C.K. Gachuiri

Effect of supplementing napier grass with desmodium and lucerne on DM, CP and NDF intake and weight gains in dairy heifers

Abstract A study was conducted to investigate the effect of feeding napier grass (Pennisetum purpureum) with or without legume supplementation on nutrient intake and live-weight gains (LWG) in dairy heifers. Thirty-two, 1-year-old Friesian and Sahiwal heifers were used. Eight heifers, four from each breed, were randomly allocated to the following four diets: napier grass alone (D1, control), napier/desmodium (D2, inter-cropped in the field), napier grass supplemented with lucerne hay (D3) and napier grass supplemented with desmodium hay (D4). Feed intake was recorded daily while LWG was measured fortnightly over the 120-day feeding period. In a separate experiment, two fistulated steers were used to estimate the rumen DM degradation of the diets. Heifers on diets D2, D3 and D4 showed significantly higher nutrient intake and LWG (P

Risk factors of gastrointestinal nematode parasite infections in small ruminants kept in smallholder mixed farms in Kenya

BackgroundHelminth infections in small ruminants are serious problems in the developing world, particularly where nutrition and sanitation are poor. This study investigated the burden and risk factors of gastrointestinal nematode parasite infections in sheep and goats kept in smallholder mixed farms in the Kenyan Central Highlands. Three hundred and seven small ruminants were sampled from 66 smallholder mixed farms in agro-ecological zones 1 (humid) and 3 (semi-humid) in the Kenyan Central highlands. The farms were visited once a month for eight months during which a health and production survey questionnaire was administered. Fecal samples were collected at each visit from each animal. Fecal egg counts (FEC) were performed using the modified McMaster technique. Associations between potential risk factors and FEC were assessed using 3-level Poisson models fit in SAS using GLIMMIX macro. Correlations among repeated observations were adjusted for using three different correlation structures.ResultsA rise in FEC was observed two months after the onset of rains. Farmer education, age category, de-worming during the preceding month and grazing system were significant predictors of FEC. Additionally, there were significant interactions between grazing system and both de-worming and age category implying that the effect of grazing system is dependent on both de-worming status and age category; and that the effect of de-worming depends on the grazing system. The most important predictors of FEC in the study area were grazing system, de-worming status and education of the farmers.ConclusionSince several factors were important predictors of FEC, controlling gastrointestinal helminths of small ruminants in these resource-poor smallholder mixed farms requires a sustainable integrated helminth control strategy that includes adoption of zero-grazing and more farmer education probably through extension services. Achieving improved helminth controls in these resource-poor farming systems offers an opportunity to increase small ruminant productivity and hence has a potential of improving the livelihood of the resource-poor farmers.

Effect of feeding napier grass, lucerne and sweet potato vines as sole diets to dairy heifers on nutrient intake, weight gain and rumen degradation

Abstract Two experiments were conducted to assess the nutrient intake, weight gain (ADG) and rumen degradation of napier grass (NG), lucerne (L) and sweet potato vines (SPV) fed to growing dairy heifers. In the first experiment, 33 Friesian heifers were randomly allocated to the three treatments namely; napier grass, lucerne and sweet potato vines which were fed for 104 days. In the second experiment, degradability of the three diets was estimated using nylon bags incubated in two rumen fistulated steers. The mean chemical composition of the forages were: dry matter (DM) 155, 807 and 123 g kg−1; organic matter (OM), 796, 854 and 852 g kg−1 DM; crude protein (CP), 118, 167 and 135 g kg−1 DM and neutral detergent fibre (NDF), 587, 408 and 506 g kg−1 DM for NG, L and SPV, respectively. The mean daily DM intake was 5.0, 5.5, and 4.2 kg while the CP intake was 0.59, 0.96 and 0.57 g for diets NG, L and SPV (P 0.05). It was concluded from the study that NG, L and SPV contained nutrient levels that would sustain acceptable growth in heifers.

Effect of treatment with formaldehyde and formic acid on immunoglobulin content of stored bovine colostrum

Colostrum was collected from the first postpartum milking of German Black Pied cows. Four independent pools of colostrum were made and the following preservation methods replicated in each pool, viz. formaldehyde treatment, 0.1% (F1) and 0.05% (F2); formic acid treatment, 0.5% (FA1) and 0.1% (FA2) and an untreated control (NF). All the colostrum batches were stored at an average incubation temperature of 28°C in 200-ml plastic bottles. Samples were collected from every batch on Day 0 (before incubation) and subsequently after every week for 4 weeks. All the samples collected were analysed for immunoglobulin (IgG1, IgG2, IgA and IgM) content of the whey fraction using the single radial immunodiffusion (SRID) method. pH was measured using a glass electrode pH meter. Formaldehyde treatment of colostrum maintained almost constant immunoglobulin levels under the conditions of this experiment. There were significant drops in the mean IgG1 (P < 0.0001) and IgM (P < 0.005) contents in the control (NF) and the formic acid treated (FA1 and FA2) colostrum. The levels of IgA and IgG2 remained fairly constant for all treatments and there was no observable trend with storage duration. The pH of formaldehyde treated colostrum remained above 4.8 for the 4 weeks of storage whereas that of the untreated control colostrum dropped to below pH 4.8 in the first 3 days and remained stable to the 4th week. This work has shown that inclusion of formaldehyde at levels as low as 0.05% (wt/vol.) preserves immunoglobulins of colostrum stored at high ambient temperature. The use of formic acid was not beneficial for preservation of colostral immunoglobulins. Thus colostrum preserved with formaldehyde may be of good feeding value for newborn calves whereas that preserved with formic acid may be useful only for older calves.