Forage utilization to improve productivity of dual-purpose cattle systems in central Veracruz, Mexico Victor Absalón-Medina Animal Science Department Morrison Hall 112

Veracruz State Variety of natural resources and agro- ecosystems oLumber, coffee and dairy cattle (high- lands) oDual-purpose cattle and other crops (lowlands) such as staples (maize), fruits More pictures at

Cattle: Key farming system Mexico’s premier producer of beef –>4.1 million head (2002) produce… –>214,000 metric tons of carcass weight (2003) 50,000 are dairy cows 2,000,000 are DP cows whose –Calves supply the beef market Beef cattle

Dual-purpose production system Most common system in Veracruz. Beef and milk are important products. Utilizing Bos taurus and Bos indicus crosses –Brown Swiss x Brahman and Holstein x Brahman cows

Dual-purpose system defined “Family-owned and –operated enterprise with small capital investment located on marginal land with few alternative uses under current infrastructure and market conditions. Management practices on dual-purpose farms often lack the sophistication of specialized operations; few farmers keep formal records, uncontrolled natural mating is predominant.” Nicholson et al., 1994

Dual-purpose system defined [2] Dual-purpose (DP) cattle operations in Veracruz: low outputs and productive efficiency –In which productive parameters? –Comparison of DP systems in Latin America… Honduras, Costa Rica, Panama, Bolivia, Colombia, Brazil, and Venezuela.

Productive Parameters Characteristics and production parameters of dual-purpose cattle farms in the Gulf coast region of Mexico and in other Latin American countries Variable Mexico Other Latin America Value Minimum Maximum Age at first calving, mo Body weight (calving), kg Calving rate, % of total cows in herd Days open Calving interval Mortality, % <1 year >1 year Culled cows, % year Marketable milk yield, kg per cow day Lactation, days Dry period, days Milk per lactation, kg Stocking rate, AU ha Source Reynoso-Campos et al.2003

Previous research Juárez et al. (1999) categorized and assessed different grass species –Determined the productive potential of each forage alternative Based on chemical composition, digestion kinetics and simulations of their productivity potentials. Predicted milk yields –Metabolizable energy allowable milk –Metabolizable protein allowable milk Grasses with low protein content Protein was first limiting… also energy

Previous research [2] Opportunities from combinations of forages –Rueda et al. (2003), Brazil –Shelton (2004), Australia Juárez data base: A critical information resource –Contains grasses and legumes. Research need: Ex ante evaluation of most promising options

Challenges Research information is frequently specific to narrow disciplinary objectives, such as improving genetic potential, improved forage yield or reproductive performance, rather than holistic, systems objectives. –Producers might invest to improve milking performance by artificial insemination but the nutritional requirements will be higher and costly. (Holmann et al., 1990)

INIFAP-funded project Three research sites (target ecozones) –Campo experimental “La Posta” Paso del Toro, Veracruz (coastal plain) –Campo experimental “Las Margaritas” Hueytamalco, Puebla (highlands) –Campo experimental “El Verdineño” Nayarit (Pacific coastal plain) Research approach (Rueda et al., 2005) –Integrated, multidisciplinary approach Mathematical models, system dynamics and geographic information system –To enhance the productivity of dual-purpose cattle systems while protecting and conserving watersheds. My project will focus on CNCPS evaluations of energy and protein allowable milk yield and body tissue reserve status throughout a calving interval. –A contributing study that is part of this INIFAP project

Management information needs Assumptions –Nutritive quality of grasses varies throughout the year (poorest in the dry season) –A mode of calvings coincides with the dry season –Low dietary nutrient availability results in low lactational and reproductive performances Objectives –Evaluate a representative herd scenario to understand current performance and limitations How do current systems work? –Evaluate alternative nutrition management scenarios To improve milk income To shorten calving intervals (relieve energy deficits) To evaluate preferred calving seasons

Expectations Earlier puberty (1 st heat) in heifers More rapid repletion of body tissue reserves –Earlier return to the ovarian cyclicity –Shorter calving intervals More milk for calves and sales. –Earlier weaning and/or weaning weight improved or both. More profit

Input information Distribution of supply and nutritive quality of forages throughout the year –Annual rainfall –Calving distribution throughout the year –Chemical composition and digestion rates of forages (Juárez et al., 2002…. key data base) Production parameters (for the CNCPS) –Age at first calving –Body condition scores, score changes –Milk production –Milk composition –Body weights, weight changes –Breed –Physiological status Early lactation (negative EB), mid/late lactation, dry period

Targeted agro-ecozone

Targeted agro-ecozone [2] Climate (Köppen classification) –Aw 1 based on annual and monthly average temperatures and rainfall A = tropical moist climates: all months with average temperatures ≥18 C. w = tropical wet and dry or savanna with extended dry season during winter Representative soil types –Arenosol Predominantly sandy, has a superficial layer of organic matter (1.15 %), pH of , more than 15% of clay; it is susceptible to be eroded. –Luvisol Gathers clay in the subsoil, also susceptible to erosion.

Rainfall T T. 1700

Temperature

Forages used by Farmers Seasons & 4123

Chemical composition and digestion rate of forages

Growth: management groups Age/growth requirements –Heifers, first-lactation and second-lactation cows –Mature cows Physiological status –Early lactation From calving until 90 days –Mid-late lactation From 90 days post-partum to ~250 days –Early dry and late dry Late = 90-day period prior to calving Meet nutritional requirements –Growth and lactation –Replete catabolized tissue –Help assure longer productive life Age at first calving sooner Overcome anestrous postpartum sooner

Current management Dry season –Forage scarcity –Cows freely roam –Supplementation with commercial feed in May Wet season –Few paddocks in the meadow –Faster grass performance Inadequate management of nutrient stocks and flows in pasture lands –Empirical fertilization of pastures and crops –Little soil analysis information –Inefficient economic investment in fertilization

Base scenario of animal management groups (S) Star grass: Cynodon plectostachyus (Ll) Llanero grass: Andropogon gayanus (C) Commercial feed

Alternative Scenario (G) Gliricidia sepium, (L) Leucaena leucocephala, (P) Pangola grass: Digitaria decumbens (M) Mulato grass: Brachiaria spp

Preliminary results Dry season: Increases in MP and ME allowable milk but still low… Rainy season: Negative energy balances were overcome. More analyses needed for the dry season, other scenarios.

Suggestions Supplement with commercial feed or available agricultural by-products to compensate protein deficits at the beginning of the dry season. –Evaluate the cost and benefits from this practice. Substitute better quality forages for star grass. Cultivate another forage for the dry season. Guazuma ulmifolia is a good prospect for this purpose.

Courtesy of professor R.W. Blake