title: Short-term effects of milking frequency on milk yield, milk composition, somatic cell count and milk protein profile in dairy goats.
abstract: Goats in Canary Islands are milked once a day by tradition, but in most countries with high technology on farms, goats are milked twice a day, which is known to improve milk yield. Therefore it is important to know whether the increase of milking frequency can improve the production without impairing milk quality. The objective of this study was to investigate the short term effects of three milking frequencies on milk yield, milk composition, somatic cell count (SCC) and milk protein profile in dairy goats traditionally milked once a day. Twelve Majorera goats in early lactation (48±4 d in milk) were used. During a 5-week period, goats were milked once a day (X1) in weeks 1 and 5, twice a day (X2) in weeks 2 and 4, and three times a day (X3) in week 3. Milk recording and sampling were done on the last day of each experimental week. Milk yield increased by 26% from X1 to X2. No differences were obtained when goats were switched from X2 to X3, and from X3 to X2. The goats recovered the production level when they returned to X1. Different patterns of changes in the milk constituents due to the milking frequency effect were observed. Fat percentage increased when switched from X1 to X2, then decreased from X2 to X3, and from X3 to X2, whereas it did not show significant differences from X2 to X1. Milking frequency did not affect the protein and lactose percentages. SCC values were unaffected when goats were milked X1, X2 and X3, but then they increased slightly when milking frequency was returned to X2 and X1. Finally, quantitative analysis showed an increase in intensities of milk protein bands from X1 to X2, but the intensities of casein bands (α(S1)-CN, α(S2)-CN, β-CN, κ-CN) and major whey proteins (α-La, β-Lg) decreased from X2 to X3.
authors.affiliation: Instituto Canario de Investigaciones Agrarias,La Laguna, Tenerife 38200,Spain.
authors.forename: Alexandr
authors.initials: A
authors.lastname: Torres
authors.affiliation: Department of Animal Science,Universidad de Las Palmas de Gran Canaria,Arucas 35413,Spain.
authors.forename: Lorenzo-Enrique
authors.initials: LE
authors.lastname: Hernández-Castellano
authors.affiliation: Department of Animal Science,Universidad de Las Palmas de Gran Canaria,Arucas 35413,Spain.
authors.forename: Antonio
authors.initials: A
authors.lastname: Morales-delaNuez
authors.affiliation: Agroindustrial Engineering Department,Universidad Nacional de Chimborazo,Riobamba 060150,Ecuador.
authors.forename: Davinia
authors.initials: D
authors.lastname: Sánchez-Macías
authors.affiliation: Department of Animal Science,Universidad de Las Palmas de Gran Canaria,Arucas 35413,Spain.
authors.forename: Isabel
authors.initials: I
authors.lastname: Moreno-Indias
authors.affiliation: Department of Animal Science,Universidad de Las Palmas de Gran Canaria,Arucas 35413,Spain.
authors.forename: Noemi
authors.initials: N
authors.lastname: Castro
authors.affiliation: Instituto Canario de Investigaciones Agrarias,La Laguna, Tenerife 38200,Spain.
authors.forename: Juan
authors.initials: J
authors.lastname: Capote
authors.affiliation: Department of Animal Science,Universidad de Las Palmas de Gran Canaria,Arucas 35413,Spain.
authors.forename: Anastasio
authors.initials: A
authors.lastname: Argüello
mesh_terms: D000818:Animals; D002364:Caseins / Q000032:analysis; D002452:Cell Count / Q000662:veterinary; D003612:Dairying / Q000379:methods*; D005260:Female; D006041:Goats / Q000502:physiology*; D007774:Lactation / Q000502:physiology; D007785:Lactose / Q000032:analysis; D008892:Milk / Q000737:chemistry* / Q000166:cytology; D008894:Milk Proteins / Q000032:analysis*; D013997:Time Factors
chemical_list: D002364:Caseins; D008894:Milk Proteins; D007785:Lactose