Consequences of the Inflammation During the Peri-Partum Period. Effect on Feed Intake, Liver Activity, Body Fat Reserves, Milk Yield and Composition and Feed Efficiency

L'ampia letteratura sul periodo di transizione delle bovine richiama sempre più ai rapporti negativi fra problemi di salute e performance delle bovine. Dimostrazioni sempre più numerose confermano l'instaurarsi, soprattutto nel primo mese di lattazione, di una condizione di “stress da malattia”, non sempre associata a manifestazioni cliniche, ma con le stesse conseguenze: i fenomeni infiammatori. I principali obiettivi dei nostri studi, sono stati quelli di meglio caratterizzare gli stati infiammatori puntando l'attenzione su due aspetti: 1°) le cause di variazione della risposta infiammatoria alla infezione microbica e i suoi rapporti con la produzione di latte, 2°) le conseguenze che i fenomeni infiammatori hanno a livello di ingestione degli alimenti, delle riserve corporee, della produzione quanti-qualitativa e quindi dell'efficienza alimentare. relativamente al primo aspetto, nelle bovine sottoposte ad analoga infezione si è osservata una risposta infiammatoria di intensità diversa e che pare in buona relazione con precedenti fenomeni infiammatori in atto o pregressi; inoltre la risposta più intensa ha portato ad un maggior calo produttivo. Le conseguenze sulla efficienza energetica sono state studiate comparando due gruppi di bovine caratterizzate da minori (Lo-lfi) o maggiori (UP-lfi) valori di un indice di funzionalità epatica (lfi). Da ciò è emerso che, nel primo mese di lattazione, specie dopo avvenuta correzione per l'energia mobilizzata delle riserve corporee, l'efficienza è minore nei soggetti con basso lfi per il probabile aumento dei costi del sistema immunitario, aumento che pare prolungarsi ben oltre il fenomeno infiammatorio.The extensive literature on transition period of the cows suggests the growing frequency of negative relationship between health problems and performance. Many evidences confirm during the first month of lactation, the presence of a particular condition named “stress disease”, which is not always associated to clinical symptoms but has the same consequences: the inflammatory processes. The principal objective of this study was to better characterize the inflammatory processes with particular attention to: 1) cause of the changes in inflammatory response to a bacterial infection and its relationship with the milk production, 2) consequences of the inflammatory processes on feed intake, body reserves, quantity and quality of milk production and then on feed efficiency. relatively to the first, we have observed a different intensity of the inflammatory response (in bovine submitted at the same infection), and this response seems correlated to previous inflammatory processes, probably not resolved; moreover, the higher intensity in the inflammations response can be responsible of the milk production decline. The consequences on feed efficiency have been studied through the comparison between two groups of cows characterized by higher (up-lfi) or low (lo-lfi) values of the liver functionality index; from that was demonstrated that during the first month of lactation, the cows with low lfi had lower efficiency values, probably caused increased charge of the immunitary system and prolonged beyond the inflammatory status itself

Blood indices calves: relationship with mother values and changes in the first days of life

To increase the knowledge on blood indices in calves, 47 pure bred and crossbred calves were studied in their first 14 days of life. Blood samples were taken at birth, from mothers and calves before colostrum administration, and till 14th day for metabolic profile determination. At birth, urea, glucose, haptoglobin, Ca, Na, Cl and K of mothers and calves were correlated, suggesting a transplacental passage. During first 2-3 days of life, globulin, GGT, GOT, ALP rose as consequence of colostrum intake and could be used as markers of its adequate administration.Changes of other parameters (Zn, albumin, cholesterol, besides haptoglobin and ceruloplasmin) are related to inflammatory conditions. However, the interpretation of typical inflammatory proteins appears difficult (e.g. high levels of haptoglobin at birth could depend by transplacental exchange or fetal synthesis; the rise of haptoglobin after birth seems related to the colostrum intake; the progressive rise of ceruloplasmin is influenced by an adaptation process) and the Zn reduction seems the better index of inflammation. Finally, genetic background seems also to influence blood indices (e.g. crossbred vs. pure bred showed higher PCV, Zn and haptoglobin levels)