Growth Performance Of Calves Research Articles

Effects of pre-weaning supplementation with fennel seed powder in two terms on growth performance, health status, and blood metabolites of Holstein dairy calves

This study investigated the effects of fennel seed powder (FSP) supplementation in liquid feed on growth performance, health, and blood parameters of preweaning dairy calves. In a 2 × 2 factorial design, 56 one-day-old female Holstein calves (n = 14/treatment) received liquid diet [colostrum (4.5 kg/d for the first 2 d), waste milk (6 kg/d from d 3 to 43, 5 kg/d from d 44 to 45, 4 kg/d from d 46 to 47, 3 kg/d from d 48 to 49)] supplemented with either of 3 or 6 g FSP (FSP3 or FSP6) in two terms (T: 25 or 50 d). Biometric and health traits were recorded daily, and blood metabolites were analyzed at d 25 and 50. The experiment was conducted under mild heat stress. The FSP6 group showed significant increase in starter dry matter intake (g/d and % of BW), starter crude protein (g/d), starter ether extract (g/d), starter ME (Mcal/d), total dry matter intake (g/d and % of BW), and total crude protein intake (g/d) during the last ten days of the experiment. The FSP6 group also had a significantly higher average daily gain (g/d), overall body weight (d 1–51), final weight (d 51), and total hip width compared with the FSP3 group. Feed conversion was higher in the FSP6–25 T or − 50 T groups than in the FSP3–25 T (but not −50 T) group. Calves receiving 3 g of FSP had a higher likelihood of experiencing elevated rectal temperature [≥ 39.4 ºC, odds ratio (OR) = 1.583 and confidence interval (CI) = 1.25 to 2.00], poor general appearance [(1 = normal and alert; 2 = ears drooped; 3 = head and ears drooped, dull eyes, slightly lethargic; 4 = head and ears drooped, dull eyes, lethargic; and 5 = severely lethargic); ≥ 2, OR = 1.47 and CI = 1.14 to 1.91)], and diarrhea [(1 = normal; 2 = soft to loose; 3 = loose to watery; 4 = watery, mucous, slightly bloody; and 5 = watery, mucous, and bloody); ≥ 3 (OR = 1.36 and CI = 1.04 to 1.76)] compared to those in the FSP6 group. Conversely, calves in the FSP6 group had fewer days of increased rectal temperature (4.75 vs. 7.11 d), poor general appearance (3.93 vs. 5.75 d), and diarrhea (3.85 vs. 5.11 d) than those in the FSP3 group. In addition, serum levels of alanine transferase (15.90 vs. 16.98 U/L for FSP6 vs. FSP3) and malondialdehyde (1.24 vs. 1.43 nmol/mL for FSP6 vs. FSP3) were significantly lower in the FSP6 group than in the FSP3 group. In addition, longer feeding of FSP was more effective than shorter feeding in lowering both traits. A triglyceride-lowering effect was observed in the FSP3 group compared with the FSP6 group (27.45 vs. 30.90 mg/dL). Overall, supplementation of liquid feed with 6 g FSP for 25 or 50 d improved growth performance in dairy calves.

Does micro-granulated yeast probiotic (Saccharomyces cerevisiae) supplementation in milk replacer affect health, growth, feed efficiency and economic gain of calves?

The goal of calf feeding systems is to provide calves with optimum nutrition to promote growth, health, and future milk production and to reduce antibiotic use which leads to a need for alternatives that reduce illness and promote growth in dairy calves. We hypothesized that feeding live yeast would improve gastrointestinal health and growth performance of calves. The aim of this study was then to evaluate the effects of supplementing a yeast probiotic Saccharomyces cerevisiae (CNCM I-4407, 1010 CFU/g, Actisaf® Sc47 powder; Phileo by Lesaffre, France) in milk replacers (MR), on health and growth of pre-weaned calves. Forty Holstein female calves were used during this trial. Each calf was weighed at 3 days of age and then introduced in the trial. Calves were randomly assigned to 2 groups (n = 20/group) and were fed MR without (control; CON) or with yeast probiotic at 1 g/calf/d (experimental; EXP). Milk replacer (12.5 % solids) was offered twice a day until 66 days of age (DOA). Body Weight (BW), wither height, hip width, body length and chest girth were collected in day 3 and day 66. Compared to CON, calves supplemented with yeast probiotic had better average daily gain (ADG, 0.456 ± 0.1 vs. 0.556 ± 0.09 kg/d, p < 0.05). There was no difference (p > 0.05) in both starter and MR intake between the two groups. Feed efficiency was better (p < 0.05) in the EXP group (2.18 ± 0.53) compared to CON (2.63 ± 0.78). No statistical differences were found between groups even if the lower total morbidity (40.91 % in the CON vs. 19.05 % in EXP) and incidence of gastrointestinal disorders (36.36 % in the CON vs. 14.29 % in EXP) were observed in calves supplemented with yeast probiotic. The severity of diarrhea was numerically lower in calves supplemented with yeast probiotic. No severe cases of respiratory disorders were highlighted in the present trial. The cost/kg of gain was higher (p < 0.05) in CON compared to EXP group. Total expenses linked to feeds and veterinary treatments were higher in CON compared to EXP group. During the study, the use 1 g/d of yeast probiotic allows to save 32.86 €/calf.It could be concluded that supplementing Actisaf® powder (Actisaf® SC 47 PWD) in MR improved health, growth performance, feed efficiency, and reduced the expenses linked to feeds and veterinary treatments.

Effects of grain processing (cracked vs. steam-flaked) and forage sources (alfalfa hay and wheat straw) as a free-choice provision on growth performance, rumen fermentation, blood metabolites, and behavior of dairy calves

The aim of this study was to investigate the interaction between physical form of starter (PFS) and forage source (FS) with free access to forage on feed intake, growth performance, rumen fermentation, blood metabolites and behavioral traits of dairy calves. A total of 48 7-day-old Holstein calves were randomly assigned to one of four treatments in a 2 × 2 factorial arrangement, with FS [alfalfa hay (AH) and wheat straw (WS)] as free-choice supply and PFS diets (cracked vs. steam-flaked) as main effects. Feeding treatments included (1) starter diet with steam flaked corn (SFC) and free access to AH (SFC-AH), (2) starter diet with SFC and free access to WS (SFC-WS), (3) starter diet with cracked corn (CRC) and free access to AH (CRC-AH) and (4) starter diet with CRC and free access to WS (CRC-WS). The calves were weaned on day 58 and remained in the experiment until day 70. All calves had free access to water and starter feed. The results showed that there was no interaction between PFS and FS in terms of starter intake, forage intake, dry matter intake (DMI), average daily gain (ADG), body weight (BW) or feed efficiency (FE). Calves fed CRC consumed more dry matter, TMR and forage than calves fed SFC diets. Regardless of the PFS diet, weaning weight, total weight and total ADG were higher in calves fed WS, while forage intake was higher in calves fed AH. Calves fed CRC-AH had the lowest rumen pH at day 68 compared to the other groups (except SFC-WS at day 70). An interaction between PFS diets and FS affected rumen proportion of propionate on day 35, since calves, which were fed CRC-AH had the highest molar percentage of propionate than calves fed other diets (except for SF-WS). At day 65, calves fed SFC starter feed had higher plasma glucose concentrations than calves fed CRC. It was found that PFS feed and FS had an interaction effect on BUN at day 65, with calves fed CRC-AH having the highest BUN. Compared to the other groups, calves fed CRC-WS had the highest BHB at day 33 and throughout the period (days 35 and 65). An interaction between PFS diets and FS affected lying time and forage eating time, with CRC-AH calves exhibiting the longest lying time and lowest forage eating time. The time spent on NNOB tended to be longer in SFC-fed calves than in CRC-fed calves, regardless of the forage source. Compared to calves fed SFC, calves fed CRC with high levels of fine particles consumed more dry matter, TMR, and forage while spending less time on NNOB. Furthermore, feeding calves chopped WS instead of AH increased weaning weight, total weight, and total ADG, although forage intake was higher in calves fed AH. In summary, a combination of cracked corn starter with free access to wheat straw appears to provide the best growth outcomes for dairy calves.

Nutritional Evaluation of Hydroponic Corn Fodder and its Effect as Substitute for Feed Concentrates for Buffalo Calves

This study investigated the effects of hydroponic corn fodder on the growth performance of buffalo calves. Twelve Bulgarian Murrah buffalo calves were divided into two treatment groups: T1, fed with Napier grass and starter feed concentrates, and T2, fed with Napier grass, starter feed concentrates, and hydroponic corn fodder, replacing 50% of the starter feed concentrate. The study found no significant differences between the two groups' average total weight gain and average daily gain. However, the average daily feed intake was significantly higher in T2, possibly due to the tender and young nature of the hydroponic corn fodder. Dry matter and crude protein intake did not show any significant differences between the two groups. The digestibility of nutrients showed a significant difference in dry matter digestibility between T1 and T2. Feed cost per d was significantly lower in T1, but the cost of feed per kg gain was lower in T2. This study suggested that supplementing buffalo calves' diets with hydroponic corn fodder could have a beneficial effect on their growth performance and economic viability. It recommends further research on the use of other grains as fodder for ruminants. Overall, this study highlighted the potential of hydroponic corn production as a sustainable source of fodder for ruminants.

Effects of castration and eucalyptus oil supplementation on growth performance, nutrient digestibility, and blood-immunity indicators of male Holstein calves

The purpose of this study was to investigate the effects of early castration and eucalyptus oil (EUC) supplementation on dry matter intake (DMI), growth performance, and immune response of Holstein calves. Fifty-six male Holstein calves 52 d old and with an initial body weight (BW) of 63.5 ± 5.27 kg were used. The animals were blocked by BW and randomly assigned into 1 of the 4 treatment groups in a randomized complete block design with a 2 (no castration vs. castration) × 2 (without vs. with EUC) factorial arrangement of treatments. The treatments were (1) uncastrated calves fed without EUC, (2) uncastrated calves fed 0.5 g/d EUC (EUC group), (3) castrated calves (steers) fed without EUC (castrated group), and (4) steers fed with 0.5 g/d EUC (castrated + EUC). The experiment was 8 wk long, including pre- and postweaning (weaned at 72 d). The EUC × castrated interactions were not significant for DMI, growth performance, nutrient digestibility, and immune response. Castration did not affect the DMI, final BW, average daily gain (ADG), or feed efficiency, except that the ADG was greater for bull calves than for steers at postweaning. Supplementation with EUC increased DMI pre- and postweaning and increased the ADG of weaned calves. Digestibility in the total digestive tract was not affected by castration (except for organic matter digestibility), whereas adding EUC improved the digestibility of dry matter, acid detergent fiber, and crude protein. Blood concentration of IL-6 at d 94 was decreased by feeding EUC. These results indicate that the EUC could be fed to either intact or castrated dairy calves to promote growth and health postweaning; castration before weaning may reduce ADG and cause inflammatory stress without affecting feed intake or feed efficiency.

367 Early Fetal to Neonatal Vitamin a Supplementation Improves Growth Performance and Development of Muscle and Pre-Adipocyte in Korean Native Calves

Abstract This study aimed to investigate the effects of vitamin A supplementation during the early fetal to neonatal stages on growth performance, blood metabolites, and the development of muscle and pre-adipocytes in Korean native calves. Twenty female newborn calves [day 0 of age; initial BW: 31.2 kg (SD 3.07)] were stratified based on whether they received vitamin A supplementation during the early fetal to neonatal stages, and then randomly allocated to four groups using a 2 × 2 factorial arrangement. Vitamin A supplementation was conducted as follows: fetal stage (control: 7,800 IU/kg of as-fed, treatment: 22,800 IU/kg of as-fed); neonatal stage (control: 17,000 IU/day, treatment: 53,000 IU/day). Growth performance, blood variables, mRNA expression in muscle tissue, and muscle fiber diameter were evaluated during the experimental period and analyzed using the MIXED procedure with Tukey's test by SAS 9.4 software. As a result, fetal-vitamin A treatment group exhibited higher (P &amp;lt; 0.05) serum vitamin A concentrations and blood glucose concentrations on the day 3 of age. Similarly, vitamin A supplementation in the neonatal stage significantly increased (P &amp;lt; 0.05) serum vitamin A concentrations at day 30 and 60 of age, as well as albumin and glucose concentrations at day 60 of age. Moreover, both birth and weaning BW were significantly greater (P &amp;lt; 0.05) in calves receiving vitamin A supplementation during the fetal stage. However, feed intake and muscle fiber diameter showed no differences (P &amp;gt; 0.05) between the groups. In addition, supplementation of vitamin A during the fetal stage resulted in upregulation (P &amp;lt; 0.05) of ZNF423 mRNA expression in the longissimus dorsi muscle, whereas neonatal supplementation upregulated (P &amp;lt; 0.05) the mRNA expression of PAX7 and MYF5. Our findings suggested that vitamin A supplementation during the early fetal to neonatal stages can enhance the growth performance of offspring calves and potentially promote an increase in pre-adipocyte and satellite cell storage in muscle tissue. This information can be applied in integrated fetal-neonatal nutrient feeding strategies in beef cattle.

PSVI-23 Effects of Creep-Feeding Supplementation on Growth Performance of Nellore Calves and Milk Yield of Dams

Abstract The study aimed to evaluate the effect of creep-feeding on growth performance of beef calves and milk yield of dams, during nursing phase. The experiment lasted 170 days, from December/2021 to May/2022, the calves were born in September/2021 and creep-feeding supplementation started from approximately 70 days of life until weaning. The experimental design used was a randomized block [blocked by body weight (BW) of calves]. The experimental units were the paddocks (8 units per treatment, and ten replicates per paddock), totalling 156 pairs cow/calf (86 pairs of male calves and 70 pairs of female calves). The treatments consisted of creep-feeding or not creep-feeding the calves: control treatment (CONT; mineral supplement ad libitum) and creep-feeding treatment (CREEP; energetic protein supplement; 5 g/kg of BW· animal-1· /day-1). There was mineral supplement ad libitum for all the dams. The pairs cow/calf were kept in an area of Urochloa brizantha cv. Marandu. The data were analyzed using the SAS PROC MIXED. Male calves subjected to CONT showed less BW (-15 kg) at weaning and decreased average daily gain (ADG; -100g/day) until weaning (P &amp;lt; 0.01; Figure 1), while female calves showed no difference in BW and ADG (P &amp;gt; 0.12; Figure 2). The dams did not show difference in milk yield until weaning (P &amp;gt; 0.27) for male and female calves (Figure 3). This difference in results related to gender is explained by the fact that there are differences in the performance of males and females, mainly due to hormonal issues. Usually, females are born lighter than males and tend to have decreased performance throughout the whole production cycle. For milk yield and performance of dams, our results agree with what is found in the literature. There are some studies which also evaluated milk production of dams when the offspring were creep-fed, and found similar milk yield for those whose offspring received supplement in relation to those who did not receive it. This is likely because calves prefer milk, supplement, and forage, in that order, so it seems unlikely that calves would replace milk with supplements. And these results show us that the difference in the BW at weaning of males was caused by the creep-feeding supplementation.

339 An Evaluation of the Effects of Feeding an Exogenous Fibrolytic Enzyme Product on the Growth Performance and Apparent Nutrient Digestibility of Growing Bison Calves Fed in a Commercial Feed Yard

Abstract While exogenous enzyme supplementation has been tested in ruminants as early as the 1960’s, industry adoption of such technologies has been slow. With high feed costs, technologies such as feed enzyme could potentially help producers to lower the production cost by improving feed efficiency. A 69-day growing experiment was conducted at a commercial feed yard in Western NE using bison calves [n = 228; initial body weight (BW) = 269 kg, SD = 41 kg] to determine the effects of supplementation of an exogenous fibrolytic enzyme from T. reesei on calf dry matter intake (DMI), growth performance and nutrient apparent digestibility. A completely randomized design was utilized with two treatments, control (CON) or enzyme (CX), and four pens, with calves assigned randomly to pen and pen assigned to TRT (48 to 66 calves per pen). Individual calf BW were obtained on day 0, day 35, and day 69. The DMI was measured daily by pen, with feed offered adjusted daily and fecal samples were composited and analyzed on pen-basis. Data were analyzed using JMP statistical software, with initial BW included as a covariate in the analyses. Average daily gain and DMI in calves fed the CX treatment was 7% greater (0.895 vs. 0.830 kg/d; P = 0.02), and 11% less (7.83 vs. 8.75 kg/d; P = 0.02) than in calves fed the CON treatment, respectively, resulting a 18% numeric improvement in feed efficiency for calves fed the CX treatment compared with calves fed the CON treatment. Apparent starch digestibility tended to improve (P = 0.07) by 15% in calves fed the CX treatment compared with calves fed the CON treatment, while apparent neutral detergent fiber (NDF) digestibility (as a percent of NDF) was numerically improved by 9% in calves fed the CX treatment compared with calves fed the CON treatment. Although the mode of action warrants further investigation, these data suggest that feeding an exogenous fibrolytic enzyme product may be beneficial for growing bison calves, likely in part because of greater apparent nutrient digestibility.

Comparable Evaluation of Nutritional Benefits of Lactobacillus plantarum and Bacillus toyonensis Probiotic Supplementation on Growth, Feed Utilization, Health, and Fecal Microbiota in Pre-Weaning Male Calves.

This study was conducted to investigate the impact of probiotic supplementation using Lactobacillus plantarum DSA 20174 and/or Bacillus toyonensis ATCC 55050 on growth performance, blood parameters, hematological measures, and fecal microbiota in pre-weaning Holstein calves. Thirty-two four-day-old male calves with a similar genetic background, weighing an average of 38.27 ± 0.12 kg, were randomly assigned to four groups. The groups consisted of a control group (CON) without supplementation, a group receiving B. toyonensis (BT) at 3 × 109 cfu/calf/day, a group receiving L. plantarum (LP) at 1 × 1010 cfu/calf/day, and a group receiving a combination of LP and BT (LP + BT) at half the dosage for each. The study found that calves supplemented with LP and LP + BT experienced significant improvements in average daily gain and final body weight compared to the control group. The LP + BT group showed the most positive effects on TDMI, starter intake, and CP intake. RBC counts tended to be higher in the probiotic groups, with the LP + BT group having the highest values. The LP + BT group also had higher total protein, albumin, globulin, and hematocrit concentrations. All probiotic groups showed higher serum IgG concentrations. Probiotic supplementation led to increased total bacterial count and decreased levels of E. coli, salmonella, and clostridium. The LP + BT group had a significant decrease in coliform count, while both LP and LP + BT groups had increased Lactobacillus populations. In conclusion, LP + BT probiotic supplement showed the most beneficial effects on growth, feed efficiency, blood constituents, and modulation of fecal microbiota composition.

Preweaning period is a critical window for rumen microbial regulation of average daily gain in Holstein heifer calves.

Rumen bacterial groups can affect growth performance, such as average daily gain (ADG), feed intake, and efficiency. The study aimed to investigate the inter-relationship of rumen bacterial composition, rumen fermentation indicators, serum indicators, and growth performance of Holstein heifer calves with different ADG. Twelve calves were chosen from a trail with 60 calves and divided into higher ADG (HADG, high pre- and post-weaning ADG, n = 6) and lower ADG (LADG, low pre- and post-weaning ADG, n = 6) groups to investigate differences in bacterial composition and functions and host phenotype. During the preweaning period, the relative abundances of propionate producers, including g_norank_f_Butyricicoccaceae, g_Pyramidobacter, and g_norank_f_norank_o_Clostridia_vadinBB60_group, were higher in HADG calves (LDA > 2, P < 0.05). Enrichment of these bacteria resulted in increased levels of propionate, a gluconeogenic precursor, in preweaning HADG calves (adjusted P < 0.05), which consequently raised serum glucose concentrations (adjusted P < 0.05). In contrast, the relative abundances of rumen bacteria in post-weaning HADG calves did not exert this effect. Moreover, no significant differences were observed in rumen fermentation parameters and serum indices between the two groups. The findings of this study revealed that the preweaning period is the window of opportunity for rumen bacteria to regulate the ADG of calves.

Effects of Different Galacto-Oligosaccharide Supplementation on Growth Performance, Immune Function, Serum Nutrients, and Appetite-Related Hormones in Holstein Calves.

Our previous study showed that early supplementation with 10 g/(d·head) of galacto-oligosaccharides (GOS) in newborn Holstein dairy calves reduced the incidence of diarrhea and improved growth performance and mineral absorption. Since the dose of 10 g/(d·head) was the lowest by dose screening in our previous study, the present study was designed to investigate whether a lower amount of GOS has similar effects on growth performance, immune function, serum nutrients in newborn Holstein heifer calves, and to further investigate its effect on appetite-related hormones. Twenty-eight healthy newborn (1 day of age) Holstein heifers with similar average body weight (41.18 ± 1.90 kg) were randomly divided into four groups (n = 7): the control group (CON group), which received heated raw milk, and three experimental groups, which received heated raw milk supplemented with 2.5 (GOS2.5 group), 5 (GOS5 group), and 10 g/(d·head) (GOS10 group) GOS. All heifer calves were fed the same starter for 28 d. Supplementation with GOS linearly increased the final body weight, average daily gain, and feed efficiency in heifer calves (p < 0.01). Compared with the control group, the average daily gain and feed efficiency of heifer calves were significantly higher in the GOS5 and GOS10 groups than in the control group (p < 0.05). Furthermore, supplementation with GOS quadratically enhanced the starter and total average daily feed intake of the heifers (p < 0.01), especially in the GOS2.5 and GOS5 groups, (p < 0.05 vs. CON). The serum concentration of immunoglobulin A was linearly increased by GOS supplementation (p < 0.05), and the levels in the GOS5 and GOS10 groups were significantly higher than those in the CON group. Meanwhile, GOS linearly decreased serum interleukin-1β and interleukin-6 concentrations (p < 0.05). The serum concentration of triglycerides was also linearly decreased (p < 0.05), whereas total protein and blood urea nitrogen were linearly increased (p < 0.05). Supplementation with GOS linearly decreased the serum concentration of leptin (p < 0.05) but increased cholecystokinin and glucagon-like peptide-1 (p < 0.05). Increasing doses of GOS linearly improved serum calcium and copper concentrations (p < 0.01) and quadratically enhanced the concentration of magnesium, which peaked in the GOS5 group (p < 0.05). In conclusion, GOS supplementation reduced the incidence of diarrhea and improved the growth performance and immune function of Holstein heifer calves.

Effects of feeding different levels of dietary corn silage on growth performance, rumen fermentation and bacterial community of post-weaning dairy calves.

The objective of this study was to evaluate the growth performance, rumen fermentation parameters and bacterial community of post-weaning dairy calves in response to five diets varying in corn silage (CS) inclusion. A total of forty Holstein weaned bull calves (80±3 days of age;128.2±5.03 kg at study initiation) were randomized into five groups (8 calves/group) with each receiving one of five dietary treatments offered as total mixed ration in a 123-d feeding study. Dietary treatments were control diet (CON; 0% CS dry matter [DM]); Treatment 1 (T1; 27.2% CS DM); Treatment 2 (T2; 46.5% CS DM); Treatment 3 (T3; 54.8% CS DM); and Treatment 4 (T4; 67.2% CS DM) with all diets balanced for similar protein and energy concentration. Results showed that calves offered CS had greater average daily gain, body length and chest depth growth, meanwhile altered rumen fermentation indicated by decreased rumen acetate concentrations. Principal coordinate analysis showed the rumen bacterial community structure was affected by varying CS inclusion diets. Bacteroidetes and Firmicutes were the predominant bacterial phyla in the calf rumens across all treatments. At the genus level, the abundance of Bacteroidales_RF16_group was increased, whereas Unclassified_ Lachnospiraceae was decreased for calves fed CS. Furthermore, Spearman's correlation test between the rumen bacteria and rumen fermentation parameters indicated that Bacteroidales_RF16_group and Unclassified Lachnospiraceae were positively correlated with propionate and acetate, respectively. The results of the current study suggested that diet CS inclusion was beneficial for post-weaning dairy calf growth, with 27.2% to 46.5% CS of diet DM recommended to achieve improved growth performance. Bacteroidales_RF16_group and Unclassified Lachnospiraceae play an important role in the rumen fermentation pattern for post-weaning calves fed CS.

Effects of corn processing index and forage source on performance, blood parameters, and ruminal fermentation of dairy calves

The objective of this study was to investigate the effects of corn processing index (CPI)—particularly at 70% and 85%—in starter feed in combination with the provision of forage, either alfalfa hay (AH) or wheat straw (WS), on feed intake, growth performance, rumen pH, and blood metabolites of dairy calves. Forty-eight male Holstein calves (43.0 ± 1.5 kg body weight) were randomly assigned (n = 12 calves per treatment) to one of four dietary treatments: (1) a textured starter diet containing 70% CPI and AH (70CPIAH), (2) a textured starter feed containing 70% CPI combined with WS (70CPIWS), (3) a textured starter feed containing 85% CPI and AH (85CPIAH), (4) a textured starter feed containing 85% CPI combined with WS (85CPIWS). Intake of starter feed (TMR) and milk was individually monitored and recorded daily, while body weight was measured weekly. On days 30 and 65, blood samples were collected from all calves 3 h after morning feeding. No interaction was detected between the CPI of starter feed diets and forage provision for starter intake, dry matter intake (DMI), metabolizable energy intake (MEI), feed efficiency (FE), average daily gain (ADG), and body weight (BW). The preweaning and overall DMI, preweaning, postweaning and overall FE and ADG, preweaning and overall starter intake, preweaning and overall ME intake, and postweaning and overall BW were greater for calves fed 85CPI than those fed 70CPI starter diets. Postweaning and overall ADG and postweaning FE were greater in calves fed WS than those fed AH. Body length and hip width were greater for calves offered 85CPI than in fed 70CPI. Wheat straw supplementation increased rumen pH at day 65 in calves fed 70CPI, but not in those fed 85CPI. No interaction was found between the CPI in the starter feed diet and the forage source for starter intake and DMI, MEI, FE, and BW. The results showed that including corn with 85% processing index in dairy calf starters improved their growth performance.

Response of calves fed starters based on either steam-flaked corn grain or steam-flaked barley grain to dietary protein content in Holstein dairy calves

We hypothesized that steam-flaking the high-starch grains can stimulate ruminal microbial activity and reduce cecal fermentation due to lowering starch escaping in to hind-hut of young calves. Therefore, the current study evaluated the effect of steam-flaking the grains (corn grain vs. barley grain) with either 18% (18CP) or 22% (22CP) dietary protein content (dry matter basis) on growth performance, microbial protein synthesis (MPS) and inflammatory markers in young calves. Female Holstein calves (48 calves with 3 d of age) were assigned randomly to the following treatments: SFC-18CP, SFC-22CP, SFB-18CP, and SFB-22CP (n = 12, each). Milk feeding schedule was identical among treatments until weaning (d 53), and calves had ad-libitum access to water and starters until the final day of experiment (d 73). Feeding SFC increased starter intake compared to calves fed SFB diet (p = 0.05; pre-weaning, have greater feed efficiency (tendency, p = 0.07; post-weaning), better fecal score (p = 0.01), and higher hip height (p = 0.03; post-weaning) compared to calves fed SFB diet. However, ruminal pH was lower (p = 0.04; pre-weaning), heart girth was smaller (p = 0.02), and post-weaning circulating tumor necrosis factor-α was greater (TNF-α, p = 0.03) for calves fed SFB compared to calves fed SFC diet. Feeding 22CP compared to 18CP diet improved hip height at weaning time (p = 0.01) and reduced pre-weaning serum amyloid A (SAA, p = 0.04). With respect to the interaction, results indicated that higher ADG (p = 0.04) and subsequently higher BW (p < 0.05) was detected for calves fed SFC along with 22CP diet compared to other experimental arrangements. The calves fed SFB along with 18CP diet had lower withers height (p = 0.01), lower urinary allantoin (p = 0.02), and MPS (p = 0.04); but higher TNF-α (p = 0.01; pre-weaning) and higher SAA (p = 0.04; post-weaning) compared to other experimental treatments. Based on the results obtained in the current study, feeding SFC can be more favorable diet than SFB diet in young calves due to improve ruminal microbial activity and more favorable immune function. Furthermore, results suggest that feeding steam flaked corn grain with 22CP diet had positive interaction resulted in higher microbial protein production and growth performance of young calves. Optimal processing method applied for high-starch grains to increase ruminal fermentation and prevent starch escaping in to the hind-gut of young calves for reducing cecal fermentation needs to be more evaluated in milk-fed calves.

A Preliminary Study of the Potential Molecular Mechanisms of Individual Growth and Rumen Development in Calves with Different Feeding Patterns.

At present, it is common to feed calves with "Concentrate", "Concentrate + hay" and TMR "Total Mixed Rations" feeding patterns in China, which achieved well feeding efficiency, but the three feeding patterns molecular regulation mechanism in actual production is still unclear. The study aimed to explore the most suitable feeding pattern for Chinese Holstein calves to improve the rumen fermentation function and growth performance of calves. In this regard, the interactions between rumen microorganisms and host metabolism were investigated. The rumen volume and weight of calves in the GF group were significantly higher than those in the GFF and TMR groups (p < 0.05), and the rumen pH of calves in the GF group was 6.47~6.79. Metagenomics analysis revealed that the rumen microbiome of GF and GFF calves had higher relative abundances of Methanobrevibacter, Methanosphaera, and Methanolacinia (p < 0.05). Prevotella multisaccharivorax was significantly more abundant in the rumen of GF calves (p < 0.05), indicating that GF group calves had a stronger ability to ferment sugars. Notably, in the pyruvate metabolic pathway, phosphoenolpyruvate carboxylase was significantly up-regulated in GF calves compared with the TMR group, and pyruvate-phosphate dikinase was significantly down-regulated. Metabolomic results showed that Ursodeoxycholic acid was significantly up-regulated in GF calves, and most of the differential metabolites were enriched in Bile secretion pathways. The association analysis study found that the microorganisms of Prevotella and Ruminococcaceae might cooperate with the host, which was helpful for the digestion and absorption of lipids and made the calves have better growth. The three feeding modes had similar effects, but the 'GF' feeding pattern was more beneficial to the individual growth and ruminal development regarding ruminal morphology, contents physiology and microorganisms. Furthermore, the synergistic effect of rumen microorganisms and the host could more effectively hydrolyze lipid substances and promote the absorption of lipids, which was of great significance to the growth of calves.

Interactions of starter starch and sodium butyrate for preweaned dairy calves: Growth performance, rumen development, and microbiota

The objective of the present study was to evaluate the effects of sodium butyrate (SB) supplementation in calf starters with varying starch content on the growth performance, rumen fermentation, morphological and functional development of the rumen, and rumen microbiota in preweaned dairy calves. In experiment 1, 120 Holstein calves (41.7 ± 2.81 kg BW; 16.0 ± 1.75 d age) were grouped and organized in a complete randomized design with a 2 × 2 factorial arrangement of treatments: (1) low starch (270 g/kg DM) starter without SB supplementation (LS), (2) low starch starter with SB supplementation (5 g/kg of dietary DM; LSB), (3) high starch (370 g/kg) starter without SB supplementation (HS), and (4) high starch starter with SB supplementation (HSB), and data on calf growth performance and intake were collected. In experiment 2, 32 individually fed Holstein calves (39.4 ± 1.05 kg BW; 2 d age) followed the same experimental design as experiment 1, and data on growth performance, intake, blood parameters, and ruminal development were collected. Calves were fed milk until fully weaned on d 65, and water and starter were provided daily ad libitum. Interactions between starter starch and SB supplementation significantly affected (P < 0.05) or showed tendencies (P < 0.10) in final BW, frame size measurements, average daily gain, dry matter intake, and selected serum indexes. For the rumen fermentation indexes, the starter starch × SB supplementation interaction tended to affect (P < 0.10) the propionate concentration and acetate/propionate ratio. For ruminal morphology and function, a starter starch × SB supplementation interaction was observed on muscularis thickness (P < 0.05); similar interaction effects were observed in the physical structure (keratinization score), proliferation and apoptosis of rumen papilla, and the expression of monocarboxylate transporter 4 and peptide transporter 1 of the ruminal epithelium (P < 0.05). For the rumen microbiota, starch × SB supplementation interaction effects were observed on the community diversity and evenness and on the abundances of the microbial genera Erysipelotrichaceae_UCG-002, NK4A214_group, and Family_XIII_UCG-001 (P < 0.05). These findings underscore the importance of considering the starch content of calf starters when incorporating SB supplementation in preweaned dairy calves.

Growth Performance and Feed Intake Assessment of Italian Holstein Calves Fed a Hay-Based Total Mixed Ration: Preliminary Steps towards a Prediction Model.

The aim of this study was to evaluate the effects of a complete hay-based total mixed ration (TMR) for calves, focusing on their feed intake, animal growth performance, and fecal output, and to develop a preliminary estimation equation for solid feed intake and body weight in Holstein heifer calves. Twenty female Italian Holstein calves (37.14 ± 2.72 kg) born between February and July were studied from the day of birth until 77 days of age. From the fourth day of life, they were fed 3 L/day of pasteurized milk twice daily and supplemented with the same hay-based TMR. The data on feed intake, fecal characteristics, and growth performances were collected and showed that these calves had adequate parameters. Moreover, the data collected was used to create equations to predict body weight and solid feed intake using a mixed model. The goodness of fit of the developed equations was evaluated by coefficients of determinations (R2). The equation obtained shows high R2 (0.98 for solid feed intake and 0.99 for calf weight), indicating the satisfactory precision and accuracy needed to predict female calves' body weight and solid feed intake.

Effect of once-a-day milk feeding on behavior and growth performance of pre-weaning calves.

The objectives of the present study were to evaluate the effects of once-a-day milk feeding on growth performance and routine behavior of preweaning dairy calves. At 22nd day of age, twenty-four Holstein calves were randomly assigned to one of two treatment groups (n = 12/treatment) based on milk feeding frequency (MF): i) 3 L of milk feeding two times a day; ii) 6 L of milk feeding once a day. The milk feeding amount was reduced to half for all calves between 56 and 60 days of age and weaning was done at 60 days of age. To determine the increase in weight and structural measurements, each calf was weighed and measured at 3 weeks of age and then at weaning. The daily behavioral activity of each calf was assessed from the 22nd day of age till weaning (60th day of age) through Nederlandsche Apparatenfabriek (NEDAP) software providing real-time data through a logger fitted on the calf's foot. There was no interaction (p≥0.17) between MF and sex of the calves for routine behavioral parameters, body weight and structural measurements. Similarly, there was no effect of MF on routine behavioral parameters, body weight and structural measurements. However, the sex of the calves affected body weight gain in calves. Male calves had 27% greater total body weight and average daily gain than female calves. There was no effect of the sex of the calves on behavioral measurements. Collectively, in the current study, no negative effects of a once-a-day milk feeding regimen were found on routine behavioral and growth parameters of preweaning calves in group housing. Once-a-day milk feeding can be safely adopted in preweaning calves from 22nd day of age.

Impact of synbiotics on growth performance and gut health in Murrah buffalo calves.

Synbiotics have been used as biotherapeutic supplements for prevention of new-born calf gastrointestinal disorders. Present study was conducted to evaluate the impact of fructo-oligosaccharide, mannan-oligosaccharide and inulin along with Lactobacillus plantarum CRD-7 and Lactobacillus acidophilus NCDC15 on the nutrient digestibility, growth performance and faecal microbial population of pre-ruminant buffalo calves. Twenty-four Murrah calves (5 days old) were randomly assigned to four groups of six calves in each using randomized block design. Calves in Group I (control) received only a basic diet of milk, calf starter and berseem with no additives. Calves in Group II (SYN1) were fed 6g fructo-oligosaccharide (FOS) + Lactobacillus plantarum CRD-7 (100 ml). Calves in Group III (SYN2) were fed 9g inulin + L. plantarum CRD-7 (50 ml), while calves in Group IV (SYN3) received 4g MOS + L. acidophilus NCDC15 (200 ml) as fermented milk having 108 CFU/ml/calf/day in addition to the basal diet. The results revealed that digestibility of dry matter, crude protein, ether extract and average daily gain were all higher (P < 0.05) in SYN1 as compared to control group. The antioxidant enzyme activity, humoral and cell mediated immunity performed well in SYN1, SYN2 and SYN3 as compared to control. Diarrhoea and faecal scouring were lower (P < 0.05) in all supplemented groups than control. Faecal Lactobacilli and Bifidobacterium counts were also higher in SYN1 group followed by SYN2 and SYN3. Faecal ammonia, lactate, pH, and volatile fatty acids level were increased in SYN1 supplemented groups. The synbiotic combination of 6g FOS + L. plantarum CRD-7 had better response on digestibility, average daily gain, antioxidant enzymes, immune response, faecal microbiota and metabolites and also reduce the faecal score and diarrhoea incidence. Therefore, supplementation of 6g FOS + L. plantarum CRD-7 can be advised for general use in order to promote long-term animal production.

Drinking Warm Water Promotes Performance by Regulating Ruminal Microbial Composition and Serum Metabolites in Yak Calves.

Yaks live in the harsh environment of the Qinghai-Tibet Plateau, and the cold climate causes lower growth efficiency. The aim of this experiment was to explore the effects of drinking warm water on the growth performance in yak calves and investigate the underlying physiological mechanisms. A total of 24 Datong yak calves were selected and randomly assigned into the cold water group (group C, water temperature around 0-10 °C without any heating; 58.03 ± 3.111 kg) and the warm water group (group W, water constantly heated at 2 °C; 59.62 ± 2.771 kg). After the 60-day experiment, body weight was measured, and rumen fluid and blood serum samples were collected for analysis. The results show that the body weight and average daily gain of yaks that drank warm water were higher compared to those that drank cold water (p < 0.05). The acetic, propionic, isobutyric, valeric, and isovaleric acid concentrations were higher in group W than in group C (p < 0.05). Additionally, warm water changed the ruminal microbes at different levels. At the phylum level, the relative abundance of Tenericutes, Kiritimatiellaeota, and Elusimicrobiota was higher in group C (p < 0.05). At the genus level, three genera were increased by warm water, including Ruminococcoides and Eubacteriales Family XIII. Incertae Sedis, and 12 genera were decreased, including Ruminococcus (p < 0.05). At the species level, unclassified Prevotellaceae and Ruminococcoides bili were increased by warm water compared to cold water (p < 0.05). According to the metabolomics results, metabolites, including valine, isoleucine, PC (15:0/22:2(13Z,16Z)), and LysoPC (18:0/0:0), were increased in the warm water group compared to the cold water group (p < 0.05), and were enriched in glycerophospholipid and amino acid metabolism pathways. This study analyzed the differences in ruminal microbes and metabolomes of yak calves provided with water at different temperatures and revealed the potential mechanism for better performance promoted by warm drinking water.