Serological investigation of brucellosis and its association with abortion in sheep and goats in selected districts of Jimma zone, southwestern Ethiop

The occurrence of brucellosis in different species of livestock has been reported from different parts of Ethiopia, however, the serostatus and risk factors of this disease in small ruminants is not well documented in southwestern parts of the country. This study was conducted from October 2016 to October 2017 to investigate the seroprevalence and associated risk factors of brucellosis as well as its association with abortion in sheep and goats in selected districts of Jimma zone. A total of 804 small ruminants (402 sheep and 402 goats) were randomly selected and blood samples were collected for serological tests. The presence of antibody to Brucella was screened by Rose Bengal Plate Test and confirmed using the complement fixation test. Seroprevalence of 4.2% in sheep and 5.2% in goats was recorded in this study. An overall seroprevalence of 4.7% was recorded in small ruminants in the study areas. Brucella seropositivity was observed more frequently among sheep and goats with a history of abortion (6.7%) than animals that have no history of abortion (3.7%), however, the difference noted was not statistically significant. Older age (OR 3.9, CI = 1.43-9.94), pregnancy (OR 2.6, CI = 1.19-5.72), late term gestation (OR 2.4, CI = 1.54-3.78), mixed flock (OR 2.8, CI = 1.33-5.89) and larger flock size (OR 2.7, CI = 1.08-6.95) were noted to have more number of reactors. Hence, it is important to consider brucellosis as one of the diseases that needs attention and further study should be conducted to identify the circulating Brucella species and other causes of abortion in sheep and goats. Besides, this finding warrants the need for further investigation on its public health impact in the region. Keywords: Brucellosis; Epidemiology; Sheep; Goat; Jimma Zon

Performance of crossbred dairy cows suitable for smallholder production systems at Holetta Agricultural Research Centre

The present study was undertaken to investigate productive and reproductive performances of F1 crossbred cows to produce and develop improved dairy cattle breed at on station and back up the on farm crossbreeding program at Holetta Research Center (HRC). One hundred fifty three F1 crossbred heifers were used to study growth performances and 111 worldwide sire (WWS) and 42 Kality (NAIC) sire records were used to analyze the data. A total of 802 milk records out of which 711 from worldwide sire (WWS) milk records and 91 from Kality (NAIC) bulls’ milk records were used to analyze the milk production performances. Least squares means of growth traits in this study birth weight (BWT), average daily gain (ADG) of crossbred heifers was 24.83 ± 2.33 kg and ADG ranges from 0.437 ± 0.01 to 0.546 ± 0.02 kg respectively. Least squares mean for age at first service (AFS), age at first calving (AFC), calving interval (CI), and number of service per conception (SPC) were 26.4±0.8 months, 35.7±o.81 months, 500.32±2.92 to 395.64 ± 4.9 days, and 1.2 ± 0.2 to 2.37 ± 0.05 services, respectively. Lactation milk yield (LMY) obtained from this result reflected progressive trend from 1st to 5th parity (1874.65 ± 67.7 to 2582.69 ± 111.2 kg) and started declining thereafter. The declining trend observed after the 5th parity is the normal biological  phenomenon from dairy cows under normal conditions. The improvement gained from this result is the outcome of the of management procedures and practices followed which have accounted for 15.5 % of early calving of young heifers and 21 % in milk yield increments made from Frisian Boran (FB) crossbred cows at HARC. The overall observed growth, reproductive and milk yield performance of FB crossbred dairy cows at HARC has shown progressively significant improvement. Thus in order to continue with the crossbreeding for development of F1 50% crossbred dairy cows to maintain the on station and backup the on farm breeding activity there is a need to do intensive and proper performance evaluation based on defined breeding  objectives. Culling procedures to avoid milking cows beyond the 5th parity is important. Research centers have to put maximum efforts to improve routine  management activities to maintain performance evaluated animals at the centers at all levels.Keywords: Crossbred, heifers, dairy cows, performanc

Productivity of Horro ewes under 12-monthly and 8-monthly mating systems

After a preliminary common lambing, Horro ewes were mated either twice at 12-month intervals or three times at 8-month intervals over a period of two years. There were no significant differences between the two mating systems in their productivity at each lambing. However, ewes in the 8-monthly system lambed on average 2.6 times during the two years, whereas ewes in the 12-monthly system lambed on average only 1.6 times during the same period. As a consequence, total production over two years increased from 2.2 to 3.5 lambs born

The effect of weaning age and feeding of different calf starter rations on testicular growth and body weight of Borena-Friesian crossbred bull calves

An experiment was conducted to determine the effects of feeding different calf starter rations, weaning age and their interactions on testicular growth and body weight of Borena Friesian (BF) crossbred bull calves at the age of 105 (closer to weaning) and 202 (nearly 6 months) days. Statistical analysis indicated no significant differences (p>0.05) in values obtained in testes diameter (TD) and scrotal circumference (SC) at both ages. There was, however, significant (p<0.05) and positive correlation between testes measurements and the body weight of bull calves. The result of this study suggests that Borena Friesian crossbred calves can successfully be weaned as early as seven weeks of age, provided that they are supplied with easily digestible solid feeds enough to support the protein and energy requirements of the growing calves. Adequate supply of proper solid feed both at pre and post weaning period, is believed to over come any adverse effect encountered during the pre-weaning period, through compensatory growth effect. Other aspects of rearing future bulls such as the effects of feed and other environmental factors on semen characteristics could be the subject of further study

Creep-feeding young lambs

A trial was conducted on 26 male twin lambs to study the effect of creep feeding on lamb development and growth Creep feeding started when the lamb’s average age was 43 days. Lambs were weaned at an average age of 93 days. The creep feed group was fed ad libitum until the age of six months while the other group was given 200 g/head/day of concentrates plus hay ad libitum. The preweaning average concentrate consumption by the creep fed group was 284 g/head/day and the postweaning consumption of the same group was 495 g/head/day. Weaning and 6 month weights were higher (p< .01) in the creep-fed group than the control one (16.7 vs 14.6 and 27.7 vs 17.8, resecti vely). Averge daily gains followed the same trend. The post weaning concentrate feed conversion ratio in the creep fed group was 4.19 while that in the control group was 4.88. The return in terms of body weight gain, on the extra ration input in the creep-fed group was 3.83 kg for each 1 kg of extra ration

Influence of birth weight and post partum age on lamb mortality in Ethiopian Horro sheep

Mortality was studied in relation to birth weight (BWT) and postpartum age in 3083 Horro lambs born over 15 years at Bako Research Center, IAR. Pre-weaning mortality rose with declining BWT (log y = 2.20- 0.35X; r = 0.9981), but the influence after weaning was less pronounced and linear (y = 23.78-1.93X; r = 0.5271). Overall, 1066 (34.6%) of the lambs died; 19.1% of lambs born died before weaning and 19.1 % of lambs weaned died before one year of age. Significantly more lambs died in the first week of life (231/2953 = 7.8%) than in any subsequent 7-day period (0.2-1.9%, P<0.001). But, although significant (P<0.01), a transient rise in mortality after weaning was small in magnitude (mean: 1.6 VS. 1.1% lambs died per week). Major gains in meat output could be achieved from Horro sheep by reducing lamb mortality; firstly by improved late-pregnancy health and nutrition of ewes, and thus BWT, and secondly by attention to ewe and lamb management during the first week after lambing

A study on fattening Ethiopian sheep. I. Performance of highland lambs under feed-lot conditions

Two trials were performed to study the fattening performance of Ethiopian highland sheep under feed-lot conditions. Three diets were tried; A-20 % hay, B -35% hay and C-50% hay. Trial I had the three diets represented on 84 non-descript highland all-milk-tooth ram lambs, while in Trial II, only, diets A and C were tried on 47 highland Horro ram lambs. The average initial veight was 20.4 kg in Trial II. Average daily gain differed significantly (

Testicular growth and its relationship with linear body measurements in Borana-Friesian crossbred bull calves at different ages

Measurements on testis and linear body size, scrotal circumference (SC), testis diameter (TD) hearth girth (HG), height at wither (HTW) and body length (BDL) at the age of 1, 3, 6, 9, 12, 15, 18 and 21 months was taken. Thirteen Borana Friesian (BoXF) crossbred bull calves born at Holetta Agricultural Research Centre (HARC) during the year 1998/99 calving season were used. The objective of the work was to determine the testis and body size of the bullcalves and their relationship at different ages to consider as criterion for early selection of breeding bulls. Statistical analysis indicated that significantly different (P<0.001) rate of increase in testis and body size of measured variables between age groups. However the magnitude of increase in size of TD, SC, HG, HTW, and BDL was not significant (P<0.05) in the age group between 18 & 21 months. Body weight (Wt) have influenced in increase of SC (P<0.001) and TD, HTW and BDL (P<0.05). HG, BDL and HTW were positive and significantly (P<0.001) correlated to TD and SC respectively, r=0.94, 0.92 and 0.68 respectively. It appears evident from the results of this study, that sexual maturity could be attained in Box F from closer to 15 months of age, since the increasing rate of testis size was lower and steady after this age. Even if the determination of sexual maturity in male needs detail examination and is complex, at field level the steady change in testis and body size may indicate the inclination of the animal to physiological maturity. The result also suggests that testis size could be described in terms of body size. Further study in this line may deal with determination of quality and quantity of semen at different ages of bull calves for indigenous and different genotypes, since the information available is quiet insufcient