborn lambs during the study period, from 3.3 % in 2000 to 4.7 % in 2010. In the same time period, average litter size of ewes in NSRS flocks increased from 2.00 to 2.19. However, a steady rise in stillbirth rate was observed within each litter size group, suggesting a gradually increasing impact on stillbirth risk of other, yet unidentified, factors. Average flock size increased during the study period. The highest stillbirth rates were found in the largest and smallest flocks. Early neonatal mortality rates (0-5 days of life) varied from year to year (minimum 2.2 %, maximum 3.2 %) and were invariably higher among triplets and quadruplets than among singletons and twins. Annual fluctuations were parallel within the various litter sizes. A significant overall decreasing trend was present within all litter sizes with the exception of singletons. Weather data for the prime lambing months (April and May) 2000-2010 indicated a relationship between low temperatures and high neonatal mortality rates. At the flock level, there was a significant positive correlation between stillbirths and early neonatal mortality rates (r = 0.13), between stillbirth rates in two consecutive years (r = 0.43) and between early neonatal mortality rates in two consecutive years (r = 0.40). Conclusions: The substantial increase in ovine stillbirth rate in recent years in Norway was to some extent related to a corresponding increase in the proportion of lambs in triplet or larger litters; however, other factors apparently have contributed. Early neonatal mortality rate exhibited year-to-year variations, partly following temperature fluctuations, which is somewhat unexpected, considering that lambing mainly occurs indoors in Norway. [ABSTRACT FROM AUTHOR]

The aim of this study was to evaluate the effect of rosemary essential oils (REO) and the forage nature on ewes' performances, immune response and lambs' growth and mortality. Forty-eight dairy ewes (Sicilo-Sarde) were fed oat-hay or oat-silage supplemented with 400 g of concentrate during pregnancy and 600 g during postpartum. The experimental concentrate contained the same mixture as the control (barley, soybean meal and mineral vitamin supplement) more 0.6 g/kg of REO. Two groups were obtained with each forage (Hay groups: H-C and H-REO; Silage groups: S-C and S-REO). REO increased the dry matter (DM) intake, the nitrogen intake and retention being higher with the silage groups (P < 0.05). REO increased solid non-fat (P = 0.004) and fat contents of colostrum which was higher with hay (P = 0.002). REO decreased lamb mortality (P < 0.05) which averaged 21% for control groups and 6% for H-REO, while no mortality was recorded with S-REO. REO dietary supply improved forage intake and tended to ameliorate colostrum production; it could be a natural additive to improve ewes' performances. [ABSTRACT FROM AUTHOR]

Case report This report documents an outbreak of acute renal failure in a flock of 9-month-old White Suffolk-cross ewe lambs. The mortality rate was moderate but the morbidity was high. The lambs had grazed a wheat stubble paddock in which there were several weed species, including Amaranthus spp. Clinical significance Renal failure in livestock has been reported internationally following the ingestion of Amaranthus spp. and although it has previously been suspected in Australia no cases have been documented. It is important for Australian veterinarians and farmers to realise the toxic potential of this group of plants. [ABSTRACT FROM AUTHOR]

Aim: To identify the Clostridium perfringens toxin genotypes prevailing in enterotoxemia suspected sheep flocks in Andhra Pradesh by using multiplex PCR. Materials and Methods: Intestinal scrapings were collected from lambs below three months of age from flocks with similar management from different Districts of Andhra Pradesh, in India. A total of 208 samples were collected with 140 from enterotoxemia suspected flocks and 68 from healthy flocks. Following processing and culture of the samples, colonies were identified by morphological and biochemical tests. All the clostridial isolates were analyzed by multiplex PCR. Results: C. pefringens were isolated from 97 out of 140 enterotoxemia suspected flocks (69.29%) and 27 out of 68 healthy flocks (39.71 %). Genotyping of the 97 iolates by multiplex PCR from enterotoxemia suspected flocks indicated C. perfringens type A, C and D 67.01% (65 out of 97); 11.34% (11 out of 97) and 21.65% (21 out of 97) respectively. Isolates from healthy flocks indicated the presence of type A and D 92.59% (25 out of 27) and 7.40% (2 out of 27) respectively. Number of isolates from enterotoxaemia suspected flocks were significantly high (P<0.001) than healthy flocks. Type A is found to be predominant in both enterotoxemia suspected and healthy flocks (67.01% and 92.59%). Conclusions: Prevalence of C. perfringens type C was reported for the first time in India. Clostridium perfringens type D and type C were found to be the major causative types for enterotoxemia. [ABSTRACT FROM AUTHOR]

The objective of the study was to investigate the association of different factors with lamb mortality. For this purpose data of 6084 lambs (1998 to 2007) was used from Province of Punjab maintained at Livestock Experiment Station, (LES) RakhKhair-e-Wala, District Layyah, of the Pak-Karakul, Thalli and Kacchi sheep breeds. The results, year of birth and season of birth had a significant (P<0.01) effect on lamb mortality rate at all ages while sex and type of birth showed non-significant effect. The maximum lamb mortality rate was 17.2%, observed in year 2001 followed by 16.6% and 5.8% in 2002 and 2004, respectively. The overall mortality rate (10.2%) was noticed in female lambs and male lamb (8.8%). The lambs during early ages showed higher mortality, when compared with those of old ages. The lambs bom in triplet or twins showed high mortality than the single born. The highest mortality rate (12.2%) was estimated during spring season following (5.5%) in summer season. The overall mortality rate (43.7%) due to pneumonia was recorded followed by gastro-enteritis (19.2%) and heat stroke (10.7%). The ewe of 3 year age showed the highest overall lamb mortality rate (44.1%) than 4 year old dam (25.7%), rate, was reduced as the dam become older. It is concluded that all these factors related to disease and management, which can be minimized by proper preventive medication and better management. [ABSTRACT FROM AUTHOR]

Copyright of Ciência Animal Brasileira is the property of Universidade Federal de Goias, Escola de Veterinaria and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

British sheep farmers were invited to complete a questionnaire about the impact of Schmallenberg virus (SBV) on animal health, welfare and their own emotional wellbeing during the 2011-2012 lambing season, through Defra and Farming Industry websites, letters to farmers who had requested SBV laboratory tests and advertisement at Sheep 2012. The 494 responders included SBV confirmed (positive by RT-PCR) (n=76), SBV suspected by farmer (n=140) or SBV not suspected (n=278). Percentage of barren ewes was similar across SBV groups, however, lamb and ewe losses were higher on responder farms where SBV was confirmed or suspected. The median percentages of all lambs born (and lambs born deformed ) that died within one week of birth was 10.4 per cent (5.5 per cent), 7.0 per cent (2.9 per cent) and 5.3 per cent (0 per cent), respectively, on SBV confirmed, suspected and not suspected farms (P<0.001). Eight to 16 per cent of SBV confirmed or suspected farms reported lamb mortality of ⩾40 per cent. Farmer perceived impact was greater where SBV was confirmed or suspected (P<0.001): 25 per cent reported a high impact on emotional wellbeing (4 per cent of SBV not suspected), 13 per cent reported a high impact on flock welfare and financial performance and 6 per cent were less likely to farm sheep next year because of SBV (<2 per cent in SBV not suspected). Overall, SBV impact has been large relative to reported sheep loss. [ABSTRACT FROM AUTHOR]

This paper reports genetic parameters for lamb survival and mortality traits on sheep farms in New Zealand. Lamb survival and mortality records were obtained from 38 flocks (103,357 lambs) from 5 yr of lambing data (2007 to 2011) and include many breeds and their crosses (predominantly Romney, Perendale, Coopworth, and Texel). A number of models were tested, all including environmental weather effects and investigating the random environmental effect of dam and litter (dam/year) as well as logit transformation for binary traits. Total heritability (direct + maternal) estimates were low for lamb viability at birth (0.01), lamb death risk to dystocia (0.01), and lamb death risk to starvation exposure (0.01) from birth to 3 d of age in an analysis accounting for direct and maternal genetic effects and the maternal environmental effects. Lamb survival heritabilities reported are very low (total heritabilities range from 0.02 to 0.06). The total heritabilities for the lamb death risk traits are lower than reported estimates of survival to 3 d of age or to weaning suggesting selection for the postmortem traits are not warranted at this time within these flocks. The total heritability for lamb birth weight was moderate (0.38) and the genetic correlations with the lamb death risk traits suggested that directional selection on lamb birth weight would have an effect on survival, although it is likely to have a nonlinear effect and therefore an optimum birth weight at which survival is maximized. This study has also shown that the total heritabilities may be overestimated when not accounting for maternal genetic and environment effects and in particular not accounting for the random environmental effect of litter (dam/year). [ABSTRACT FROM AUTHOR]

Achieving higher lamb weaning percentages by reducing lamb mortality can improve the profitability of sheep enterprises. In this paper we estimated the financial benefits from providing shelter to reduce the mortality of twin lambs in self-replacing Merino or dual-purpose Merino flock enterprises in south-west Victoria. A whole-farm bio-economic model (MIDAS) was initially used to estimate the increase in profit from reducing mortality of twin lambs and a second analysis included the costs of using perennial grass hedges to provide the shelter during lambing. The economic value of providing shelter was tested at three rates of twinning (10, 30 and 50%), three rates of mortality without shelter (70, 50 and 30%) and two levels of reduction in lamb mortality by providing shelter (25 and 50% reduction). A sensitivity analysis to wool and lamb prices, costs of establishing the grass hedges and stocking rates in the shelter area were also tested. Overall, more than 2500 scenarios were tested. Across the range of twinning rates and levels of twin mortality tested, at standard wool and meat prices, providing shelter to the dual-purpose Merino ewe flock was always profitable ($0.05 to 11.35/ewe) and the profits from providing shelter to the self-replacing Merino ewe flock were generally lower ($0.15 to $6.35/ewe). The impacts of changing wool and lamb prices depended on enterprise type, whereas the costs of establishment of the hedges or stocking rate of ewes in the hedge area during lambing had little impact on profitability. The main factor that determined the economic return from shelter was the reduction in mortality provided by the shelter but the proportion of twin-bearing ewes in the flock and the base rate of lamb mortality without shelter was also important. Overall, based on the assumptions used, we conclude that the profitability of many sheep enterprises lambing during frequent high chill weather conditions in temperate areas of south-eastern Australia could be improved by providing low cost shelter for twin-bearing Merino ewes lambing from July to September. Achieving higher lamb weaning percentages by reducing lamb mortality can improve the profitability of sheep enterprises. We estimated the financial benefits from providing shelter to reduce the mortality of twin lambs on two modelled sheep enterprises in south-west Victoria. The reduction in mortality that could be achieved was a key factor determining benefits and the profitability of sheep enterprises lambing during high chill weather conditions could be improved by providing low cost shelter. [ABSTRACT FROM AUTHOR]

Vitamin E concentrations in dried pastures, stubble and most grains are below the recommended requirement of 10-25 mg/kg dry matter (DM). Sheep grazing in an environment when dry pastures and cereal crop stubbles are their primary source of nutrients for a few months have a high risk of developing vitamin E deficiency. If the low vitamin E status coincides with late gestation, the neonate is likely to have a deficiency of vitamin E. Some of the consequences of this are well known, with nutritional myopathy (with high mortality) a risk in young growing sheep unless vitamin E supplements are provided. Vitamin E plays an important role in the management of oxidative stress. Sperm are subject to oxidative damage due to high metabolic rate and high concentration of polyunsaturated fatty acids in their membranes. Oxidative stress may also compromise follicular development and ovarian activity. Vitamin E is also involved with improvement in immune response. For these reasons, vitamin E status is important for reproductive efficiency in both males and females and in the survival of lambs and weaners. In addition, vitamin E deficiency is potentially exacerbated by a lack of other nutrients involved in the management of oxidative stress and immune function, such as selenium (Se) and sulfur amino acids. A Se concentration of 0.1 mg/kg DM in feedstuffs is required to maintain immune competency in sheep. In considering possible consequences for reproduction, further investigation is justified into: (i) effects of low vitamin E, in combination with low levels of other natural antioxidants, on the quality and quantity of sperm produced before and during mating; (ii) follicle development, fertilisation and embryonic mortality in Se-supplemented ewes; (iii) assessment of supplementing formulated antioxidants to rams and ewes during the mating season; (iv) managing oxidative stress in the newborn - consequences of large doses of vitamin E to ewes before parturition to boost lamb reserves; (v) potential benefits to lamb survival through boosting maternal innate immunity; (vi) choices for boosting antioxidant and immune function in ewes and lambs through 'immune pack' nutrient options that may target nutrients lacking in dry grass pastures; (vii) the potential role of heat stress in modifying the requirements for, and responses to, vitamin E in extensive grazing systems. Nutrient and environment related oxidative stress can impact rams and ewes during the reproductive period, resulting in low reproductivity and high lamb mortality. Managing oxidative stress of the newborn by giving ewes large dose of dietary antioxidants, like vitamin E and selenium, could boost immune competency of ewes and lambs to improve lamb survival. A number of related issues remain to be resolved for Australian environments. [ABSTRACT FROM AUTHOR]

AIM: To compare the vascular and neuronal changes in the central nervous system (CNS) of lambs that died in the first 3 days after birth, from various causes, with control lambs subject to euthanasia. METHODS: Dead lambs (n=65) were collected daily during the period 07 September 2010 to 26 September 2010 from a flock of 200 twin-lamb-bearing ewes. Age-matched lambs from the same flock were subject to euthanasia as a control group (n=39). Necropsies were conducted on all study lambs. The cause of death in lambs found dead was categorised as starvation-mismothering-exposure complex (SME), dystocia, or other, based on gross necropsy findings. Deaths were categorised as SME in lambs with necropsy lesions of pericardial, perirenal and mesenteric fat catabolism, an empty gastrointestinal tract and completely inflated lungs. Dystocia was diagnosed by the presence of a swollen tongue, injected sclera and subcutaneous oedema and haemorrhage around the head and neck or hind limbs. Deaths were categorised as other if an obvious cause of death could not be ascertained and if evidence of infection was identified. The CNS of each lamb necropsied was assessed grossly for haemorrhage, and using histopathology to determine vascular and neuronal changes. Immunohistochemistry was performed on selected cases (n=36) to confirm neuronal death. RESULTS: Of the 65 lambs found dead, 16 (25%) had evidence of cerebral and spinal meningeal haemorrhage, whereas of the 39 clinically normal control lambs, all displayed gross evidence of cerebral and spinal meningeal haemorrhage. There was no evidence of parenchymal vacuolation, neuronal vacuolation or ischaemic neurons in any of the lamb brain sections including those that died with evidence of dystocia. There was no difference, within the regions examined, in mean vascular score between lambs categorised by cause of death (p>0.05). The overall mean vascular score for the brain stem was greater than the mid brain (p=0.02) and the cortex (p=0.005) but did not differ from either the spinal cord or cerebellum (p>0.3). The vascular score for the spinal cord was greater than the mid brain (p=0.01) and cortex (p=0.003). Lambs that died of dystocia had less immunoreactivity for microtubule associated protein 2 (MAP2) in the hilus/CA4 region of the hippocampus (p=0.02) and dentate gyrus of the hippocampus (p=0.006) than those that were subject to euthanasia. CONCLUSIONS: Neither gross nor histological vascular changes in the CNS could be used to distinguish newborn lambs that had been subject to euthanasia from those that died with evidence of SME or dystocia, so meningeal haemorrhages in or on the brain and spinal cord of lambs that die in the neonatal period cannot be used to support a diagnosis of birth injury or dystocia. The CA4 region and the dentate gyrus of the hippocampus are useful regions for detecting hypoxic/ischaemic injury in lambs with evidence of dystocia. There was no evidence that hypoxia/ischaemia contributed to lambs dying of SME. CLINICAL RELEVANCE: The results of this study suggest that vascular changes in the CNS of newborn lambs may be produced artefactually. Caution is warranted with respect to interpretation of these vascular changes. [ABSTRACT FROM PUBLISHER]

This study was conducted to evaluate effects of non-genetic factors on litter size, age at first parturition (AFP), parturition interval (PI), seasonality of parturition, and pre-weaning mortality rate of sheep and goats flock with 587 kids and 467 lambs owned by 60 households. The litter size, AFP and PI (months) of lambs were 1.52 + 0.04, 12.43 + 0.1, 9.19+0.08, respectively, while the corresponding values were 1.47 + 0.04, 11.95 + 0.13 and 9.05 + 0.08 for kids. The average pre-weaning mortality rate was 14.84 and 12.59% for lambs and kids, respectively. Ewes of parity three had (p <0.05) higher litter size than parity one. Does having parity four and five had (p <0.05) higher litter size than parity three while does and ewes having parity three had (p <0.05) higher litter size than parity one. Site and season influenced litter size (p <0.5) and pre-weaning mortality of (p <0.01) lambs and kids. Birth weight (p <0.05) and parity influenced (p <0.01) pre-weaning kid mortality. To exploit reproductive potential of dams and enhance rural income from small ruminants, improved management measures have to be warranted. [ABSTRACT FROM AUTHOR]

Lamb mortality rates are unacceptably high with associated welfare and economic costs. Stillbirths/dystocia, starvation/hypothermia and infectious disease account for the majority of deaths in the neonatal period. Many of the problems are preventable but multifactorial aetiologies and retrospective investigation can make them a challenge to resolve. Ewe nutrition, genetics, management and the environment all need to be considered providing opportunity for veterinary involvement on sheep farms. [ABSTRACT FROM AUTHOR]

This study was designed to examine the effect of birth weight, gender, birth type, lambing season, and dam parity and health status on lamb morbidity and mortality during the neonatal (first four weeks of life) and post-neonatal (first 5-12 weeks of life) periods in lambs born in two flocks in the 2009 lambing season in Kars, Turkey. EPI INFO 6 was used to determine differences in morbidity or mortality rates and risk according to risk factors including birth weights, genders, type of birth, lambing seasons, and parity and health of dams. The significance level was set at P<0.05 for all comparisons. The neonatal morbidity and mortality rates (48% and 33.3%, respectively) and risk of the lambs in the low birth weight group were significantly higher than those of the lambs in the medium birth weight (18.9%, χ2=10.4, OR=3.9 for morbidity and 1.6%, χ2=32.5, OR=30, for mortality) and high birth weight (9.8%, χ2=26.9, OR=8.5 for morbidity and 1.2%, χ2=46.5, OR=42.7 for mortality) groups (P<0.01 and P<0.001, respectively). The neonatal mortality rate and risk of lambs born in the winter season (9.2%) were significantly (P<0.01) higher than those of lambs born in the spring season (1.8%, χ2=9.6 and OR=5.5). Lambs born to primiparous ewes had a neonatal morbidity rate (29.6%) and risk significantly higher than those of ewes at second parity (13.9%, χ2=6.4, OR=2.6) and third parity (11.1%, χ2=7.8, OR=3.3) (P<0.05 and P<0.01, respectively). Similarly, lambs born to primiparous ewes had a neonatal mortality rate (14.8%) and risk significantly higher than those of ewes at second parity (2.9%, χ2=9.3, 0=5.7), third parity (0%, χ2=14.1) and >4 parity (2.4%, χ2=4.2, OR=6.9) (P<0.001, P<0.001 and P<0.05, respectively). Lambs born to ill ewes had a neonatal morbidity rate (64.7%) and risk significantly higher (P<0.001) than those of lambs bom to healthy ewes (13.8%, χ2=30.38, 0R=11.4). In the present study, it was concluded that the most significant risk factors for lamb morbidity and mortality were season of birth, parity, birth weight and health status of dams. Therefore, timely implemented health and management measures targeting these factors are required to reduce disease and death. [ABSTRACT FROM AUTHOR]

The objective of this research was to compare the growth performance, incidence of prolapse and mortality, carcass characteristics, blood hormone concentration, and N balance of lambs implanted with increasing dosages of zeranol. One hundred forty-four crossbred lambs (29.6 ± 4.9 kg) were used in a completely random design and placed into 16 feedlot pens (4 pens/treatment) for a 116 d finishing study. Lambs were fed an 84.7% corn and 15.3% market lamb pellet (DM basis) diet ad libitum. Treatments were 0, 12, 24, and 36 mg zeranol (Ralgro; Schering-Plough), and lambs were implanted in the ear according to treatment on d 0. Lambs were weighed. Thirty lambs (67.6 ± 3.4 kg) and 96 lambs (65.8 ± 5.1 kg) were harvested on d 84 and d 118, respectively. Carcass data were collected 24 h after chill. Blood samples were collected on d 0, 28, 56, 70, 82, 99, and 116 from 64 lambs (29.6 ± 2.1 kg) in the feedlot study (subsample of 4 lambs per pen) and analyzed for thyroxine, triiodothyronine, and IGF-I. A second study was conducted to compare effects of 0, 12, 24, or 36 mg zeranol on N balance in 16 crossbred lambs (34.8 ± 2.1 kg). There were no differences among treatments for BW, ADG, DMI, and G:F (P > 0.05) in the feedlot study. However, there was a linear increase for incidence of prolapse (P = 0.006; 2.78, 5.55, 24.98, and 27.75%, respectively) and mortality (P = 0.005; 0.00, 5.55, 11.10, and 13.88%, respectively) as zeranol dosage increased. Carcass characteristics, blood hormone concentrations, and N balance were not affected by treatment (P > 0.05). These results indicate zeranol increases incidence of prolapse and mortality without increasing growth performance. [ABSTRACT FROM AUTHOR]

Abstract: We studied breed and breed by environment interaction effects on lamb mortality during the summer grazing period. One hundred forty-six Norwegian sheep farms that stocked the two most common breeds – Norwegian White Sheep (NWS) and Spælsau together and grazed both in the same free-range grazing areas were used. Average summer mortality of lambs on the study farms was 8.7% for NWS and 6.3% for Spælsau. For 110 of the 146 sheep flocks Spælsau had the lower lamb mortality during summer. The higher mortality observed amongst NWS lambs may suggest a higher environmental sensitivity for this breed, which coincides well with results previously obtained for lamb autumn weights of the same two breeds. Analysing genotype by environment interactions with a probit threshold model revealed that the breeds differed significantly in lamb mortality, and that they ranked their flock environments in a slightly, albeit significantly, different way, i.e., breed by environment interactions did affect lamb mortality. The consequences of the threshold model''s assumptions and the constraints on interpretation of results are discussed. [Copyright &y& Elsevier]

Abstract: The aim of the presented research was to statistically analyse the survival of 20,044 Polish Merino lambs between birth and 100 day of their life, using classification trees and logistic regression. The lamb survival trait was expressed in binomial scale: 1 for survival, 0 for mortality. Two different models of the trees were developed, depending on the division criterion: they were the function of entropy and the Gini index. For comparison purposes, an additional statistical analysis was carried out using a multiple logistic regression. The quality of decision tree models and multiple regressions was compared taking into consideration the following criteria: average error function, average squared error, lift cumulative, Kolmogorov–Smirnov statistics and the area under the Receiver Operating Characteristic curve. A statistical analysis was conducted using the Enterprise Miner 6.2 software included in the SAS package. The calculated quality criteria of four models that were developed lead to the conclusion that the classification trees established based on the Gini index, and on the function of entropy, are the most accurate in defining the variability of characteristics under examination, i.e. survival of lambs up to 100 days of age. In the case of the best classification model available, i.e. a tree built using the Gini index, the ranking of variable importance, which was developed based on the “Importance” measure, leads to the conclusion that the flock, type, and the year of a lamb''s birth are the most significant differentiating factors. [Copyright &y& Elsevier]

A study was carried out on six hill farms, located in the main hill regions of Northern Ireland, over three breeding seasons to investigate the effect of sire breed on ewe dystocia, lamb survival and weaned lamb output. On each farm, groups of 26 to 40 purebred Scottish Blackface ewes (n=3174) were crossed with Blackface, Swaledale, North Country Cheviot, Lleyn and Texel sires by natural service (year 1) and artificial insemination (years 2 and 3). Each of the mating groups was initially balanced for ewe age, live weight and condition score, and a total of 15 sires of each breed were used over the 3 years. In total, 2272 ewes were recorded at lambing, producing 3451 lambs, over the 3 years. Sire breed had a significant effect (P<0.001) on lamb birth weight with Blackface and Swaledale the lowest and Texel the highest. The proportion of ewes with dystocia was higher with Texel sires compared with Lleyn, Swaledale and Blackface sires (P<0.05). Ewes mated to Cheviot sires had more dystocia than those mated to Blackface and Swaledale sires (P<0.05), while ewes mated to Lleyn sire breed had more dystocia (P<0.05) than those mated to Blackface sire breed. Most of the incidence of dystocia was attributable to increased lamb birth weight (P<0.001), and some to litter size (P<0.05). Swaledale, Cheviot, Lleyn and Texel sire breeds increased the incidence of malpresentations (P<0.05). Lamb live weight at weaning was higher with Texel- and Cheviot- and Lleyn-sired lambs compared with Blackface- and Swaledale-sired lambs (P<0.01). The level of lamb mortality at birth was not affected by sire breed. However, lamb mortality at weaning was lower for Lleyn-sired lambs compared with the other lamb genotypes (P<0.05). These results indicate that the use of sires from larger breeds, such as Lleyn and Texel, within the Blackface ewe flocks can increase lamb output, with no apparent detrimental effects on lamb mortality or ewe survival, but increased assistance at lambing will be required. [ABSTRACT FROM AUTHOR]

The aim of the present study was to report the main dystocia causes in sheep in Agreste and semiarid region of Pernambuco and to evaluate some factors related to their occurrence, besides of determining the efficiency of the treatment choices. The higher incidence of dystocia occurred in rainy season corresponding to 61.7%. Results showed a major predominance of maternal dystocia (71.6%) over fetal dystocia (29.4%) with higher incidence in primiparous and gemelar pregnant Santa Inês ewes. The main maternal dystocia was ringwomb while fetal dystocia was maldisposition in anterior presentation. Maternal survival rate correspond to 100% and 88.6%, while lambs achieved 41.2% and 46.7% after obstetrical maneuver and caesarean section, respectively, with predominance of unviable lambs in both procedures. Obstetrical maneuver and left flank cesarean section remain as safe options for the treatment of sheep dystocia and are also important coadjutants in minimizing the economical impact that this disease causes in Pernambuco. [ABSTRACT FROM AUTHOR]

We investigated the dynamics of 8 populations of a bighorn sheep (Ovis canadensis) metapopulation in Hells Canyon, USA from 1997 to 2003. Pneumonia was the most common cause (43%) of adult mortality and the primary factor limiting population growth. Cougar (Puma concolor) predation was the second most-frequent source (27%) of adult mortality but did not reduce the rate of population growth significantly. Most pneumonia-caused mortality occurred in fall and early winter and most cougar predation occurred in late winter and early spring. Average annual survival of adult males (0.84) was lower than females (0.91). Pneumonia was the most common known cause of lamb mortality (86%), and pneumonia-related mortality was detected whenever summer lamb survival was, 50%. Pneumonia-caused mortality rates in lambs were high from 21 days to 91 days of age and peaked at 42 days to 70 days. Summer pneumonia epizootics in lambs were independent of pneumonia-caused mortality in adults. Pneumonia-caused mortality occurred at the population level and was not synchronized geographically or temporally among populations. Although catastrophic all-age pneumonia-epizootics have previously been described in bighorn sheep, we found that chronic, although sporadic, pneumonia-caused mortality in adults and lambs can also have important effects on the dynamics of bighorn sheep populations. [ABSTRACT FROM AUTHOR]

A study of ewe performance was undertaken in 795 sheep flocks based on data from the Norwegian Sheep Recording System. Herd level data included in the annual report for 1998 were used as the basis for the study. Average flock size was 75.3 ewes. The material was considered as representative of the better and more motivated sheep farmers in the mountain valley regions in south-eastern Norway. The average number of lambs born per ewe, inclusive (and exclusive) of barren ewes, was 1.89 (2.02), and of autumn lambs (those surviving from birth in the spring to autumn) 1.60 (1.66). The average autumn weight of the lambs corrected to 145 days of age was 42.4 kg, giving an overall performance of 67.9 kg lambs live weight per ewe. When including artificially reared lambs, overall performance was 70.4 kg per ewe. Artificial rearing of lambs, mostly triplets which had been removed from the ewe, was practised on 395 of the farms. In the 74 flocks with a rate of artificial rearing of more than 10% of all lambs, overall performance per ewe was 13.3 kg higher than in flocks with no artificial rearing. Total lamb mortality from birth to autumn recording, including stillborn lambs, was 12.44%. Mortality had a skewed distribution, some flocks having very high mortality figures. The arithmetic means (and medians) for mortality were as follows: 2.75 (2.29)% stillbirths, 2.93 (2.30)% died during the indoor feeding period, 0.88 (0.00)% at spring pasture, and 6.16 (4.40)% at summer pasture. In regression models using Proc Genmod in SAS ® , it was found that average number of autumn lambs per ewe was negatively associated with the rate of barren ewes, late lambing date (flock average day in year when lambing took place), and total lamb mortality. The corrected autumn weight of the lambs was positively associated with the average number of lambs born per ewe and non-fertility rate, and negatively associated with flock size and total lamb mortality. The Dala breed had a positive effect on number of autumn lambs per ewe, and Spæl breed a negative effect on corrected autumn live weight of the lambs. [ABSTRACT FROM AUTHOR]

The role of infectious diseases including coxiellosis in causing poorer reproductive performance of primiparous ewes are not well studied. The aims of this study were to determine if natural exposure to Coxiella burnetii is widespread in breeding ewes and whether seropositivity is associated with poor reproductive performance of primiparous ewes. Seropositivity to Coxiella burnetii was 0.08% (CI95% 0.01, 0.36) in primiparous ewes and 0.36% (CI95% 0.07, 1.14) in mature ewes. Coxiella burnetii was not detected in aborted or stillborn lambs using qPCR. These findings suggest C. burnetii infection was unlikely to be an important contributor to abortion and perinatal mortalities observed for primiparous ewe flocks, and exposure to C. burnetii was not widespread in ewes on farms located over wide geographical region of southern Australia. Whilst ewes on these farms were not an important reservoir for C. burnetii , sporadic zoonotic transmission from sheep is reported and has public health implications. • Study conducted on 28 farms over wide geographic region of southern Australia. • Very low C. burnetii seropositivity in primiparous ewes with abortion or perinatal mortality. • C. burnetii was not detected in aborted or stillborn lambs using qPCR. • Very low C. burnetii seropositivity in randomly selected mature ewes. • C. burnetii not a major contributor to abortion & lamb mortality for primiparous ewes. [ABSTRACT FROM AUTHOR]

• 53 % of lamb mortalities were associated with dystocia in Australian studies since 1990. • Dystocia is a major contributor to lamb mortality for all litter sizes. • Dystocia is a key contributor to lamb mortality for both Merino and non-Merino ewes. • Dystocia has significant negative impacts for farm income and sheep welfare. • Impact of dystocia on farm profitability is strongly influenced by lamb sale price. Dystocia contributes to lamb and ewe mortality in the periparturient period but impacts for extensive sheep production systems remain poorly understood. Here we show that lamb and ewe mortality associated with dystocia has important impacts on sheep production in Australia and New Zealand, and quantify financial impacts for the Australian sheep industry. A systematic review of the literature identified 11 publications published since 1990 that reported sheep mortality due to dystocia in Australia or New Zealand. Assumptions for ewe breeding flock structure and reproductive performance were based on Australian sheep industry data. The proportion of lamb mortality attributable to dystocia (including stillbirths and perinatal deaths with evidence of hypoxic injury) pooled across all studies (pooled proportional mortality ratio) was 47 % (95 % Confidence Interval (CI): 38, 55). Pooled proportional mortality ratio for Australian studies was 53 % (95 %CI: 47, 60), and for New Zealand studies was 35 % (95 %CI: 19, 51). Pooled proportional mortality ratio was similar for lambs born to Merino and non-Merino ewes, although more data are needed to determine effects of ewe breed independent of other factors. Pooled proportional mortality ratio was higher for single lambs (59 %; 95 % CI: 55, 63) than twin (47 %; 41, 54) or triplet (49 %; 46, 52) lambs. However, the number of dystocia-associated mortalities is higher for twin-born lambs than for singles because total mortality is higher for twin-born lambs. It is estimated that approximately 7.7 million lamb deaths and 297,500 ewe deaths per year are attributable to dystocia in Australia for the national flock of 38 million breeding ewes. The whole-farm bio-economic Model of an Integrated Dryland Agricultural System (MIDAS) was used to determine the impacts of dystocia-associated ewe and lamb mortality on Australian farm profit. Dystocia is estimated to reduce Australian national farm profit by AU$780 million or $23.00 per ewe mated based on an assumed lamb sale price of AU$6.50 per kg carcass weight. These estimates do not include the costs of reduced productivity for surviving ewes and lambs, intervention, post-farmgate impacts, delayed genetic progress, or impacts on animal welfare and access into sheep meat and wool markets. Reducing dystocia through improved genetics and sheep management will improve animal welfare and farm profit. [ABSTRACT FROM AUTHOR]

A Nellore iamb was presented with soft fluctuating swelling at right inguinal region suggesting abdominal herniation. Herniorraphy was performed under anaesthesia. Though hernial contents were found at inguinal region, hernial ring was actually at high right para lumbar fossa. The contents were not covered with peritoneum (false hernia) and were repositioned into abdomen. Regular post operative care and dressing assured recovery. [ABSTRACT FROM AUTHOR]