Small Ruminant: Nutrition and Parasites

After a previous 84-d performance phase, a study was conducted using 16 West African Dwarf (WAD) ewes. Ewes (Initial BW 17.5 ± 0.19kg) were used in a completely randomized design to study the effects of increasing level of Mexican sunflower leaf meal (MSLM) on nitrogen balance. The experimental animals were assigned to 4 treatment groups A (O%MSLM), B(15%MSLM), C (30%MSLM) and D (45%MSLM) of 4 replicates each and were fed with grass (Panicum maximum) plus concentrate diet mixture of Mexican sunflower leaf meal (MSLM) and wheat bran (WB) such that 0%, 15%, 30% and 45% of WB was replaced by weight with MSLM gravimetrically. About 60% of the diet came from the concentrate while 40% came from grass. The experiment lasted for one week. Digestibility was determined using a 6-d total urine and fecal collection. Ewes were given ad libitum access to feed and water and routine vaccination and medication followed standard procedures. Parameters measured were nitrogen intake (NI), nitrogen balance (NB), nitrogen apparent digestibility (NAD) and nitrogen retention(NR). Data were analyzed using descriptive statistics and ANOVA. Concentrate DMI (CDMI) ranged from 181.8 g/d (45%MSLM) to 536.8 g/d (15%MSLM) and grass DMI (GDMI) ranged from 130.6 g/d (0%MSLM) to 215.9 g/d (30%MSLM) and this was significant (P < 0.05). Positive NB was observed for animals on all treatments. This suggested that the various diets were able to meet the protein need of the animals for maintenance and production. Urinary nitrogen g/d was greater (P < 0.05) with increasing inclusion of MSLM in the ration while protein retention increased from treatment A (0%MSLM) to treatment B (15%MSLM) (90.4 90.8%) and subsequently decreased from treatment B (15%MSLM) to D (45%MSLM) (90.8 85.0%). Data obtained for Nbalance in this study ranged from 6.28 – 15.0 g/d. Animals on treatment B (15.01g/d) had the greater N-balance, and this was significantly (P < 0.05) greater compared with animals on treatment D (6.28g/d) but numerically more (P > 0.05) than observed values for animals on treatments C (9.05g/d) and A (9.32 g/d). This suggested that the fermentable OM in the WB apparently encouraged greater N digestibility and it is an indication that a favorable energy: N balance resulted from diet B. This trend was the same for nitrogen intake (7.39 – 16.5g/day) and absorbed (6.36 – 15.1 g/d). Nitrogen balance was positively related to DMI and N intake. The overall regressions were NB = 2.39 + 0.07 DMI; R2 = 0.93, (P = 0.37) and NB = 0.72 +0.91 NI; R2 = 0.99, (P = 0.13). This study showed that a greater level of NI and DMI improved (P < 0.05) N-balance. The low level of nitrogen balance in animals on treatment D could have been due to the level of feed intake. Mexican sunflower leaf meal incorporation in the diets of sheep improved nitrogen intake, balance and retention.