title: Lactation curves for first lactation Egyptian buffalo.
abstract: First lactation records of 1538 buffalo maintained at the Animal Production Research Institute farms in 1967 to 1990 were used to determine lactation curves for three lactation lengths: > 28 and < 150 d, > 149 d, and > or = 308 d, as well as all records. Daily milk yields were summed by 14-d intervals for analyses. Yields peaked at the first, fifth, sixth, and seventh periods for > 28 and < 150 d, > 149 d, > or = 308 d, and all records. Herd-year-season significantly affected milk yield in all periods. Persistency for all records and three groupings (> 28 d, > 149 d, and > or = 308 d in milk) was highest for the > or = 308-d group (1.02 vs. .85 for > 149 d, .57 for > 28 d, and .47 for all records). Herd-year-season of calving significantly affected persistency in all records and the three subset groupings. Persistency was higher for buffalo calving in spring and summer for all records, records > 28 d, and records > 149 d but in summer and autumn for the > or = 308 d, the correlation coefficient between persistency and milk yield (r = .06) was not significant but was negative with season of calving (r =-.11).
authors.affiliation: Animal Production Research Institute, Ministry of Agriculture, Giza, Egypt.
authors.forename: G H
authors.initials: GH
authors.lastname: Metry
authors.forename: K A
authors.initials: KA
authors.lastname: Mourad
authors.forename: J C
authors.initials: JC
authors.lastname: Wilk
authors.forename: B T
authors.initials: BT
authors.lastname: McDaniel
mesh_terms: D000375:Aging; D000818:Animals; D002417:Cattle / Q000502:physiology*; D003612:Dairying / Q000706:statistics & numerical data*; D004534:Egypt; D005260:Female; D007774:Lactation / Q000502:physiology*; D011247:Pregnancy; D012621:Seasons; D013997:Time Factors