Effect of milk replacer feeding rate and functional fatty acids on dairy calf performance and digestion of nutrients

Abstract

Calves fed large amounts of milk replacer (MR) gain more body weight preweaning than calves fed less MR; however, postweaning growth may be reduced because of impaired digestion of nutrients. This was explored in the current research, as was the inclusion of functional fatty acids (NT) that could ameliorate some poor growth and digestion issues in calves fed large amounts of MR. Two MR rates [moderate (MOD) or aggressive (AGG)] with and without NT were compared using 48 male Holstein calves initially 3d old (43±1.5kg of body weight) randomly assigned to treatments. The MOD rate was fed at 0.66kg of dry matter (DM) for 49d. The AGG rate was fed for 4d at 0.66kg of DM, 4d at 0.96kg of DM, then 34d at 1.31kg of DM, followed by 0.66kg of DM for the last 7d. Calves were completely weaned at 49d. The MR contained 27% crude protein and 17% fat. The textured starter was 20% crude protein. Starter and water were fed free-choice for the first 56d when calves were housed in individual pens. From 56 to 112d, calves were grouped (4 calves/pen), maintaining the same MR rate and NT treatments, and fed starter blended with 5% chopped grass hay free-choice with free-choice water. Digestibility was estimated from fecal collections made on d 19 to 23, 40 to 44, and 52 to 56. Data were analyzed as a completely randomized design with a factorial arrangement of MR rate and NT using repeated measures with a mixed procedure. Fiber and starch digestion increased with age and was lower for AGG versus MOD. Calf average daily gain and hip width change were greater before approximately 6wk of age for AGG versus MOD, but this was reversed from approximately 6 to 16wk. Calves fed AGG had lower average daily gain per unit intake of DM, crude protein, and metabolizable energy from 8 to 16wk than calves fed MOD. Preweaning starter intake was less for calves fed AGG versus MOD. Calves fed AGG had greater body weight gain than MOD over 112d, but hip width change did not differ. Feeding NT improved digestibility of organic matter, DM, neutral detergent fiber, and acid detergent fiber (over 50% improvement for neutral detergent fiber and acid detergent fiber), which resulted in 10.7kg (13%) more body weight gain and 1.4cm (16%) more hip width change over 112d. This was a greater improvement in growth than the difference in AGG and MOD programs over 112d.

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

“…Starter fed in the current study and the previous digestibility studies (Hill et al, 2010(Hill et al, , 2016bChapman et al, 2016) was low in fiber and high in starch. Calves fed higher-fiber starters with high amounts of MR or milk might report larger amounts of BW gain during or immediately after weaning resulting from growth of gut tissue and accumulation of gut fill from poor digestion of starter rather than muscle or bone growth.…”

“…By wk 3 of the study, ADG did not differ among treatments (Figure 2), although calves on HI and HIMOD were fed significantly more MR than MOD calves. Hill et al (2016b) reported that digestibility of NDF and ADF from a high corn and oats starter (high in starch) increased from 3 to 8 wk of age (calves weaned at 7 wk of age), likely reflecting increasing maturation of the digestive system. In their data, the digestion of ADF and NDF was lower in calves fed HI versus MOD (~0.7 kg/d of DMI), reflecting slower maturation of the digestive system in calves more than about 0.7 kg/d of MR. Lower digestibility of starter could result in greater amounts of gut fill and gut tissue.…”

“…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.…”

Nutraceuticals

“…Supplementing short-chain fatty acids such as butyrate can improve GIT development and calf performance. 61 Furthermore, the effect may be more pronounced in milk replacer diets in which the primary fat source is not milk fat. Milk fat already contains a significant quantity of butyrate; however, the exact concentrations of these short-chain fatty acids to supplement in milk replacer are not known.…”

“…Milk fat already contains a significant quantity of butyrate; however, the exact concentrations of these short-chain fatty acids to supplement in milk replacer are not known. 59,61 Supplementing omega-3 PUFAs and altering the omega-6 to omega-3 PUFA ratio to transition and early lactating cows was investigated as a strategy to improve health and production performance. Feeding whole flaxseed as a source of the omega-3 PUFA, specifically a-linolenic acid, from calving until 105 days in milk (DIM) decreased the serum concentrations of the proinflammatory eicosanoid, prostaglandin E 2 .…”