Usefulness of clinical observations and blood chemistry values for predicting clinical outcomes in dairy goats with pregnancy toxaemia

Background

Pregnancy toxaemia (PT) is a disease that affects pregnant goats during their last month of gestation and is characterized by a high case fatality rate. This study involved 32 does maintained on a commercial dairy goat farm that were diagnosed with PT. A physical examination was performed on and haematology parameters obtained from each doe, at the time of diagnosis. The data from the 24 PT goats that died was compared with the corresponding data from the 8 PT goats that survived.

Results

Polypnea, swollen limbs, anorexia with absence of ruminal motility, recumbency, nervous signs and drooping ears were the most frequently observed clinical manifestations. Nineteen out of 21 recumbent goats died. Sixteen out of 17 goats with anorexia and absence of ruminal motility died. Mean beta-hydroxybutyric acid (BHBA) values in the goats that died were not significantly different from those in goats that survived. The blood values for pH and pCO₂ (p?<?0.005) as well as for HCO₃ ^?, BE and K⁺ (p?<?0.001) were significantly lower in the goats that died than in those that survived.

Conclusions

The clinical signs most indicative of a poor prognosis are anorexia with absence of ruminal motility and recumbency. Among the blood parameters to be considered, hypokalaemia and metabolic acidosis are the most relevant. Goats with PT have a high mortality and their condition can deteriorate very fast. Based on the authors’s experience, a good strategy to minimize the economic losses caused by PT is to focus on the offspring survival rate since an early decision (induction of kidding or caesarian surgery) can increase the number of alive kids.

     

Feeding corn during the last 12 days of gestation improved colostrum production and neonatal activity in goats grazing subtropical semi-arid rangeland

The objectives were to investigate if partial substitution of a grazing diet with a supplemental high-starch feed during the last 12 d of gestation improved colostrum yield and neonatal activity in goat does grazing semi-arid rangeland. For the first objective, 25 pregnant does were randomly assigned to 1 of 2 treatments: 1) grazing only (control; n = 11), and 2) grazing plus 0.6 kg/d of supplemental corn (as fed), a high starch feed, during the last 12 ± 1.0 d before parturition (SC; n = 14). Colostrum was collected at parturition and again at 1, 3, 6, and 10 h postpartum for yield and composition. In all goats, blood concentrations of glucose and plasma progesterone were determined. Total colostrum yield/10 h was greater (P = 0.002) in the SC does (1,102 ± 144 g) than in control does (405 ± 50 g). From 6 to 10 h postpartum, contents of colostrum protein and solids not fat were less (P ≤ 0.012) whereas lactose contents were greater (P = 0.035) in the SC does than in control does. Concentration of glucose in the blood at parturition was greater (P = 0.037) in the SC does (160 ± 13 mg/dL) than in control does (115 ± 12 mg/dL). A significant decrease (P = 0.001) in plasma progesterone concentrations occurred 1 d before parturition in control does, whereas the decrease (P = 0.008) occurred 3 d before parturition in SC does. For the second objective, 20 does (10 per group) and their single kids were randomly assigned to the same treatments as above for evaluation of dietary treatment on neonatal activity. Kid activity was assessed using videos recorded during the first 90 min after birth. Frequency of low-pitched bleats was greater (P < 0.001) in kids of SC does than in kids of controls. Frequencies and durations of teat seeking from 30 to 90 min after birth and of suckling activity were greater (P ≤ 0.015) in kids of SC does than in kids of controls. Duration of parturition was longer (P = 0.001) in control does (58 ± 10.2 min) than in SC does (21 ± 2.8 min). Finally, percentage of fetal malpresentation was greater (P = 0.036) in control does (33.3%) than in SC does (9.0%). We conclude that partial substitution of the grazing diet with a high-starch feed, corn, during the last 12 d of gestation improved colostrum yield and neonatal activity in goats grazing subtropical semi-arid rangeland.     

Economic contribution and viability of dairy goats: implications for a breeding programme

To augment the incomes of smallholder farmers in Kenya and consequently improve their nutrition and income, many development organisations and policy makers are increasingly promoting dairy goat farming. Among the key organisations supporting the initiative is Heifer Project International—Kenya (HPIK). However, the economic contribution and viability of dairy goats under the HPIK project have not been studied so far. The aim of the present study was to determine the contribution of dairy goats to household income and the performance of the dairy goat enterprise using gross and net margins from dairy goat farming as an indicator of economic viability. A survey covering 71 farmers was carried out in the Coast, Nyanza, and the Rift Valley provinces of Kenya using a set of pre-tested structured and semi-structured questionnaires. Results showed that, on average, the dairy goat enterprise contributed, correspondingly, about 15.2% and 4.8% to the total livestock and overall household income and was viable. Differences in gross and net margins across agroecological zones were attributed to milk prices. Despite the existence of non-viable enterprises in two of the provinces, the few present suggest the possibility of obtaining reliable incomes from the enterprise. Redoubling of effort or re-orientation of production to match the local and external requirements would, however, be necessary. Costs and revenues were similar across the agroecological zones. Farmers with positive gross margins had better milk and stock sales and vice versa. The success of a dairy goat enterprise is attributed to location and good management. Besides, farmers’ awareness of the market demands within and outside the community is important in establishing production goals and may be crucial to achieving a positive gross margin.     

Energetic-protein supplementation in the last 60 days of gestation improves performance of beef cows grazing tropical pastures

Background: Nutrition is one of the most important factors that affect animal performance, and it therefore also impacts on financial results in beef systems. In this way, finding the best strategy for feeding supplements is of paramount importance. Aiming to evaluate the effect of supplement feeding strategies for beef cows in the last third of gestation, two experiments were conducted. In Experiment 1, 35 pregnant Nellore cows were assigned to a completely randomized design with four treatments: control, which received no supplement; supplementation for the last 30 d of gestation(30-d; 3.0 kg/d); supplementation for the last 60 d of gestation(60-d; 1.5 kg/d); or supplementation for the last 90 d of gestation(90-d; 1.0 kg/d). All supplemented treatments received the same total amount of supplement throughout the experiment: 90 kg(20% of crude protein). A second experiment(Experiment 2) was delineated to evaluate the effects of the amounts offered in Experiment 1 on intake and metabolism. Four multiparous pregnant Nellore cows were assigned to a 4 × 4 Latin square design, with periods of15 d each.Results: There was a linear effect of the number of days of supplementation on calving body weight(BW; P 0.05)and a quadratic effect on BW change from parturition to d 31 post-calving(P 0.05), with cows on the 60-d strategy losing less BW post-calving. No difference was found in offspring birth BW(P 0.10). A significant linear effect on interval from parturition to conception(P 0.05) was observed, with the highest calving to conception interval being observed in the 90-d strategy. The level of supplementation did not affect forage intake or neutral detergent fiber digestibility(P 0.10). Nitrogen excreted through urine tended to increase linearly with the level of supplementation(P 0.10).Conclusion: Providing 1.5 kg of supplement during the last 60 d of gestation improves cow performance after calving, reducing the magnitude of BW lost, and reduces the number of days from calving to re-conception in the following breeding season compared to the usually recommended period of supplementation of 90 d pre-partum.     

Associations of Neospora caninum seropositivity with gestation number and pregnancy outcome in Danish dairy herds.

The prevalence and distribution of seropositivity towards the protozoan parasite Neospora caninum were studied in single blood samples from 1561 cows from 31 Danish dairy herds. Blood samples were analysed by an indirect enzyme-linked immunoassay and an indirect fluorescent-antibody test. Seroprevalence in 15 herds with previous abortions assigned to neosporosis ranged from 1% to 58%, with a mean frequency of 22%. In eight out of 16 herds without a history of N. caninum related abortions, no seroreactors were found. In the remaining eight herds, the seroprevalence ranged from 6% to 59%. The prevalence and distribution of seropositivity, gestation number prior to sampling, and breed were related to abortions and perinatal deaths using a random-effects logistic-regression model. Abortion risk was significantly increased in seropositive animals (OR=3) and in 2nd-gestation cows (OR=3). Perinatal death was significantly influenced by gestation number and breed, but not by serostatus. Reproductive performance and culling risk of cows were not affected by serostatus. Seropositivity increased with “age” (i.e. gestation number) (P=0.02). In open cows, seropositivity tended to decrease with distance from calving (P=0.05). The proportion of seropositive pregnant cows increased with trimester (P=0.02).     

Abortion and stillbirth among dairy goats as a consequence of Coxiella burnetii

The clinical signs and pathological findings of clinical Q fever in dairy goats in the Netherlands are described. The disease is characterized by endemic or epidemic abortion in late pregnancy, stillbirth, or the birth of weak kids. These consequences of Coxiella burnetii infection appear to have increased during recent years in the Dutch dairy goat population. Detection of the agent in placental tissue by immunohistochemistry has proven diagnostically useful.     

Influence of sex steroids on the viability and CD11b, CD18 and CD47 expression of blood neutrophils from dairy cows in the last month of gestation

In the period around parturition, cows experience an increased susceptibility for the development of Escherichia coli mastitis. This increased susceptibility has been correlated with a decreased functionality of neutrophils. In the current study, it is suggested that the decreased neutrophil functionality may be induced by the extensive alterations in sex steroid levels occurring around parturition. It was first hypothesized that 17beta-estradiol and progesterone influence the viability, apoptosis and necrosis of blood neutrophils from cows in their last month of gestation. Subsequently, it was hypothesized that 17beta-estradiol modulates the expression of CD11b, CD18 or CD47 thereby explaining its influence on the migration of bovine neutrophils. Neither 17beta-estradiol nor progesterone significantly influenced viability, apoptosis or necrosis in spontaneous apoptosis conditions. However, when apoptosis was induced with TNF-alpha and gliotoxin, progesterone exerted a survival effect (P<0.05). In addition, 17beta-estradiol treatment of bovine blood neutrophils significantly decreased the expression of CD47 (P<0.05) but not of CD11b or CD18. It can be concluded that 17beta-estradiol and progesterone do not affect spontaneous apoptosis of bovine blood neutrophils while a survival effect was observed for progesterone on induced neutrophils apoptosis. Moreover, our results concerning the influence of 17beta-estradiol on the CD11b, CD18 and CD47 expression extend previous demonstrations of the suppressive effect of 17beta-estradiol on neutrophils migration and indicate that the altered expression of CD47 may contribute to this phenomenon.     

Changes in plasma progesterone concentrations from days 17 to 42 of gestation in mares maintaining or losing pregnancy

Plasma progesterone concentrations were measured in 179 mares bled on alternate days commencing with a positive pregnancy diagnosis on Days 17 to 18 after ovulation and concluding on Days 42 to 45. During this period 17 mares (10 per cent) lost their pregnancies, 11 before Day 25. In 15 mares the timing of the pregnancy loss could be determined with adequate accuracy; in only one did a decline in progesterone precede the loss. Thus pregnancy loss between Days 17 and 42 was rarely caused by a fall in plasma progesterone.     

Induction of sexual activity in lactating anovulatory female goats using male goats treated only with artificially long days

Two experiments were conducted to determine the response of Creole male goats treated with long days and melatonin implants, and the response of the anovulatory does to male effect using males treated only with artificially long days. All animals were allocated to open sheds. In Exp. 1, one group of males was under natural photoperiod (CG; n = 7); the second group was submitted to 2.5 mo of long days followed by the insertion of two s.c. melatonin implants (LD+MEL; n = 7); the third group was subjected only to 2.5 mo of long days (LD; n = 7). Testicular weight was measured every 2 wk. Plasma testosterone concentrations were determined weekly. A treatment x time interaction was detected (P < 0.001) for testicular weight and plasma testosterone concentration. In the LD+MEL and LD groups, testicular size and plasma testosterone levels varied in a similar way, but differed from those observed in CG (P < 0.001). In this latter group, testicular weight displayed seasonal variations and peaked in June, whereas in treated groups this peak occurred in March. In CG, testosterone varied in a seasonal manner and plasma concentrations increased in June and remained elevated throughout the study. In experimental groups, testosterone increased in February and peaked in March. In Exp. 2, one group of males was left under natural photoperiod (CG, n = 5) and the other one was submitted to 2.5 mo of artificially long days (LD, n = 4). On March 16, two control and two treated males were put in contact with 20 and 19 females, respectively. Sexual behavior of the bucks was observed during the 5 d following male introduction. Progesterone assays and estrous behavior were used to determine ovarian and behavioral responses of the females to teasing. The anogenital sniffing, nudging, and mount instances registered in LD-treated males were greater than those observed in CG (P < 0.05). Of the does exposed to CG, none ovulated and only two of 20 females displayed estrous behavior. All does in contact with LD-treated males ovulated and showed at least one estrous behavior during the 15 d following joining (P < 0.001). These results indicate that the sexual activity of male goats from subtropical latitudes can be induced using only artificially long days. In addition, males treated in this way are capable of stimulating sexual activity in anovulatory females by the male effect.     

Field efficacy of eprinomectin against a natural Muellerius capillaris infection in dairy goats

The field efficacy of eprinomectin against a natural infection with Muellerius capillaris was evaluated in adult dairy goats. A total of 13 animals were included in a crossover treatment study. Animals were treated with eprinomectin (0.5 mg/kg) in the spring and again in the autumn of 2006, and monitored by enumeration of the lungworm larvae per gram of faeces (LPG). The reduction in LPG on days 7, 21 and 42 after treatment was used to evaluate the anthelmintic efficacy. Both in the spring and in the autumn a 100% reduction (P<0.01) in LPG was observed on days 21 and 42. These results illustrate that eprinomectin applied as a topical pour-on is a practical alternative to benzimidazole treatment of lungworms in dairy goats. No adverse reactions to the eprinomectin treatment were observed.     

Direct and indirect measurement of somatic cell count as indicator of intramammary infection in dairy goats

Background

Mastitis is the most important and costly disease in dairy goat production. Subclinical mastitis is common in goats and is mainly caused by contagious bacteria. Several methods to diagnose subclinical mastitis are available. In this study indirect measurement of somatic cell count (SCC) by California Mastitis Test (CMT) and direct measurement of SCC using a portable deLaval cell counter (DCC) are evaluated. Swedish goat farmers would primarily benefit from diagnostic methods that can be used at the farm. The purpose of the study was to evaluate SCC measured by CMT and DCC as possible markers for intramammary infection (IMI) in goats without clinical symptoms of mastitis. Moreover to see how well indirect measurement of SCC (CMT) corresponded to direct measurement of SCC (DCC).

Method

Udder half milk samples were collected once from dairy goats (n = 111), in five different farms in Northern and Central Sweden. Only clinically healthy animals were included in the study. All goats were in mid to late lactation at sampling. Milk samples were analyzed for SCC by CMT and DCC at the farm, and for bacterial growth at the laboratory.

Results

Intramammary infection, defined as growth of udder pathogens, was found in 39 (18%) of the milk samples. No growth was found in 180 (81%) samples while 3 (1%) samples were contaminated. The most frequently isolated bacterial species was coagulase negative staphylococci (CNS) (72% of all isolates), followed by Staphylococcus aureus (23% of all isolates). Somatic cell count measured by DCC was strongly (p = 0.000) associated with bacterial growth. There was also a very strong association between CMT and bacterial growth. CMT 1 was associated with freedom of IMI while CMT ≥2 was associated with IMI. Indirect measurement of SCC by CMT was well correlated with SCC measured by DCC.

Conclusions

According to the results, SCC measured with CMT or DCC can predict udder infection in goats, and CMT can be used as a predictor of the SCC.     

Control of gastrointestinal parasitism with nematodes in dairy goats by treating the host category at risk

Infections of the gastrointestinal tract with parasitic nematodes remain one of the main limiting factors in grazing dairy goats. The usual mode of control of these parasitic diseases has up to now been based on the repeated use of anthelmintics. However, the prevalence rates of anthelmintic resistances, in particular to benzimidazoles, are now particularly high in the French dairy goat production. This situation makes it mandatory to reconsider the usual mode of control of these nematodes and to look for short term, alternative solutions which combine the control of gastrointestinal infections and management of anthelmintic resistances. One of the possible options is to leave a part of the flock without treatment during the grazing season in order to maintain alleles of susceptibility to anthelmintics within the worm populations. Previous epidemiological observations identifying the categories of host populations at risk are presented which provide the rationale for targeted applications of treatments. The results of assays on experimental flocks and from farm surveys examining the advantages and drawbacks of selective treatments are presented. The value of these results in combination with other alternative solutions of control are discussed in order to use minimum treatments with maximum benefits.     

Genetic and environmental factors associated with nematode infection of dairy goats in northwestern France

The helminth parasitism (strongyles and Muellerius) of dairy goats was investigated in commercial farms of northwestern France. The study was undertaken in spring (n = 263 goats) and autumn (n = 165); the breed, age, polledness, absence or presence of wattles, and reproductive status were recorded for each goat. The faecal output of strongyle eggs was significantly related to breed, polledness, presence of wattles and age. The faecal output of first stage larvae of Muellerius was correlated with breed, age and pregnancy.     

Prevalence of microorganisms associated with udder infections in dairy goats on small-scale farms in Kenya

Six hundred and thirty clinically-normal milk samples from dairy goat flocks comprising a mixed population of German Alpine, Toggenburg, Saanen and Galla crosses were examined over a 3-month period to determine the prevalence of bacterial organisms. Bacteria were isolated in 28.7% of the milk samples (181/630) either singly (92.8%) or in combination (7.2%). The most prevalent bacterial organisms were Staphylococcus spp. (60.3%), followed by Micrococcus spp. (17.7%), Acinetobacter spp. (5%), Actinomyces spp. (5%) and Streptococcus spp. (1.1%). The Staphylococcus spp. were mainly coagulase negative (64.3%). Coagulase-negative staphylococci and coagulase-positive staphylococci accounted for 37.5% and 22.7% respectively of the total bacteria isolated. The isolation of bacteria, some of which are important in clinical and subclinical mastitis, in apparently normal caprine milk, indicates that particular attention should be given to the management of these dairy goat flocks in order to avoid the development of cases of clinical mastitis.     

Electrocardiographic confirmation of a twin pregnancy in a mare at 8 months of gestation

A 15-year-old Warmblood mare, at 8 months of gestation, was presented to the Ghent University Faculty of Veterinary Medicine for evaluation of suspected stage one labor. Transrectal ultrasonography revealed no clear signs of placentitis or stage one labor. The combined thickness of uterus and placenta was 11 mm and the cervix was closed. Twin pregnancy was suspected by transabdominal ultrasonography but could not be confirmed with certainty. An electrocardiogram (ECG) was recorded from the mare's abdominal wall to register a fetal ECG. To confirm twin pregnancy, registration of both fetal ECGs simultaneously on the same ECG trace was attempted. Twelve different electrode configurations were used. In 11 recordings, one fetal ECG was visible. Only one specific right-sided electrode configuration showed both fetal ECGs at the same time, which confirmed twin pregnancy. Although electrocardiographic diagnosis of a twin pregnancy in a mare is possible, this case highlights the need for multiple electrode configurations and the high likelihood of false negatives.     

Inhibition of prolactin in the last trimester of gestation decreases mammary gland development in gilts

Prolactin is required for mammary development in various species but its possible role for mammogenesis in pigs is not known. The goal of the present study was therefore to determine the effect of prolactin inhibition by bromocriptine during the last third of gestation on mammary gland development in gilts. Twenty-eight primigravid gilts were assigned as controls (n = 15) or received 10 mg of bromocriptine orally thrice daily (n = 13) from d 70 to 110 of gestation. Jugular blood samples were collected on d 70 of gestation and every 8 d thereafter and were assayed for prolactin, IGF-I, estradiol, and progesterone. Gilts were slaughtered on d 110 of gestation and fetuses were counted and weighed. One row of mammary glands was used for dissection of parenchymal and extraparenchymal tissues and for determination of DNA, RNA, dry matter, protein, and fat contents. Tissue from the other row was used for measures of prolactin receptor number and affinity. Concentrations of prolactin were drastically reduced throughout the bromocriptine treatment period (P < .001), whereas there was no overall treatment effect on progesterone and IGF-I levels (P > .10). Total weight and extraparenchymal tissue weight of the mammary glands were unaffected by treatment (P > or = .1), but weight of parenchymal tissue, total DNA, and total RNA decreased (P < .01) with bromocriptine treatment. Percentages of fat and dry matter in parenchymal tissue increased with bromocriptine treatment (P < .01) and the percentage of protein decreased (P < .01). Number of prolactin receptors in parenchymal tissue decreased with bromocriptine treatment (P < .001) and receptor affinity increased (P < .001). Average fetal weight was lower in gilts receiving bromocriptine than in control gilts (P = .05), but fetal number did not differ (P > .1). These results clearly demonstrate that prolactin is essential for normal mammary gland development and can affect fetal growth during the last third of gestation in gilts.     

Subcellular distribution of copper in the liver of fetal deer in the last month of gestation

Fetal deer, in the last month of gestation, accumulate high concentrations of copper in the liver. Livers from fetal deer in late gestation were homogenised and fractionated by continuous sucrose density gradient centrifugation. The distribution of copper closely followed that of DNA; approximately two thirds of the metal was localised to the nuclear fractions with the remaining third in the cytosolic fractions. The fractionation procedure was repeated with digitonin, a lysosomal perturbant: lysosomes were disrupted and the marker enzyme, N-acetyl-beta-glucosaminidase, shifted from the particulate fractions to the cytosolic fractions; the distribution of copper was unaffected. Differential centrifugation of homogenate confirmed that approximately two thirds of the copper was associated with the nuclear fraction. Further confirmation of a nuclear localisation of copper was provided by X-ray microanalysis of purified nuclei.     

Evaluation of detomidine as a sedative in goats.

Intramuscular (i.m.) and intravenous (i.v.) administration of detomidine at doses of 10, 20 and 40 micrograms/kg body mass was evaluated for its sedative and analgesic properties in 15 goats (Capra hircus). The drug produced dose- and route-dependent sedation. The 10 micrograms/kg dose was effective only when administered i.v. There was no observable analgesia at this dose. Higher doses produced effective sedation and moderate analgesia of the body with either route of administration. Severe ataxia and sternal recumbency were seen in all the animals after the dose of 40 micrograms/kg. Other effects of detomidine in these goats included mild to moderate salivation, depressed respiratory rate, decreased rectal temperature, bradycardia and hyperglycaemia. Plasma concentrations of total protein, sodium, potassium and chloride were not affected.