Comparison of the effects of high and low milk-replacer feeding regimens on health and growth of crossbred dairy heifers

Context: Pre-weaning growth in dairy heifers is highly dependent on the amount of milk fed. Both milk replacer (MR) and associated labour are costly, encouraging restricted milk rations and once-a-day feeding. Aims: This study compared performance relating to the growth and health of calves receiving one of two commercial feeding regimens: High or Low. Methods: All heifers born during the Spring (January–March) calving block on a commercial UK farm with mixed-breed genetics were recruited at birth, randomly assigned to the High (n = 104, receiving MR-A) or Low (n = 88, receiving MR-B) feed group and reared indoors on straw bedding, with free access to concentrate. Both groups initially received MR twice daily. The High group continued to receive MR twice daily throughout the experiment, whereas the Low group calves were reduced to a single MR feed daily during Weeks 4–8. Blood samples were taken in Weeks 1 and 6 to assess passive transfer and measure circulating insulin-like growth factor 1 (IGF1). The Wisconsin calf-scoring system was used to assess health of calves in Weeks 1, 2, 4, 6 and 8 and at 6 months and size was also measured at these times. Data were analysed by univariate and multivariate models. Key results: Passive transfer was good in both groups (serum total protein (mean ± s.d.) 60.9 ± 9.1 mg/mL) with no differences in pre-weaning disease incidence; diarrhoea occurred in 64.5% and bovine respiratory disease in 26.3% of calves. High group calves were significantly heavier, taller and longer at all pre-weaning examinations except recruitment owing to more growth in the first month, and remained significantly larger at 6 months: weight 157 ± 8 vs 149 ± 7 kg, height 103 ± 5 vs 100 ± 5 cm, length 90 ± 4 vs 88 ± 5 cm. Plasma IGF1 concentrations at around Week 6 were doubled in the High group (101 ± 38.6 vs 55 ± 34.1 ng/mL). Bovine respiratory disease was associated with reduced weight gain. Heifers with diarrhoea were leaner at weaning. High feed group, weight at recruitment and good passive transfer were positively associated with weight at 6 months. Conclusions: Higher feeding levels pre-weaning increased growth rates and IGF1, although the disease incidence was unaffected. Implications: Previous studies have shown that more growth and higher IGF1 pre-weaning are associated with a lower age at first calving and an increased chance of reaching the end of first lactation. These in turn improve long-term performance

Performance and feed intake of five beef suckler cow genotypes and pre-weaning growth of their progeny

peer-reviewedThe effect of beef suckler cow genotype on feed intake, performance, milk yield and on pre-weaning growth of their progeny was determined over four lactations. The five cow genotypes examined were Limousin (L), Charolais (C), Limousin × Holstein-Friesian (LF), Limousin × (Limousin × Holstein-Friesian) (LLF) and Simmental × (Limousin × Holstein-Friesian) (SLF). The herd calved in spring and the progeny spent from April until weaning (October/ November) at pasture with their dams. Live weight (kg) at the start of the indoor winter period was greater (P 0.05) between the genotypes but followed a similar trend to grass silage intake. The decrease in live weight over the indoor winter period was greater (P < 0.01) for L and C cows than for LLF and SLF, whereas LF were intermediate. The increase in live weight during the grazing season was greater (P < 0.01) for C cows than all except L, which were intermediate. Calving difficulty score was greater (P < 0.01) for C cows than LLF, L and SLF, whereas LF were intermediate. Birth weight of calves from LF cows was lower (P < 0.001) than C with L being intermediate, but greater than LLF, with SLF being intermediate. Milk yield (kg/day) was higher (P < 0.001) for LF (9.7) and SLF (8.7) cows than the other genotypes (5.5 to 7.0), which did not differ significantly. Pre-weaning live-weight gain was greater (P < 0.001) for progeny of LF cows than all other genotypes except SLF, which in turn were greater than L and C, with LLF being intermediate. In conclusion, calf pre-weaning growth was higher for cow genotypes with higher milk yield, which was also associated with higher cow DM intake.B. Murphy was in receipt of a Walsh Fellowship provided by Teagasc

Environmental Enrichment of Calves Using Stationary and Mechanical Brushes

While there is research on enrichment and brush use in adult cows, there is limited research addressing brush use in calves. The objectives were to substantiate brushes as enrichment devices for calves and determine if exposure to stationary brushes pre-weaning affects brush use post-weaning. Calves were randomly grouped into treatment group B (with brush, n = 10) or treatment group N (no brush, n = 10). During pre-weaning, calves were housed individually in hutches from birth until at least 8 weeks of age, and group B had access to stationary brushes. During post-weaning, calves entered group housing and had access to a mechanical and stationary brush until at least 11 weeks of age. Physical performance characteristics were recorded throughout the trial, and behavior was recorded using video cameras for 12 h/d twice a week. During pre-weaning, treatments had similar ADG (0.610 kg/d), weight (41.8 kg), hip height (75.8 cm), and wither height (72.4 cm). During post-weaning, treatments had similar ADG (0.747 kg/day), changes in hip height (0.212 cm/day), and changes in wither height (0.204 cm/day). This suggests exposure to stationary brushes pre-weaning did not affect growth. In preliminary analysis for 16 calves pre-weaning, group B (n = 8) used stationary brushes for 133.8 s/12 hr, demonstrating that calves utilized stationary brushes as enrichment tools during pre-weaning. The treatments spent similar durations interacting with pen fixtures pre-weaning (434.9 vs. 419.0 ± 98.41 s/12 hr for B and N respectively). In preliminary analysis of 11 calves post-weaning, there was a treatment by week trend for mechanical brush use, indicating that calves exposed to brushes pre-weaning used the mechanical brush quicker post-weaning. The use of the stationary brush post-weaning was minimal, thus we conclude calves preferred the mechanical brush. We expect further analysis to show behavioral differences between treatments, indicating that exposure to a brush pre-weaning affects behavior post-weaning.The Ohio State University, College of Food, Agricultural, and Environmental Sciences, Ohio Agricultural Research and Development CenterWill C. Hauk Endowment fundNo embargoAcademic Major: Animal Science

Genetic aspects of calving, growth, and carcass traits in beef cattle

The aim of this thesis was to learn more about the genetic background of calving, growth and carcass traits of beef cattle breeds in Sweden, and to assess the possibility of including calving traits and commercial carcass traits in the genetic evaluation. In addition, the genetic relationship between field-recorded growth rate and daily weight gain at station performance testing was investigated. The breeds studied were Charolais, Hereford and Simmental. Records of birth weight, pre-weaning gain, post-weaning gain, carcass fleshiness grade, carcass fatness grade, carcass weight, calving difficulty score and stillbirth were analysed using linear animal models. The estimated direct heritabilities were moderate to high for birth and carcass weight, moderate for pre- and post-weaning gain, carcass fleshiness and fatness grades, low for calving difficulty score and very low for stillbirth. Maternal heritabilities tended to be lower than the direct ones. Genetic relationships between direct and maternal genetic effects were generally antagonistic. Moderate to high genetic correlations were estimated between post-weaning gain in the field and at the station, showing considerable breed differences, and the added value of station testing was questioned. Genetic relationships were generally weaker between growth traits and both carcass fleshiness and fatness grade than between growth and carcass weight. Male and female birth weights were found to be the same trait genetically, and strong genetic relationships were estimated between birth weight and calving traits. Less than unity genetic correlations between calving difficulty at first and later parities indicated that partly different sets of genes control these traits. Some antagonistic relationships were found between carcass and calving traits. It was concluded that it would be feasible to include commercial carcass records and calving difficulty score in the genetic evaluation, and that both direct and maternal effects should be considered for pre-weaning traits. Information on correlated traits should be used for selection against stillbirth as direct selection would be inefficient due to small progeny group size and very low heritability. Joint genetic evaluation of pre-weaning gain and carcass weight was recommended to reduce selection bias

Roles of Dietary Cobalt and Administration of Mixed Rumen Bacteria in Regulating Hematological Parameters of Pre-weaning Twin Lambs

Cobalt (Co) is required by rumen microorganism for vitamin B12 synthesis. Vitamin B12 is an important cofactor for methionine synthesis and gluconeogenesis. In young ruminants up to 6–8 wk old, the rumen has not been completely developed and rumen microorganisms are not ready to supply vitamin B12. The aim of this research was to determine the potency of mixed rumen bacteria and dietary supplementation of Co and its effect on plasma glucose, blood minerals (Co, Fe, and Zn) concentrations, and hematology of pre-weaning twin lambs. Twelve one month-old local twin lambs were assigned to 4 groups in a randomized complete block design. Lambs were fed cow milk at 10% body weight, adjusted weekly for 80 d. Mixed rumen bacteria were offered at 15 mL/d (8.295x1010 cfu). Dietary treatments were: 1) basal diet (Control), 2) basal diet + 1 mg/kg DM cyanocobalamin (VitB12) and 3) basal diet + 1 mg/kg DM of Co + administration of 15 mL mixed rumen bacteria (CoBac). There were no treatment effects on neither plasma glucose and blood mineral concentrations nor hematological profiles. This study demonstrated that pre-weaning twin lambs are not responsive to supplementation of Co and administration of mixed rumen bacteria

Calf pre-weaning traits and immunoglobulin response to bovine viral diarrhea virus vaccination

Calfhood vaccination for bovine viral diarrhea virus (BVDV) is a relatively new concept, and protocols are evolving. Our objective was to determine effects of BVDV type I vaccination protocol, calf behavior (chute score, and chute exit velocity), and gender on calf gain and immunoglobulin (Ig) response. Crossbred calves (n = 64) were randomly allotted to one of two vaccination protocols. In protocol 1, calves were vaccinated at 60 d of age (d 0) and at weaning (d 147). Calves assigned to protocol 2 were vaccinated against BVDV type I at 21 d prior to (d 126) and at weaning (d 147). Blood samples were collected from half of the calves in each protocol group on d 0 (60 days of age), d 21, d 126 (21 days prior to weaning), and d 147 (at weaning); serum was harvested and Ig titers were determined. Titers for BVDV type I were transformed (log base 2) and analyzed using a mixed model procedure. Calves vaccinated at d 0 and weaning had larger (P \u3c 0.0001) titers than calves vaccinated at d 126 and weaning (7.5 ± 0.36 and 5.1 ± 0.36, respectively). Mean BVDV titers were larger (P \u3c 0.0001) on d 147 when compared with d 126, d 21, and d 0 (8.3 ± 0.39, 5.1 ± 0.40, 5.9 ± 0.39 and 5.7 ± 0.39, respectively). A treatment × day interaction (P \u3c 0.0001) also affected BVDV titers. However, BVDV titers were not affected (P \u3e 0.05) by calf gender, chute score, or chute exit velocity. Weaning weight and pre-weaning average daily gain (ADG) were not related to BVDV type I titers. This study indicated that vaccinating beef calves against BVDV was effective in triggering an Ig response. Furthermore, our results suggest that calves should be vaccinated against BVDV type I at 60 d of age for greater disease resistance

EFFECT OF INBREEDING ON PRE-WEANING GROWTH TRAITS IN THALLI SHEEP

Pedigree records of 17250 Thalli sheep with 17030 lambings maintained at the Livestock Experiment Station, Rakh Ghulaman, Distt. Bhakkar, Pakistan during the period from 1975 to 2004 were utilized in the present study. Average values for birth weight, weights at 60 and 90 days of age, weaning weight and pre-weaning average daily gain were 4.11 ± 0.82, 11.58 ± 3.57, 14.92 ± 4.56, 18.95 ± 4.56 and 0.12 ± 0.04 kg, respectively. Coefficients of inbreeding ranged from 10.15 to 37.50 percent for 295 animals, being 1.70 percent of the flock. Inbreeding significantly (P<0.01) affected birth and 60 days weight. Birth weight and 60 days weight decreased by 0.051 and 0.048 kg for each 1 percent increase in the level of inbreeding. However, inbreeding had non significant effect on weight at 90 days of age, weaning weight and pre-weaning average daily gain. The regression values for these traits were 0.010, 0.083 and 0.105, respectively. It was concluded that inbreeding showed deleterious effects only in early stages of life but as the lambs grew older the effect of inbreeding on pre-weaning traits diminished

Nutrient utilisation, growth and chemical body composition of pre-weaned lambs reared artificially : effects of feeding milk replacer and pellets : a thesis presented in partial fulfilment of the requirements for the degree of Doctor of Philosophy in Animal Science at Massey University, Palmerston North, Manawatū, New Zealand

Listed in 2016 Dean's List of Exceptional ThesesUnderstanding how nutrient supply controls lamb growth is important in improving the efficiency of nutrient utilisation. Estimation of metabolisable energy (ME) requirements for lamb maintenance and growth pre-weaning has been limited to milk-only fed lambs. This is due, at least in part, to the difficulty of measuring pasture intake in pre-weaned lambs, which restricts the determination of nutrient balances and nutrient use efficiencies. The aims of this thesis were to: 1) evaluate the effect of various milk and pellets combinations on lamb growth, organ development, body composition and utilisation of energy for maintenance and growth, 2) derive equations for predicting feed intake, and 3) develop a growth simulation model for use as a tool to develop feeding strategies for lambs. Lambs were offered various diet combinations from age one day until slaughter at 18 kg live weight (LW). Addition of solid feed to the milk diet of pre-weaned lambs improved their growth rates, efficiency of gain and enhanced rumen development. Increasing daily ME intake from 1.5 times maintenance to ad libitum at a constant protein to energy ratio did not alter the total chemical body composition of the lambs fed to a fixed LW. Increasing the crude protein content of milk replacer, and therefore the corresponding protein to energy ratio, increased average daily gain and efficiency of gain in lambs. Further, the protein content in the empty bodies of lambs increased whilst fat content decreased. Growth and body composition of lambs were unaffected by altered pellet protein content. The study also showed that lambs fed in excess of their protein and energy requirements reached maximum potential protein deposition rates. Based on a model developed, overestimating the maintenance energy requirements of milk-only fed lambs underestimated their daily fat deposition rates and underestimating the maintenance requirements of lamb offered milk and ad libitum access to pellets over estimated their daily fat deposition. A greater percentage increase in fat deposited in gain increased the energy requirements for gain in the lambs. This study has contributed to the knowledge on rearing lambs artificially with various combinations of milk and pellets. The findings will provide a useful platform for future studies aiming to develop feeding strategies to improve pre-weaning lamb growth

Allelic Frequency of Kappa-Casein Locus (Asp148/Ala) in F1: Simmental (Bos Taurus) X Ongole Grade (Bos Indicus)

This study was conducted to detect the genetic variants (single nucleotide polymorphism) of kappa-casein locus (Asp148/Ala) in F1: Simmental (Bos taurus) x Ongole grade (Bos indicus), SIMPO. Genomic DNA was isolated from blood sample of 40 SIMPO (21 males and 19 females). A 780 bp specific fragment of kappa-casein gene spanning from the forth exon region (517 bp) to forth intron (263 bp) was successfully amplified. The result of the PCR-RFLP (Polymerase Chain Reaction - Restriction Fragment Length Polymorphisms) analysis using HindIII enzyme showed that two genotypes (AA and AB) were found at this locus in SIMPO. The frequencies of A and B alleles in SIMPO were 0.79 and 0.21, respectively. The frequency lies between B. taurus (Simmental) and B. indicus group

Protocol for a Scoping/Systematic Review: Scoping Review of Vaccination for the Prevention of Calf Scours in Cow-Calf Operations

Background: The use of antimicrobials in the livestock industry has been a topic of increasing concern in the last  few years. Calf scours is one of the main causes of mortality among calves younger than 1 month and affects the development of the animal, representing severe economic losses to the producers. The causes of the disease include a variety of viral, bacterial and protozoal pathogens, and other non-infectious causes. The treatment efficacy, in particular of antimicrobial therapy, depends on the type of infection. Blanket antimicrobial treatment for calf scours without identification of the pathogen may contribute to antimicrobial resistance. In this review we explore the available literature for evidence of effective methods to prevent calf scours in cow-calf operations in California through the use of vaccination.Objectives:  The objective of this scoping review is to examine and describe the existing literature on vaccination for the prevention of calf scours that might reduce the incidence of calf scours by different causes, and therefore reduce the use of antimicrobials due to calf scours.Design: Primary research on vaccination for pathogens that cause calf scours will be considered for inclusion, such as studies conducted in pre-weaned calves that report the efficacy of vaccines for the prevention of calf scours. The process for selection and inclusion of the studies will be reported in a flow chart according to the Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA). The results will be summarized in tables and charts describing study types, interventions and outcomes