title: Low pasture allowance until late gestation in ewes: behavioural and physiological changes in ewes and lambs from lambing to weaning.
abstract: Low pasture allowance during gestation affects ewes' BW at parturition, the bond with their lamb, lamb development, and thus also may affect their responses to weaning. The objectives were to determine if native pasture allowance from before conception until late pregnancy affects ewe-lamb behaviours at lambing, ewes' milk yield, lambs' BW, and the behavioural and physiological changes of ewes and lambs at weaning. From 23 days before conception until 122 days of pregnancy, 24 ewes grazed on two different native pasture allowances: high (10 to 12 kg of dry matter (DM)/100 kg of BW per day; HPA treatment; n=12) or low (5 to 8 kg of DM/100 kg of BW per day; LPA treatment; n=12). Thereafter, all ewes grazed on Festuca arundinacea and received rice bran and crude glycerine. Ewes' body condition score (BCS) and BW were recorded during pregnancy and postpartum periods. Milk yield was determined on days 32, 41 and 54 after lambing. Lambs' BW was recorded from birth until 72 days after lambing. Latency from parturition until the ewe licked her lamb, maternal behaviour score (a test that evaluates maternal attachment to the lamb) and latency for lamb to stand up and suckle were determined. The behaviour of the lambs and ewes was recorded before and after weaning (at 65 days). The ewes' serum total protein, albumin and globulin concentrations were measured before and after weaning. The HPA ewes presented greater BW (P<0.005) and BCS (P<0.005) than the LPA ewes during pregnancy and postpartum (P<0.04), and had a greater milk yield than the LPA ewes (P<0.03). Treatments did not influence any behaviour at lambing, lambs' BW, neither the ewes' behavioural and physiological changes at weaning. HPA lambs paced and vocalized more than LPA lambs (P<0.0001). The variation of albumin concentration before and after weaning was greater in the HPA lambs than in the LPA lambs (P<0.0001). In conclusion, although ewes' BW, BCS and milk production were affected by pasture allowance until late pregnancy, this did not affect the behaviours that lead to the establishment of the mother-young bond, nor the ewes' behavioural responses at weaning. Lambs reared by ewes that grazed on low pasture allowance during pregnancy presented fewer behavioural changes and a lower decrease of albumin concentration after weaning. Lambs' BW was not affected by the feeding received by their mothers.
authors.affiliation: 1Departamento de Biología Molecular y Celular,Universidad de la República,Lasplaces 1620,Montevideo 11600,Uruguay.
authors.forename: A
authors.initials: A
authors.lastname: Freitas-de-Melo
authors.affiliation: 2Departamento de Fisiología,Facultad de Veterinaria,Lasplaces 1620,Montevideo 11600,Uruguay.
authors.forename: R
authors.initials: R
authors.lastname: Ungerfeld
authors.affiliation: 3Laboratório de Etologia Aplicada e Bem-Estar Animal,Departamento de Zootecnia e Desenvolvimento Rural,Universidade Federal de Santa Catarina,Rodovia Admar Gonzaga,1346 Florianópolis,SC 88.034-001,Brazil.
authors.forename: M J
authors.initials: MJ
authors.lastname: Hötzel
authors.affiliation: 4Facultad de Ciencias Agropecuarias,Universidad Autónoma del Estado de Morelos,Av. Universidad 1001,Colonia Chamilpa,Cuernavaca,Morelos 62210,México.
authors.forename: A
authors.initials: A
authors.lastname: Orihuela
authors.affiliation: 5Departamento de Producción Animal y Pasturas, Facultad de Agronomía,Universidad de la República,Garzón 780,CP 12 400,Montevideo,Uruguay.
authors.forename: R
authors.initials: R
authors.lastname: Pérez-Clariget
mesh_terms: D000821:Animal Feed; D000824:Animal Nutritional Physiological Phenomena; D000818:Animals; D000831:Animals, Newborn; D001522:Behavior, Animal; D001823:Body Composition; D001835:Body Weight; D004032:Diet / Q000662:veterinary*; D005260:Female; D031751:Festuca; D007774:Lactation; D039382:Maternal Nutritional Physiological Phenomena; D008892:Milk / Q000737:chemistry*; D049590:Postpartum Period; D011247:Pregnancy; D011248:Pregnancy Complications; D012756:Sheep / Q000502:physiology*; D014886:Weaning
keywords: milk yield; pacing; sheep; stress; undernutrition