Abstract #523
Section: Production, Management and the Environment (orals)
Session: Production, Management, and the Environment 4
Format: Oral
Day/Time: Wednesday 3:15 PM–3:30 PM
Location: Room 264
Session: Production, Management, and the Environment 4
Format: Oral
Day/Time: Wednesday 3:15 PM–3:30 PM
Location: Room 264
# 523
Pasture and supplement intake, milk production, and partial economic profit in commercial dairy systems: Effects of two contrasting productive strategies.
M. N. Méndez*1, M. Aguerre1, P. Chilibroste2, 1Red Tecnológica Sectorial de Lechería, Montevideo, Uruguay, 2Departamento de Producción Animal y Pasturas, Facultad de Agronomía, UdelaR, Paysandú, Uruguay.
Pasture and supplement intake, milk production, and partial economic profit in commercial dairy systems: Effects of two contrasting productive strategies.
M. N. Méndez*1, M. Aguerre1, P. Chilibroste2, 1Red Tecnológica Sectorial de Lechería, Montevideo, Uruguay, 2Departamento de Producción Animal y Pasturas, Facultad de Agronomía, UdelaR, Paysandú, Uruguay.
The objective of this work was to determine the factors that have major impact on pasture dry matter intake (DMI) by cows in commercial dairy farms. Fortnightly visits to commercial dairies were carried out between June 2016 and May 2017 to record supplement on offer, pasture access time (PAT), herbage mass (HM) and allowance (HA), milk production per cow, and feed and milk prices. Dairy farms were categorized in high (>8.5 kg DM/cow; HPI, n = 8) or low (<7.0 kg DM/cow; LPI, n = 8) daily pasture DMI per cow, estimated by energy balance (NRC, 2001). Potential pasture DMI per cow was estimated from recorded HA using the equation of Baudracco et al. (2010) for dairy cows grazing without supplementation. The 2 groups were compared with the MIXED procedure and considered different when P ≤ 0.05. This study reveals 2 contrasting productive strategies, with dairy systems (LPI) that aimed for a higher yield per cow (23.3 ± 0.7 L/cow/day, P ≤ 0.01) based on greater supplementation (12.0 ± 0.3 kg DM/cow/day, P ≤ 0.01) and lower pasture DMI (5.5 ± 0.3 kg DM/cow/day, P ≤ 0.01) versus systems (HPI) that aimed to produce under a limited amount of supplement (5.8 ± 0.3 kg DM/cow/day) and high pasture inclusion (10.1 ± 0.3 kg DM/cow/day), albeit achieving lower milk production (19.0 ± 0.7 L/cow/day). Although to a lesser extent in HPI, pasture DMI was conditioned by supplementation level and not by pasture management in both groups, since cows could have harvested higher amounts of pasture according to HM (2303 ± 178 kg DM/ha, P = 0.16), PAT (12.7 ± 0.6 h, P = 0.14) and HA (29.4 vs 23.2 ± 3.1 kg DM/cow/d for HPI and LPI respectively, P ≤ 0.01). Even though HPI offered greater HA, pasture DMI was closer to potential DMI than in LPI (differences between potential and actual pasture DMI: 3.6 vs 6.9 ± 0.3 kg DM/cow/day respectively, P ≤ 0.01). Therefore, disconnection between grazing and supplementation management was more accentuated in the LPI systems. Both strategies resulted in similar margin over feeding costs (3.00 ± 0.15 US$/cow/day). These results reinforce the importance of an efficient grazing management, applying supplementation as a complementary tool to balance the diet and not as an isolated food, disconnected from the offered forage.
