Comparing different maize supplementation strategies to improve resilience and resistance against gastrointestinal nematode infections in browsing goats.

Leslie Gárate-Gallardo,Juan Felipe De Jesús Torres-Acosta,Armando Jacinto Aguilar-Caballero,Carlos Alfredo Sandoval-Castro,Ramón Cámara-Sarmiento,Hilda Lorena Canul-Ku

doi:10.1051/parasite/2015019

Abstract

The effect of maize grain supplementation on the resilience and resistance of browsing Criollo goat kids against gastrointestinal nematodes was evaluated. Five-month-old kids (n = 42), raised worm-free, were allocated to five groups: infected + not supplemented (I-NS; n = 10), infected + maize supplement at 108 g/d (I-S108; n = 8), maize supplement at 1% of body weight (BW) (I-S1%; n = 8), maize supplement at 1.5% BW (I-S1.5%; n = 8), or infected + supplemented (maize supplement 1.5% BW) + moxidectin (0.2 mg/kg BW subcutaneously every 28 d) (T-S1.5%; n = 8). Kids browsed daily (7 h) in a tropical forest for 112 days during the rainy season. Kids were weighed weekly to adjust supplementary feeding. Hematocrit (Ht), hemoglobin (Hb), and eggs per gram of feces were determined fortnightly. On day 112, five goat kids were slaughtered per group to determine worm burdens. Kids of the I-S1.5% group showed similar body-weight change, Ht and Hb, compared to kids without gastrointestinal nematodes (T-S1.5%), as well as lower eggs per gram of feces and Trichostrongylus colubriformis worm burden compared to the I-NS group (P > 0.05). Thus, among the supplement levels tested, increasing maize supplementation at 1.5% BW of kids was the best strategy to improve their resilience and resistance against natural gastrointestinal nematode infections under the conditions of forage from the tropical forest.

Highlights

Gastrointestinal nematode (GIN) infections significantly reduce growth rates of goat kids grazing or browsing in the tropical deciduous forest of Mexico [33, 34]
Supplementing at 1.5% body weight (BW) either without GIN infection or infected (I-S1.5%) resulted in higher cumulative BW change (CBWC) and daily BW gain (P < 0.05) than the group kept without supplement (I-NS) or the group receiving a fixed amount of supplement (I-S108 groups)
Supplementing at 1% BW (I-S1%) improved growth compared to the infected + not supplemented (I-NS) group (Table 3)

Summary

Introduction

Gastrointestinal nematode (GIN) infections significantly reduce growth rates of goat kids grazing or browsing in the tropical deciduous forest of Mexico [33, 34]. Recent studies [17] showed that a large proportion of plants of the tropical deciduous forest (TDF) consist of browsing legumes with high protein and low energy content The latter results in excess of rumen degradable nitrogen (RDN). A reduction in fecal egg counts or GIN burden (resistance) has been less evident [18, 24] Another way to improve the effect of supplementary feeding on resilience against GIN could be to adjust the amount of supplement offered to growing animals. Previous field trials showed that the positive effect on the resilience against GIN in kids was reduced as the experiments progressed into the rainy season These studies were carried out using fixed amounts of supplements per animal (85–100 g DM/d during the whole trial). The objective of the present experiment was to compare the effect on resilience and resistance against GIN either from a fixed supplementation level (100 g DM/d) or from supplementation that increases as a proportion of the animal’s live weight (1 or 1.5% BW)

Methods

Results

Discussion

Conclusion