Transition milk or milk replacer powder as waste milk supplements to cold-stressed neonatal Holstein dairy calves: Effects on performance, feeding behavior, and health.

Young calves are more susceptible to cold than older animals due to their limited ability to regulate body temperature and lack of fat reserves and may have difficulty consuming the energy needed to cope with the cold by maintaining body temperature and meeting their metabolic needs, especially when fed constant levels of waste milk (WM) with less solids, which can be detrimental to health and future performance. An alternative to overcome this problem is increasing the milk's solids content to the existing volume by using different sources [milk replacer powder (MR) or transition milk (TM)]. Thus, we aimed to evaluate the effects of increasing the total solids of WM via MR (WM+MR) or TM (WM+TM) on the performance, feeding behavior, and health-related variables of cold-stressed dairy calves during pre- and post-weaning. We hypothesized that feeding WM supplemented with MR or TM as potential liquid feed enhancers would improve milk dry matter and energy intake of the calves with a positive impact on body development and have no negative impact on feeding behavior and health. Additionally, we hypothesized that MR would not differ from TM. As a sample size calculation at 80% power using power analysis (PROC POWER) in SAS 9.4, a total of 51 Holstein-Friesian vigorous male calves [vigor score 21-27; 17 per treatment; 4-d old; body weight (BW) = 40.0 ± 0.63 kg (mean ± SD)] were selected, assigned randomly to treatments, and housed in individual pens in an outdoor barn. Irrespective of the type of treatment, all calves were fed 6 kg/d liquid feed from d 1 to d 53 of the experiment. In a step-down weaning program, calves received 0.5 kg liquid feed from d 54 to d 60. All calves were weaned on d 61 and remained in the study until d 101 as post-weaning evaluation. The calves had ad libitum access to starter feed and fresh drinking water across the experiment. Intake, growth, and behavior data were analyzed using a general linear mixed model and health data were analyzed using mixed logistic regression, mixed linear regression, and survival analysis models in SAS. We found that supplementation was responsible for a greater dry matter intake (DMI; P = 0.004), superior average BW (P = 0.037), and increased crude protein (CP; P = 0.001) and crude fat (CF; P = 0.001) intakes, with the most favorable outcomes observed for the WM+TM group when compared with WM+MR. Animals fed WM (control group; CON) showed a smaller average daily gain during the first 40-d of life (P = 0.026), showing slight changes during the whole period of evaluation when compared with the supplemented groups (SUP; WM+MR and WM+TM). No difference between MR- and TM-SUP groups, probability of having abnormal appearance (P = 0.032) and pneumonia occurrence (P = 0.022) was reduced in the SUP than in CON animals, with no effect on diarrhea among treatment groups (P = 0.461). Using milk supplements added to WM is an alternative to improve the intake, performance, and health of young calves under cold stress. Our findings showed that SUP animals outperformed the CON group in terms of DMI, average BW, and intake of CP and CF, with the TM-SUP group displaying the most favorable outcomes. Moreover, the SUP groups demonstrated reduced odds of experiencing abnormal appearance and pneumonia, highlighting the positive impact of supplementation on calf health.

Effects of replacing steam-flaked corn with shredded sugar beet pulp on feed sorting, behavior, blood metabolites, and growth performance of dairy calves.

This experiment was conducted to investigate the effects of partial replacement of steam-flaked corn (SFC) with shredded sugar beet pulp (SBP) in the starter diet on selective intake (sorting), feeding and chewing behavior, blood biochemical parameters, and growth in newborn female Holstein dairy calves. A total of 48 calves (3 d old; 40.1 ± 0.84 kg body weight; mean ± SE) were randomly assigned to 1 of 2 feeding treatments containing 0 or 25% SBP (percentage of dry matter [DM]) in the starter diet. Calves were weaned on d 61 and remained in the study until d 81. Intake of starter feed and total intake of DM (milk DM + starter feed DM), crude protein, and neutral detergent fiber were increased (P < 0.05) by feeding SBP; however, intake of starch (P < 0.01) and total intake of ether extract (P = 0.03) were decreased with no apparent effect on total intake of ME. Average daily gain, feed efficiency, final weight, and skeletal growth also showed no significant changes. Circulating concentrations of glucose, total protein, and albumin were not affected by partial replacement of SBP with SFC; however, higher concentrations of blood urea-N (P = 0.01) and a lower albumin-to-globulin ratio (P = 0.03) were observed in SBP- vs. SFC-fed calves. Calves fed SBP sorted more for particles retained on the 4.75-mm sieve (P = 0.02) and against particles retained on the 0.6-mm sieve and bottom pan (P < 0.01). Intake of neutral detergent fibers and starch from particles retained on all sieve fractions was increased and decreased (P < 0.01), respectively, by replacing SFC with SBP. Replacement of SBP with SFC was associated with increased meal length and meal size and increased rumination frequency and length, but decreased intervals between rumination (P ≤ 0.01). Calves fed SBP spent more time eating, rumination, and standing and less time lying and non-nutritive oral behaviors (P < 0.01). In general, 25% replacement of SFC with SBP did not affect calf performance but increased time spent rumination and eating and decreased non-nutritive oral behaviors.

Substituting corn silage with reconstituted forage or nonforage fiber sources in the starter diets of Holstein calves: effects on performance, ruminal fermentation, and blood metabolites.

We examined the effects of replacing corn silage (CS) with reconstituted alfalfa hay (AH) or beet pulp (BP) in the starter diet on the nutrient intake and digestibility, growth performance, rumen fermentation characteristics, selected blood metabolites, and health status in Holstein dairy calves. Newborn female calves (n = 54; 3 d of age; 39.8 ± 1.36 kg BW) were assigned randomly to 3 groups receiving starter diets containing CS [10% dry matter (DM) basis; CS diet) and reconstituted AH (10% DM, RAH diet) or BP (10% DM; RBP diet). The starter diets had the same nutrient composition and DM content. The calves were weaned on day 50 and the study continued until day 70. Nutrient intake, body weight (at weaning and at the end of the study), daily weight gain, feed efficiency, and body measurements (including heart girth, withers height, body length, body barrel, hip height, and hip width) were not affected by the diet (P > 0.05). Health-related variables including rectal temperature, fecal score, and general appearance score were not influenced by the diets (P > 0.05). During the postweaning period, apparent total tract digestibility of DM, organic matter, and crude protein were higher for RBP (P = 0.001); however, digestibility of neutral detergent fiber was lower in RAH compared with CS or RBP (P = 0.001). Daily amount of nutrient digestibility did not change across the diets (P > 0.05). Rumen fluid pH and total volatile fatty acid concentration and profile were not different across the diets after weaning (P > 0.05). Calves fed RAH or RBP had higher blood concentration of ß-hydroxy butyric acid compared with CS only before weaning (P = 0.03). Blood albumin concentration was higher for RBP compared with CS or RAH during the preweaning (P = 0.006) and overall (P = 0.005) periods; however, it was lower for CS compared with RBP after weaning (P = 0.03). Concentration of other blood variables including glucose, blood urea N, total protein, and globulin did not change across the diets (P > 0.05). Calves, in general, were healthy, and replacing CS with RAH or RBP in the starter diet had no beneficial effect on their feed intake or growth performance indicating that CS and reconstituted AH or BP can be used interchangeably in dairy calf starter diets until 70 d of age, allowing dairy producers more choices in selecting the feed ingredients.