Lactating performance, water and feed consumption of rabbit does reared under a Mediterranean summer circadian cycle of temperature v. comfort temperature conditions

Abstract

The general aim of this research was to study the effect of high ambient temperature on the performance of does during lactation, specifically the following factors: average daily feed (ADFI) and water (ADWI) intakes, daily milk yield (DMY); milk composition: dry matter (DM), CP and gross energy (GE); doe BW (DW); individual kit weaning weight (IWW) and litter survival rate during lactation (SR). The study was undertaken comparing the performance of two groups of contemporary does reared under the same management, feeding regime and environmental conditions, except the environmental temperature and humidity. A total of 80 females were randomly allocated, at 60 days of age, into two identical and continuous rooms. In one room, the temperature was maintained permanently within the thermo-neutral zone (between 18°C to 22°C); thus, environmental conditions in this room were considered as comfort conditions. In the second room, the environmental temperature pattern simulated the daily temperature cycles that were characteristic of the summer in Mediterranean countries (24°C at 0800 h, increasing up to 29°C until 1100 h; maintenance at 29°C to 31°C for 4 h and decreasing to about 24°C to 26°C around 1700 h until 0800 h of the following day), which were considered as thermal stress conditions. Females followed a semi-intensive reproductive rhythm, first artificial insemination at 4.5 months of age, with subsequent 42-day reproductive cycles. Traits were recorded from a total of 138 lactations. Does were controlled up to the 5th lactation. Data were analyzed using linear and linear mixed models. High ambient temperature led to a lower ADFI (−9.4%), DW (−6.2%) and IWW (−8%), but it did not affect ADWI. No significant difference was found either for DMY, milk composition (DM, CP and GE) and SR during the lactation period. Heat stress was moderate, and does were able to adapt to it behaviorally by decreasing feed intake (to reduce heat production), but also live weight, allowing them to preserve milk yield and composition for assuring litter survival. On the other hand, water consumption could not be the main animal mechanism to overcome heat stress.Keywords: food and water consumption, heat stress, milk yield, milk composition, rabbits ImplicationsAssessing the effect of heat on lactating doe performance is crucial before defining the best strategies regarding management and selection practices to alleviate the negative impact of this factor on animal welfare and production. This study evaluates lactation performance of two groups of does that were raised and reproduced either under circadian cycle of temperature emulating the Mediterranean summer or under constant comfort temperature conditions. We show that rabbit does were able to adapt to moderate heat stress by decreasing feed intake, and thus live weight, but preserving milk yield and composition to ensure litter survival.

Heat Stress Affects Faecal Microbial and Metabolic Alterations of Rabbits

“…However, the influence of HS on the microbial composition and metabolites of rabbits is yet unclear. As a thermostatic animal, rabbits in an ambient temperature higher than 30°C will exhibit heat stress symptoms, resulting in reduced feed consumption, reduced feed utilization and feed efficiency, inhibition of viability and fecundity, and limited meat quality ( Marai et al, 2002 ; Bakr et al, 2015 ; Camp et al, 2018 ). Therefore, a better understanding of the physiological changes of microbial components and metabolites under high temperature will help to develop special methods to deal with high temperature rabbit raising in the future.…”

Impacts of Heat Stress on Rabbit Immune Function, Endocrine, Blood Biochemical Changes, Antioxidant Capacity and Production Performance, and the Potential Mitigation Strategies of Nutritional Intervention

“…As summarized in Figure 3 , when rabbits are exposed to heat stress, they dissipate excess heat produced inside the body manifested by specific behavioral and physiological changes in rabbits. Heat stress severely reduces the feed intake in rabbits due to the effect on the feeding center of the lower thalamus and heat increment ( 55 ). The sympathetic nerve resulting in reduced gastrointestinal function can decrease food intake during heat stress ( 21 ).…”

Genotype by heat conditions interaction effects on growth and litter traits in rabbits

“…Within this context, Boddicker et al ( 36 ) observed that HC during the first half of gestation may have a negative consequence on postnatal offspring growth and development. Furthermore, Habeeb ( 37 ) and Bakr ( 38 ) observed that heat conditions had a negative and significant effect on daily feed intake and body weight at weaning. Decreased feed intake results in a lower supply of nutrients, thus reducing the weight and growth rate of rabbits.…”