Thermogenesis, blood metabolites and hormones, and growth of lambs born to ewes supplemented with algae-derived docosahexaenoic acid

Neonatal lamb mortality is a major factor affecting profitability in the sheep industry, and lamb thermogenesis is a key element in neonatal lamb survival. Increased lamb vigor has been reported when ewes were supplemented during late gestation with algae-derived docosahexaenoic acid (DHA); however, the effects of DHA on lamb thermogenesis and immunocompetence have not been investigated. Eighty twin-bearing Targhee ewes (ages 2 to 5 yr; 68.5 ± 3 kg) were assigned randomly to 1 of 2 supplement treatments to determine the effects of feeding DHA to ewes during late gestation and early lactation on lamb thermogenesis, serum metabolites and hormones, and lamb growth. Supplement treatments were 12 g·ewe(-1)·d(-1) of algae-derived DHA (DHA Gold Advanced Bionutrition Corp., Columbia, MD; algae-derived DHA); and no algae-derived DHA (control). Supplements were individually fed daily during the last 30 d (±7 d) of gestation and pen fed (6 pens/treatment with 6 or 7 ewes/pen) during the first 38 d (±7 d) of lactation. One hour after lambing and before nursing, twin-born lambs were weighed, blood sampled via jugular puncture, and placed in a dry cold chamber for 30 min (0°C), and rectal temperatures were recorded every minute for 30 min. Lambs were removed from the cold chamber, blood sampled, warmed for 15 min, and returned to their dam. Ewes were blood sampled, and colostrum samples were collected 1 h postpartum. Ewe and lamb sera were assayed for glucose, NEFA, cortisol, and leptin. Lamb rectal temperature, glucose, NEFA, cortisol, leptin, and birth weights did not differ between treatments. The BW at 38 d was greater (P = 0.03) for lambs born to control ewes than for lambs born to algae-derived DHA-supplemented ewes; however, the colostrum of algae-derived DHA-supplemented ewes had a greater specific gravity (P = 0.05) than for control ewes. Overall, despite a potentially positive effect on ewe colostral IgG concentrations, supplementation of algae-derived DHA during late gestation and early lactation had a negative effect on lamb BW and did not affect indices of lamb thermogenesis.     

Pathology in the ovine foetus caused by an ovine pestivirus

Homogenised tissues or tissue culture supernatant fluid containing a noncytopathic pestivirus obtained from a lamb with a neurologic form of border disease, were inoculated into ewes at different stages of pregnancy. Foetal death occurred in 9 ewes of those inoculated between 19 and 47 days of pregnancy while 3 ewes did not lamb. Eight of the foetuses were aborted between 77 and 132 days of pregnancy; of these 6 were autolysed or mummified and one had arthrogryposis. The one full-term dead lamb had a hairy birth coat and lissencephalic micrencephaly. Foetal death occurred in only 7 of 14 ewes inoculated between 57 and 72 days of pregnancy. Four of these ewes aborted between 77 and 108 days of pregnancy and 3 gave birth to full-term, dead, hairy lambs. The remaining 7 ewes gave birth to live hairy lambs with severe inco-ordination. All lambs carried to term and aborted foetuses or lambs that could be examined had a range of intracranial malformations including focal leucomalacia, micrencephaly, hydranencephaly, porencephaly, lissencephaly and cerebellar hypoplasia. Some lambs also had skeletal abnormalities including arthrogryposis, scoliosis and brachygnathia inferior. The pestivirus isolate used in these trials produced more severe effects on the ovine foetus than previously observed in similar inoculation trials using pestivirus isolates from border disease lambs without nervous signs.     

Vaccination of sheep with a live incomplete strain (S48) of Toxoplasma gondii and their immunity to challenge when pregnant

Sixty-four ewes were vaccinated with tachyzoites of an incomplete strain (S48) of Toxoplasma gondii grown either in the peritoneal cavity of mice (group 1) or vero cell culture (group 2) and 30 ewes (group 3) were not vaccinated. All the ewes were mated 77 days later and challenged orally with 2000 sporulated oocysts at 89 to 90 days of gestation. Ten additional unvaccinated (group 4) and 10 vaccinated (group 5) control ewes were not challenged. The unvaccinated ewes developed a characteristic febrile response to challenge while in the vaccinated ewes the fever commenced earlier but was less severe and of shorter duration. After challenge, the antibody titres against T gondii rose rapidly to high values in the vaccinated ewes while the ewes in group 3 responded more slowly. Only eight of the 45 fetuses/lambs (17.8 per cent) from group 3 were viable compared with 72.3 per cent of those in group 1 and 80.8 per cent of those in group 2. Gestation in the unvaccinated challenged ewes was shortened and the mean birthweight of their single, viable offspring was significantly lower than the weight of single lambs from the vaccinated (groups 1 and 2) and control ewes (groups 4 and 5). Examination of precolostral sera showed that almost two-thirds of the lambs from the vaccinated ewes were infected in utero. The 20 control ewes appeared clinically normal at all times and lambed normally. The two vaccine preparations were equally effective.     

Hydrops amnii in sheep associated with hydranencephaly and arthrogryposis with wesselsbron disease and rift valley fever viruses as aetiological agents.

During the 1974/75 lambing season numerous reports were received from various parts of the Republic of South Africa and South West Africa of severe abdominal distension in ewes after vaccination with the attenuated Rift Valley fever and/or attenuated Wesselsbron disease vaccine. The ewes were vaccinated at different stages of gestation in spite of recommendations to the contrary, the syndrome being especially obvious in ewes immunized with one or both of these vaccines during the first trimester of pregnancy. In some of the flocks hydrops amnii was recorded in as many as 15% of the ewes. Many of the ewes so affected showed a prolonged gestation of up to 6-7 months and, towards the end of gestation, were unable to rise or walk. They eventually died of ketosis, hypostatic pneumonia and complications due to dystocia. The foetuses examined were malformed and larger than normal with a mass of 3,6-6,7 kg. They usually showed arthrogryposis, brachygnathy inferior, hydranencephaly, hypoplasia or segmental aplasia of the spinal cord and neurogenic muscular atrophy. The amnion contained 8,0-18,0 1 of amniotic fluid, the endometrium was oedematous, and cystic tube-like dilatations, 1-10 mm in diameter, filled with a clear fluid, were scattered in the endometrium. No definite conclusions as to the aetiology of the syndrome could be drawn from serological tests performed on the ewes, lambs or foetuses. Preliminary experimental work confirmed previous observations that the attenuated Wesselsbron disease vaccine virus is responsible for this syndrome and that the wild-type virus is also implicated. In addition, the attenuated Rift Valley fever vaccine virus was found to the responsible for arthrogryposis and hydranencephaly without hydrops amnii and for micrencephaly and arthrogryposis associated with hydrops amnii in the ewe.     

Transplacental transmission of Bluetongue virus serotype 8 in ewes in early and mid gestation

The ability of Bluetongue virus serotype 8 (BTV-8) originating from the 2006 European outbreak to cross the ovine placenta during early and mid gestation was investigated in two separate experiments. In the first experiment, 16 ewes were infected with BTV-8 at 70-75 days gestation. The foetuses were collected at 18-19 days after infection (dpi). BTV-8 could be isolated from at least two organs of 19 out of 40 lambs and from 11 out of 16 infected ewes. In the second experiment, 20 BTV-8 infected ewes in early gestation (day 40-45) were euthanized at 10 days (10 ewes) or 30 days (10 ewes) after infection. The presence of BTV could be demonstrated in two foetuses from two ewes at 10 dpi and in 4 foetuses from four ewes at 30 dpi. The main pathological findings in the foetuses in mid gestation were meningo-encephalitis and vacuolation of the cerebrum. In the foetuses early at gestation, haemorrhages in various foetal tissues and necrosis and haemorrhages in the placentomes were found. These experiments demonstrate for the first time the presence of infectious BTV in lamb foetuses at different stages of gestation, combined with a difference in transmission rate depending on the gestation stage. The high transmission rate found at mid term gestation (69%) makes our model very suitable for further research into the mechanisms of transplacental transmission and for research into the reduction of this route of transmission through vaccination.     

Trial of a novel experimental Toxoplasma iscom vaccine in pregnant sheep

Fifteen vaccinated ewes (group 1) and 13 unvaccinated ewes (group 2) were each challenged orally with 2000 sporulated Toxoplasma gondii oocysts at 91 (+/- 1) days' gestation. Another four pregnant ewes acted as unvaccinated unchallenged controls. Lamb mortality in group 1 was 36.4% after a mean gestation of 141 days while in group 2 it was 64.7% after a mean gestation of 131.5 days. These differences were not statistically significant. However, substantially more specific antibody was detected in precolostral sera from live lambs from vaccinated ewes than in live lambs from unvaccinated ewes in group 2.     

妊娠后期母羊饲粮精料比例对羔羊生长性能、消化性能及血清抗氧化指标的影响

本试验旨在研究妊娠后期母羊饲粮精料比例对羔羊生长性能、消化性能和血清抗氧化指标的影响。试验选用66只妊娠90 d、平均体重为(44.45±2.20)kg的初产湖羊,按照体重相近原则随机分为3组,每组11个重复,每个重复2只。各组母羊妊娠期饲粮精料比例分别为50%、40%和30%,分娩后母羊饲喂相同的全混合日粮(TM R)。羔羊10日龄,每只母羊取1只羔羊断母乳,饲喂代乳粉;15日龄补饲开食料;20日龄补饲苜蓿干草,自由采食至60日龄。每10 d测定1次羔羊体重,51~60日龄进行羔羊消化代谢试验,20和60日龄采集羔羊血液测定血清抗氧化指标。结果表明:妊娠后期母羊饲粮精料比例对羔羊1、10、20、30、40、50、60日龄体重,20、60日龄体尺指标及营养物质表观消化率均无显著影响(P0.05)。随母羊饲粮精料比例降低,20日龄羔羊血清总抗氧化能力(T-AOC)、超氧化物歧化酶(SOD)活性极显著升高(P0.01),60日龄50%组显著或极显著低于其他2组(P0.05或P0.01);30%组20和60日龄羔羊血清谷胱甘肽过氧化物酶(GSH-Px)活性极显著高于其他2组(P0.01);血清中MDA的含量在20日龄时随母羊饲粮精料比例的降低而极显著降低(P0.01),60日龄时50%组显著高于30%组(P0.05)。结果提示,妊娠后期母羊饲粮的精料比例对产后早期断奶羔羊的体重、体尺、营养物质表观消化率无显著影响,但随母羊饲粮精料比例的降低,羔羊血清的抗氧化能力提高。     

Effects of maternal undernutrition during early pregnancy on growth, muscle cellularity, fiber type and carcass composition in lambs

Seventy-two Rambouillet ewes were fed one of two different levels of energy and protein during gestation to determine the effects of maternal undernutrition on growth and development in their offspring. Levels of energy and protein for the two groups of ewes were: 70% of National Research Council (NRC) requirements 30 d prior to breeding and the first 100 d of gestation and then alfalfa hay fed at 70% of the average consumed by group 2, and 100% of NRC requirements 30 d prior to breeding and throughout gestation. Dissection data from the leg and muscle characteristics were recorded for each lamb. Neither dissected muscle and fat percentages nor proximate analyses of dissected muscles was influenced by ewe undernutrition during early pregnancy. However, the reduced conception rate, increased embryonic/fetal mortality, decreased birth weights and increased lamb mortality resulted in a severe reduction in kilograms of lamb per ewe bred. Feeding ewes 70% of NRC requirements during gestation resulted in lambs with heavier semitendinosus muscle weights, larger muscle fiber diameters and shorter sarcomere lengths than in lambs from adequately fed ewes. No influence of ewe diet, birth type or sex was observed for proportions of muscle fiber type (beta R, alpha R or alpha W). Therefore, low level feeding of ewes during early gestation had no detrimental effects on the carcass or muscle fiber characteristics of their lambs at slaughter.     

Evaluation of ewe and lamb immune response when ewes were supplemented with vitamin E

Fifty-two Targhee twin-bearing ewes were used in a factorial arrangement of treatments to investigate the role of supplemental vitamin E (vit E); 0 (NE) vs 400 IU of vit E x ewe x (-1)d(-1) (E) and parainfluenza type 3 (PI3) vaccination; none (NP) vs PI3 vaccination (P) in immune function. Parainfluenza type 3 vaccination was used to evoke an immune response. Ewes receiving PI3 were vaccinated at 49 and 21 d before the expected lambing date. Ewes receiving vit E were orally dosed daily, 32 to 0 d before lambing. Blood was collected from ewes at the time of the initial PI3 vaccination and 4 h postpartum. Blood was collected from lambs (n = 104) at 3 d postpartum. Ewe and lamb sera were analyzed for anti-PI3 antibody titers, immunoglobulin G (IgG) titers, and vit E concentrations. Colostrum was collected 4 h postpartum and analyzed for IgG. The model for ewe and lamb analysis included the main effects of vit E and PI3, sex (lambs model only), and their interactions. No interactions were detected (P > 0.20) for any ewe or lamb variables. Serum anti-PI3 titers were greater (P < 0.01) in P ewes and their lambs than NP ewes and their lambs. Serum vit E concentrations were greater (P < 0.01) in E ewes and their lambs than NE ewes and their lambs. Colostral IgG titers and serum anti-PI3 titers did not differ (P > 0.20) between E and NE ewes. Serum IgG titers in E ewes and their lambs did not differ (P > 0.15) from IgG titers in NE ewes and their lambs. Lamb anti-PI3 titers did not differ (P = 0.76) between lambs reared by E and NE ewes. These results indicate that, although supplemental vit E to the ewe increased lamb serum vit E concentration, it had no effect on measures used in this study to assess humoral immunity in the ewe or passive immunity to the lamb.     

The influence of colostral antibodies on the immunization of lambs against adenoviruses

The effect of colostral antibodies on the immune response in lambs following adenovirus vaccination was studied. Young lambs of different ages, born from vaccinated ewes, were vaccinated with an inactivated and aluminium hydroxide-adsorbed sheep adenovirus vaccine. In a group of lambs vaccinated at 5–7 days of age, the titre of humoral antibodies declined in parallel to unvaccinated controls. In lambs vaccinated at 24–35 days of age, antibody titres to adenovirus stabilised and persisted after an initial fall. Cell mediated immunity, as measured by blastogenic responses of circulating lymphocytes, was stimulated in both groups, but higher numbers of IgG-producing cells became evident in the group of lambs vaccinated at 24–35 days of age.     

Colostral transfer of Bacteroides nodosus antibodies in sheep.

Ovine contagious foot rot may cause lameness in sheep, resulting in decreased wool growth and low weight gain. Affected neonatal lambs are difficult to treat, and treatment is labor intensive; thus, a method of prevention is warranted. Vaccination of ewes with a multivalent vaccine in an oil adjuvant induced development of antibody to the somatic O antigen of Bacteroides nodosus, and this antibody was detected in serum of newborn lambs after consumption of colostrum from the vaccinated ewes. Antibody titers were determined in 48 unvaccinated ewe/lamb pairs, and in 50 once-vaccinated and 78 twice-vaccinated pairs. Serum and colostrum O-agglutinin titers to B nodosus were determined by a microtitration agglutination test. Lambs from vaccinated ewes had significantly (P less than 0.05) higher O-agglutinin titers than those from unvaccinated ewes, and double vaccination of ewes resulted in the highest potentially protective titers (greater than 1:2,400) in ewes and lambs.     

Teratogenicity of a mutagenised Rift Valley fever virus (MVP 12) in sheep

A 5-fluorouracil mutagenised Rift Valley fever virus strain, which was shown to be attenuated and immunogenic in cattle and sheep, was evaluated for its ability to cause teratogenic effects in pregnant sheep. A group of 50 sheep at various stages of pregnancy was inoculated with the virus and the pregnancies followed to term. There were two abortions and 14% of the lambs produced by vaccinated ewes showed teratogenic effects, the most prevalent being spinal hypoplasia, hydranencephaly, brachygnathia inferior and arthrygryposis. The foetal malformations of the central nervous and musculo-skeletal systems were mostly consistent with those observed in sheep vaccinated with the attenuated Smithburn RVF strain. The teratogenic effects of MVP12 were not seen in previous experiments by other authors as immunisation of sheep took place in the second to third trimester of pregnancy, when the foetal brain tissue has completed most of its cell division.     

Humoral immunity in the ewe. 3. The influence of adjuvants and immunisation regimes on immune reactivity in the breeding ewe and her progeny

Breeding ewes were immunised with clostridial vaccine using different inoculation schedules. Results, showing differences in the class of antibody produced, were heavily dependent on the vaccination regime used. Immunoglobulin M (IgM) levels were significantly lower in ewes given double doses of vaccine compared to ewes given a single inoculation or no treatment at all (P less than 0.01). Neonatal lambs showed significant de novo IgM production with interference in this antibody production in the lambs of ewes vaccinated with the clostridial vaccine (P less than 0.05). Immunoglobulin G1 (IgG1) levels were significantly increased in all lambs which had mothers vaccinated with the clostridial vaccine prior to or during pregnancy (P less than 0.025). The greatest quantity of IgG1 was transferred to lambs when their mothers were given a double injection with primary inoculation prior to conception and booster prepartum (P less than 0.025). No antigen specific immunoglobulin G2 (IgG2) was detected in the lambs. Ewes were also immunised with BSA and their isotype specific serum antibody response was compared with their respective lambs. There was no detectable anti-BSA IgM in the lambs of all groups of ewes though specific IgG1 antibodies could be readily detected in the lambs of hyperimmunised ewes. The efficiency of transfer was related directly to the ability of the adjuvant to maximise IgG1 production in the ewe. Although immunised ewes produced high levels of IgG2, this was not transferred passively to the lamb.     

Vaccination of ewes for prevention of vertical transmission of Neospora caninum

OBJECTIVE: To evaluate the immunologic response of a killed tachyzoite vaccine against Neospora caninum and its effectiveness in preventing vertical transmission of N caninum in sheep. ANIMALS: 40 Dorset ewes seronegative for N caninum. PROCEDURE: Group-A ewes (n = 20) were vaccinated on days 1 and 126 with a killed N caninum tachyzoite preparation in a commercially available adjuvant. Group-B ewes (n = 20) were sham vaccinated. Blood samples were collected from ewes every 2 weeks and a recombinant ELISA (rELISA) was used to determine serum antibody titers against N caninum. During pregnancy, ewes were challenged with live N caninum tachyzoites. Precolostral serum was collected from lambs and tested for antibodies against N caninum by use of an indirect fluorescence antibody test and the rELISA. Tissue specimens from stillborn lambs or lambs that died within 2 weeks of birth were collected and examined for N caninum antigen and DNA by use of immunohistochemistry and polymerase chain reaction assay, respectively. RESULTS: Serum antibody titers against N caninum were significantly higher in group-A ewes, compared with group B ewes, following vaccination. Serum antibodies against N caninum were detected in 100% (33/33) of group-B lambs and 75% (18/24) of group-A lambs. In tissue specimens, N caninum DNA was detected in 9 of 11 group-B lambs and 0 of 10 group-A lambs. Histologically, N caninum tachyzoites were observed in 4 group-A lambs and 3 group-B lambs. CONCLUSIONS AND CLINICAL RELEVANCE: The killed tachyzoite vaccine against N caninum stimulated a humoral immune response in sheep and provided partial protection against vertical transmission.     

The effects of bovine viral diarrhoea-mucosal disease (BVD) virus on the ovine foetus

Bovine viral diarrhoea-mucosal disease (BVD) virus has been incriminated as a cause of abortion, hairy birth coat and unthriftiness in sheep. Intravenous inoculation of 40 ewes 34 to 45 days pregnant with the V/TOB strain of virus produced death in two of four foetuses 9 days after inoculation and in all but one of 31 foetuses between 11 and 56 days. The highest levels of virus in placentomes and foetal tissues occurred between 9 and 15 days after inoculation and in foetal fluids between 11 and 18 days. Virus was not detected in any foetus later than 21 days after inoculation. Groups of 10 ewes infected between 59 and 62 days (Group B) and 70 and 76 days (Group C) of gestation had 73% and 62%, respectively, of abortions or perinatal foetal deaths. Birth weights of lambs born to infected ewes in groups B and C were significantly lower than those born to uninfected control ewes. Virus was recovered consistently from the cotyledons of the foetal membranes of live lambs, and irregularly from the tissues of full term foetuses that were dead at birth but on no occasion from mummified foetuses. There were no specific gross or microscopic lesions in tissues selected from aborted foetuses and the results highlight the difficulties associated with the diagnosis of BVD abortions and perinatal death of foetuses under field conditions.     

妊娠后期母羊饲粮营养水平对产后羔羊生长性能、器官发育和血清抗氧旨标的影响

本试验在干物质采食量一致条件下,改变精料补充料与饲草比例调控妊娠后期母羊饲粮营养水平,旨在研究其对产后羔羊生长性能、器官发育和血清抗氧化指标的影响.选用健康、年龄[(11.0±1.0)月龄]和体重[(44.43±2.20) kg]相近、妊娠90 d的怀双羔初产湖羊母羊66只,分为3组,每组22只.以干物质为基础按照精料补充料与饲草比例分别为5∶5(5∶5组)、4∶6(4∶6组)和3∶7(3∶7组)饲喂至产羔,产羔后各组母羊饲喂相同的全混合日粮,自由采食.出生10、60 d屠宰羔羊测定各组织器官重量,出生20、60 d采集羔羊血清测定血清抗氧化指标.结果表明:1)妊娠后期母羊饲粮营养水平对羔羊初生重、哺乳期(出生0～60 d)羔羊体重均无显著影响(P>0.05),但随营养水平降低,羔羊初生重有降低趋势(0.05≤P<0.10),出生40和50 d体重有增加趋势(0.05≤P<0.10).2)出生0d,随着妊娠后期母羊饲粮营养水平的降低,羔羊的胸深极显著提高(P<0.01),体斜长显著降低(P<0.05);出生60 d,随着妊娠后期母羊饲粮营养水平的降低,羔羊的胸深、曲冠臀长显著或极显著提高(P<0.05或P<0.01).3)出生10 d,羔羊的肝脏、肺脏的重量随妊娠后期母羊饲粮营养水平的降低而显著降低(P<0.05);出生60 d,各组羔羊的组织器官重量差异不显著(P>0.05).4)出生20和60 d,随着妊娠后期母羊饲粮营养水平的降低,羔羊血清中总抗氧化能力(T-AOC)、超氧化物歧化酶(SOD)活性、谷胱甘肽过氧化酶(GSH-Px)含量显著或极显著提高(P<0.05或P<0.01),丙二醛(MDA)含量极显著降低(P<0.01).妊娠后期通过精料补充料与饲草比例调控母羊饲粮营养水平时发现,低营养水平(低精料补充料比例)能够降低羔羊初生重,但经补偿生长作用,羔羊血清抗氧化能力得到提高,生长性能也得到恢复.     

Protection of lambs against enteric colibacillosis by vaccination of ewes

Pregnant ewes were vaccinated twice, seven weeks and three weeks before lambing, with a multivalent formalin-killed Escherichia coli vaccine containing an added K99, F41 antigen preparation. Lambs born to vaccinated and unvaccinated ewes were exposed to oral infection with E coli B44 (09:K30, K99, F41). All 10 lambs from vaccinated ewes were protected whereas all 10 control lambs developed severe diarrhoea and five died or were killed in extremis. In the following year, previously immunised ewes were given a single dose of the vaccine two weeks before lambing. Eleven of their 12 lambs were protected against a similar challenge, which caused the death of six of eight control lambs and severe diarrhoea in the two survivors. Higher levels of antibody to the K99, F41 preparation were detected by enzyme-linked immunosorbent assay in the serum and colostrum from vaccinated ewes and in the serum of their lambs when compared with similar samples from control ewes and lambs.     

The effect of high calcium intake by pregnant Awassi ewes at late gestation on minerals status and performance of ewes and newborn lambs

Calcium (Ca) requirement increase rapidly by pregnant ewes at late gestation as a result of high fetal growth. Furthermore, Ca deficiency results in poor growth and bone development in growing newborn lambs. The aim of this study was to evaluate the effect of calcium supplementation (Calcium carbonate–CC) and vitamin AD₃E injection (75,000 IU/shot) to pregnant Awassi ewes at late gestation (− 45 days prepartum) on their mineral levels and performance of their newborn lambs. Forty pregnant Awassi ewes at late gestation (65 ± 6.1 kg) were selected before parturition (− 45 days; using hormonal sponges for estrus synchronization) and randomly divided to 4 dietary treatments. The treatments were: group 1 Control (1.4% CC); group 2 (2.4% CC); group 3 (1.4% CC + 2 shots vitamin AD3E at − 45 and − 21 days prepartum); group 4 (2.4% CC + 2 shots vitamin AD3E at − 45 and − 21 days prepartum). Blood samples were collected from ewes (− 45, 0 days prepartum: 30 and 60 days postpartum) and lambs (0, 30 and 60 days old). Average milk yield and samples were collected. Body weights of lambs were taken at birth, 30 and 60 days old. Blood serum and milk samples were prepared and analyzed by AAS for Ca, Mg, Co, Mn and Cu concentrations.Calcium concentrations in bloods serum of ewes, 0 and 60 days postpartum, and lambs at weaning (60 days old) from group 4 were significantly (P < 0.05) higher compared to other groups. No significant effect (P > 0.05) of treatment on Co, Mg and Cu in blood serum of ewes and lambs except for Cu concentration in ewes. Moreover, a significant increase (P < 0.01) in milk inorganic% (30 and 60 days samples) in ewes from group 2 when compared with other groups. The average milk yield (AMY) of ewes from group 2 and 4 at late stage of lactation (45–60 days) were significantly higher (P < 0.05) compared to groups 1 and 3. In addition, Ca% in colostrums samples from ewes in groups 2 and 4 were significantly higher (P < 0.01). The average daily gain (ADG) and total body gain for lambs up to weaning (60 days old) were significantly higher (P < 0.05) in groups 1 and 2 compared with the other groups.In conclusion, increasing level of Ca intake in feed of Awassi ewes at late gestation, with or without vitamin AD₃E injections, improve the calcium concentration in colostrums and blood serum of ewes and their lambs without negative effect in their health and performance.     

Akabane disease in sheep

Perinatal lamb mortality, associated with malformations of the CNS due to Akabane viral infection, occurred in 4 of 9 flocks of ewes lambing on 3 farms between 26 May and 14 November, 1976. Cases were restricted to ewes conceiving prior to the second week of March and lambing between 26 May and 19 July. As judged by seroconversion in sentinel flocks on 2 of the farms, field infection with Akabane virus occurred mainly between mid-February and mid-April. Malformations of the CNS occurred in 42.5%, 51.2%, 100% and 31.0% of the dead lambs examined in the affected flocks respectively. Prevalence in the 4 affected flocks, expressed as the proportion of ewes lambing which delivered at least one malformed foetus, was 6.1%, 8.4%, 88.9% and 5.7% respectively. Lamb mortality due to malformations of the CNS was 7.1%, 5.5%, 92.3% and 5.7% of lambs born. Age-specific prevalence was calculated for 3 of the 4 flocks and 2-year-old ewes accounted for 71.4% and 76.9% of total cases respectively in 2 flocks, whereas in one flock malformations occurred at equivalent frequencies throughout several older age groups. Birthweights of affected lambs were usually significantly lighter than those of unaffected lambs of similar sex and birth-type, and their mean duration of gestation was slightly, and significantly, prolonged. Micrencephaly (88.1% of cases) and hydrocephalus (68.7% of cases) were the outstanding pathological features of the malformations with hydranencephaly, microgyria, porencephaly and attenuation of the spinal cord occurring at much lower frequencies.(ABSTRACT TRUNCATED AT 250 WORDS)     

A survey on the incidence and cause of ovine abortion in Hawkes Bay

The results of a postal survey which yielded a 57% response and which examined the incidence and cause of abortions in central Hawkes Bay flocks, is presented. Data were provided from a total of 3,952,000 ewes from 1975-80. Overall, highly significant differences in the incidence of abortion were recorded between properties (range 0-16%); years (1975-0.86%, 1976-0.75%, 1977-0.86%, 1978-2.42%, 1979-2.78%, 1980-2.04%); ewe age (maiden 2-year -5.3%, mixed age -1.6%);flock size (higher incidence in smaller flocks); and winter management systems (of the flocks which were experiencing greater than a 2% abortion rate, 73.2% were being rotationally mob stocked during the winter compared with only 23.8% being set stocked). Bacteriological examination of aborted lambs during 1979 revealed that Campylobacter spp. were involved exclusively. In the 1980 survey, only half of the lambs examined showed Campylobacter infection, the other half yielding Toxoplasma either as pure or mixed infections. The results of a trial which utilised 10,592 2-year ewes demonstrated significant differences between animals vaccinated with a killed Campylobacter vaccine and non-vaccinated controls in the following reproductive parameters: ewes aborting, dry dry ewes, total lambs born and lambs marked.