Effects of protein sources for milk replacers on growth performance and serum biochemical indexes of suckling calves

This study investigated the effects of protein sources for milk replacers on growth performance and serum biochemical indexes of suckling calves. Fifty Chinese Holstein bull calves with similar BW and age were randomly allocated to 5 groups(1 control and 4 treatments) of 10 calves in each group. Five types of milk replacers were designed to have the same level of energy and protein. The protein source for milk replacers of the control group was full milk protein(MP). The protein source of milk replacers of the 4 treatment groups was composed of MP and one vegetable protein(VP)(30 and 70% of total protein). The4 types of VP were soybean protein concentrate(SP), hydrolyzed wheat protein(WP), peanut protein concentrate(PP), and rice protein isolate(RP). Results of the experiment showed: 1) there was no significant difference on average daily gain(ADG) and feed:gain ratio(F:G) among the MP, SP and RP groups(P > 0.05), whereas the ADG and F:G of the WP and PP groups were significantly lower compared with the MP group(P < 0.05); 2) there was not a significant difference in withers height, body length and heart girth among treatment groups compared with the MP group(P > 0.05). Thereby the 4 VP milk replacers had no adverse effects on body size of calves; 3) all groups showed no significant difference in the serum contents of urea nitrogen, total protein, albumin, globulin, β-hydroxybutyrate, growth hormone, insulin-like growth factor-1, and the ratio of albumin to globulin(A:G)(P> 0.05). In conclusion, SP or RP(accounts for 70% of the total protein) as calf milk replacers could substitute MP, whereas wheat gluten and PP had a significant adverse effect on growth performance in this experiment.

Artificial rearing influences the morphology,permeability and redox state of the gastrointestinal tract of low and normal birth weight piglets

Background： In this study the physiological implications of artificial rearing were investigated. Low（LBW） and normal birth weight（NBW） piglets were compared as they might react differently to stressors caused by artificial rearing. In total, 42 pairs of LBW and NBW piglets from 16 litters suckled the sow until d19 of age or were artificially reared starting at d3 until d19 of age. Blood and tissue samples that were collected after euthanasia at 0, 3, 5, 8 and 19 d of age. Histology, ELISA, and Ussing chamber analysis were used to study proximal and distal small intestine histomorphology, proliferation, apoptosis, tight junction protein expression, and permeability. Furthermore, small intestine,liver and systemic redox parameters（GSH, GSSG, GSH-Px and MDA） were investigated using HPLC.Results： LBW and NBW artificially reared piglets weighed respectively 40 and 33% more than LBW and NBW sowreared piglets at d19（P 〈 0.01）. Transferring piglets to a nursery at d3 resulted in villus atrophy, increased intestinal FD-4 and HRP permeability and elevated GSSG/GSH ratio in the distal small intestine at d5（P 〈 0.05）. GSH concentrations in the proximal small intestine remained stable, while they decreased in the liver（P 〈 0.05）. From d5 until d19, villus width and crypt depth increased, whereas PCNA, caspase-3, occludin and claudin-3 protein expressions were reduced. GSH,GSSG and permeability recovered in artificially reared piglets（P 〈 0.05）.Conclusion： The results suggest that artificial rearing altered the morphology, permeability and redox state without compromising piglet performance. The observed effects were not depending on birth weight.