Economic weights of fertility, prolificacy, milk yield and longevity in dairy sheep

Neiker-Tecnalia Basque Institute for Agricultural Research and Development, Vitoria, Basque Country, Spain
animal (Impact Factor: 1.84). 03/2007; 1(2):193-203. DOI: 10.1017/S1751731107657814
Source: PubMed


Economic weights have been estimated in two breeds (Latxa and Manchega) using economic and technical data collected in 41 Latxa and 12 Manchega dairy sheep flocks. The traits considered were fertility (lambing per year), prolificacy (number of lambs), milk yield (litres) and longevity (as productive life, in years). A linear function was used, relating these traits to the different costs in the flock. The variable costs involved in the profit function were feed and labour. From this function, economic weights were obtained. Labour is considered in the Latxa breed to be a constraint. Moreover, farm profits are unusually high, which probably means that some costs were not included according to the economic theory. For that reason, a rescaling procedure was applied constraining total labour time at the farm. Genetic gains were estimated with the resulting economic weights to test if they give any practical difference. Milk yield only as selection criterion was also considered. The medians of the estimated economic weights for fertility, prolificacy, milk yield and longevity were 138.60 € per lambing, 40.00 € per lamb, 1.18 € per l, 1.66 € per year, and 137.66 € per lambing, 34.17 € per lamb, 0.73 € per l, 2.16 € per year under the linear approach in the Latxa and Manchega breeds respectively. Most differences between breeds can be related to differences in production systems. As for the genetic gains, they were very similar for all economic weights, except when only milk yield was considered, where a correlated decrease in fertility led to a strong decrease in profit. It is concluded that the estimates are robust for practical purposes and that breeding programmes should consider inclusion of fertility. More research is needed to include other traits such as somatic cell score, milk composition and udder traits.

Download full-text


Available from: Manuel Ramon,
63 Reads
  • Source
    • "The introduction of economic factors in defining selection goals is not new (Hazel and Lush, 1942). However, only recently a few studies were devoted to derive economic values for selected traits by different approaches (profit functions, herd model) in dairy sheep (Tolone et al., 2011; Fuerst-Waltl and Baumung, 2009; Wolfova et al., 2009; Legarra et al., 2007a, 2007b). Amer et al. (2001) suggested that while the terms economic value and economic weight are often used synonymously, they may also be defined as the absolute and the relative benefit of improving a trait, respectively. "
    [Show abstract] [Hide abstract]
    ABSTRACT: Generally, all traits of economic importance should be included in the breeding goal of livestock breeding programmes. The main aim of this study was to examine economic values for a combination of dairy and meat traits of the dual purpose Bardhoka (BAR), Balusha (BAL), Sharri (SHA) and Kosova (KOS) sheep breeds in Kosovo. The underlying herd model is based on a deterministic approach considering a sheep flock with milk production, lamb fattening and replacement stock. In order to examine the economic impact for different sheep breeds, the production traits considered were milk (milk yield) and fattening (daily gain). For each lactation cycle among the breeds the main revenues resulted from selling milk (€ 61.82/46.03/26.37/27.22) and fattened lambs (€ 34.06/39.88/35.42/33.92) for BAR/BAL/ SHA/KOS, respectively. For BAR and BAL the economic value per average ewe place and year was € 37.7 for both breeds, while for SHA and KOS it was €35.1 and € 32.5, respectively. For lamb fattening, daily gain was found to have the highest economic value at € 7.00 for BAL, SHA and KOS, while for BAR it was € 6.67. The relative economic values for milk yield and daily gain for BAR, BAL, SHA and KOS were 84.96:15.04, 84.42:15.58, 83.45:16.55, and 2.36:17.64, respectively.
    Italian Journal of Animal Science 10/2015; 14(4):603-609. DOI:10.4081/ijas.2015.3808 · 0.72 Impact Factor
  • Source
    • "Morin and Charroin (2009) in Roquefort (France; 372 ewes and 233 L/ewe), Thomas (2004) in the United States and Canada (145 ewes and 178 L/ewe), Legarra et al. (2007) in the Basque Country (Spain; 407 ewes and 94 L/ewe), and Gelasakis et al. (2012) in Macedonia and Thessaly (Greece; 210 ewes and 277 L/ewe). Nevertheless , Legarra et al. (2007) "
    [Show abstract] [Hide abstract]
    ABSTRACT: Twenty dairy sheep farms of Assaf breed, located in the Spanish autonomous community of Castilla y León and included in a group receiving technical support, were used to study their production cost structure and to assess their economic profitability during 2009. On average, farms had 89.2 ± 38.0 ha (own, 38%), 592 ± 63 ewes, yielded 185.9 ± 21.1 × 10(3) L/yr (i.e., 316 ± 15 L/ewe), and were attended by 2.3 ± 0.2 annual working units (family, 72%). Total annual income was €194.4 ± 23.0 × 10(3)/yr (€1.0 = $1.3) from milk (78.6%), lamb (13.2%), culled ewes (0.5%), and other sales (0.8%, wool and manure), and completed with the European Union sheep subsidy (6.9%). Total costs were €185.9 ± 19.0 × 10(3)/yr to attend to feeding (61.6%), labor (18.2%), equipment maintenance and depreciation (7.6%), finances (3.0%), animal health (2.5%), energy, water and milking supplies (2.2%), milk recording (0.5%), and other costs (4.4%; assurances, shearing, association fees, and so on). Mean dairy sheep farm profit was €8.5 ± 5.8 × 10(3)/yr (€7.4 ± 8.3/ewe) on average, and varied between €-40.6 and €81.1/ewe among farms. Only 60% of farms were able to pay all costs, the rest had negative balances. Nevertheless, net margin was €31.0 ± 6.5 × 10(3)/yr on average, varying between €0.6 and €108.4 × 10(3)/yr among farms. In this case, without including the opportunity costs, all farms had positive balances. Total annual cost (TAC; €/ewe) and total annual income (TAI; €/ewe) depended on milk yield (MY; L/ewe) and were TAC = 161.6 + 0.502 MY (r(2) = 0.50), and TAI = 78.13 + 0.790 MY (r(2) = 0.88), respectively, with the break-even point being 291 L/ewe. Conversely, farm TAC (€/yr) and farm TAI (€/yr) were also predicted as a function of the number of ewes (NOE) per flock, as TAC = 18,401 + 282.8 NOE (r(2) = 0.89) and TAI = 330.9 NOE (r(2) = 0.98), with the break-even point being 383 ewes/flock. Finally, according to the increasing trend expected for agricultural commodity prices, it was calculated that a 10% increase of concentrate price will require 5.2% milk price increase for constant profit. Similarly, a 10% increase of forage price will require 2.0% milk price increase to maintain profitability. Under these scenarios of increasing the commodity prices of key feedstuffs, a change of flock feeding should be expected to compensate the losses in farm profitability. Most Assaf dairy sheep farms studied were economically profitable, with flock size, milk yield, and feeding costs key for their profitability.
    Journal of Dairy Science 06/2014; 97(8). DOI:10.3168/jds.2013-7884 · 2.57 Impact Factor
  • Source
    • "resistance. Productive lifetime of breeding females in itself should be defined as a trait characterising exclusively the health status of animals (Reinsch and Dempfle, 1998), and the EV of this trait should only include the impact of changes in the culling rate for adverse health and female mortality rate on the economics of the evaluated production system (Conington et al., 2004; Roughsedge et al., 2005; Legarra et al., 2007). When productive lifetime is defined in this way, average survival rate may be used as an alternative trait. "
    [Show abstract] [Hide abstract]
    ABSTRACT: The objective of the present review was (i) to survey different approaches for choosing the complex of traits for which economic values (EVs) are calculated, (ii) to call attention to the proper definition of traits and (iii) to discuss the manner and extent to which relationships among traits have been considered in the calculation of EVs. For this purpose, papers dealing with the estimation of EVs of traits in livestock were reviewed. The most important reasons for incompatibility of EVs for similar traits estimated in different countries and by different authors were found to be inconsistencies in trait definitions and in assumptions being made about relationships among traits. An important problem identified was how to choose the most appropriate criterion to characterise production or functional ability for a particular class of animals. Accordingly, the review covered the following three topics: (i) which trait(s) would best characterise the growth ability of an animal; (ii) how to define traits expressed repeatedly in subsequent reproductive cycles of breeding females and (iii) how to deal with traits that differ in average value between sexes or among animal groups. Various approaches that have been used to solve these problems were discussed. Furthermore, the manner in which diverse authors chose one or more traits from a group of alternatives for describing a specific biological potential were reviewed and commented on. The consequences of including or excluding relationships among economically important traits when estimating the EV for a specific trait were also examined. An important conclusion of the review is that, for a better comparability and interpretability of estimated EVs in the literature, it is desirable that clear and unique definitions of the traits, complete information on assumptions used in analytical models and details on inter-relationships between traits are documented. Furthermore, the method and the model used for the genetic evaluation of specific traits in a certain breeding organisation are important for the exact definition of traits, for which the economic values will be calculated, and for the inclusion or exclusion of relationships among traits in the calculation of the EVs in livestock breeding.
    animal 06/2013; 7(9):1-13. DOI:10.1017/S1751731113001018 · 1.84 Impact Factor
Show more