Effect of solid feed on energy and protein utilization in milk-fed veal calves1

Abstract

Little knowledge on the digestive and metabolic utilization of solid feed in veal calves is available. The objectives of the study were to determine the effects of 2 solid feeds offered at 2 feeding levels (FL90 and FL105) in addition to a milk replacer on heat production (HP) and protein and fat deposition in veal calves. Sixteen calves (148.0 +/- 3.7 kg) received milk replacer (75% of a reference DE allowance) and solid feeds that consisted of corn grain and pelleted hydrolyzed wheat gluten without (CO) or with (CS) chopped wheat straw. The solid feed supply provided 15 or 30% of the reference DE allowance to achieve FL90 or FL105, resulting in 4 treatments: CO90, CS90, CO105, and CS105. A fifth treatment consisted of using the milk replacer alone at FL90 (treatment M90) and was measured in 4 other calves. All calves were kept individually for 7 d in a respiration chamber to estimate energy and N balances and fasting HP. The digestibility coefficients of DM, OM, GE, and major nutrients were at least 94% for M90 and decreased when solid feed was added (P < 0.05). Methane production was negligible in M90 calves and increased when solid feed was given (ranging 8 to 23 L/d between CO90 and CS105, P < 0.01), indicative of ruminal fermentation. The provision of increasing amounts of solid feed decreased urinary energy in connection with a tendency (P = 0.09) for a reduction of urinary glucose excretion. The metabolizability of DE was greater with the milk replacer (95.6%) and decreased when straw was added (P < 0.01). Neither CO90 or CS90 affected HP and total energy retention (P > 0.05). Dietary treatment had no effect (P > 0.05) on activity HP (53 kJ/kg of BW(0.85) daily) but did affect thermic effect of feeding; efficiency of utilizing ME for maintenance and growth was greatest for the M90 calves (84.5%, P = 0.02). Fasting HP tended (P = 0.09) to increase at the greatest FL (308 vs. 298 kJ/kg of BW(0.85) daily). Maintenance ME requirement increased (P = 0.04) from 364 to 382 kJ/kg of BW(0.85) daily when feeding level increased (P = 0.04) but was not affected by ingestion of solid feed. The provision of solid feed to veal calves was associated with a reduced efficiency of N retention (P = 0.04), and energy retained as protein tended to decrease (P = 0.08), probably as a result of an imbalanced AA supply of the solid feeds. The data were used to calculate the energy contents of solid feed. The utilization of energy from solid feed differed from that of milk replacer.

Determination of energy and protein requirements for crossbred Holstein × Gyr preweaned dairy calves

“…Unlike what was observed by Labussiere et al (2009), the inclusion of starter feed in the diet did not affect (P > 0.83) the efficiency of use of MP for gain (k), which, in the current study, was 77 ± 8.5% ( Figure 4). The NRC (2001) suggests a k of the order of 80% with calves, whereas the studies of Blome et al (2003) and Bartlett et al (2006) showed protein gain efficiency values to be somewhat lower: 66 and 74%, respectively.…”

Nutrient Digestibility of Veal Calves Fed Large Amounts of Different Solid Feeds During the First 80 Days of Fattening

“…Calves fed CG showed the greatest DM digestibility compared to those fed CGS and CGSES, suggesting an improved feed efficiency in calves fed milk-replacer plus corn grain alone. This is in accordance with findings by Labussiere et al (2008a) who reported that the inclusion of 11% of straw in solid feeds based on corn grain and wheat gluten for 12-15 weeks old veal calves resulted in decreased DM digestibility. The higher fibrous content of CGSES solid feed in the current study might also explain the lower apparent digestibility of CP, NFC, and ash in CGSES compared to CG calves.…”

“…Calves fed CGS showed intermediate digestibility coefficients for these nutrients. Digestibility of NDF did not differ among feeding treatments (Table 3) and this result was unexpected considering findings by Labussiere et al (2008a) who reported lower NDF digestibility coefficients for veal calves fed a solid feed that included straw. Possible explanations for our results might be either a high individual variability or a similar degradation of this nutrient among feeding treatments.…”

Utilization of roughages and concentrates relative to that of milk replacer increases strongly with age in veal calves

“…Therefore, we calculated the decrease in DCP from MR required for equal carcass gain with increasing DCP for SF at each of the 2 R:C ratios. When assuming DCP contents of MR,SF 50:50,and SF 20:80 at 197,42, and 66 g/kg based on calf studies (Ortigues et al, 1990;Moody et al, 2007;Labussiere et al, 2009a), the reduction in MR intake with increasing SF intake would be 0.21 kg of MR/kg of SF for an R:C ratio of 50:50 and 0.33 kg of MR/kg of SF for an R:C ratio of 20:80. Hence, the theoretical reduction in MR intake with increasing SF intake is only 34 to 48% of the reduction observed in the current study, suggesting that DE from SF was more limiting than DCP when exchanging MR for SF.…”

“…Furthermore, SF intake will likely affect the carcass weight:live weight ratio, which needs to be considered when comparing feeding strategies. When MR is exchanged for SF on a digestible energy (DE) basis (see e.g., Labussiere et al, 2009a), assumptions have to be made with regard to the DE content of all dietary ingredients before the start of the experiment. With increasing quantities of MR being replaced by SF, these design problems are exacerbated.…”