Mixed Crop Livestock Research Articles

Crop–Livestock Interactions in the West African Drylands

Many semiarid regions of Sub-Saharan Africa (SSA) are experiencing vast increases in human population pressure and urbanization. These augment the demand for agricultural products and have led to the expansion, intensification, and often closer integration of crop and livestock production systems. The transition of crop and livestock production from the current relatively extensive, low input/output modes of production to more intensive, higher input/output modes of production presents numerous challenges to the achievement of required long-term production increases from these farming systems. This paper provides an overview of the challenges facing agricultural production in semiarid SSA with a focus on West Africa. A description of mixed crop–livestock farming systems and their evolution is followed by an overview of the principal linkages between crops and livestock: income, animal power, feed, and manure. The most detailed discussions relate to nutrient cycling in these farming systems. Most livestock derive their feed almost exclusively from natural rangeland and crop residues, and livestock manure is a precious soil fertility amendment. However, most farmers have insufficient livestock and therefore manure to sustain food production. Nutrient harvests from cropland often exceed nutrient inputs, and soil nutrient depletion is a principal concern. The paper concludes with a discussion of strategies that may improve the productive capacity of these mixed farming systems.

Importance of crop residues in crop–livestock systems in India and farmers’ perceptions of fodder quality in coarse cereals

The mixed crop–livestock systems of India are underpinned by the crop residues which contribute on an average 40–60% of the total dry matter intake per livestock unit. There is however considerable regional variation in the dominant type of crop residue: rice and wheat straws in irrigated regions compared to coarse cereal straws and hay from leguminous crops in the drier, semi-arid regions. This paper synthesizes a series of recent studies on the role and importance of crop residues and farmers’ perceptions of fodder quantity and quality in coarse cereal and groundnut based feeding systems. Crop improvement programs for sorghum, pearl millet and groundnut have traditionally focused on grain/pod yield improvement, pest and water stress tolerance. Only relatively recently have dual-purpose (grain and fodder) plant types been developed. While the nutritive value of fodder from dual-purpose crops can be determined through in vivo and in vitro analysis, such experimental procedures cannot necessarily capture the often-subjective quality attributes that farmers (and their animals) value. Results indicate that farmers perceive a range of quality traits, some of which could be screened for relatively easily, whereas others may be more difficult to assess. These findings highlight the importance of farmer participatory evaluation of fodder traits in the development of improved dual-purpose varieties. However the impact of these varieties on poor farm households will be contingent on the complementary improvement in the effectiveness of seed systems.

Harnessing the Potential of Livestock in Mixed Farming Systems in India

The most dominant form of livestock production in India relates to mixed crop livestock system. Pressure on agricultural land forces cultivators to maintain livestock for manure purposes, consume the meat or egg to meet the need for dietary protein and of course to ensure a little milk for the children and the aged. Smaller the farm size, greater is the need to keep a given fleet of livestock so that real income reaches a moderate figure. Productivity of farm livestock in regard to both meat and milk in India happens to be below the world average. Inadequate provision of fodder and lack of good grazing lands are the most important factors holding up productivity growth. Crop residues from cereals and pulses like rice bran or wheat bran serve as good cattle feed but they have more lucrative uses epitomized in bran scams. The paper argues in favour of technological change in fodder and introduction of cultivated grazing lands.

Feed intake and lactation performance of dairy cows offered napiergrass supplemented with legume hay

Inadequate and low quality feed resources and declining soil fertility limit smallholder dairy production and crop yields in western Kenya. Integrating legumes into mixed crop–livestock smallholder production systems may improve feed resources and soil fertility. Mucuna [ Mucuna pruriens var. utilis (L.) DC (Wright) Burck] and lablab [ Lablab purpureus L. (Sweet)] are adapted legumes that can serve both functions, but data are limited which assess their use as supplements to cattle diets. The objective was to evaluate the potential benefits to dairy cow performance of feeding mucuna and lablab cv. Rongai hays as supplements to a basal diet of mature napiergrass [ Pennisetum purpureum (Schum.) cv. Bana]. Eight multiparous Friesian cows were used in two 4×4 Latin squares. Treatments were (i) napiergrass basal diet fed alone (NG), (ii) napiergrass supplemented with mucuna hay (MH), (iii) napiergrass supplemented with lablab hay (LH), and (iv) napiergrass supplemented with a commercial dairy meal (CDM). The supplements were fed at iso-nitrogenous levels to meet the crude protein (CP) requirement of a 350-kg lactating cow producing 8–10 kg milk day −1. The MH, LH, and CDM treatments increased ( P<0.01) total dry matter intake (TDMI) (130, 136, and 142 g kg −1 BW 0.75, respectively) compared to NG (108 g kg −1 BW 0.75). Supplementation also increased ( P<0.01) apparent DM digestibility (587, 625, and 615 g kg −1, for MH, LH, and CDM, respectively) compared to NG (558 g kg −1) and daily yield of 4% fat corrected milk (FCM) (4.20, 4.15, and 5.21 kg, for MH, LH, and CDM, respectively) compared to NG (3.69 kg). Supplements increased mean body condition score, but they had no effect on body weight (BW) gain. Results show that milk production can be increased by supplementing a napiergrass-based diet with mucuna or lablab hay, highlighting the importance of integrating legumes into the low-input, mixed cropping systems in the tropics.

Biodiversity of domestic livestock in the Republic of Yemen.

This paper describes the domestic livestock of the Republic of Yemen and aspires to complement earlier sources listing or partially describing 'breeds'. It attempts to cover all species and provide indications of production parameters through a literature review and via field observations made by the author in 1999. Information is provided on livestock numbers and the economic importance of animal production. Most animals are kept in sedentary mixed crop-livestock production systems; transhumant systems have the next greatest number of stock; with nomadic systems being of least and declining importance. Yemen's livestock appear to comprise at least 11 breeds of sheep, 5 breeds of goat, 2 breeds of cattle, 4 breeds of camel, 2 breeds of donkey and 1 breed of horse. There are no data on breeds of poultry but domestic fowl (where clearly considerable diversity exists) and pigeons are kept. There is little formal information on the history and relationships of most breeds. Some appear to be of ancient local origin, whereas others show affinities with those of neighbouring and other countries. None of the identified types is considered endangered, so conservation would be premature. A more formal and detailed genetic characterization, to add to the largely morphological and traditional classification, may, however, reveal such a need.

Traditional cattle-husbandry systems in Eritrea: cattle–man relationships

Through surveys and participatory rural appraisal methods, the study documents the traditional cattle-husbandry systems in both the mixed crop–livestock system in the highlands and the pastoral system in the lowlands in Eritrea. Herding, grazing, breeding strategies, heat detection, milking letdown, food habits, marketing, housing and traditional veterinary practices are described in each system. The pastoral system is based on large, mobile, predominantly female herds that go for long-range grazing and cattle are mainly kept for milk and milk products. In the highland farming communities, cattle are sedentary, relatively fewer, predominantly male and are mainly kept to provide energy for agricultural purposes.

CROP RESIDUES FOR MULCH AND FEED IN CROP–LIVESTOCK SYSTEMS: IMPACT ON MAIZE GRAIN YIELD AND SOIL PROPERTIES IN THE WEST AFRICAN HUMID FOREST AND SAVANNA ZONES

A study was conducted in the humid-forest, forest-savanna, and Guinea savanna zones of West Africa from 1993 to 1999 to examine the effect of managing crop residues from cereal–legume cropping systems for mulch and fodder for sheep. Increasing the proportion of total crop residues produced from a unit area of land and used as mulch increased maize grain yield, soil organic carbon, nitrogen and available phosphorus. The extra increases obtained when more than half the crop residues were applied as mulch were relatively small, however, suggesting that 25–50% of the crop residues could be removed as feed without any detrimental effect. When any crop residues rejected by sheep were mixed with livestock urine and faeces and returned to the respective fields from where the crop residues had been removed, subsequent grain yield and soil organic carbon, nitrogen, and available phosphorus increased. The study demonstrated the possibility of managing crop residues for increased productivity in smallholder mixed crop–livestock systems.

Impact of grazing on plant species richness, plant biomass, plant attribute, and soil physical and hydrological properties of vertisol in East African highlands.

Understanding the problems of grazing land in vertisol areas and seeking long-lasting solutions is the central point where mixed crop livestock is the second stay for the majority of the population. In order to understand this, the current study was conducted at two sites, one with 0-4% slope and the other with 4--8% slope at Ginchi watershed, 80 km west of Addis Ababa, Ethiopia. The specific objectives of the study were to quantify changes in plant species richness, biomass, plant cover, and soil physical and hydrological properties. The grazing regimes were: moderate grazing (regulated), heavy grazing (free grazing), and no grazing (closed to any grazing), which was considered the control treatment. The results showed that the biomass yield in nongrazed plots was higher than in the grazed plots. However, the biomass yield in grazed plots improved over the years. Species richness and percentage of dominant species attributes were better in medium grazed plots than the other treatments. Soil compaction was higher in very heavily grazed plots than in nongrazed and medium-grazed plots. In contrast to that, the soil water content and infiltration rate were better in nongrazed plots than in grazed plots. Soil loss in grazed plots decreased with the increase of biomass yields and as the soil was more compacted by livestock trampling during the wet season. Finally since the medium stocking rate is better in species richness and plant attributes, and lies between nongrazed and heavily grazed plots in the rest of the measured parameters, it could be the appropriate stocking rate to practice by the smallholder farmer.

Prevalence of bovine dermatophilosis in a tropical highland region of Ethiopia.

A study was made of bovine dermatophilosis on 540 animals at a high altitude (2400-2500 m above sea level) in Ethiopia. Eighty-two (15.4%) of the animals were affected by the disease which was more prevalent in local animals than was previously assumed. There was a significant (p < 0.05) difference in the prevalence among different age groups. However, the difference in the prevalence of the disease between males and females was not significant (p > 0.05). Associated risk factors included the relatively high average annual rainfall and humidity, tick infestation (76%) and management, related to the mixed crop-livestock production system. The possible impact of the disease on Ethiopian agriculture is indicated.

Implications of livestock feeding management on soil fertility in the smallholder farming systems of sub-Saharan Africa

The role of livestock in nitrogen cycling in mixed crop–livestock farming systems of sub-Saharan Africa was explored. Cattle were fed a range of diets to investigate the effects on partitioning of nitrogen between urine and faeces and on the chemical composition of the manures produced. The trade-offs in efficiency between using the feed resources as a direct soil amendment for crop production compared with feeding to livestock and use of the manure as a fertiliser are discussed. Increased dry matter (DM) and nitrogen intake of a poor quality basal diet (barley straw) was achieved by supplementation with 15 and 30% of DM offered as Calliandra calothyrsus, Macrotyloma axillare or poultry manure. Urinary-N excretion for the basal diet (0.5 mg kg −1 liveweight (W) per day) was similar to C. calothyrsus at 15 and 30% supplementation (1.3 and 0.8 mg kg −1 W per day, respectively) and M. axillare at 15 and 30% supplementation (0.4 and 0.6 mg kg −1 W per day, respectively). In contrast, feeding poultry manure, a supplement containing highly degradable N, resulted in larger excretions of excess rumen ammonia as N in the urine, 17.5 and 23.2 mg kg −1 W per day for 15 and 30% supplementation, respectively. Diets containing the largest rate of C. calothyrsus supplementation had the lowest digestibility of N in the acid detergent fibre (ADF) and neutral detergent fibre (NDF) fractions. This was reflected in faeces from cattle fed diets supplemented with C. calothyrsus, which had substantially greater amounts of N bound to fibre (ADF and NDF) fractions than faeces from the other diets. When incubated in leaching tubes prunings of C. calothyrsus showed net N mineralisation from week 2, whereas barley straw, M. axillare and poultry manure immobilised N for >28, 24 and >28 weeks, respectively. Faeces derived from supplementation with C. calothyrsus and M. axillare resulted in shorter nitrogen immobilisation in leaching tubes (16 weeks) than supplementation with poultry manure (24 weeks) when compared with faeces derived from animals fed straw only (28 weeks). Similarly, reduced N uptake from 10-week-old maize plants was observed in pots to which faeces had been added compared with the control treatment. A second crop of maize had increased N uptake. Feeding poor quality crop residues like barley straw to animals produces manures with a decreased capacity to immobilise mineral N in the soil. This was shown with faeces derived from feeding ruminants a diet of only barley straw, which had a faster N mineralisation rate than fresh barley straw, a shorter and smaller N immobilisation stage in leaching tubes and gave greater N uptake in maize grown in pots. These results indicate that N losses in urine from livestock may be less important than previously thought. Most of the N is excreted in the faeces, which must be conserved and managed to maximise nutrient cycling.

Nutrient balance patterns in African livestock systems

This paper presents an overview of the current status, problems and prospects for achieving a better nutrient balance to support varying levels of productivity from the three major livestock systems in Africa. In free range grazing systems, livestock nutrient deficiencies are mainly overcome by moving the animals to better grazing areas. This makes monitoring and managing of nutrients within a system very difficult. Nutrient recovery, cycling and synchronization of manure with other recycled or purchased sources are greater in mixed crop–livestock systems. In these systems, inclusion of nitrogen-fixing leguminous forage/tree crops as companions or rotation crops with cereals further improves the nutrient use efficiency and balance. With more favourable market and policies, commercialized dairy systems are developing around the urban areas of Africa. Such systems heavily depend on purchased feeds and nutrients, and have serious implications for the nutrient balance and sustainability of land use systems in the rural areas which supply the feeds, and for the urban areas because of the risk of pollution from the accumulating animal wastes.