Using alternative energy sources for animal feed, such as hybrid corn varieties rather than genetically modified ones, is important. Therefore, the objective of this work was to assess the effects of supplementation at the end of gestation with Mexican Puma hybrid corn grain on productive and behavioral parameters in sheep. Twenty Columbia multiparous ewes were used; along with their diet, they were provided 600 g/animal/day of cracked corn during the last 20 days of pregnancy and the first week of lactation. The animals were divided into two groups: one fed commercial cracked corn (n = 11) and the other Mexican Tlaoli Puma hybrid cracked corn (n = 9). The productive parameters evaluated in the mother were: body weight, body condition score (BCS), feed intake, weight change, glucose, and ketone body levels, as well as the estimated quality of milk using Brix refractometer values on days 15 and 30 of lactation. In lambs, their rectal and external temperature was measured 2 h after birth, while their weight was measured 2 h after birth and every week until week 6 postpartum. Behavioral parameters were measured in the first two hours postpartum, including the maternal latency of cleaning the offspring, duration of the first nursing episode, the lamb’s latencies of standing and nursing, and vocalizations in mother and lamb. Weight, BCS and weight change were not affected by the group but were affected by time; these parameters increased at the end of gestation and decreased significantly after delivery (p 0.05) and remained at low values. Glucose levels were not affected by the group but were affected by time; they increased significantly after birth (p 0.05) and decreased as parturition approached (p 0.05). Mothers in both groups began cleaning their offspring within the first three minutes after giving birth and emitted a similar frequency of vocalizations (p > 0.05). However, mothers in the commercial maize group had a longer nursing episode than those in the hybrid maize group (p 0.05). Temperatures and lamb weight were similar in both groups (p > 0.05); however, lamb weight increased as they aged (p < 0.05). It is concluded that supplementing sheep at the end of gestation with Puma hybrid Mexican corn grain can yield similar productive and behavioral benefits as supplementing with commercial grain.
Terrazas et al. (Fri,) studied this question.