Effects of Dietary Quebracho Tannin on Performance Traits and Parasite Load in an Italian Slow-Growing Chicken (White Livorno Breed)

Abstract

Tannins have shown numerous biological activities and are very appreciated in food animal production, especially for their antimicrobial, antiparasitic, antioxidant, anti-inflammatory and antivirus effects. The aim of the present study was to evaluate the effect of two levels of dietary Quebracho tannin (QT) on growth and performance traits, and possible effects on intestinal parasite load in Italian White Livorno pullets. A 140-day trial was carried out on 180 35-day-old females, fed on two levels of dietary QT inclusion: 0%, 1% and 2%. Birds were reared under free-range conditions. Dietary Quebracho tannin may be used up to 1% in growing female White Livorno chickens without any adverse effects. The results observed in this study on the use of dietary QT at 2% might have not reflected the real effect on performance traits due to the initial inclusion of dietary QT at 3%. Nevertheless, by reducing QT to 2%, a progressive normalization of body weight gain, feed intake and feed conversion ratio was observed, resulting in compensatory growth. QT was demonstrated to drastically reduce fecal outputs of Nematodes eggs (Ascaridia spp. and Heterakis spp.) and Coccidia oocytes (Eimeria spp.). The inclusion of 2% produced highly dry droppings.

Keywords: Quebracho tannin; growing laying hen; pure breed.

Figure 1

Body weight from birds fed different levels of dietary Quebracho tannin (QT) (mean ± SEM) for a 140-day period starting from 35 days old. * Indicates a difference between treatment and QT0 (Dunnett’s t-test, p < 0.05). QT0 = basal diet; QT1 and QT2 = the basal diet supplemented with QT at 1% and 2%, respectively.

Figure 2

Trends in: (a) Average daily weight gain; (b) Daily feed intake; (c) Feed conversion ratio from birds fed different levels of QT (mean ± SEM) for a 140-day period starting from 35 days old. * Indicates a difference between treatment and QT0 (Dunnett’s t-test, p < 0.05). QT0 = basal diet; QT1 and QT2 = the basal diet supplemented with QT at 1% and 2%, respectively.

Figure 3

Total blood protein (TBP) from birds fed different levels of QT (mean ± SEM) for a 140-day period starting from 35 days old. * Indicates a difference between treatment and QT0 (Dunnett’s t-test, p < 0.05). QT0 = basal diet; QT1 and QT2 = the basal diet supplemented with QT at 1% and 2%, respectively.

Figure 4

Dropping dry matter at two different ages from birds fed different levels of QT (mean ± SEM). * Indicates a difference between treatment and QT0 (Dunnett’s t-test, p < 0.05). QT0 = basal diet; QT1 and QT2 = the basal diet supplemented with QT at 1% and 2%, respectively.

Figure 5

Ascaridia-Heterakis (A-H) and Eimeria spp. load in fecal samples from 174-day-old birds. * Indicates a difference between treatment and QT0 (Dunnett’s t-test, p < 0.05). QT0 = basal diet; QT1 and QT2 = the basal diet supplemented with QT at 1% and 2%, respectively. EPG = eggs per gram; OPG = oocytes per gram.