title: Matua bromegrass hay for mares in gestation and lactation.
abstract: Matua bromegrass hay (Bromus willdenowii Kunth) is a high quality forage, but its value for mares during gestation and lactation is not well known. Intake, rate of passage, performance, and reproduction by gestating and lactating Quarter Horse mares fed the hay was investigated. In this experiment, 12, 2- to 12-yr-old gravid mares (mean BW = 553 kg, SD = 36) were fed Matua hay (CP = 11.5%) or alfalfa hay (Medicago sativa L.) (CP = 15.4%) for variable days prepartum (mean 59.9 d; SD = 23.5) and for 70 d postpartum. Matua and alfalfa hay were fed as the roughage portion of the diet with a grain supplement. Mares, blocked by age, expected date of foaling, and BW, were assigned randomly within blocks to treatments (six mares per treatment). Forage type did not affect intake, gestation length, birth weight, number of foals, foal weight gain, day of first postpartum ovulation, cycles per conception, or pregnancy rate at 70 d. On d 1, milk from mares fed alfalfa hay contained less (P < 0.03) CP than milk from mares fed Matua hay. Milk CP decreased (P < 0.01) in all mares over time. In a separate experiment, voluntary intake and rate of passage of Matua (CP = 15.5%), alfalfa (CP = 24.9%), and Timothy (Phleum pratense L.) (CP = 4.1%) hays were determined in nine 2-yr-old pregnant mares (mean BW = 447 kg; SD = 21). Diets were 100% forage. Timothy hay did not meet CP requirements for mares. Voluntary intake of alfalfa hay was higher (P < 0.01) than Matua hay. Intake of Timothy hay was lower (P < 0.01) than the mean of alfalfa and Matua hay. Rate of passage offorage was measured by passage of Cr-mordanted fiber. Passage rate and retention time did not differ between Matua and alfalfa hay; however, the retention times of Matua and alfalfa hays were shorter (P < 0.01) than for Timothy hay. Our results indicate that Matua hay is a forage that can be used safely for mares during gestation and early lactation and for their young foals.
authors.affiliation: Department of Animal and Food Sciences, Texas Tech University, Lubbock 79409, USA.
authors.forename: K A
authors.initials: KA
authors.lastname: Guay
authors.forename: H A
authors.initials: HA
authors.lastname: Brady
authors.forename: V G
authors.initials: VG
authors.lastname: Allen
authors.forename: K R
authors.initials: KR
authors.lastname: Pond
authors.forename: D B
authors.initials: DB
authors.lastname: Wester
authors.forename: L A
authors.initials: LA
authors.lastname: Janecka
authors.forename: N L
authors.initials: NL
authors.lastname: Heninger
mesh_terms: D000821:Animal Feed; D000824:Animal Nutritional Physiological Phenomena; D000818:Animals; D031724:Bromus; D004043:Dietary Fiber / Q000008:administration & dosage; D002149:Energy Intake; D005260:Female; D005772:Gastrointestinal Transit; D006736:Horses / Q000378:metabolism / Q000502:physiology*; D007774:Lactation / Q000378:metabolism / Q000502:physiology*; D000455:Medicago sativa; D008892:Milk / Q000737:chemistry; D008894:Milk Proteins / Q000032:analysis; D009751:Nutritional Requirements; D009753:Nutritive Value; D031784:Phleum; D011247:Pregnancy; D011256:Pregnancy Outcome / Q000662:veterinary; D011270:Pregnancy, Animal / Q000378:metabolism / Q000502:physiology*; D011897:Random Allocation
chemical_list: D004043:Dietary Fiber; D008894:Milk Proteins