Advances in research on responsive feeding and children's eating behaviors

Background:Given that the formation of eating behaviors in childhood is largely dependent on parental feeding,it is necessary to consider eating behaviors along with feeding behaviors when exploring child nutrition.Responsive feeding can not only promote the development of self-regulation ability,prevent overweight and obesity,and develop healthy dietary behaviors but also enhance the psychosocial ability,cognitive ability,and language ability of infants.it is of great significance for the growth and development of infants to identify whether the feeding behavior of caregivers is responsive feeding as early as possible.Methods:The progress of the literature summarizes the relevant concepts,evaluation tools,and the relationship between responsive feeding and dietary behavior.Results:This is a fact that China lacks the unified response feeding definition and responsive feeding evaluation tools suitable for homes in China.The relationship between responsive feeding and dietary behavior is in the stage of infancy,and systematic response feeding and dietary behavior have not been formed.Conclusion:It is time to pay attention to the dietary behavior of Chinese children.Intervening measures such as promoting the application of responsive feeding should be actively carry out,accordingly,childhood obesity can be prevented.

Stress and immunological response of heifers divergently ranked for residual feed intake following an adrenocorticotropic hormone challenge

Background： When an animal is exposed to a stressor, metabolic rate, energy consumption and utilisation increase primarily through activation of the hypothalamic-pituitary-adrenal（HPA） axis. Changes to partitioning of energy by an animal are likely to influence the efficiency with which it is utilised. Therefore, this study aimed to determine the physiological stress response to an exogenous adrenocorticotropic hormone（ACTH） challenge in beef heifers divergently ranked on phenotypic residual feed intake（RFI）.Results： Data were collected on 34 Simmental weaning beef heifers the progeny of a well characterized and divergently bred RFI suckler beef herd. Residual feed intake was determined on each animal during the postweaning stage over a 91-day feed intake measurement period during which they were individually offered adlibitum grass silage and 2 kg of concentrate per head once daily. The 12 highest [0.34 kg DM/d] and 12 lowest[-0.48 kg DM/d] ranking animals on RFI were selected for use in this study. For the physiological stress challenge heifers（mean age 605 ± 13 d; mean BW 518 ± 31.4 kg） were fitted aseptically with indwelling jugular catheters to facilitate intensive blood collection. The response of the adrenal cortex to a standardised dose of ACTH（1.98 IU/kg metabolic BW^（0.75）） was examined. Serial blood samples were analysed for plasma cortisol, ACTH and haematology variables. Heifers differing in RFI did not differ（P = 0.59） in ACTH concentrations. Concentration of ACTH peaked（P 〈 0.001） in both RFI groups at 20 min post-ACTH administration, following which concentration declined to baseline levels by 150 min. Similarly, cortisol systemic profile peaked at 60 min and concentrations remained continuously elevated for 150 min. A RFI × time interaction was detected for cortisol concentrations（P = 0.06） with high RFI heifers had a greater cortisol response than Low RFI from 40 min to 150 min relative to ACTH administration. Cortisol response was positively associated with RFI status（r = 0.32; P 〈 0.01）. No effect of RFI was evident for neutrophil, lymphocytes, monocyte, eosinophils and basophil count. Plasma red blood cell number（6.07 vs. 6.23; P = 0.02） and hematocrit percentage（23.2 vs. 24.5; P = 0.02） were greater for low than high RFI animals.Conclusions： Evidence is provided that feed efficiency is associated with HPA axis function and susceptibility to stress, and responsiveness of the HPA axis is likely to contribute to appreciable variation in the efficiency feed utilisation of cattle.

Lipopolysaccharide immune stimulation but not β-mannanase supplementation affects maintenance energy requirements in young weaned pigs

Background: Pathogen or diet-induced immune activation can partition energy and nutrients away from growth,but clear relationships between immune responses and the direction and magnitude of energy partitioning responses have yet to be elucidated. The objectives were to determine how β-mannanase supplementation and lipopolysaccharide(LPS) immune stimulation affect maintenance energy requirements(MEm) and to characterize immune parameters, digestibility, growth performance, and energy balance.Methods: In a randomized complete block design, 30 young weaned pigs were assigned to either the control treatment(CON; basal corn, soybean meal and soybean hul s diet), the enzyme treatment(ENZ; basal diet + 0.056% β-mannanase),or the immune system stimulation treatment(ISS; basal diet + 0.056% β-mannanase, chal enged with repeated increasing doses of Escherichia coli LPS). The experiment consisted of a 10-d adaptation period, 5-d digestibility and nitrogen balance measurement, 22 h of heat production(HP) measurements, and 12 h of fasting HP measurements in indirect calorimetry chambers. The immune chal enge consisted of 4 injections of either LPS(ISS) or sterile saline(CON and ENZ), one every48 h beginning on d 10. Blood was collected pre-and post-challenge for complete blood counts with differential,haptoglobin and mannan binding lectin, 12 cytokines, and glucose and insulin concentrations.Results: Beta-mannanase supplementation did not affect immune status, nutrient digestibility, growth performance,energy balance, or MEm. The ISS treatment induced fever, elevated proinflammatory cytokines and decreased leukocyte concentrations(P < 0.05). The ISS treatment did not impact nitrogen balance or nutrient digestibility(P > 0.10),but increased total HP(21%) and MEm(23%), resulting in decreased lipid deposition(-30%) and average daily gain(-18%)(P < 0.05).Conclusions: This experiment provides novel data on β-mannanase supplementation effects on immune parameters and energy balance in pigs and is the first to directly relate decreased ADG to increased MEm independent of changes in feed intake in immune challenged pigs. Immune stimulation increased energy partitioning to the immune system by 23% which limited lipid deposition and weight gain. Understanding energy and nutrient partitioning in immune-stressed pigs may provide insight into more effective feeding and management strategies.