ABSTRACT
Mastitis is the most common disease of adult dairy cattle. The disease continues to be one of the most perplexing and costly diseases of dairy cattle. The present study was conducted to detect bovine mastitis cows and identify potential risk factors for the distribution of bovine mastitis of smallholder dairy farmers using the California mastitis test. A cross-sectional study was conducted from September 2013 to May 2015 in the southern zone of Tigray, Northern Ethiopia, on 146 head of randomly selected cattle, of which 99 (67.8%) were crossed zebu and 47 (32.2%) pure local zebu using the California mastitis test and questionnaire. The overall prevalence was 65 (45.5%), of which 72.3% of crossed local and 27.69% of local zebu were found positive for the CMT test. The investigated risk factors were the season of lactation (OR = 0.510, CI = 0.208-1.247, P=0.140), washing hands between consecutive milking events (OR = 0.354, CI = 0.146-0.856, P=0.021), and history of previous mastitis (OR = 0.441, CI = 0.226-0.858, P=0.016), which had significant (P < 0.05) effect on the present prevalence of bovine mastitis in the study area. A high prevalence of bovine mastitis was observed in the southern zone of Tigray. The summer season of lactation and not washing hands between consecutive milking of cows were significant mastitis causation risk factors in addition to the history of previous mastitis disease history.
ABSTRACT
This study investigated the effect of replacing noug (Guizotia abyssinica) (L.f.) Cass. seed cake by dried Leucaena leucocephala (Lam.) de Wit leaves on feed intake, live weight gain, nutrient digestibility, and nitrogen balance of highland sheep in Tigray Region in northern Ethiopia. Twenty intact yearling male highland sheep weighing 16.9 ± 1.62 kg were used in a randomized complete block design and included the following four treatments: T1 (control, wheat straw ad libitum + 200 g noug seed cake (NSC) + 150 g wheat bran (WB)); T2 (wheat straw ad libitum + 170 g NSC + 44.3 g dried L. leucocephala (DLL) + 150 g WB); T3 (wheat straw ad libitum + 140 g NSC + 87.3 g DLL + 150 g WB); and T4 (wheat straw ad libitum + 110 g NSC + 130.2 g DLL + 150 g WB). Sheep fed on T4 diet consumed higher total dry matter (658 g/head/day) and recorded the highest average daily weight gain (59 g/head/day). Sheep fed on T4 diet had higher dry matter (61 %), organic matter (63 %), and crude protein (75 %) digestibility values than the other treatments. Sheep fed on T3 diet demonstrated higher feed conversion ratio (11.93) than sheep kept on the other treatments. All sheep exhibited positive nitrogen balance, with the highest nitrogen retention being measured in T4 (12 g/head/day). It is concluded that partially replacing NSC by DLL can improve total dry matter intake, digestibility of nutrients, and body weight gain in highland sheep fed on wheat straw as the basal diet.