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

Abstract

Calves fed >0.7 kg of dry matter from milk replacer (MR) typically have greater growth preweaning but lower growth postweaning. This is partially explained by lower digestibility of starter due to less development of the rumen at and after weaning; however, it is unclear when digestibility matures postweaning to levels typical of mature ruminants. Thus, we fed Holstein calves (initially 2 to 3 d of age) 3 MR programs (MOD = 0.66 kg daily for 39 d, and then 0.33 kg daily for 3 d, n = 15 calves; HIMOD = 0.88 kg daily for 5 d, and then 1.1 kg daily for 23 d, then 0.66 kg daily for 18 d, and then 0.33 kg daily for 3 d, n = 16 calves; HI = 0.88 kg daily for 5 d, then 1.1 kg daily for 37 d, then 0.56 kg daily for 7 d, n = 15 calves). The MR consisted of 28% crude protein and 20% fat and was reconstituted to 14% solids and fed at 0630 and 1400 h daily. A 39% starch textured starter (19% crude protein) was fed free-choice for the first 56 d of a nursery trial with calves in individual pens. From 56 to 112 d, calves were grouped by MR program into pens of 3 to 4 calves and offered a starter with the same ingredient composition blended with 5% chopped grass hay for ad libitum consumption. Digestion was estimated at 11 and 16 wk. Measurements in the first and second 56 d were analyzed separately in a completely randomized design using repeated measurements when applicable. Preplanned contrasts of MOD versus HIMOD and MOD versus HI were used to separate means. Milk replacer dry matter intake was 26.6, 42.4, and 48.7 kg in calves fed MOD, HIMOD, and HI, respectively. Starter intake was less for calves fed HIMOD and HI versus MOD from 3 to 8 wk. Efficiency of metabolizable energy and protein used for body weight gain did not differ among programs. During the second 56 d, body weight gain and hip width changes were greater for calves fed MOD than HI. Total 112-d body weight gain and total hip width changes were 101.4, 101.3, and 101.7 kg, and 9.0, 9.1, and 8.7 cm for MOD, HIMOD, and HI, respectively. Digestibility of all nutrients except starch were greater at 16 versus 11 wk of age. Digestibility of dry matter, organic matter, neutral detergent fiber, and acid detergent fiber were less for HI versus MOD at 11 wk of age explaining much of the why postweaning body weight gain advantages were lost postweaning in calves fed the HI program. Feeding more than 0.66 kg of dry matter intake from a MR during the preweaning phase did not increase total body weight or hip width gain from 0 to 4 mo of age.

Effects of milk replacer feeding rate and long-term antibiotic inclusion in milk replacer on performance and nutrient digestibility of Holstein dairy calves up to 4 months of age

“…This was also evident when MR were fed at the same maximum rates in 2 different studies by Dennis et al (2017Dennis et al ( , 2018. Similarly, Hill et al (2016b) reported similar 112-d BW and hip width gains when MR were fed at 0.66 kg/d and weaning occurred at 42 d compared with feeding up to 1.1 kg/d and weaning at 49 d. When Hill et al (2016a) fed calves up to 1.31 kg/d and weaned at 49 d, 112-d BW gain appeared to be slightly greater for calves fed 1.31 kg/d versus calves fed 0.66 kg/d and weaned at 49 d, but 112-d hip width gain appeared slightly less for calves fed 1.31 kg/d.…”

“…The substitution of starter intake for milk or MR is a relatively small amount of total DMI (<15 kg) over the first 4 mo of a calf's life. However, the delay in starter intake can slow rumen development and reduce starter digestibility pre-and postweaning (Terré et al, 2007a,b;Hill et al, 2010Hill et al, , 2016b. Reduced postweaning digestion can also last 4 wk or more (Hill et al, 2016b;Dennis et al, 2018).…”

“…However, the delay in starter intake can slow rumen development and reduce starter digestibility pre-and postweaning (Terré et al, 2007a,b;Hill et al, 2010Hill et al, , 2016b. Reduced postweaning digestion can also last 4 wk or more (Hill et al, 2016b;Dennis et al, 2018). Growth advantages are frequently lost by 4 mo of age when comparing milk or MR programs that deliver a moderate amount of DM (0.66 kg of DM/d) to programs that feed more than 0.66 kg of 2095 DM (Hill et al, 2007(Hill et al, , 2016a.…”

Effects of gradual and later weaning ages when feeding high milk replacer rates on growth, textured starter digestibility, and behavior in Holstein calves from 0 to 4 months of age

“…During weaning, starter consumption rapidly increases for calves fed high amounts of milk, whereas calves receiving 0.7 kg/d of DM or less from milk gradually increase starter consumption through the preweaning period. Lack of transitional feeding behaviors can delay rumen development, resulting in reduced starter digestibility for at least 4 wk after weaning (Terré et al, 2007;Osorio et al, 2012;Hill et al, 2013Hill et al, , 2016b. For example, calves allotted increasing amounts of pasteurized whole milk using computerized autofeeders averaged less than 0.1 kg/d starter intake up to 6 wk of age when fed 8, 10, or 12 L/d, whereas starter intake averaged 0.3 kg/d for calves allotted 6 L/d (Rosenberger et al, 2017).…”

Symposium review: Re-evaluation of National Research Council energy estimates in calf starters

“…Thereafter, the disap-pearance of starch in the digestive tract was essentially complete. Quigley et al (2019a, b) conducted an analysis of 3 studies (Hill et al, 2016b;Dennis et al, 2018a;Quigley et al, 2018) using individual digestibility measurements (n = 207). Multiple modeling approaches were used (Quigley et al, 2019a), including linear mixed models, exponential models, and broken-line regression models.…”