Potential risk factors associated with ill-thrift in buffalo calves (Bubalus bubalis) raised at smallholder farms in Egypt

The position of geochemical variables as causal co-factors of diseases of unknown aetiology

Abstract

The term diseases of unknown aetiology (DUA) or idiopathic diseases is used to describe diseases that are of uncertain or unknown cause or origin. Among plausible geoenvironmental co-factors in causation of DUA, this article focusses on the entry of trace elements, including metals and metalloids into humans, and their involvement in humoral and cellular immune responses, representing potentially toxic agents with implications as co-factors for certain DUA. Several trace elements/metals/metalloids (micronutrients) play vital roles as co-factors for essential enzymes and antioxidant molecules, thus, conferring protection against disease. However, inborn errors of trace element/metal/metalloid metabolisms can occur to produce toxicity, such as when there are basic defects in the element transport mechanism. Ultimately, it is the amount of trace element, metal or metalloid that is taken up, its mode of accumulation in human tissues, and related geomedical attributes such as the chemical form and bioavailability that decisively determine whether the exerted effects are toxic or beneficial. Several case descriptions of DUA that are common worldwide are given to illustrate our knowledge so far of how trace element/metal/metalloid interactions in the immune system may engender its dysregulation and be implicated as causal co-factors of DUA.

Article highlights

The importance of a proper understanding of geochemical perturbations in human metabolisms is emphasisedIt is proferred that such an understanding would aid greatly in the decipherment of diseases of unknown aetiology (DUA)The thesis presented may pave the way towards better diagnosis and therapy of DUA.

New insights on ill-thriftiness in early-weaned buffalo calves

Aim:

The present study was designed to: (1) Investigate the effect of weaning time on various metabolic indices and growth pattern in buffalo calves compared to cow calves under field condition and (2) Shed light on the potential relationship between early weaning, growth metabolites, and suboptimal growth (ill-thrift) in buffalo calves.

Materials and Methods:

A total number of 18 neonatal calves of both sexes and species (cattle and buffalo) were included in the study. Animals were divided into three groups according to their age at weaning as following: Cow calves (n=8) weaned at 4.5 months, buffalo calves (n=6) weaned at 3.5 months (early-weaned), and buffalo calves (n=4) weaned at 5.5 months (late-weaned). Morphological traits, growth metabolites, and hormonal profile were measured at monthly interval over the period of the study and around the time of weaning (2 weeks pre- and post-weaning).

Results:

The obtained results showed that the trend of growth pattern was significantly increased in a linear pattern in cow calves and late-weaned buffalo calves, whereas early-weaned buffalo calves showed sharp decline in their body weight (BW) post-weaning. By the end of the study, early-weaned buffalo calves showed the lowest BW gain (ill-thrift). There is a positive association between the morphological traits and various growth metabolites and hormonal indices. A significant decrease (p<0.05) in the concentrations of growth hormones (insulin-like growth factor-1 [IGF-1] and insulin) and other metabolites were reported in early-weaned buffalo calves compared to other animals. There is no association between stress indices (cortisol level and neutrophil to lymphocyte ratio) and growth rate.

Conclusion:

Suboptimal growth rate (ill-thriftiness) is common in early-weaned buffalo calves and is attributed to low blood levels of growth metabolites, in particularly, IGF-1. In addition, the strong positive associations between concentrations of IGF-1 and morphological characters of growth suggest that IGF-1 is a reliable indicator for assessing metabolic status of individual calves.