THE EFFECT OF TANNIN SUPPLEMENTATION OF MID-LACTATION DAIRY COWS DIETS ON METABOLIC PROFILE PARAMETERS AND PRODUCTION CHARACTERISTICS

Abstract

The aim of this study was to examine the effect of using tannin supplement in ration for mid-lactation dairy cows (90±17 days in milk) and the number of lactation on metabolic profile parameters values. Additionally, the effect of tannin supplementation on cows’ production characteristics in the 2nd lactation was evaluated. Research was conducted on 80 Holstein cows divided into two groups of 40 cows (control and experimental group) that included 16 cows in 2nd and 12 in 3rd and 4th lactation. The tannin supplement Tanimil SCC (40 g/cow/day; 40% of tannins) was added in the total mixed ration (TMR) of experimental group, while the control group of cows was fed ration without the tannin supplement. The trial lasted 60 days. Dairy cows, fed diet supplemented with tannin, had markedly lower values (P<0.05) of ß-hydroxybutyrate concentration (0.79 vs. 0.96 mmol/L) and lower blood urea concentration (5.89 vs. 6.93 mmol/L). Difference in the blood glucose concentrations (3.92 vs. 3.89 mmol/L) was not significant. The lactation number had no significant effect on values of metabolic profile parameters (concentration of glucose, ß-hydroxybutyrate and urea). The effect of interaction of lactation number and tannin supplement on the values of examined parameters of metabolic profile was not significant. Supplementation of tannin in the diet for cows in the second lactation, had a positive effect (P<0.05) on the milk yield (4.42%) and yield of 4% fat corrected milk (FCM, 5.24%). The use of tannin, improved concentration (3.20 vs. 3.12%) and yield (from 1.16 to 1.24 kg/day) of milk protein (P<0.05). Addition of tannin also improved concentration and yield of milk fat, as well as the concentration of lactose. The supplementation of Tanimil SCC to mid-lactation dairy cows had a positive impacts on reduction of blood content of ß-hydroxybutyrate and urea, and improved productive performances of cows in the second lactation. Key words: tannins; lactating cows; nutrition; metabolic profile; milk yield and composition UČINEK PREHRANSKEGA DODATKA S TANINOM V PREHRANI KRAV SREDI LAKTACIJE NA PARAMETRE PRESNOVNEGA PROFILA IN NJIHOVE PROIZVODNE LASTNOSTI Povzetek: Cilj študije je bil proučiti učinek dodajanja tanina v obroku pri kravah molznicah sredi laktacije (90 ± 17 dni v mleku) in števila dojenj telet na nekatere parametre presnovnega profila. Poleg tega je bil ovrednoten tudi učinek dodajanja tanina na proizvodne lastnosti krav v drugi laktaciji. Raziskave so bile izvedene pri 80 kravah pasme Holstein, razdeljenih v dve skupini po 40 krav (kontrolna in poskusna skupina), ki so vključevale 16 krav v 2. in 12 v 3. in 4. laktaciji. Dodatek tanina Tanimil SCC (40 g/kravo/dan; 40 % taninov) je bil dodan v skupni mešani obrok (TMR) poskusne skupine, medtem ko je bila kontrolna skupina krav krmljena brez dodatka tanina. Poskus je trajal 60 dni. Krave molznice, hranjene s krmo z dodanimi tanini, so imele izrazito nižje vrednosti (P < 0,05) koncentracije β-hidroksibutirata (0,79 v primerjavi z 0,96 mmol/L) in nižjo koncentracijo sečnine v krvi (5,89 v primerjavi z 6,93 mmol/L). Razlika v koncentraciji glukoze v krvi (3,92 v nasprotju z 3,89 mmol/L) ni bila statistično značilna. Dojenje ni značilno vplivalo na vrednosti parametrov presnovnega profila (koncentracije glukoze, β-hidroksibutirata in sečnine). Medsebojni vpliv števila laktacij in dodatka tanina na vrednosti pregledanih parametrov presnovnega profila ni bil statistično značilen. Dopolnilo tanina v krmi krav v drugi laktaciji je imelo pozitiven učinek (P < 0,05) na mlečnost (4,42 %) in na količino mleka s popravljeno vrednostjo 4-odstotne maščobe (FCM, 5,24%). Uporaba tanina je izboljšala koncentracijo beljakovin (3,20 v primerjavi z 3,12%) in izkoristek mlečnih beljakovin (od 1,16 do 1,24 kg/dan) (P < 0,05). Dodatek tanina je izboljšal tudi koncentracijo in izkupiček mlečne maščobe ter koncentracijo laktoze. Dodatek Tanimila SCC kravam na sredini laktacije je pozitivno vplival na znižanje vsebnosti β-hidroksibutirata in sečnine v krvi ter izboljšal produktivnost krav v drugi laktaciji. Ključne besede: tanini; krave v laktaciji; prehrana; presnovni profil; mlečnost in sestava mleka