Seasonal changes in nutritional status and reproductive performance of Zebu cows kept under a traditional agro-pastoral system in Tanzania.

The objectives of this study were to assess changes in nutritional status/body condition score, percentage pregnancy and calving rate in Zebu cows and to establish the relationship between body condition score loss and postpartum interval to resumption of ovarian activity. A total of 198 cows and postpubertal heifers of the Tanzanian Shorthorn Zebu kept under a traditional management system were randomly selected from 200 smallholder herds. Factors investigated during bi-weekly visits include body condition score (BCS), heart-girth circumference, milk yield and reproductive status of the animals, pregnancy/nonpregnancy and cyclicity/non-cyclicity. Local weather conditions and dates of occurrence of other reproductive events such as calving were also recorded. Calvings occurred all year round but with a strong seasonal distribution characterized by annual peaks observed between April and July. The annual calving pattern was closely related to rainfall, with peak precipitation occurring a few months before peak calving. The overall percentage pregnancy varied from 30% to 50% throughout the year. Postpartum cows exhibited minimum mean BCS and heart-girth circumference 12-14 weeks after calving, and cows with BCS loss >1 point exhibited the longest time interval from calving to onset of ovarian activity.

Comparison of the effects of atipamezole and tolazoline on analgesia, cardiopulmonary and rectal temperature changes induced by lumbosacral epidural injection of medetomidine in goats.

The present study was carried out in order to compare the reversing effects of alpha(2)-adrenergic receptor antagonists, atipamezole and tolazoline on analgesia, cardiopulmonary depression and rectal temperature changes induced by epidural administration of medetomidine in goats. Eight clinically healthy, small East African goats of both sexes weighing between 12 and 17kg (mean 14.4+/-1.8kg) were used in this study. The animals were randomly divided into two groups of four animals. The first group was given 20µg/kg medetomidine followed by intravenous (IV) administration of 80µg/kg atipamezole, 30min after the initial injection. The second group was given same treatment for medetomidine as group one but followed by IV administration of 2.2mg/kg tolazoline, 30min after the initial injection. In both treatment groups, medetomidine was administered epidurally through the lumbosacral interspace. Analgesia of the flank and perineum was evaluated at every 10min intervals up to 60min. The cardiopulmonary and rectal temperature values were monitored and recorded at every 5min interval up to 60min. In both groups, lumbosacral epidural injection of medetomidine induced generalised analgesia, variable cardiopulmonary depression effects and non-significant changes on rectal temperature. These changes developed as early as 5min and continued until alpha(2)/alpha(1) antagonists were administered. Intravenous administration of alpha-adrenergic receptor antagonists; atipamezole and tolazoline reversed analgesia, cardiopulmonary and rectal temperature changes induced by lumbosacral epidural injection of medetomidine in goats. However, atipamezole appeared to be superior (P<0.05) to tolazoline. From this study, it was concluded that IV administration of 80µg/kg atipamezole was better than 2.2mg/kg tolazoline in reversing analgesia and cardiopulmonary depression effects induced by lumbosacral epidural injection of medetomidine in goats. This indicates the superiority of atipamezole to tolazoline as an antidote for medetomidine induced effects in goats.

Analgesic, behavioural and cardiopulmonary effects of epidurally injected medetomidine (Domitor) in goats.

This study was carried out in order to evaluate the analgesic, sedative, immobilizing and cardiopulmonary effects of medetomidine in goats after lumbosacral epidural injection of three (10, 20 and 30 micrograms/kg body weight) doses. The volume of the injection for all three medetomidine doses was 5 ml in sterile water. Seventeen clinically healthy, Small East African goats of either sex and weighing between 12 and 22 kg (mean +/- SD; 14.8 +/- 2.5 kg body weight) were used. The animals were randomly assigned to two groups. Seven goats were used for evaluating analgesic, behavioural and cardiopulmonary effects while 10 were used for experimental surgery. The cardiopulmonary values and rectal temperature were determined and recorded at time 0 (preinjection) and at 5, 10, 15, 20 and 30 min, and thereafter at 15-min intervals up to 180 min after injection. Analgesia of the flank and perineum was determined at time 0 (preinjection) and at 5, 10, 15, 30, 60, 120 and 180 min using a scoring system. The spread of analgesia to the thorax, neck, forelimbs and head was also determined and recorded. The onset and duration of lateral recumbency was noted and recorded. Medetomidine at the given doses induced variable cardiopulmonary depression, which was not detrimental to the animals. All three doses (10, 20 and 30 micrograms/kg) of medetomidine induced adequate analgesia of the flank and perineum. Analgesia extended to the thorax, forelimbs, neck and head. The duration of lateral recumbency was 136 and 166 min for the 20 and 30 micrograms/kg medetomidine doses, respectively. The duration of lateral recumbency was not determined for the animal given 10 micrograms/kg medetomidine. Signs of sedation (lowering of the head, drooping of the lower lip, partial to complete closure of the eyes and salivation) were noted after administration of all three doses. It can be concluded from this study that all three doses induced adequate analgesia of the flank and perineum. Surgical analgesia of the flank of goats was achieved after lumbosacral epidural administration of 20 micrograms medetomidine/kg, diluted in 5 ml of sterile water. Surgery was not performed with the other doses (10 and 30 micrograms/kg) of medetomidine.

Suboptimal reproductive performance of dairy cattle kept in smallholder herds in a rural highland area of northern Tanzania.

The objectives of the present study were to assess the reproductive performance and cumulative incidence risk of reproductive disorders and to compare the success of artificial insemination (AI) to natural service (by handmating; NS) in dairy cattle kept in smallholder herds under a zero-grazing system in a rural highland area of Tanzania. Data on occurrence of all normal and abnormal reproductive events were collected for 215 adult animals belonging to 74 households. The median and range of the intervals: intercalving, calving to first service, and calving to pregnancy were 477 (335-860), 154 (38-486) and 206 (61-567) days, respectively. Breed and parity did not affect the reproductive parameters (P>0.05). However, cows in the milked group had a shorter median calving interval than those in the suckled group (P<0.001). The overall percentage pregnant and the percentage pregnant to first service were higher in the NS than in the AI group (49 vs. 32%; P=0.007) and (67 vs. 25%; P<0.001), respectively. The median numbers of services per pregnancy were not different between the AI (3) and NS (2) groups (P=0.17). The cumulative incidence risk of abortion, dystocia, prolapse, retained fetal membranes, mastitis, milk fever and cyclic non-breeders were 16.0, 1.7, 2.5, 4.2, 5.0, 1.7, and 6.1%, respectively. Hoof overgrowth (4.6%) and hoof deviation (4.6%) were the most-frequent digital problems. We concluded that reproductive parameters and cumulative incidence risk of abortion show suboptimal reproductive performance in rural-based, zero-grazed smallholder dairy herds in Tanzania particularly those using AI.

Comparison of xylazine and lidocaine effects for analgesia and cardiopulmonary functions following lumbosacral epidural injection in goats.

The present study was carried out in order to compare the effects of xylazine and lidocaine on analgesia and cardiopulmonary parameters following epidural injection in goats. Twelve healthy Small East African goats of both sexes (mean +/- SD; 15.6 +/- 1.9 kg body weight) were used. The goats were randomly assigned to two groups of five and seven animals. The first group (n = 5) was given 2% lidocaine-HCl at 4400 micrograms/kg body weight. The second group (n = 7) was administered 2% xylazine-HCl at 150 micrograms/kg body weight. All drugs were diluted in 5 ml of sterile water and were injected epidurally through the lumbosacral interspace with the injection taking over 20 s. Both drugs induced analgesia within 5 min. Signs of sedation, cardiopulmonary changes and lateral recumbency developed within 5-7 min after administration of epidural xylazine. Tail flaccidity and hind limb paralysis developed 3 min after epidural administration of lidocaine. The time from recumbency to regaining normal stance was 60 and 158 min for xylazine- and lidocaine-treated animals respectively. Xylazine induced adequate analgesia of the flank and perineum, which extended to the head and forelimbs. In contrast, lidocaine induced adequate bilateral flank and perineal analgesia extending up to the third thoracic vertebra. For both drugs, analgesia of the flank and perineum persisted for the entire 180-min observational period. Epidural injection of xylazine and lidocaine caused variable depression effects on the cardiopulmonary values but was not so low as to cause concern. It is concluded that lumbosacral epidural injection of xylazine at 150 micrograms/kg body weight in 5 ml of water for injection offers the most desirable sedation and analgesia of the flank and perineum. The longer duration of analgesia may be useful for postoperative analgesia and relief of continuous straining in goats.

The sequelae of fragmented anconeal process (FAP) lesion in pigs: a radiologic, macroscopic and histopathological investigation.

The development of the anconeal process its lesions and their sequelae were scrutinized during the follow-up radiographic study (every 5 months) of porcine osteochondrosis of elbow joint bones done in 80 Danish Landrace pigs from day 42 of age to 38 months of age. The anconeal process was observed radiologically to be ossified at the age of between 6 to 7 months. Normally it ossifies by pyramidal extension from the proximal ulna. However, fragmented/ separated anconeal process lesion was demonstrated in 15 pigs (the process was "ununited' with the rest of the proximal ulna). The diagnosis was confirmed in nine pigs at gross post-mortem and microscopically when the pigs were slaughtered due to other reasons than lameness of the front leg. These cases were interpreted as "fragmented/separated anconeal process' (FAP/SAP). This lesion showed a tendency to heal with increasing age. The lesions were healed in all surviving pigs at the age of 25-26 months.

Multiple dental developmental abnormalities following canine distemper infection.

Multiple dental developmental abnormalities (e.g., dental impaction, partial eruption, oligodontia, enamel hypoplasia, and dentin hypoplasia) in a 10-month-old, female, Tanzanian tropical mixed-breed puppy are reported. Various permanent teeth were involved. These included impacted mandibular canine and first and third premolar teeth; a partially erupted maxillary canine tooth; oligodontia of a mandibular fourth premolar tooth; enamel hypoplasia of the maxillary and mandibular canine teeth, incisors, and premolars; and dentin hypoplasia of the maxillary incisors, maxillary premolars, and mandibular premolars. The puppy had clinical canine distemper at the age of two months and had no history of any other systemic nor generalized infection prior to the time when the dental abnormalities were observed.

Radiological aspects on the course of development of porcine epiphyseal osteochondrosis (OCD) from 42 up to 147 days of age.

The articular-epiphyseal (A-E) cartilage complex of the distal humeral and femoral epiphyseal condyles of eight intact pigs (4 male & 4 female) of the same age were radiologically examined every 3 weeks, beginning at 42 days up to 147 days of age; to determine the age of onset, the course and trend of development of osteochondrosis (OCD). The earliest Dyschondroplasia (Osteochondrotic) lesions were demonstrated radiologically in the A-E complexes of the humeral condyles of 42-day-old pigs and in the femoral condyles at 63 days of age. Thus the radiographic examination of live animals to demonstrate subchondral radiolucency typical for OCD lesions in the condylar A-E complexes of pigs is not of limited value until the animals were > 100 days old as indicated in earlier reports. Also the course of further development of OCD lesions associated with A-E complexes was followed. The radiolucency was seen to develop to a certain extent, and then either to regress, and stabilize or even to progress as the animal grows. Some lesions regressed completely. Also some of the regressed lesions may become active again and become progressive. However, the course of development of femoral condyle A-E complexes OCD lesions was seen to be progressive continuously, or progressive then stable and then progressive again. The regressive course and trend of osteochondrotic lesions was not observed in the femoral condyle A-E complexes up to day 147 of age. Therefore, the course and trend of development of the A-E complexes OCD is not constantly the same.

The sequelae of distal ulna physeal dyschondroplasia (osteochondrosis) lesions in breeding swine--a radiological investigation in Danish Landrace pigs.

A radiological follow-up study of osteochondrotic lesions in the distal ulna was carried out in 58 Danish Landrace breeding sows for a period of 15 months (October 1992 to December 1993). This was part of a major project involving the radiological investigation of articular-epiphyseal and physeal development to investigate osteochondrotic lesions in pigs. The radiological lesions were graded from 1 to 5 with increasing severity. It was observed that not all pigs passed through all grades. Only 21% of the pigs had no radiological osteochondrotic lesions (grade 1) during the first radiography series. After 5-7 months, the number of pigs without osteochondrotic radiological lesions were observed to have increased dramatically (21-69%), but the converse was true for grades 2 (mild), 3 (moderate), 4 (severe) and 5 (very severe): (33-17%), (21-9%), (19-5%) and (7-0%) respectively. This was observed with increasing age and weight. The 3rd radiography series indicated that the percentage of pigs without osteochondrotic lesions increased up to 82%, and that grades 2, 3, and 4 had fallen to 14%, 2% and 2% respectively, while grade five remained at 0%. This indicated that the distal ulna osteochondrotic lesions can be important in breeding pigs during the period of growth before first pregnancy. During the first pregnancy the osteochondral ossification fault can be corrected, and the lesions heal. The ulna growth plates were not closed at the second, but mostly closing during the third radiography series.