Milk Replacer Acidification for Free-Access Feeding: Effects on the Performance and Health of Veal Calves

Objectives of this study were to investigate the effects of milk replacer (MR) acidification for free- access feeding on pre- and post-weaning performance, morbidity and mortality of calves. Calves were randomly assigned to free-access feeding of acidified (ACID, n = 31) or non-acidified (NON, n = 31) MR, and weaned at 42 days. ACIDMR was prepared to pH 4.0 - 4.5 using formic acid. Intakes were measured daily and weights weekly. Samples of ACID and NON MR were analyzed for coliform and aerobic bacterial growth. After weaning, calves transitioned to a grain-fed veal diet, weighed every 2 weeks. At slaughter (approximately 6 months of age), lungs were evaluated for gross pathological changes and dressed carcass weights were obtained. Generalized linear mixed models were constructed to examine the effects of MR acidification. Differences by treatment group for pre- and post-weaning morbidity and mortality were tested using Pearson’s χ2 and Fisher’s exact tests. ACID calves consumed less MR than NON (10.6 vs. 11.7 L/d, P = 0.02). Acidification tended to promote earlier onset of starter ration consumption (32.0 vs. 39.5 d, hazard ratio = 1.5, P = 0.07), but did not affect average daily starter ration or water intakes across the pre-weaning period. ACID and NON calves did not differ for BW at weaning, pre- or post-weaning ADG or dressed carcass weight. ACID MR had less coliform (P < 0.001) and aerobic bacterial growth (P < 0.001) than NON MR, but odds of disease treatment and mortality did not differ. ACID calves tended to have lower odds of pulmonary lesions during post-mortem inspection than NON calves (OR = 0.3, P = 0.07). These results indicate that under free-access feeding conditions, acidification limited bacterial growth and MR intake, but there were no long-term impacts of acidification on calf performance or health. In conclusion, acidification to pH 4.0 - 4.5 will significantly reduce bacterial growth in milk fed to calves.

Effects of different planes of milk feeding and milk total solids concentration on growth,ruminal fermentation,health,and behavior of late weaned dairy calves during summer

Background:In recent years,there has been an increasing interest in using high quantities of milk or milk replacer(MR)in heat-stressed calves to alleviate the negative effects of high environmental temperatures on their performance.However,observations have indicated a decline in growth performance in the weaning and postweaning period,which might be optimized with increasing total solids(TS)in milk and weaning age.This study aims to optimize the effects of higher quantities of milk on late weaned calves'performance by increasing TS concentration or delivery route in summer conditions.Method:Forty-eight newborn Holstein calves were used in a 2×2 factorial arrangement with the factors of preweaning total plane of milk(PM)intake(low vs.high)and milk TS content(12%vs.17%).The treatments were(1)low PM(LPM)intake with 12%TS(TS intake=45.9 kg),(2)LPM intake with 17%TS(TS intake=65.1 kg),(3)high PM(HPM)intake with 12%TS(TS intake=63.7 kg);and(4)HPM intake with 17%TS(TS intake=90.3 kg).Calves were weaned at d 83,and the study was terminated at d 103 of age.Performance data(every 10 day),skeletal growth(d 80 and 100),ruminal fermentation parameters(d 48 and 91),and behavioral measurements(d 69,70,93 and 94)were analyzed as repeated measurements with PROC MIXED of SAS 9.4(SAS Institute Inc.,Cary,NC).Results:Calves receiving HPM consumed less PMR from d 44 to 83 of age,but they had higher ADG from d 24 to 53 of age compared to those fed LPM(PM×age,P<0.001).In addition,calves receiving milk with 17%TS had lower PMR intake from d 14 to 83 of age,but greater ADG from d 34 to 53 compared to those receiving milk with 12%TS(TS×age,P<0.001).Calves that received HPM had greater skeletal growth parameters compared to LPMfed calves,with a similar effect evident for calves fed milk with 17%TS compared with those fed milk with 12%TS.Calves receiving milk with 17%TS had greater fecal scores and diarrhea occurrence than those fed milk with 12%TS in HPM,but not LPM.Conclusions:Increasing PM and milk TS concentration improved growth in summer-exposed calves as demonstrated by increased pre-weaning ADG,pre-and post-weaning BW,and structural growth.

Multi-center Study of Enteral Feeding Practices in Hospitalized Late Preterm Infants in China

Objective To investigate the current enteral feeding practices in hospitalized late preterm infants in the Beijing area of China. Methods A multi-center, cross-sectional study was conducted. Infants born after 34 weeks and before 37 weeks of gestation were enrolled from 25 hospitals in the Beijing area of China from October 2015 to October 2017. Data on enteral feeding practices were collected and analyzed. Results A total of 1,463 late preterm infants were enrolled, with a mean gestational age（GA） of 35.6（34.9, 36.1） weeks. The percentage of exclusive breastfeeding was 4.5% at the initiation of enteral feeding but increased to 14.4% at discharge. When human milk was not available, most infants（46.1%） were fed with preterm infant formula. The rate of exclusive human milk feeding in infants born at 34 weeks gestation was higher than at discharge（21.1% of infants born at 34 weeks＇ GA versus 12.1% of infants born at 35 weeks＇ GA versus 12.3% of infants born at 36 weeks＇ GA, P 〈 0.001）. Only 28.4% of late preterm infants achieved full enteral feeding at discharge, and only 19.2% achieved 120 kcal/（kg·d） by enteral feeding at discharge. Importantly, 40.5% of infants did not regain the birth weight at discharge. Conclusion Enteral feeding support of late preterm infants has not been standardized to achieve optimal growth. Moreover, the human milk feeding rate was low, and many late preterm infants did not achieve the goal of enteral feeding and failed to regain birth weight at the time of discharge. More aggressive enteral feedings protocols are needed to promote human milk feeding and optimize growth for late preterm infants.

Effect of Fruit-flavored Agent and Green Pigment on Production Performance of Simmental Cows

[Objective] The paper was to increase utilization rate of roughage to solve current shortage of forage and improve production performance of Simmental cow.[Method] Fruit-flavored agent and green pigment were added in roughage of Simmental cow respectively,and their effects on feed intake,milk production and milk quality of Simmental cow were studied.[Result] After adding fruit-flavored agent and green pigment,the feed intakes of Simmental cow were increased by 30.69% and 12.27%,while the milk productions were increased by 1.74 and 2.25 kg,respectively,and the differences were all significant（P 〈 0.05）.[Conclusion]Adding 0.3% and 0.1% fruit-flavored agent and green pigment in roughage of Simmental cow could significantly improve feed intake and milk production,which can also delay the decline of milk production during late lactation stage and improve milk quality.

Optimizing the growth and immune system of dairy calves by subdividing the pre-weaning period and providing different milk volumes for each stage

In systematically considering the advantages and disadvantages of complementarity in high or low milk feeding,novel milk feeding schemes involving altering the volume of supplied milk in different stages of the pre-weaning period but maintaining the total milk feeding volume were tested.Twenty-seven newborn male Holstein calves were selected and randomly assigned to 3 treatments.Calves in the control(CON)group were fed 7 L of milk daily from 4 to 66 d of age.Calves in the low-high(LH)group were fed 6 L of milk daily at the beginning,and then the daily feeding volume was later increased to 7 to 8 L of milk,which served as the early-period low-volume feeding group.The calves in the high-low(HL)group were fed 7 to 8 L daily at the beginning,and then the daily feeding volume was decreased to 6 L of milk,which served as the early-period high-volume feeding group.Then all calves were fed 3 L of milk daily from 67 to 70 d of age,weaned at 70 d of age,and then fed starter feed to 100 d of age.All calves had access to the starter feed from 15 to 100 d of age.The diarrheal condition of calves was recorded daily and the growth performance including the starter feed intake and body weight of calves was recorded at 70 and 100 d of age.Then,five 100-d-old calves from each treatment were sampled for measurement of plasma indices,ruminal morphology,and volatile fatty acids.When compared with the CON and LH groups,calves in the HL group exhibited a significantly increased body weight and lower diarrhoeal rate.When compared with the CON group,calves in the HL group exhibited a significantly increased average daily feed intake,ruminal epithelium papillae length,total volatile fatty acids,and percentages of propionate and butyrate.Moreover,the significantly increased plasma immunoglobulin G(IgG)content and a trend of decreased tumor necrosis factor-α(TNF-α)content(P=0.083)were also identified in the HL group when compared with the CON group.Overall,the early-period high-volume feeding for calves produced greater body weight gain and a lower incidence of diarrhea.