title: Feeding strategies for rearing replacement heifers in small-scale dairy production systems in the highlands of Central Mexico.
abstract: The growth of Holstein heifers in the campesino dairy systems in the highlands of Mexico was evaluated in three feeding strategies. Thirty-three heifers from 11 farmers, grouped according to strategy, were weighed every 14 days for 28 weeks. The live weight change over each 14-day period was estimated by individually regressing live weight over period, taking the regression coefficient as an unbiased estimate of live weight change. Regression coefficients were analysed as a randomized design with feeding strategies as treatments. Strategies were as follows: S1: grazed or cut pasture all year, maize silage and maize straw in the dry season, and 1.0-1.5 kg concentrate/heifer per day. S2: maize straw in the dry season, cut pasture forage, grazing of native grass, weeds from maize fields, and 1.0-1.5 kg concentrate/heifer per day. S3: maize straw in the dry season, grazed native grasses and weeds in the rainy season. Live weight gains were: S1, 0.511 kg/heifer per day; S2, 0.271 kg/heifer per day; and S3, 0.252 kg/heifer per day. Despite the better gains in S1, they are 24% below recommendations, arriving to service at 20 months of age. Not rearing their replacements may be a better alternative for campesino farmers under current economic conditions.
authors.affiliation: Centro de Investigación en Ciencias Agropecuarias, Universidad Autónoma del Estado de Mexico, Instituto Literario No. 100, Co. Centro, 50000 Toluca, México. caj@coatepec.uaemex.mx
authors.forename: C M
authors.initials: CM
authors.lastname: Arriaga-Jordán
authors.forename: A
authors.initials: A
authors.lastname: García-Martínez
authors.forename: B
authors.initials: B
authors.lastname: Albarrán-Portillo
authors.forename: A
authors.initials: A
authors.lastname: Espinoza-Ortega
authors.forename: O A
authors.initials: OA
authors.lastname: Castelán-Ortega
mesh_terms: D000821:Animal Feed; D000824:Animal Nutritional Physiological Phenomena; D000818:Animals; D001835:Body Weight; D002417:Cattle / Q000254:growth & development*; D003612:Dairying / Q000191:economics / Q000379:methods*; D005260:Female; D006801:Humans; D008800:Mexico; D012424:Rural Population; D012820:Silage; D003313:Zea mays / Q000378:metabolism