Effect of offer level of kikuyu grass (pennisetum clandestinum) on production, milk quality and nitrogen balance in Holstein cows

To test the effect of two pasture allowance (PA) on milk production (Mprod) and composition, and nitrogen balance (N) in Holstein cows grazing kikuyu grass, a study was conduced with six cows with two or more parturition in second month of nursing (188.5 ± 41 d) randomly assigned to two treatments: 2.5 (L) and 3.5 kg of dry matter (MS)/100 kg of body weight (BW) (H) in a cross-over design with two 14 days periods and 25 days between-periods. During three days before began the experimental period, the milk production was registered, cows were weighted (BW) and body condition score (BCS) were determined. Elsewhere, milk samples were recollected and analyzed to protein and fat, and faecal samples were analyzed to basal chromium content. Then, the cows were individually allocated in a kikuyu prairie using metallic wands and tied with a bow fixed to neck. The cows were supplement during the two milking, supply simultaneously 5.0 g of chromic oxide. During the last four days of each experimental period were collected individual samples of milk and analyzed to protein, fat, total solids, urea, cheese yield and cheese protein content. Elsewhere, were collected faeces samples and analyzed to N, non-degradable neutral detergent fiber and chromium as well as urine samples that were analyzed to N, creatinine and allantoin content. Ruminal fluid samples were collected the last experimental day and analyzed to pH and ammonium content. Elsewhere, each cow was weighted and body condition scored. It was calculated the pasture dry matter intake (pDMI), total dry matter intake (tDMI) and substitution rate (ST). It was estimated the N intake (Nint), N in faeces (Nfae), N in urine (Nurin), N in milk (Nmilk), N replenished (Nrep), the N efficiency to milk protein production (Neffic) and microbial protein synthesis (Mprot). The CMSF was lower in cows of the OFBaja treatment as was the CMST (p <0.01). Treatments did not affect the PDCN, the GCC and the LW of the animals. There was also no effect of treatments on the quality of milk and rumen activity. The treatment OFBaja had greater EUN (p <0.02) without affecting other variables of the N balance. It was concluded that 3.5 PA, compared with 2.5 kg, improved Nint and reduced Neffic but did not affect BW, Mprod nor milk composition.

• Autores: Héctor Jairo Correa C.; Rodríguez, Yeisson Gustavo; Martha Lucía Pabón R.; Carulla J.E.
• Tipo de recurso: Article of journal
• Fecha de publicación: 2012
• Institución: Universidad Cooperativa de Colombia
• Repositorio: Repositorio UCC
• OAI Identifier: oai:repository.ucc.edu.co:20.500.12494/42859
• Acceso en línea: https://www.scopus.com/inward/record.uri?eid=2-s2.0-84869845836&partnerID=40&md5=bd840b01be87bcdae98b74a959ccd1d7; https://hdl.handle.net/20.500.12494/42859
• Palabra clave: Animalia; Pennisetum; Pennisetum clandestinum
• Rights: closedAccess
• License: http://purl.org/coar/access_right/c_14cb