Objective selection criteria and mating strategy of indigenous Nguni cattle under low-input in-situ conservation programs

O Tadaa*, V Muchenjeb and K Dzamac aDepartment of Animal Production and Technology, Chinhoyi University of Technology, P. Bag 7724, Chinhoyi, South Africa. bDepartment of Livestock and Pasture Science, University of Fort Hare, P. Bag X1314, Alice 5700, South Africa. cDepartment of Animal Sciences, Stellenbosch University, P. Bag X1, Matieland 7602, South Africa.
*Corresponding Author: Tel: +263 772 116 441, Email: tadao@cut.ac.zw

Abstract

Participatory Rural Appraisal techniques were employed to determine the breeding objectives of Nguni cattle under community-based management of indigenous livestock genetic resources. Six groups each composed of nine representative farmers from communal and small-scale conservation enterprises participated in deriving the objective selection criteria of breeding animals using data on economic weights of preferential traits. The shuffled focus groups brainstormed on the mating strategy and management of breeding animals within low-input conservation enterprises. An economic-weight dependent culling method (EWCM) and two-tier open nucleus breeding scheme were conceptualized. The Nguni breeding animals ideally need to maintain optimum body condition score (4 - 6) and low tick counts across seasons under low-input production system. The indigenous breeding bulls need to have high reproductive efficiency while breeding cows must have calved before reaching 27 month age. The farmers set a two-and-half-year service period of breeding bulls in the in-situ conservation enterprise before culling. Farmers are recommended to objectively assess breeding animals and maintain an updated performance data and information recording system.

Keywords: economic weight-dependent culling, focus group discussion, preferred traits, two-tier open nucleus breeding

Introduction

Quantification of the levels of economic benefit associated with growth, fertility and adaptability traits expressed by farmed livestock has been a central issue in the development of breeding objectives (Roessler et al., 2008; Kassie et al., 2010). Furthermore, it was noted that in developing countries where animal production is still mostly subsistence-oriented and livestock fulfil many functions (Tada et al., 2012), a considerable number of breeding programs have failed due to lack of smallholders' participation in the planning and designing phase (Kosgey et al., 2006). This necessitates the input of the rural cattle producers in formulating the breeding objectives of a conservation program intended to benefit them.

The in-situ conservation program of the indigenous Nguni cattle, pioneered by the University of Fort Hare, has been in place for two cattle generations (6-7 years) in the Eastern Cape Province of South Africa. Efforts by the Industrial Development Cooperation, Department of Rural Development and Agrarian Reform and other academic institutions resulted in active participation of other provinces in preserving the Nguni cattle (IDC, 2010). A high number of young bullocks are erupting in the conservation enterprises because of the balanced birth sex ratio observed by Tada et al. (2013a). This also resulted in a high ratio of breeding male to breeding female animals (17%) and a high bulling rate in communal and small-scale conservation enterprises (Tada et al., 2013a). A selection model based on the knowledge of the farmers on preferential traits is justified to identify potential productive young breeding bulls for marketing within and outside the rural areas. Selection is possible because genetic and phenotypic variation exist as observed in other studies on health, reproductivity, growth and adaptability of this indigenous breed (Reed, 2008; Nqeno et al., 2010; Scholtz and Theunissen, 2010).

The low-input Nguni conservation enterprises are characterised by random mating and a high inbreeding rate has been postulated (Mapiye et al., 2009; Tada et al., 2012). A proper mating strategy may address these breeding concerns as well as other effects of low effective population sizes so as to sustainably maintain the overall goal of community-based in-situ conservation of the indigenous cattle. Some schools of thought had long established that improving food security and alleviating poverty through the conservation of farm animal genetic resources in Africa, as well as utilization of local farm animal populations depends on the ability of communities to decide on and implement appropriate breeding strategies (Wollny, 2003; Gizaw et al., 2010). The selection criteria can be influenced by socio-economic and biophysical conditions of an area. Hence, different communities may have different criteria or same criteria but different strengths of selection parameters. Therefore, the objective of the study was to determine a farmer-derived selection criteria and mating strategy for young breeding Nguni cattle under low-input production systems. It was hypothesized that, given the proper tools, low-input Nguni cattle farmers are able to make recommendations on the breeding objectives of their enterprises.

Materials and Methods

Description of the study sites and selection of participants
The study was conducted in the Eastern Cape Province of South Africa in form of a group discussion with 54 farmers from 54 Nguni cattle conservation enterprises representing 75% of the target population. The farmers who participated in the preliminary study on the use of choice experiments to determine economic weights of most preferred traits in young breeding Nguni animals were considered (Tada et al., 2013b). Thirty participants represented communal enterprises while 24 were from small-scale enterprises. The criteria involved selecting a representative farmer, literate and willing to implement cattle recording system. Farmers were first exposed to interactive discussions on the value of animal records, traits of economic importance and recording.

Data and information collection
Focus group discussions were used to elicit responses from the farmers on the derivation of the selection model and mating strategy of breeding animals. The discussions were conducted in Xhosa vernacular. Six groups of nine individuals each were randomly created composed of five and four farmers representing communal and small-scale enterprises, respectively. The small-scale enterprises were defined as livestock holdings with less than 100ha farm sizes and not exceeding 500 cattle. With the assistance of trained moderators, groups of farmers were presented with economic weights and values of the most preferred trait levels from the previous study involving choice experiments (Table 1 and 2) (refer to Tada et al., 2013b). The traits used in the study were; tick infestation (TI), body condition score (BCS), aggression and mating behaviour (AMB) of bulls, and age at first calving (AFC) of cows.

Table 1 Estimates of economic weights and values of traits level in young breeding Nguni bulls
|Trait Level |Economic |p-value |Economic values |
| |weight ± s.e | | |
|Poor Body Condition Score (1 - 3) |-0.987±0.095 |p < 0.05 |-R8 494.00 |
|Good Body Condition Score (4 - 6) |0.447±0.073 |p < 0.05 |R3 849.00 |
|Over Body Condition Score (7 - 9) |Base level |R4 645.00 |
|Low Tick Infestation (visible ticks < 10) |0.573±0.103 |p < 0.05 |R4 927.00 |
|Medium Tick Infestation (tick count of 10 - 30) |0.581±0.084 |p < 0.05 |R5 001.00 |
|High Tick Infestation (tick count of > 30) |Base level |-R9 928.00 |
|High Aggression and Mating Behavior |4.408±0.095 |p < 0.05 |R37 939.00 |
|Average Aggression and Mating Behavior |2.534±0.094 |p < 0.05 |R21 807.00 |
|Low Aggression and Mating Behavior |Base level |-R59 746.00 |
|Price |-0.001±0.0017 |p < 0.05 | |
|Constant |10.106±0.375 |p < 0.05 | |

NB: Economic value of trait level used as a base is zero (0). US$1.00 = R7.80 (South Africa Reserve Bank, 2011

Table 2 Estimates of economic weights and values of traits level in first parity Nguni cows
|Trait Level |Economic |p-value |Economic value |
| |weight ± s.e | | |
|Poor Body Condition Score (1 - 3) |-0.057±0.055 |p> 0.05 |-R 413.00 |
|Good Body Condition Score (4 - 6) |1.080±0.061 |p< 0.05 |R7 834.00 |
|Over Body Condition Score (7 - 9) |Base level |-R7 421.00 |
|Low Tick Infestation (visible ticks < 10) |1.496±0.059 |p < 0.05 |R10 859.00 |
|Medium Tick Infestation (tick count of 10 - 30) |0.829±0.067 |p < 0.05 |R6 015.00 |
|High Tick Infestation (tick count of > 30) |Base level |-R16 874.00 |
|Age at First Calving ≤ 27 months |2.368±0.068 |p < 0.05 |R17 185.00 |
|Age at First Calving 27 – 36 months |1.303±0.076 |p < 0.05 |R9 454.00 |
|Age at First Calving > 36 months |Base level |-R26 638.00 |
|Price |-0.001±0.0002 |p < 0.05 | |
|Constant |8.973±0.310 |p < 0.05 | |

NB: Economic value of trait level used as a base is zero (0). US$1.00 = R7.80 (South Africa Reserve Bank, 2011).

The group activity involved the objective determination of trait levels that brings the most perceived retains to the enterprise. An independent culling method was “modified” to an Economic Weight-dependent Culling Method (EWCM). The EWCM caters for only the positive and significant economic weights of trait levels in the selection criteria for the breeding animals. Ranking according to the part worth values was done in descending order on the trait levels under consideration. The group activity also involved discussions on the economically acceptable threshold trait level to be included in the selection model. The effect of the seasonal differences on body condition scores and tick infestation challenge were also discussed by the farmers. Each group made a short presentation of their task to all the participants.

Derivation of a mating strategy was achieved through another interactive discussion with randomly shuffled group members. Each group behaved as Nguni conservation enterprise and needed to; (1) identify sources of breeding stock, (2) determine the duration of the breeding bull in the herd, (3) determine methods of identification and culling the breeding animals, and (4) device a sound recording and record keeping system. The groups made a presentation of their work and with the help of the workshop moderator the business linkages were formed between the “Nguni conservation enterprises” i.e. participant focus groups. The linkages between “Nguni conservation enterprises” formed through common sources of breeding stock, record keeping system, and destination of culled animals were the basis of formulating a systematic open-nucleus breeding scheme.

Statistical analyses
All the descriptive statistics of the demographic factors, frequencies of choices, method of cattle identification, duration of breeding bulls in an enterprise, and information on sources of breeding stock, culling and record keeping system were analysed using GenStat 7.2.2 (2008). The trait levels of Nguni breeding cattle were ranked using Kruskal-Wallis test for the order of inclusion in the breeding objective. This was done for the two selection models i.e. first parity cows and young breeding bulls.

Results

A significant majority (>50%) of the farmers were above 50 years of age in both communal and small-scale enterprises. No significant differences (p > 0.05) were observed in the education levels attained by farmers in communal and small-scale enterprises although primary (42%) and secondary education (46%) had significantly high frequencies than college education (12%). It was also observed that 21% of the respondents were females while 79% were males.

Criteria of selecting young breeding Nguni bulls
The criteria of selecting young breeding Nguni bulls were farmer-derived and followed an economic weight-dependent culling method (EWCM) in three steps as explained below and illustrated schematically on Figure 1;
Step One: The young Nguni bulls need to have a high score on Aggressiveness and Mating Behavior (AMB). A medium AMB score is only acceptable given that Tick Infestation (TI) score is low and the Body Condition Score (BCS) is good i.e. 4 to 6 on a scale of 1 to 9.

Step Two: The TI score need to be medium or low depending on the season where a medium score may be acceptable under hot-wet and post-rain season unlike during the hot-dry and cold-dry season.

Step Three: The acceptable BCS need to be in the range of 4 to 6 depending on the season where a score of 4 is acceptable during the hot-dry and cold-dry season, and a score of 6 in the post rain and hot-wet season.

Criteria of selecting first parity breeding Nguni cows
The criteria followed a three-step procedure presented below and schematically on Figure 2.
Step One: The age at first calving need to be less than 27 months. First-calvers of 27 – 36 months are acceptable only if the TI is low and the BCS is good (4 – 6).

Step Two: The TI need to be low. A medium score of TI is only acceptable (a) in the hot-wet and post-rain season, (b) when the age at first calving is below 27 months and (c) the BCS is 4 – 6 depending on the season i.e. a score of 4 is acceptable during the hot-dry and cold-dry season, and a score of 6 in the post rain and hot-wet season.

Step Three: The acceptable BCS need to be in the range of 4 to 6 depending on the season with a score of 4 is acceptable during the hot-dry and cold-dry season, and a score of 6 in the post rain and hot-wet season.

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Figure 1 Selection criteria of young breeding Nguni bulls in communal conservation enterprises

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Figure 2 Selection criteria of first parity breeding Nguni cows in communal conservation enterprises

Mating strategy and management of Nguni cattle conservation enterprises
The farmers concurred on a two-tier open-nucleus breeding scheme with a minimum of three enterprises as a mating strategy of the in-situ conservation program. The linkages were formed from common sources of breeding stock. The schematic representation of the breeding scheme is in Figure 3. A continuous breeding season was also highlighted by all farmers. The maximum service period of the breeding bull in the herd of an enterprise was set at two-and-half years.

Furthermore, to increase the accuracy of selection, branding was the method of identification favoured by most farmers (86%) while others preferred ear-tagging (14%). Farmers agreed when culling the breeding animal to follow the selection criteria of an economic weight-dependent culling method (EWCM) (Figure 1 and 2). All the farmers (100%) indicated a need for a sound record keeping system in form of a booklet in order to implement the selection criteria and mating strategy. The data and information to be captured include; pedigree, sex, phenotypic characteristics, husbandry practices, animal dynamics, reproductive efficiency, and product quantification (Figure 4).

Discussion

The communal low-input Nguni cattle production is characterised by lack of pedigree records and standard performance data, and information recording (Mapiye et al., 2009; Tada et al., 2012). This makes it difficult to compute genetic parameters (i.e. phenotypic and additive genetic variances and covariances) of the preferred traits by the farmers in the hope of coming up with a selection index. The independent culling level method was modified to cater for the limitation of relative economic values of traits and trait levels using results from a preliminary study on choice experiment. The culling levels considered were based on positive and significant economic weights to give the name “Economic Weight-dependent Culling Method”. Only three traits were considered in the formulation of the breeding objectives in an effort to maximize genetic progress in any one trait (Hazel and Lush, 1943; Hazel et al., 1994).

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Enterprise exists include; Productive breeding bulls (Y), Infertile heifers, cull cows and unproductive breeding bulls (X).
Enterprise entries include; Productive breeding bulls and cows and heifers from genetically distant commercial stud herds (R, S, T e.t.c), and Proven animals from other enterprises (Y).

Figure 3 Schematic representation of the two-tier open nucleus breeding scheme for Nguni cattle conservation enterprises.

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Figure 4 Individual animal record sheet for capturing performance data and information

Under smallholder production systems, conventional breeding methods are constrained by absence of individual animal identification and records, low level of literacy, small herd sizes per household and uncontrolled breeding (Mapiye et al., 2009; Tada et al., 2012). To design viable genetic improvement schemes under small-scale sector, the prevailing production conditions and/or systems and production goals must be fully understood. The views of the targeted communities were accounted for through focus group discussions as all farmers had an equal opportunity to express their ideas. Farmers of indigenous Sheko cattle in Ethiopia reported a success story achieved through focus group discussions (Desta et al., 2011). Because breeding and conservation programs are becoming increasingly cognisant of factors such as sustainability with many intangible benefits, the views of the farmers were considered very crucial in this low-input conservation system. Though the majority of farmers indicated preference for branding their cattle as a way of identification, this may be because it is a cheaper method compared to ear-tags and the reading is visible from a distant. This is important to the rural enterprises as it limits labour use and injuries associated with handling untamed cattle. Consideration of preferential traits that farmers understand, easily measure and record as well as derive direct economic value is seen as a way to increase the accuracy of selection on those traits and overall genetic progress.

The involvement of farmers in the determination of the EWCM and a two-tier open nucleus mating strategy in upgrading the rural livestock and in-situ conservation of Nguni cattle is an approach to increase the adoption level of the intervention. It has been established that livestock development interventions in the smallholder sector of developing countries had been missing the farmer participatory component (Wollny, 2003; Kosgey et al., 2006; Roessler et al., 2008). Such participation in the planning and design of breeding programs is set to encourage success. In a study conducted by Mapiye et al. (2009) in the Eastern Cape Province of South Africa in communal and small-scale sector, farmers revealed that adaptability and growth traits are the most treasured traits in selecting beef breeds and breeding stock. Therefore, involving farmers in selecting traits for genetic improvement is a forward step towards the adoption of a breeding model at community level where communal property is in the hands of many.

The use of economically viable traits in the selection criteria has also been reported, through choice experiment procedures, in Vietnam where adaptive and performance traits were preferred particularly in resource-driven/subsistence production systems (Roessler et al., 2008). These findings had similar meaning under this study where reproductive efficiency, tick and disease resistance and animal body condition have positive implications on the breeding objectives.

Animal performance recording systems have been known for long to affect genetic improvement programs (Kahi et al., 2003). An establishment of performance data and information recording system for these rural enterprises is seen as a basis of formulating a database for animal evaluation. For accurate performance evaluation in terms of genetic and phenotypic trends, computation of genetic parameters, selection criteria and mating system designs, the cattle records are fundamental. In many cases, breeding programs are only implemented successfully where accurate recording is possible. This accurate record keeping requires money, expertise and a well-developed infrastructure, which is partially or completely lacking in most rural areas of developing countries (Rege et al., 2001). The UFH Nguni cattle restoration program assisted the rural farmers on that regard. In Kenya, nucleus breeding schemes were developed to circumvent the high costs arising from performance recording and selection (Rege et al., 2001). Therefore this open nucleus scheme can be a good strategy for genetic improvement in the rural areas of Eastern Cape Province of South Africa where the expertise and structures required for operating an efficient genetic improvement program are minimal.

Bondoc and Smith (1993) recommended the establishment of two-tier open nucleus breeding systems to maximise genetic improvement, reduce inbreeding rate and reduce the total cost of recording in the participating herds. Open nucleus systems provide approximately 10% more genetic gain than a closed system because there are more animals which are potential candidates for selection. This system has potential to integrate farmers’ resources, reduce overhead costs and encourage more farmer participation (Bondoc and Smith, 1993; Wollny, 2003). The advantages of a two-tier open nucleus include; 1) generation of genetic gain with sire selection as the main activity, 2) movement of bulls from the nucleus to sire progeny in the other communal and or small-scale conservation enterprises, 3) introduction of dams born in the participating enterprises selected objectively on easily and cheaply measured traits, and 4) selection in the participating enterprises i.e. bulls born in the nucleus are used to produce cows and breeding bulls in other genetically distant enterprises while dams in the herds are used to produce both bulls and cows in this and other production systems.

The groups of farmers concurred with each other and set a two-and-half year service period limit for a breeding bull in an enterprise. This was because the average age at first calving of the Nguni breed was observed by the farmers to be 31 months and the breed standards accept 39 months (Nguni Cattle Breeders Society, 2011), an approximate period that would preclude the breeding bull to mate its daughters. The breeding bull would leave the enterprise at the time when its first crop of heifers are about to be serviced. In this way, formation of inbred lines is discouraged as mating is controlled despite the absence of a defined breeding season. Farmers amicably defended the idea of continuous roaming of breeding bulls and breeding cows given the nature of the community resources as well as the difficulty in maintaining camps and separating breeding bulls. Cattle dipping frequency ranged from 1-2 times per month, farmers dipped their cattle more in the hot–wet and hot–dry seasons than the post-rain and cold–dry seasons (Tada et al., 2013a).

Conclusions and Recommendations

Farmers managed to define the enterprise breeding objective in terms of economic-weight dependent culling method and a two-tier open nucleus breeding scheme. The selection method is an improved version of the independent culling method and it is closer to a selection index. The basis of identification of superior breeding animals was the performance records of individual animals using preferential traits that farmers understand, easily measure and see a direct economic value. The farmers set a two-and-half year maximum service period for breeding bulls in an enterprise before exchanging or culling. The farmer-determined breeding objectives form an enabling policy for a sustainable community-based management of indigenous cattle genetic resources. It is recommended for farmers to implement cattle recording system and objectively assess livestock performance. The economic-weight dependent culling method and a two-tier open nucleus breeding schemes are available tools for in-situ conservation of Nguni cattle in the rural enterprises.

Acknowledgements
The authors are grateful to the farmers under the UFH Nguni Cattle Program in the Eastern Cape Province for cooperation during the study period. The project was funded by Adam Fleming through the Nguni Project Operations (P329) of the University of Fort Hare.

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