title: NMR-metabolomics profiling of mammary gland secretory tissue and milk serum in two goat breeds with different levels of tolerance to seasonal weight loss.
abstract: Goats are of special importance in the Mediterranean and tropical regions for producing a variety of dairy products. The scarcity of pastures during the dry season leads to seasonal weight loss (SWL), which affects milk production. In this work, we studied the effect of feed-restriction on two dairy goat breeds, with different tolerance levels to SWL: the Majorera breed (tolerant) and the Palmera breed (susceptible). Nuclear magnetic resonance (NMR) was used to compare the metabolome of an aqueous fraction of the mammary gland and milk serum from both breeds. Goats in mid-lactation were divided by breed, and each in two feed-regime groups: the control group and the restricted-fed group (to achieve 15-20% reduction of body weight at the end of the experiment). Milk and mammary gland samples were collected at the end of the experimental period (23rd day). (1)H NMR spectra were collected from the aqueous extract of the mammary gland biopsies and the milk serum. Profiling analysis has led to the identification of 46 metabolites in the aqueous extract of the mammary gland. Lactose, glutamate, glycine and lactate were found to be the most abundant. Analysis of milk serum allowed the identification of 50 metabolites, the most abundant being lactose, citrate and creatine. Significant differences were observed, in mammary gland biopsies and milk serum, between control and restricted-fed groups in both breeds, albeit with no differences between the breeds. Variations seem to be related to metabolism adaptation to the low-energy diet and are indicative of breed-specific microflora. Milk serum showed more metabolites varying between control and restricted groups, than the mammary gland. The Majorera breed also showed more variations than the Palmera breed in milk samples, which could be an indication of a prompt adaptation to SWL by the Majorera breed.
authors.affiliation: Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Oeiras, Portugal. adealmeida@rossvet.edu.kn.
authors.forename: Mariana
authors.initials: M
authors.lastname: Palma
authors.affiliation: Veterinary Physiology, Vetsuisse Faculty, University of Bern, Bern, Switzerland.
authors.forename: Lorenzo E
authors.initials: LE
authors.lastname: Hernández-Castellano
authors.affiliation: Department of Animal Science, Universidad de Las Palmas de Gran Canaria, Arucas, Gran Canaria, Spain.
authors.forename: Noemí
authors.initials: N
authors.lastname: Castro
authors.affiliation: Department of Animal Science, Universidad de Las Palmas de Gran Canaria, Arucas, Gran Canaria, Spain.
authors.forename: Anastasio
authors.initials: A
authors.lastname: Arguëllo
authors.affiliation: ICIA - Instituto Canario de Investigaciones Agrarias, Valle Guerra, Tenerife, Spain.
authors.forename: Juan
authors.initials: J
authors.lastname: Capote
authors.affiliation: Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Oeiras, Portugal. adealmeida@rossvet.edu.kn.
authors.forename: Manolis
authors.initials: M
authors.lastname: Matzapetakis
authors.affiliation: Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Oeiras, Portugal. adealmeida@rossvet.edu.kn and Instituto de Biologia Experimental e Tecnológica, Oeiras, Portugal and Centro Interdisciplinar de Investigação em Sanidade Animal, Faculdade de Medicina Veterinária, Universidade de Lisboa, Lisboa, Portugal.
authors.forename: André Martinho
authors.initials: AM
authors.lastname: de Almeida
mesh_terms: D000220:Adaptation, Biological; D000818:Animals; D001947:Breeding; D005260:Female; D006041:Goats; D008321:Mammary Glands, Animal / Q000378:metabolism*; D055442:Metabolome; D055432:Metabolomics / Q000379:methods; D008892:Milk / Q000378:metabolism*; D019906:Nuclear Magnetic Resonance, Biomolecular; D012621:Seasons; D015431:Weight Loss