Major causes of lamb mortality at Ebinat woreda, Amhara National Regional State, North-western Ethiopia
A year-round (from September 2008 to August 2009) study was conducted to investigate causes of lamb mortality at Ebinat woreda, Amhara National Regional State, northwestern Ethiopia. Two hundred and forty one lambs under the age of six months were exploited for analysis of this study. Out of the 241 lambs observed, 96 were found dead giving the overall mortality of 40.0% (96/241). Most of the mortalities were due to diarrhea 49 (51.0%), pneumonia 37 (38.5%) and others 10 (10.4%). Result of this study showed that there was a significant variation (2 = 3.847; df = 1; P = 0.050) in mortality between the two sexes. Season as a variable had a significant (2 = 9.963; df = 1; P = 0.002) influence on lamb mortality. Our study indicated that there was a strong association (2 = 40.432; df = 3; P = 0.000) between body condition scoring and mortality of lambs. There was significant variation (t = 27.61; df= 75; P=0.00) in birth weight between single-born lambs and multiples. Sex and dam parity, as factors, had shown no specialized features against specific variation seen on birth type basis. Result of faecal egg counts indicated that highest values were recorded in wet season especially in July and August during the higher rainfall. Result of t-test of mean PCV significantly varies (t = -1.13; df = 165; CI = -3.00 – 0.80) between the two seasons showed that higher value was recorded in dry season (29.33±5.12) than in wet season (28.23±5.88). This study has found that mortality in lambs born alive is likely to be above 40 per cent and may represent high loss of deaths in sheep husbandry practices of the area. Mortality from diarrhea and pneumonia could be minimized by timing of mating to ensure that lambing occurs in the dry/hot season (January/February) so that lambs are weaned at the beginning of the rainy season (June/July). Mortality of lambs can also be reduced by improving flock health, nutritional management, and housing.
Key words: diarrhoea, diseases, lamb, mortality, pneumonia, season.