PSIX-41 Effect of progressive increase the hours of daily light exposure during winter months in Holstein bulls fed high-concentrate diets. (7th December 2018)

• Record Type: Journal Article
• Authors: Marti, S; Medinya, C; Pérez, A; Verdú, M; Solé, A; Quintana, B; Devant, M
• Is Part Of: Journal of animal science. Volume 96(2018)Supplement 3
• Page Start: 16
• Page End: 16
• Publication Date: 2018-12-07
• Subjects: BEEF -- PHOTOPERIOD -- BEHAVIOR -- EFFICIENCY; Livestock -- Periodicals; Livestock; Electronic journals; Periodicals; 636.005
• DOI: 10.1093/jas/sky404.036
• Languages: English
• ISSNs: 0021-8812

Abstract

Abstract: One hundred and ten Holstein male calves (335 ± 4.3 kg and 243 ± 0.96 d of age) were enrolled in a randomize design to study the effect of increasing the hours of daily light exposure on performance, eating, and sexual and agonistic behavior. Calves were allocated in 6 pens with 1 computerized concentrate feeder, 1 straw feeder (5 feeding spaces) and 1 water bowl. Pens were separated with a thick black plastic curtain to block the light between pens. Artificial light (300 lux at eye height) was provided during winter months increasing 1 h of light every 14 d from October (11 h of light/d) to December (16 h of light/d) and remaining at 16 h of light/d until February. Pens were assigned to 1 of the 2 treatments according to natural photoperiod (NP) or modified photoperiod (PMP). Concentrate intake was recorded daily, BW and animal behavior fortnightly. Data were analyzed using a mixed-effects model with repeated measures including photoperiod, period and their interaction as main effect and pen as random effect. Final BW, ADG and concentrate intake were not affected by treatment. However, number of feeder visits increased (P < 0.001) after 16 h of light/d in PMP compared with NP, and meal size and intermeal duration decreased (P < 0.05) after 16 h of light/d in PMP compared with NP. Sexual and agonistic behaviors such as fighting (10.1 and 5.6 ± 2.05 times/15 min for NP and PMP), attempts to mount (7.7 and 2.3 ± 0.97 times/15 min for NP and PMP) and mounts (3.3 and 0.7 ± 0.31 times/15 min for NP and PMP) were greater for NP than in PMP animals. Progressive increase of hours of light a day modifies eating behavior, reduces sexual and agonistic behaviors but does not improve feed efficiency or growth.