Feeding and lying behavior of heat-stressed early lactation cows fed low fiber diets containing roughage and nonforage fiber sources

Abstract

In addition to reduced nutrient intake, an environmental thermal load may directly affect milk yield in heat-stressed dairy cows. Feeding and lying behaviors of early lactation cows fed low fiber diets containing neutral detergent fiber (NDF) from roughage and nonforage fiber sources (NFFS) were investigated under summer conditions in Thailand. Immediately after calving, 30 multiparous cows (87.5% Holstein × 12.5% Sahiwal) were randomly allocated to dietary treatments for 63 d in a completely randomized design. The dietary treatments contained 25% of dry matter (DM) as dietary NDF. The control diet consisted of 13.9% roughage NDF from rice straw (RS). Two additional treatments were created by replacing 3.9% of DM with NDF from either soy hulls (SH) or cassava (Manihot esculenta Grantz) residues (CR), so that the roughage NDF content was reduced to 10%. During the experimental period, the minimum and maximum temperature-humidity indices (THI) were 86.4±2.5 and 91.5±2.7 during the day and 74.2±2.1 and 81.0±2.5 during the night, respectively, indicating conditions appropriate for induction of extreme heat stress. The duration of feeding and lying bouts decreased linearly with increasing THI. The DM intake during the day was greater for cows fed diets containing SH and CR than for those fed the diet containing NDF from RS. The number of meals during the day and night was lower, whereas meal size and meal length during the day and night were greater for cows fed diets containing SH and CR. Cows fed diets containing SH and CR lay down less frequently and longer during the day. These results suggest that under the severe heat stress during the day, early lactation cows fed the diet containing NFFS increased DM intake by increasing meal length and meal size rather than by increasing meal frequency and they spent more time lying. Cows fed diets containing NDF from SH and CR produced more 4% fat-corrected milk, lost less body weight, and had lower rectal temperatures measured at the 1530h milking. Therefore, reducing the filling effect may contribute to reducing heat load derived from the change in feeding and lying behavior. This should be considered as a factor for impairing productivity of heat-stressed early lactation cows.

Relationship between THI level and dairy cows’ behaviour during summer period

“…Along with the increase in THI by 1 unit between the W and H periods, there was observed a decrease in LTD by 38 min/d in the cubicles, while in the manure alleys it increased by 15 min/d. The declines in lying bouts' length demonstrated by Allen et al (2015) and Kanjanapruthipong et al (2015) caused by an increase in THI were confirmed by LTH calculated in different areas of the barn. However, it is characteristic that despite very unfavourable conditions in the barn during the period between 12:00 pm and 04:00 pm, the cows staying in the feeding alley returned and lay down in the cubicles.…”

“…According to Metz (1985) depriving cows of the possibility to have a rest in a lying position for 3 h, and according to Kanjanapruthipong et al (2015) for 2 h, causes a deterioration in an animal's welfare by disturbing their daily routine. In the H periods, after morning milking occurred depriving the possibility of lying for around 1 h, which resulted in a disturbance of cows comfort.…”

The influence of trees on the thermal environment and behaviour of grazing heifers in Brazilian Midwest

“…According to Legrand et al (2011), cows spend more time standing without feeding and less time lying as heat load increased. Based on the Kanjanapruthipong et al (2015) results, as THI was increased, the duration of feeding and lying time was decreased as well.…”

Substitution of corn silage with shredded beet pulp affects sorting behaviour and chewing activity of dairy cows

“…Increased ambient heat load elicits variable behavioural responses, including reduced feed intake (Collier, Beede, Thatcher, Israel, & Wilcox, ), decreased meal length and therefore a lower rate of intake in dairy cows (Kanjanapruthipong, Junlapho, & Karnjanasirm, ). Under a high heat load, cows tend to eat more frequently and spend less time lying compared with cows that are not experiencing heat stress (Shiao et al, ).…”