Energetic-protein supplementation in the last 60\xa0days of gestation improves performance of beef cows grazing tropical pastures

Aline Gomes Da Silva,Edenio Detmann,Mariana Benevides Monteiro,Román Enrique Maza Ortega,Lincoln Da Silva Amorim,Victor Valério De Carvalho,Mário Fonseca Paulino,Jéssika Almeida Bitencourt,Henrique Jorge Fernandes,Josilaine Aparecida Da Costa Lima,Felipe Henrique De Moura

doi:10.1186/s40104-017-0209-x

Abstract

BackgroundNutrition is one of the most important factors that affect animal performance, and it therefore also impacts on financial results in beef systems. In this way, finding the best strategy for feeding supplements is of paramount importance. Aiming to evaluate the effect of supplement feeding strategies for beef cows in the last third of gestation, two experiments were conducted. In Experiment 1, 35 pregnant Nellore cows were assigned to a completely randomized design with four treatments: control, which received no supplement; supplementation for the last 30 d of gestation (30-d; 3.0 kg/d); supplementation for the last 60 d of gestation (60-d; 1.5 kg/d); or supplementation for the last 90 d of gestation (90-d; 1.0 kg/d). All supplemented treatments received the same total amount of supplement throughout the experiment: 90 kg (20% of crude protein). A second experiment (Experiment 2) was delineated to evaluate the effects of the amounts offered in Experiment 1 on intake and metabolism. Four multiparous pregnant Nellore cows were assigned to a 4 × 4 Latin square design, with periods of 15 d each.ResultsThere was a linear effect of the number of days of supplementation on calving body weight (BW; P < 0.05) and a quadratic effect on BW change from parturition to d 31 post-calving (P < 0.05), with cows on the 60-d strategy losing less BW post-calving. No difference was found in offspring birth BW (P > 0.10). A significant linear effect on interval from parturition to conception (P < 0.05) was observed, with the highest calving to conception interval being observed in the 90-d strategy. The level of supplementation did not affect forage intake or neutral detergent fiber digestibility (P > 0.10). Nitrogen excreted through urine tended to increase linearly with the level of supplementation (P < 0.10).ConclusionProviding 1.5 kg of supplement during the last 60 d of gestation improves cow performance after calving, reducing the magnitude of BW lost, and reduces the number of days from calving to re-conception in the following breeding season compared to the usually recommended period of supplementation of 90 d pre-partum.

Highlights

Nutrition is one of the most important factors that affect animal performance, and it impacts on financial results in beef systems
Experiment 1 There was a linear effect of number of days of supplementation on cow body weight (BW) at calving (Table 4; P < 0.05)
Body weight at calving ranged from 508 kg for cows in the 30-d strategy to 531 kg for cows in the 90-d strategy

Summary

Introduction

Nutrition is one of the most important factors that affect animal performance, and it impacts on financial results in beef systems In this way, finding the best strategy for feeding supplements is of paramount importance. Because the last third of gestation usually coincides with the dry season and, with low quantity and quality of forage, producers in tropical conditions, as in Brazil, are usually oriented to supplement pregnant cows for the last 90 d of gestation. The objective with this experiment was to study whether this period of supplementation could be reduced to avoid extra labor and, reduce feeding costs. We conducted a study to evaluate the effects of different supplementation strategies for pregnant beef cows in the last third of gestation, receiving supplementation for 90, 60 or 30 d pre-partum

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Discussion

Conclusion