Modeling lactation curve of Saudi camels using a linear and non-linear forms of the incomplete Gamma function

Aziz Mahmoud A., Faye Bernard, Al-Eknah Marzouk, Musaad Abdelgader. 2016. Modeling lactation curve of Saudi camels using a linear and non-linear forms of the incomplete Gamma function. Small Ruminant Research, 137 : pp. 40-46.

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Abstract : The objectives of this study were to describe lactation curve of Saudi camels using the linear and non-linear forms of the incomplete Gamma function, to estimate lactation curve characteristics and to determine the appropriate form describing lactation curve. Records of weekly milk yield representing 9 parities were collected from 56 she-camels. Data were collected over the period 2007–2013. The results revealed that averages of total milk yield, lactation length and daily milk yield of the nine parities, ranged between 967.3 and 3107.21 kg, between 273 and 416 days and between 2.96 and 7.40 kg/day, respectively. Initial milk yield (a) estimated by the linear and non-linear forms of the nine parities ranged between 0.194 and 1.775 and between 0.155 and 1.818, respectively. The increasing rate (b) ranged between 0.754 and 1.414 and between 0.750 and 1.533, while the decreasing rate (c) ranged between −0.054 and −0.020 and between −0.059 and −0.036, respectively. Days to attain peak production, peak production and persistency, as well as persistency percentage were also estimated. It is concluded that the linear form of the incomplete Gamma function is more appropriate for describing lactation curve of camel milk yield than its non-linear counterpart. (Résumé d'auteur)

Mots-clés Agrovoc : Dromadaire, Lactation, Rendement laitier, Production laitière, Lait de chamelle, Modèle mathématique, Modèle de simulation

Mots-clés géographiques Agrovoc : Arabie Saoudite

Mots-clés complémentaires : Camelus dromedarius

Mots-clés libres : Dromedary, Saudi Arabia, Gamma function, Milk yield, Lactation curve

Classification Agris : L52 - Animal physiology - Growth and development
L53 - Animal physiology - Reproduction
U10 - Mathematical and statistical methods

Champ stratégique Cirad : Axe 1 (2014-2018) - Agriculture écologiquement intensive

Auteurs et affiliations

  • Aziz Mahmoud A., King Faisal University (SAU)
  • Faye Bernard, CIRAD-ES-UMR SELMET (FRA)
  • Al-Eknah Marzouk, King Faisal University (SAU)
  • Musaad Abdelgader, Range Protection and Improvement Center in Al-Jouf Area (SAU)

Source : Cirad-Agritrop (

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