Effects of the Physiological Status and Diet on Blood Metabolic Parameters in Amiata Dairy Donkeys.

Federica Salari,Cristina Roncoroni,Carlo Boselli,Giovanni Brajon,Mina Martini,Iolanda Altomonte

doi:10.3390/ani11113292

Abstract

Simple SummaryThis study investigated the physiological responses of donkeys feeding two different diets during maintenance, pregnancy and lactation. To investigate how the metabolic state influences dairy production, we also assessed the relationships between the blood metabolic profile and milk quality. We found that pregnancy and the first months of lactation led to lower feed intake and increases in blood non-esterified fatty acids (NEFAs), which was linked to the difficulty that the jennies have in meeting the higher energy needs. The intake of the concentrate in the diet was associated with the increase in blood glucose, both during maintenance and lactation. Higher NEFA were related to lower de novo synthesized milk fatty acids, whereas higher plasma B-HBA were related to higher somatic cell count. This paper contributes to the knowledge of physiological responses of jennies during milk production phases and provides information for donkey milk producers.Body weight changes and blood metabolic parameters in jennies feeding two different diets and in three physiological statuses were investigated (maintenance vs. pregnancy; maintenance vs. lactation). The relationships between blood metabolic profile and milk quality were also evaluated. Fourteen jennies were allocated to two groups (1: pregnant/lactating; 2: non-pregnant, non–lactating). Pregnant jennies and maintenance jennies (during the first 10-week measurement period) fed a diet consisted of ad libitum grass hay (diet 1); lactating jennies and maintenance jennies (during the last 10-week measurement period) fed ad libitum grass hay plus 2 kg/head/day of concentrate (diet 2). Blood sampling was performed on the jennies of both groups; individual milk samples were also collected during the first 70 days in milk. Higher blood NEFA (p < 0.05) were found in pregnant compared to maintenance jennies (diet 1) (68 vs. 37 μmol/L). Lactating jennies showed higher (p < 0.01) average blood NEFA (268 vs. 26 μmol/L) and glucose (66 vs. 55 mg/dL) compared to the maintenance (diet 2). Blood glucose was positively correlated to milk fat (p < 0.05), while negative significant correlations between de novo milk fatty acids and NEFAs were observed. Positive correlations between plasma B-HBA and somatic cell count (p < 0.01) were also found.

Highlights

In industrialized countries donkeys provide different roles and produce meat and milk
The lowest intakes were in pregnant jennies, which is probably due to the lower abdominal space available for feed [4] because of the abdominal cavity occupied by the conceptus, membranes and fluids
The significant increase (p < 0.01) in non-esterified fatty acids (NEFAs) that we found during pregnancy compared to maintenance, could be related to the decreased ingestion that normally occurs in the last phases of pregnancy, which leads to lipomobilization

Summary

Introduction

In industrialized countries donkeys provide different roles (i.e., donkey-assisted activities for humans) and produce meat and milk. Income generation, empowerment and food security to marginalized groups and families. Donkey milk is similar in composition to human milk and has shown beneficial properties in vivo and in vitro studies [1]. The number of farms breeding donkey for milk production is increasing, especially in Europe and in Asia. Donkey farming has moved from traditional forms of management to more organized, intensive and semi-intensive farming systems. These changes in donkey farming mean that specific knowledge of the milk production, nutrition and welfare of donkeys is required [2,3]

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