Effect of milk replacer program on calf performance and digestion of nutrients with age of the dairy calf

Abstract

Calves fed large amounts of milk replacer (MR) gain more body weight preweaning than calves fed less-aggressive programs; however, postweaning growth may be reduced. Limited research suggests that less than optimal digestion of the postweaned diet due to large amounts of MR with reduced dry feed intake preweaning may contribute to growth impairment postweaning. Current research was conducted to compare growth and postweaning digestion in 3-d-old male Holstein calves fed various MR programs. The MR programs were a conventional [CON; 0.44 kg of dry matter (DM) 21% crude protein (CP), 21% fat powder fed for 42d], moderate (MOD; 0.66 kg of DM 27% CP, 17% fat powder fed for 42d), and aggressive program (AGG; up to 0.87 kg of DM 27% CP, 17% fat powder fed for 49d). All calves were fed a 20% CP textured starter and water ad libitum for 56d. The trial used 96 calves (initially 41 ± 1.9 kg of body weight) received 5 wk apart in 2 groups of 48 calves. During d 51 to 56, fecal samples were collected from 5 calves per treatment randomly selected from calves in the first group. Selected nutrients and acid-insoluble ash (used as an internal flow marker) were analyzed in the starter and feces to estimate digestibility. Data were analyzed as a randomized complete block design with starting time of each group of calves as a block. Repeated measure analysis was performed on overall (0 to 56d) data. Means were separated with a protected least significant difference test. Pen was the experimental unit. Calves fed CON had the least average daily gain [CON=0.35, MOD=0.51, and AGG=0.55 kg/d; standard error of the mean (SEM)=0.018], feed efficiency (CON=0.35, MOD=0.49, and AGG=0.48 gain/feed, SEM=0.016), and change in hip width (CON=3.3, MOD=4.1, and AGG=4.1cm, SEM=0.20) compared with calves fed other programs. Calves fed AGG had the greatest change in BCS and least starter intake compared with calves fed the other programs. Digestibility of organic matter was 79, 78, and 68% and neutral detergent fiber was 54, 51, and 26% for calves fed programs CON, MOD, and AGG, respectively, and were least for calves fed AGG. These results indicate that postweaning digestion is lower than optimal and contributes to lower postweaning growth in calves fed aggressive compared with conventional or moderate MR programs.

Nitrogen utilization, preweaning nutrient digestibility, and growth effects of Holstein dairy calves fed 2 amounts of a moderately high protein or conventional milk replacer

“…Our results support research by Cowles et al (2006), Guindon et al (2015), and Chapman et al (2016), that observed calves consuming up to 0.9 to 1.3 kg DM of MR daily during the preweaning period gained more weight, had greater skeletal growth, and were more efficient than calves fed approximately 0.5 kg DM of MR. As shown in Figure 1, we found a significant treatment by week interaction for starter intake that resulted in an overall treatment effect. Overall, calves on the accelerated feeding programs consumed less starter than conventionally fed calves, which was attributed to the greater difference in starter intake during wk 3, 4, 5, and 6 of the preweaning period.…”

“…Digestibility results were opposite those of other trials (Terré et al, 2007a,b;Hill et al, 2010, Chapman et al, 2016. However, those earlier experiments determined nutrient digestibilities after calves were weaned, whereas in the current study, calves were still being fed MR. Hill et al (2010) observed reduced DM and OM digestibility in the immediate 3 d postweaning with calves fed up to 1.1 kg DM of MR daily.…”

“…The decrease in starter intake during the preweaning period with these high feeding rates of milk and MR can inhibit rumen development and digestibility of nutrients postweaning (Terré et al, 2007a,b;Hill et al, 2010;Chapman et al, 2016). Chapman et al (2016) showed that calves fed 0.87 kg of DM of a 27% CP, 17% fat MR preweaning had a reduction in postweaning OM digestibility of 11% and a reduction in NDF digestibility of 28% compared with control calves fed 0.44 kg of DM of a 21% CP, 21% fat MR. Terré et al (2007a,b) also showed that digestibility of NDF was 40% less in calves fed greater levels of MR. Results from these studies show that large amounts of MR fed preweaning may further impair fiber digestion as the calf ages.…”

Effect of milk replacer program on calf performance and digestion of nutrients in dairy calves to 4 months of age

“…During the nursery trial, ADG per unit of ME intake or CP intake did not differ. This was previously reported and discussed by Chapman et al (2016). Calves fed HI used nutrients no more efficiently than calves fed MOD throughout the 56-d nursery period (Table 2).…”

“…We are aware of 5 estimates of digestibility postweaning in calves fed low versus high amounts of MR. Each reported lower OM digestibility in calves when MR DMI was greater than about 0.7 kg of DMI daily compared with calves fed less than 0.7 kg of DM daily. Terre et al (2007a,b), Hill et al (2016b), and Chapman et al (2016) compared low and moderate (0.4 to 0.7 kg of DMI from MR) and high (0.9 to 1.1 kg DMI from MR) feeding programs and found less OM and fiber digestion postweaning with high versus moderate and low MR feeding programs. Reduced digestibility in calves fed more MR was likely associated with less development of the rumen (Terre et al, 2007a,b;Suarez-Mena et al, 2011) because of lower preweaning starter intake.…”