No abstract

Brucellosis is one of the most notorious and widespread zoonosis caused by Brucella abortus. It is of serious economic implications to the cattle industry and thus enormous financial losses to most countries. This study focused on it serological prevalence at the Nkwen main abattoir of Bamenda (Northwest region, Cameroon) from June to September 2013. Blood samples were collected from 198 cattle and the sera were screened using the competitive enzyme linked immuno sorbent assay (C-ELISA). Results showed a seroprevalence of 4.04% in the cattle population screened. A percentage of 4.40% of the 111 bulls and 3.45% of the 87 cows were recorded as infected. There was no evidence (P>0.05) of differences in sex on the seroprevalence of brucellosis in cattle. There was no association between brucella infection and age (P>0.05). About three percent of cattle were positive for those within (<5) age group with 5(4.67%) for those above 5 years of age. The two breeds commonly consumed in the area the Red and White Fulanie with the Red Fulani having a higher infection than the White Fulani (P<0.05). The study also showed that Brucella infection was dependent on location as 5 out of the 15 villages accounting for 100% infection namely: Fundong (37.5%), Wum (25%), Nso (Jakiri) (12.5%), Metah (12.5%) and Fonta (12.5%). From these results it was concluded that brucellosis is present in the population of cattle screened. There is therefore the need for good control measures and sanitary conditions to limit the spread of the disease.

Seventy-two cows were selected for an on-farm study on the effect of feed supplementation before calving on milk production, ovarian activity and calf growth of Holstein, indigenous Red Fulani cows and their crosses. Prepartum feed supplementation was done using cotton seed cake (80 %), maize (18 %), bone meal (1 %) and kitchen salt (1 % NaCl). Supplementation levels consisted of a low supplemen-tation fed at 1 kg per animal per day and high supplementation fed at 2 kg per animal per day. In addition, Red Fulani cows received the supplements in two different ways namely a prepartum supplementation consisting of 1 kg per cow per day and pre-and post-partum supplementation consisting of 1 kg per cow per day before calving and 1 kg per cow per day post-partum up to 30 days after calving. Blood samples were analysed using ELISA Progesterone kits to determine the length of post-partum anoestrus. Results show that prepartum levels of feeding did not have any effect (P>0.05) on body condition score (BCS) at 12 weeks after calving, calf birth weight, average daily weight gain of calves, milk pro-duction and post-partum anoestrus. High BCS at calving was shown to influence BCS at 12 weeks of lactation. Holstein cows had bigger calves (P<0.01) at birth (45 kg) compared to traditional cows (36 kg) and crosses (34 kg). There was little benefit of pre-partum supplementation on the parameters investigated in this study. Consequently, low income farmers are advised to concentrate their efforts of supplementation early in lactation.

A study was carried out to evaluate the viability of extended cattle semen, without freezing, under different storage conditions. The semen was collected from Holstein Friesian bulls using artificial vaginas. The semen was extended and stored in a 3-by-4 factorial design (storage system × ice change). The storage media were ice boxes, buckets, and refrigerator. The ice in these media was either replaced daily, on the first and third day, first day only, or no ice at all after the semen collection. Results showed an overwhelming evidence of the effect of storage medium and ice change on sperm viability (P<0.0001). Individual motility before processing was highest in the refrigerator with averages of 44.5%, 39.5% in ice boxes, and 10% in buckets during the 8-day experiment. There was no significant difference (P>0.05) in progressive motility after processing in the refrigerator (34%) and in ice boxes (33%) but significantly higher (P<0.01) to the 10% obtained in buckets. It was shown that spermatozoa in the ice box retained 45% individual motility up to the sixth day after semen was collected on the condition that the ice was changed on the third day. Progressive motility after processing in the ice box was 40% up to the sixth day with the ice changed on the third day while the spermatozoa were well preserved up to the fourth day in the same medium if the ice put on the first day was not changed. This study shows that, if farmers plan to inseminate cows within the first day after semen collection, they can use buckets with ice for the transportation of the extended semen ampoules from the artificial insemination center. Otherwise, the semen needs to be kept in ice boxes and the ice changed on the third day after collection and this semen could be used within a week.

The objective of this work was to evaluate the effect of two synchronization methods with prostaglandins F2α (PGF2α) on heifers and multiparous cows. Fourty-three Bos indicus cows (white and Red Fulani) were divided into four groups in a two-by-two factorial structure, parity x method of synchronization. The synchronization methods consisted of a two-dose regime which involved injection of animals on day 0 with PGF2α (Lutalyse) at 5 ml per cow intramuscularly. On day 11, the injection was repeated at the same dosage. On day 14 (72 h after the second injection), a fixed-time artificial insemination (AI) was done. On day 15 (96 h after the second injection), a second insemination was done. The one-and-a-half-dose regime consisted of an injection similar to the first treatment mentioned above on day 0. Thereafter, cows were observed for heat, and anyone showing heat was inseminated. A second dose was given on day 11 to all animals not having shown any heat. A fixed-time AI was done on days 14 and 15. Blood samples were collected on the day 0 of insemination for each cow while day 11 and day 21 after insemination. Progesterone was analysed by means of standard ELISA progesterone kits to determine its profiles after insemination. Results show no evidence of the effect of treatments on conception rates (P>0.05). Similarly, heifers and multiparous cows had similar conception rates (P>0.05). Between 3 weeks and 3 months of pregnancy, there was a loss of embryos of 28 % in heifers and 20 % in multiparous cows, but the difference between the two groups was not significant (P>0.05). It recommended that farmers do not synchronize animals with poor body condition score (BCS). They should also monitor weight gains of heifers, remove them from the herd when they have been mixed with young growing bulls and put them in a breeding herd. The two-dose regime is better to be used in areas where the inseminator cannot easily be available.