title: Milk production in dairy goats supplemented with different levels of ruminally protected methionine.
abstract: The objective of the study reported in this Research Communication was to evaluate graded levels of ruminally protected methionine (RPM) in dairy goat rations on milk production and live weight changes during 155 d of lactation. Twenty-five primiparous dairy goats (crosses of Toggenburg, French Alpine and Saanen; 45·4 ± 1·0 kg BW) were fed a basal diet (10·10% CP, 6·13 DP and 2·34 Mcal/kg ME) of corn silage, oat hay, alfalfa hay and concentrate (80% forage, 20% concentrate). After kidding, the treatments, which consisted of four oral doses of ruminally protected methionine (RPM) at 0, 1, 2 and 3 g/d, were randomly assigned to the goats. The experiment was conducted for 110 d with measurements of milk production and composition, body weight and dry matter intake. No treatment effects were detected in milk production and composition. However, goats with RPM showed a positive live weight changes during lactation which were improved as dose was increased (linear P < 0·01) whereas goats without RPM showed weight loss during the experiment.
authors.affiliation: Maestría en Ciencias de la Producción y de la Salud Animal,Universidad Nacional Autónoma de México,México D.F., 04510,México.
authors.forename: Erick
authors.initials: E
authors.lastname: Alonso-Mélendez
authors.affiliation: Departamento de Producción Agrícola y Animal,Universidad Autónoma Metropolitana,Unidad Xochimilco, México D.F. 04960,México.
authors.forename: Germán D
authors.initials: GD
authors.lastname: Mendoza
authors.affiliation: Maestría en Ciencias de la Producción y de la Salud Animal,Universidad Nacional Autónoma de México,México D.F., 04510,México.
authors.forename: Francisco A
authors.initials: FA
authors.lastname: Castrejón-Pineda
authors.affiliation: Maestría en Ciencias de la Producción y de la Salud Animal,Universidad Nacional Autónoma de México,México D.F., 04510,México.
authors.forename: Andrés E
authors.initials: AE
authors.lastname: Ducoing-Watty
mesh_terms: D000821:Animal Feed; D000818:Animals; D001835:Body Weight / Q000187:drug effects; D003612:Dairying / Q000379:methods*; D004032:Diet / Q000662:veterinary*; D019587:Dietary Supplements; D004435:Eating / Q000187:drug effects; D005260:Female; D006041:Goats / Q000502:physiology*; D007774:Lactation / Q000187:drug effects* / Q000502:physiology; D008715:Methionine / Q000008:administration & dosage* / Q000378:metabolism; D008892:Milk / Q000737:chemistry; D010298:Parity; D011247:Pregnancy; D012417:Rumen / Q000378:metabolism*
chemical_list: D008715:Methionine
keywords: Methionine; goat; milk production