Effect of diet on preweaning performance of Sahiwal calves

Effects of Bacillus licheniformis and Combination of Probiotics and Enzymes as Supplements on Growth Performance and Serum Parameters in Early-Weaned Grazing Yak Calves

Early weaning is an effective strategy to improve cow feed utilization and shorten postpartum intervals in cows; however, this may lead to poor performance of the weaned calves. This study was conducted to test the effects of supplementing milk replacer with Bacillus licheniformis and a complex of probiotics and enzyme preparations on body weight (BW), size, and serum biochemical parameters and hormones in early-weaned grazing yak calves. Thirty two-month-old male grazing yaks (38.89 ± 1.45 kg body weight) were fed milk replacer at 3% of their BW and were randomly assigned to three treatments (n = 10, each): T1 (supplementation with 0.15 g/kg Bacillus licheniformis), T2 (supplementation with a 2.4 g/kg combination of probiotics and enzymes), and a control (without supplementation). Compared to the controls, the average daily gain (ADG) from 0 to 60 d was significantly higher in calves administered the T1 and T2 treatments, and that from 30 to 60 d was significantly higher in calves administered the T2 treatment. The ADG from 0 to 60 d was significantly higher in the T2- than in the T1-treated yaks. The concentration of serum growth hormone, insulin growth factor-1, and epidermal growth factor was significantly higher in the T2-treated calves than in the controls. The concentration of serum cortisol was significantly lower in the T1 treatment than in the controls. We concluded that supplementation with probiotics alone or a combination of probiotics and enzymes can improve the ADG of early-weaned grazing yak calves. Supplementation with the combination of probiotics and enzymes had a stronger positive effect on growth and serum hormone levels, compared to the single-probiotic treatment with Bacillus licheniformis, providing a basis for the application of a combination of probiotics and enzymes.

Gut microbiome colonization and development in neonatal ruminants: Strategies, prospects, and opportunities

Colonization and development of the gut microbiome is a crucial consideration for optimizing the health and performance of livestock animals. This is mainly attributed to the fact that dietary and management practices greatly influence the gut microbiota, subsequently leading to changes in nutrient utilization and immune response. A favorable microbiome can be implanted through dietary or management interventions of livestock animals, especially during early life. In this review, we explore all the possible factors (for example gestation, colostrum, and milk feeding, drinking water, starter feed, inoculation from healthy animals, prebiotics/probiotics, weaning time, essential oil and transgenesis), which can influence rumen microbiome colonization and development. We discuss the advantages and disadvantages of potential strategies used to manipulate gut development and microbial colonization to improve the production and health of newborn calves at an early age when they are most susceptible to enteric disease. Moreover, we provide insights into possible interventions and their potential effects on rumen development and microbiota establishment. Prospects of latest techniques like transgenesis and host genetics have also been discussed regarding their potential role in modulation of rumen microbiome and subsequent effects on gut development and performance in neonatal ruminants.

Carcass and efficiency metrics of beef cattle differ by whether the calf was born in a dairy or a beef herd

Beef originates from the progeny of either dairy or beef dams. The objective of the present study was to identify contributing factors to the differences in the carcass merit of progeny from both dam types. This goal was achieved using slaughter records from 16,414 bucket-reared dairy animals (DXD), 5,407 bucket-reared dairy-beef animals (BXD), 42,102 suckle-reared animals from a beef × dairy F1 cross dam (BXF1), and 93,737 suckle-reared animals from a beef × beef cow (BXB). Linear mixed models were used to quantify the least squares means for carcass characteristics in the various progeny genotypes. Nuisance fixed effects adjusted for in the models were: animal heterosis and recombination loss, dam parity, age at slaughter, and contemporary group; age at slaughter was replaced as an independent variable with both carcass weight and carcass fat score where the dependent variable was age at slaughter. In a follow-up analysis, models were re-analyzed where the genetic merit of the sire was adjusted for; a further analysis set the genetic merit of the dam for the dependent variable to be identical for both the dairy and beef dams. The final analysis adjusted to a common sire and dam genetic merit facilitating the estimation of just differences in early-life rearing strategies. Irrespective of the genetic merit of the sire and dam, animals originating from beef herds had heavier and more conformed carcasses. BXB animals had a 67 kg heavier carcass, with a conformation score (scale 1 [poor] to 15 [excellent]) of 5 units greater compared with DXD animals. When the genetic merit of all dams was set to be equal, BXB animals were heavier and better conformed than BXD animals. When the genetic merit for both the sire and dam were set to be equal, carcasses of the BXB animals were 15 kg heavier, with a 0.69 unit superior conformation score compared with the DXD animals; this difference is due to early life experiences. In conclusion, the majority of the inferiority in carcass metrics of calves from dairy herds compared with beef herds is due to differences in the genetic merit of the parents. Nevertheless, even after adjusting the parents to the same genetic merit, progeny from dairy herds were still inferior to their contemporaries born in beef herds, due most likely to the persistence of early life experiences.

Effect of weaning age and milk feeding level on pre- and post-weaning growth performance of Sahiwal calves

The Sahiwal cow is a tropical dairy breed native to Pakistan. The objective of the present study was to evaluate pre- and post-weaning growth of Sahiwal calves weaned either at 8 or 12 weeks and offered milk at either 10% or 15% of bodyweight (BW) from birth to weaning. Colostrum fed Sahiwal calves (n = 48) were randomly allocated to four treatments of 12 calves each. Calves were offered milk either at 10% (low-milk) or 15% (high-milk) of BW in two weaning programs (early or late). Early weaned calves were offered milk until Day 35, adjusted weekly for liveweight and then reduced by one-third in each subsequent week until weaned at Day 56 (early weaned). Late-weaned calves were offered milk until Day 63 and were weaned at Day 84 (late-weaned) by reducing milk offered by one-third in each subsequent week. Calves were offered a concentrate ration (21% crude protein and 2.93 metabolisable energy, Mcal/kg) from Day 28 to Day 112. Final BW at 16 weeks was highest (77.6 ± 1.8 kg; P < 0.01) in high milk-fed late-weaned calves and lowest in low milk-fed early weaned calves (60.2 ± 1.8 kg). High-milk early weaned and low milk late-weaned calves had comparable final BW (70.7 ± 1.8 vs 72.0 ± 1.8 kg), although lower than that of high-milk late-weaned calves, but still at an acceptable lower feeding cost to gain per kg liveweight (US$ 3.2 vs 2.5). Thus, offering milk to Sahiwal calves at 15% of BW and weaning at 8 weeks saves milk and labour required for additional days to feed these calves.

Effect of feeding strategies on weaning weight and milk production of Holstein × Zebu calves in dual purpose milk production systems

The objective of this study was to evaluate the effect of five feeding strategies on calf weaning weight, and cow milk production and composition in Brazilian Holstein × Zebu cows. A total of 60 cows and their calves were allocated to each of five treatments. Cows in treatments 1, 2 and 3 were milked for 270 days and cows in treatments 4 and 5 were milked for 180 days. Calves in treatment 1 (CON) were not supplemented with concentrate whereas calves from treatment 2 (CLPN) received 1 kg of concentrate daily from 90 to 270 days of age and calves from treatment 3 received 1 kg of concentrated from 180 to 270 days of age. Calves in treatment 4 (CCPS) were supplemented with 1 kg of concentrate from 90 to 180 days of age and calves in treatment 5 (CLPS) were supplemented with 1 kg of concentrate from 90 to 270 days of age. Calves from the CLPS treatment had greater milk and protein intakes (P < 0.05) and greater growth rate than calves from the other treatments. Our results indicate that the traditional system of feeding calves with no concentrate results in a weight gain of 600 g/day. The CLPS treatment produced calves with the highest live weight and growth rate. The nutritional strategy with restricted supply of milk for the calves with concomitantly short-term concentrate supplementation does not improve performance of calves but did increase feed costs.