Tinyiko Edward Halimani

Influence of parity, birth order, litter size and birth weight on duration of farrowing and birth intervals in commercial exotic sows in Zimbabwe

Although the farrowing process has an impact on postnatal piglet survivability and growth performance, information on factors that influence the farrowing process under field conditions is rare. The objective of the study was to determine factors influencing the duration of farrowing and birth intervals in Large White×Landrace crossbred sows. Data were collected from the Pig Industry Board, Acturus, Zimbabwe. The durations of farrowing were log transformed to normalize them, while birth intervals remained skewed after the transformation. As a result, Friedmans test was used to analyse for factors affecting birth intervals. The mean duration of farrowing was 217 min. Number of piglets born alive (NBA), average birth weight and the presence or absence of stillbirths influenced ( P P Y =0·1011 x 2 −1·771 x +37·917 ( P Y =0·0021 x 2 −0·121 x +23·952 ( P

Breeding for resistance to gastrointestinal nematodes - the potential in low-input/output small ruminant production systems.

Highlights • Resistance to anthelmintics in small ruminants is documented worldwide.• Genetic resistance in GIN have been studied in experimental and commercial flocks.• Limited in low-input low-output farming systems.• Nematode eradication has evolved to manipulation of host-parasite equilibrium.• Selection for resistant hosts can be considered a sustainable control strategy.

Estimation of Genetic and Phenotypic Parameters for Production Traits and Somatic Cell Count for Jersey Dairy Cattle in Zimbabwe

Genetic and phenotypic parameters for production traits and somatic cell count (SCC) for Jersey dairy cattle in Zimbabwe were estimated. A total of 10986 lactation records were obtained from Zimbabwe Livestock Identification Trust, with cows calving in the period from 1996 to 2008. An ASReml program fitting an animal model was used for the analyses. Heritability estimates for milk yield, fat yield, protein yield, fat percentage, protein percentage, and Log10SCC were 0.30, 0.32, 0.33, 0.42, 0.44, and 0.08, respectively. The corresponding repeatability estimates were 0.39, 0.38, 0.39, 0.49, 0.51, and 0.16, respectively. The genetic and phenotypic correlations between different production traits ranged from −0.86 to 0.95 and from −0.88 to 0.98, respectively. The genetic and phenotypic correlations between production traits and Log10SCC were weak almost nonsignificantly differentl from zero. The results imply that milk traits for Jersey dairy cattle in Zimbabwe are more heritable. Therefore, these traits may be preferred by breeders as selection criteria for development of effective genetic improvement programme.

Antibacterial activity of aqueous and methanol extracts of selected species used in livestock health management

Abstract Context: Salvadora persica L. (Salvadoraceae), Colophospermum mopane (J.Kirk ex Benth.) J. Léonard (Leguminosae) and Dichrostachys cinerea (L.) Wight & Arn. (Leguminosae) crude extracts are used by local farmers against many livestock infections with little or no side effects usually associated with synthetic antimicrobials. However, their efficacy has rarely been tested. Objective: These plants were tested for potential antibacterial activity against clinical isolates of Staphylococcus aureus ATCC33862 and Escherichia coli ATCC25922. Minimal inhibitory concentrations (MIC) of the crude plant extracts were determined. Materials and methods: Aqueous and methanol extraction of 100 g each of the bark of C. mopane, roots of D. cinerea and leaves of S. persica was done by placing the samples in 250 mL of either water or methanol. Nutrient broth was used as growth medium for the bacteria, and McFarland standard for bacterial standardization. 2,3,5-Triphenyltetrazoliumchloride (TTC) was the indicator salt. Each of the aqueous and methanol extracts (100 μL) was tested. Gentamycin and ampicillin were the controls. Results: MIC of aqueous extracts ranged from 1.03–14.6 mg/mL against S. aureus, and from 12.1–34.3 mg/mL against E. coli. Methanol extracts ranged between 5.31 and 9.64 mg/mL against S. aureus, and between 7.86 and 13.6 mg/mL against E. coli. Aqueous and methanol extracts of S. persica were significantly higher (p < 0.05) than C. mopane and D. cinerea. Discussion and conclusion: Colophospermum mopane, S. persica and D. cinerea exhibited antibacterial activity, with methanol extracts performing better than aqueous extracts, justifying use as ethnoveterinary medicine. Further study to isolate the active components should be pursued.

Management and control of gastrointestinal nematodes in communal goat farms in Zimbabwe

Goats are an important source of livelihood especially in smallholder communities. Infections with gastrointestinal nematodes (GIN) remain the most prevalent parasitic diseases affecting small ruminants. The study was conducted to assess management, the level of knowledge and control of gastrointestinal nematodes. Surveys were conducted in Chipinge, Shurugwi, Binga, Tsholotsho and Matobo districts, representing the five natural/agro-ecological regions (NR) in Zimbabwe. Data was collected in 135 households using a pre-tested semi-structured questionnaire. Results indicated that goats were ranked the most important livestock species, with high flock sizes in NR IV and V. Partitioning of roles was such that the adult males were involved in decision-making while females and children were involved in day-to-day management of animals. Farmers showed low levels of input use, with natural pasture (98.4%) being the main feed source and indigenous breeds (73.2%) being kept. Farmers ranked food and financial benefits as the main reasons for keeping goats. Gastrointestinal nematodes ranked the highest as the most common disease, with majority of farmers (57%) not controlling or treating animals and 63% of farmers not having knowledge on the spread of GIN. Access to veterinary services, anthelmintic class used and breeds used by the farmers had the highest effects on parasitic infections in households. Farmer education is required for capacitation of farmer in terms of disease prevention and control so as to improve goat production.

Physical and chemical properties of meat from scavenging chickens and helmeted guinea fowls in response to age and sex

ABSTRACT 1. The effects of age and sex on body weight, carcass traits, physical and chemical properties of breast muscle from chickens and helmeted guinea fowls managed under village free-range conditions were assessed in random samples of 48 guinea fowls and 48 chickens obtained from local markets. 2. Guinea fowls had higher body weight, hot carcass weight, cold dressed weight and breast weight than chickens. 3. Guinea fowls had more dry matter, protein and less fat than chickens. Ash content did not differ between guinea fowls and chickens. Protein and fat increased, whereas dry matter and ash decreased with age (P < 0.05) 4. Chicken meat was lighter, less red and more yellow than guinea fowl meat. Cooking loss was higher in guinea fowls, male and grower birds than chickens, females and adult birds, respectively. Shear force was affected by age, as mature birds had a higher value than growers. 5. Guinea fowl carcasses contained more meat that was leaner, higher in protein and redder compared with chicken meat. As age increased the meat increased in protein and fat content and shear force, whereas colour became darker, redder and yellower.

Performance of growing cattle on poor‐quality rangelands supplemented with farm‐formulated protein supplements in Zimbabwe

Farmers use different non-conventional protein supplements and different feeding strategies to aid their animals survive the dry season in Zimbabwe. The strategies can be giving supplements once a week or once every other day up to very little supplement daily. Supplements are either legume crop residues or forage legumes. However, the efficacy of the use of non-conventional protein supplements in promoting growth and at the same time lowering the age at first calving is little understood. The study tested whether supplementing with farm-formulated non-conventional feeds could reduce live weight loss during the dry season and promote live weight gain as well as early development of sexual maturity in beef cattle. In a completely randomized design, thirty dams with calves on hooves were allocated to five different treatments which were repeated during the dry season for 3 years. The 3-year study results show that weight loss can be controlled, resulting in positive growth in both the pre-weaning and post-weaning phases of growing cattle. Yearlings fed solely on natural pasture lost significant weight during the dry season as compared to supplemented groups. The period to puberty and first calving was achieved at 18 and 27 months, respectively. Using non-conventional protein supplements could thus improve livestock productivity in resource-poor farming communities. It was concluded that smallholder farmers can supplement cattle with a kilogram per day of low-cost farm-based non-conventional legume meal to improve livestock productivity in semi-arid regions of Zimbabwe.

A Proposed Selection Index for Jersey Cattle in Zimbabwe

A multitrait selection index (I T) for Zimbabwean Jersey cattle was constructed. The breeding objective was defined in terms of production and functionality traits. The production component of the index included milk yield (M), butterfat yield (F), protein yield (P), butterfat percent (F%), and protein percent (P%), while the functional component included the somatic cell count (SCC). The index was termed as I T = 0.0004M + 0.0109F + 0.0313P + 1.0004F% + 2.4491P% − 0.1905SCC. The accuracy of the index was 91.1%, and the correlation between this index and the aggregate breeding objective was 0.954. A selection index is more important in the selection of sires and cows. This leads to the greatest genetic progress and hence productivity in the dairy sector. Therefore, the application of the selection index developed is necessary if the dairy cattle industry is to maximise the exploitation of genetics and to improve its relative competitive position.

Effect of age and sex on carcass characteristics and internal organ weights of scavenging chickens and helmeted guinea fowls

ABSTRACT The objective of the study was to determine the effect of age and sex on carcass characteristics and internal organ weights in scavenging guinea fowls and chickens. Ninety-six scavenging birds, purchased from farmers, were used comprising 48 guinea fowls and 48 chickens from communal farmers. Guinea fowls comprised 25 females and 23 males, with 21 growers and 27 adults. Chickens had 18 females and 30 males with 19 growers and 29 adults. Guinea fowls had heavier body weight and relative hot carcass and cold dressed weight than chickens and which increased with age. Breast and wing relative weights were higher in guinea fowls. Chickens recorded the higher weight of leg and drumstick than guinea fowls. The neck, feet and head weights were heavier in chickens except for the back which was similar to guinea fowls. Chickens had significantly higher abdominal fat than guinea fowls. Relative weights of the heart, liver, kidney, lung and gizzard were higher in chickens. Relative total intestinal weight and lengths of total intestines, small and large intestines were higher in chickens than in guinea fowls. Relative lengths of the intestines decreased with age. Chickens and guinea fowls could have different capacities to utilize scavengeable feed resources.

Effects of strain and sex on the behaviour of free-range slow-growing chickens raised in a hot environment

ABSTRACT Behaviour is a good indicator of the well-being of chickens. The objective of the study was to compare foraging behaviour in males and females of three indigenous chicken strains under generally hot free-range conditions. Behavioural activities were monitored in 21-wk-old Potchefstroom Koekoek (PK), Ovambo (OV) and Naked Neck (NN) chickens. Birds were separated by sex and allocated to four pens of Chloris gayana. Three birds per pen were randomly chosen and marked with paint 20 min before observation. Temperature humidity index (THI) was calculated and main effects analysed using the general linear models procedure. Naked Necks spent more time walking than OV and PK. Strain did not affect other behaviours. Females spent more time foraging, while males dominated standing and walking. There was negative correlation between THI and time spent foraging. There was interaction between strain and sex on time spent standing. Foraging and drinking behaviours were more prominent in the morning (07:00 h) and late afternoon (17:00 h) compared to the 12:00-h period, whereas preening and dust-bathing were dominant around mid-day. Strain, sex and THI influence behaviour in free-range chickens. Breeding programmes should be cognizant of these attributes in order to produce hardier birds in view of worsening climatic uncertainties.