Effect of free-choice and traditional feeding systems on goat feeding behaviour and intake

Abstract

The influence of two feeding systems – free-choice and traditional – on feeding behaviour and nutrient intake was investigated using six goats for each system. All goats were allocated to individual feeding cages. In free-choice system (group F) alfalfa hay, pasture hay, flaked barley, chick peas and broad beans grain, and beet-pulp in an unrestricted amount were offered. In the traditional system (group T), alfalfa hay in an unrestricted amount and flaked barley, according to 50% of goat energy requirements, were distributed. Dry matter intake (DMI) for each feed, total faeces output, live weight (LW), and body condition score (BCS) were measured over 13 periods: one in dry physiologic stage (D), three in pregnant stage (P1–P3) and nine in lactation (L1–L9). DMI and faecal output were measured daily for 5 consecutive days, while LW and BCS were measured at the beginning and end of each period. During pregnancy, both groups showed similar level of DMI. In group F, DMI strongly increased before delivery (+12%); in group T, it increased from period D to P1 (+44%). The shift from pregnancy to lactation in group F produced an increase in DMI from 76.4 to 89.03 g/kg MW and in group T from 74.68 to 79.26 g/kg MW. In both groups DMI reached its highest value in period L2 (120.59 g/kg MW in the F group and 96.84 g/Kg MW in the T group). The availability of food in unlimited amount did not cause an unusual intake in F group goats. In the F group, the diet feed contribution changed according to goat physiologic stage: barley and beet-pulps intake decreased during pregnancy; on the other hand, chick peas, broad beans and alfalfa hay increased. The diet chemical composition also changed: the CP content progressively increased with advancing pregnancy (12.6 vs. 16.4%), while the starch decreased (33.3 vs. 31%), and the NDF remained almost constant (above 40%). After delivery, a reverse trend was observed. During lactation, the CP content decreased by 3–4 percentage units, the starch increased by 2–3 percentage units and the NDF remained at the same value (40%). In group T, the diet was poorer in CP for 1 percentage units, and starch for 9 percentage units, while NDF doubled. The feeding adjustment of the diet might be interpreted as a need for animals to better meet their requirements. In fact, according to physiological stage evolution, the goats increased diet CP content in late pregnancy and starch content during lactation. Variation of live weight and BCS progressively improved from the first to the second year, and remained at higher levels than those of group T (around plus 10 kg of live weight and plus 0.5 in BCS). Group T remained the same during all the trial. The use of free-choice system has the advantage that farmers don’t need any particular knowledge in feeding and nutrition.