Nutrient restriction during pregnancy and litter size affect the feeding behaviour, feed preference and welfare of the aged ewe’s offspring

The present work evaluates the effect of a nutrient maternal restriction induced by a lower forage allowance of natural grassland (LFA) and the type of birth [single (S) and twins (T)] and its interaction on the feed preference, the feeding behaviour, and welfare indicators of aged offspring ewes. A total of 28 Corriedale, seven years old, multiparous ewes in the anestrus period (spring) were used: 11 singles (S) and 4 twins (T) born to high forage allowance mothers (HFA: 10 – 12 DM/100 kg LW·day), and 9 S and 4 T born to LFA (5 – 8 DM/100 kg LW·day) from 23 days before conception to 122–123 days of gestation. The ewes were subjected to a feeding behaviour trial during 5 days after and adaption period of 14 days to eat alfalfa hay ad libitum and 300 g of rice bran. Eight days before the registration began animals were transferred to a roofed barn and located in individual pens with separated alfalfa and rice bran feeders, and a free-available water source. The feed preference was registered twice a day. Dry matter intake (DMI) was daily determined. Behaviour of each ewe was recorded every 10 min from 0800 to 1200 h, and from 1400 to 1800 h. The percentage of ewes that preferred to rice eat bran first was greater in LFA than HFA ewes (73% vs. 45%; P = 0.04). The alfalfa hay intake was greater in LFA than in HFA ewes (3078 vs. 2949 ± 0.61 g/day; P = 0.04) and in S than in T ewes (3126 vs. 2932 ± 61.0 g/day, P < 0.01). All ewes ate the total offered amount of rice bran (300 g/d each), thus DMI showed the same response that alfalfa intake previously described. The % of time eating alfalfa hay was greater for LFA than HFA (38.0 vs 29.2 ± 3.4; P < 0.01). These variables were not influenced by the interaction. The time spent eating and standing up, and time spent resting were affected by the interaction treatment × TB (P ≤ 0.05 in all cases) as T-LFA ewes spent more time eating (P = 0.02) and thus, standing up (P = 0.02), but less resting (P = 0.02) and with no apparent activity (P = 0.05) than T-HFA with no differences between LFA and HFA groups in the S ewes. In conclusion the maternal nutrient restriction affected the preference for feed, the ingestive behaviour and the welfare of aged female offspring.