Revista Colombiana de Ciencias Pecuarias
Print version ISSN 0120-0690
RUEDA, Sandra L; TABORDA, Lorena M and CORREA, Héctor J. Relationship between the microbial protein flow to the duodenum and some metabolic and productive parameters of lactating cows in a dairy herd of the Antioquia east. Rev Colom Cienc Pecua [online]. 2006, vol.19, n.1, pp. 27-38. ISSN 0120-0690.
With the purpose to estimate the microbial protein flow to the duodenum (MPFD) in lactating cows from the urinary excretion of allatoin and establish its relationship with some productive parameters, were used eight cows (4 Holstein and 4 BON x Holstein) in different lactation stage (55 to 361 days in lactation) they were kept under confinement conditions for 9 days eating kikuyu grass (Pennisetum clandestinum), commercial mixed food and mineralized salt. During the 3 last days was registered the milk production (MPD) and were collected samples to analyze the crude protein (CPM) and urea nitrogen (MUN) concentration. In samples of the grass and of the commercial mixed food were analyzed the dry matter (DM), crude protein (CP), ash, ether extract (EE), neutral detergent fiber (NDF), insoluble nitrogen in detergent fiber (INDF) and were estimated the non structural carbohydrates (NSC) and the total digestible nutrients (TDN). The dry matter intake (DMI) (11.63 ± 1.8 kg/cow/d) and total nitrogen intake (TNI) (249.9 ± 57.7 gr/cow/d) were determined. Besides, the rumen degradable protein (RDP), both, the grass and the commercial mixed food using the in situ technique, and the NSC: RDP relationship (1.1 ± 0.15 gr: gr) were determined. Urine excretion (UE) of each cow was collected during the last 2 days in which the nitrogen (UN) (23.08 ± 5.64 kg/cow/d) and allantoin concentration (16.9 ± 15.1 g/d) were determined and the MPFD (482.9 ± 509.7 g/cow/d) was estimate from this last. The other hand, using the TDN intake was estimate the MPFD (PMFDNRC) (769.80 ± 161.20 g/cow/d). Linear regression equations between UN and UE (p<0.03), MPFD and DMI (p<0.04), MPFD and TNI (p<0.04), and between the MPD and MPFD (p<0.05), the CPM and MPFD (p<0.03), and the MUN and MPFD (p<0.06), were estimated. The linear regression equation between NSC: RDP relationship and MPFD was not statistically significant (p> 0.7). The results suggested that the urine allantoin excretion can used to estimate the MPFD.
Keywords : allantoin; estimation; regression.