Use of metabolic profiles in dairy cattle in tropical and subtropical countries on smallholder dairy farms

Metabolic profile testing has generally been used as part of a multidiscipl inary approach for dairy herds in temperate climates. Our goal was to evalu ate the effectiveness of the technique for identifying constraints on produ ctivity in small herds in environments less favorable for milk production. Metabolites tested were chosen for stability in the sample after collection of blood, ease of analysis and practical knowledge of the meaning of the r esults, Blood levels of five different metabolites in low-producing dairy c ows belonging to smallholders in tropical and subtropical environments were measured. The study involved 13 projects with 80 cows in each, carried out in six Latin American, six Asian, and one southern European countries. Dat a were also collected on feeding, body condition score (BCS) and weight cha nge, parasitism, and reproduction. In Chile, Mexico, Paraguay, Philippines, Uruguay, and Venezuela, globulin levels were high in >17% of cows sampled on each occasion. Globulin levels were also high in Turkey and Vietnam on o ne or more occasions. In Paraguay, 49% of cows had high globulin levels at two to three months after calving. These results suggest that inflammatory disease was present to a potentially important degree, although this was no t always investigated and not always taken into account. In all countries e xcept Mexico and Venezuela, high P-hydroxybutyrate (BHB) levels before calv ing in many cows highlighted the presence of condition loss in late pregnan cy, an important potential constraint on productivity and fertility. Fewer cows showed high BHB levels in lactation, whereas change in BCS and weight was more sensitive for measuring negative energy balance. Urea concentratio ns were low in only small numbers of cows suggesting that dietary protein s hortages were not common. Albumin values were low mainly in cows where glob ulin values were high and, hence, did not generally provide additional info rmation, The exception was in China where pregnant yaks over winter had hig h BHB and low albumin values, suggesting that they were seriously underfed. This observation stimulated a successful nutritional intervention in the f ollowing winter. Inorganic phosphate values were within the reference range in most countries a majority of the time suggesting, contrary to expectati on, that this mineral was not commonly a constraint. The use of metabolic p rofile testing proved valuable in drawing attention to important potential constraints on productivity in dairy cows in tropical and subtropical envir onments and in confirming those which were not. (C) 1999 Elsevier Science B .V. All rights reserved.