Evaluating the Adequacy of the CNCPS Model Luis Orlindo Tedeschi Bertha Rueda-Maldonado Francisco “Paco” Juárez-Lagunes

Mexican dual-purpose lactating cow evaluation

DescripciónEntradaUnidades Tipo de animal2Vacas lechera lactantes Edad66Meses Sexo4Vaca Peso corporal511Kg Raza2Cruzado (doble propósito) Peso maduro550Kg Condición Corporal31 = flaca a 5 = gorda Sistema de cruza2Dos vías Raza de la Madre17Brahman Raza del Padre15Holstein Dias gestante55D Días en lactancia174D Lactación5# Intervalo entre partos13Meses Promedio del Hato2866Kg Producción de leche10Kg/d Grasa en leche3.6% Proteína en leche3.2Kg% Prod. De leche relativa5Escala de 1 a 9 Peso becerro al nacer38Kg Edad al 1er parto33Meses

Descripción ambiental AditivoNo Velocidad del viento16Km/h Temperatura previa27ºC Humedad relativa previa80% Temperatura actual28ºC Humedad relativa actual80% Horas luz solar12Horas Exposicion a tormentas1Si Temp. Min. Nocturna18ºC Profundidad del pelo0.6Cm Grosor de la capa1Delgada Cubierta en el pelo1No lodo Animales sofocados1No ActividadPastoreo intensivo

BASE DE DATOS

Edad % M.sec a FDN, % MS Lig.,% FDN 1 PC, % MS Solubilida d % de PC 2 NNP, % P.Sol 3 PIDN, % PC 4 PIDA, % PC 5 E.E. % MS MIN, % MS FDN disp., %MS 6 FDN no disp., %MS 7 CNE % MS

Digestion Rate of NDF-N in Tropical Forages F.I. Juarez, A.N. Pell, and J.B. Robertson. Cornell University INIFAP

Objectives l To measure the NDF-N digestion kinetics of tropical grasses. l To determine the effects of plant maturity and N fertilization on rate and extent of digestion.

Table 1. NDF-N x 6.25 content (%CP).

Table 2. Effect of fertilization on NDF-N x 6.25 (%CP).

Table 3. Effect of Age (days) on NDF-N x 6.25 (%CP).

Table 4. NDF-N x 6.25 of 4 tropical grasses (%CP).

Table 5. NDF and NDF-N x 6.25 extent of digestion (%).

Table 6. NDF and NDF-N x 6.25 rates of digestion (%/h).

N Fertilization and CP, NDF and NDF-N x 6.25.

Table 8. Effect of Age (d) on CP, NDF and NDF-N x 6.25.

CP, NDF and NDF-N x 6.25 of 4 grasses.

Conclusions - 1 l NDF-N as % of CP averaged 35 with a range of l The NDF-N variation was primarily due to species but N fertilization and maturity also were factors.

Conclusions - 2 l NDF-N is potentially ruminally available. l Extent and rate of NDF-N digestion is affected by fertilization. l NDF-N was digested faster than NDF.

Requirements for accurate prediction in the tropics l Must accurately predict requirements for maintenance, growth, pregnancy, lactation, and energy reserves l Must accurately predict absorbed energy and protein feeds being fed for each specific farm condition l Tabular nutrient requirements and feed values developed in North America are not adequate for the tropics

CNCPS for feed management l Develop a model to predict requirements and feed biological values on each farm l Use the model to identify the factors that are first limiting performance –Energy –Protein –Amino acids –Minerals

CNCPS components for the tropics l Breed adjustments for maintenance, growth, and lactation l Tropical forages CHO and Protein fractions and digestion rates l Dry matter intake equations l Ruminal adjustment for N and branched-chain amino acids deficiencies

Dual-purpose Lactating Cows l Fifty 3/4 Holstein x 1/4 Brahman lactating cows with: –Body weight = 511 kg (550 mature), Condition score = 3, and milk production = 10 kg/d l Rotational grazing Pangola grass and supplemented with 3.5 kg/d of concentrate l From Juarez Lagunes et al. (1999) in J. Dairy Sci. 82:2136

Feed Composition ItemUnitPangola grass Sorghum grain SBM NDF%DM Lignin%NDF Protein%DM SolCP%CP NPN%SolCP Juarez Lagunes et al. (1999), Table 10

Digestion Rates ItemUnitPangola grass Sorghum grain SBM CHO A%/h CHO B1%/h CHO B2%/h Prot. B1%/h Prot. B2%/h Prot. B3%/h Juarez Lagunes et al. (1999), Table 10

Sensitivity to NDF and Lignin ME milk Kg/d MP milk Kg/d MP Bacteria g/d NDF 1, %DM Lignin 2,%NDF Lignin = 6% DM. 2 NDF = 70% DM. From Juarez Lagunes et al. (1999), Table 4 Note: ME decreases 1.25 and 0.69 of % units/% of NDF and Lignin increase, respectively

Sensitivity to NDF Digestion Rate NDF 1 Dig. Rate ME milk Kg/d MP milk Kg/d MP Bacteria g/d 3%/h %/h %/h CHO A and 16%/h. Juarez Lagunes et al. (1999), Table 5