Comparison of levels and duration of detection of antibodies to bovine viral diarrhea virus 1, bovine viral diarrhea virus 2, bovine respiratory syncytial virus, bovine herpesvirus 1, and bovine parainfluenza virus 3 in calves fed maternal colostrum or a colostrum-replacement product.

Colostrum-replacement products are an alternative to provide passive immunity to neonatal calves; however, their ability to provide adequate levels of antibodies recognizing respiratory viruses has not been described. The objective of this study was to compare the serum levels of IgG at 2 d of age and the duration of detection of antibodies to bovine viral diarrhea virus 1 (BVDV-1), bovine viral diarrhea virus 2 (BVDV-2), bovine respiratory syncytial virus (BRSV), bovine herpesvirus 1 (BHV-1), and bovine parainfluenza virus 3 (BPIV-3) in calves fed maternal colostrum (MC) or a colostrum replacement (CR) at birth. Forty newborn male Holstein calves were assigned to the CR or the MC group. Group CR (n = 20) received 2 packets of colostrum replacement (100 g of IgG per 470-g packet), while group MC (n = 20) received 3.8 L of maternal colostrum. Blood samples for detection of IgG and virus antibodies were collected from each calf at birth, at 2 and 7 d, and monthly until the calves became seronegative. Calves in the MC group had greater IgG concentrations at 2 d of age. The apparent efficiency of absorption of IgG was greater in the MC group than in the CR group, although the difference was not significant. Calves in the CR group had greater concentrations of BVDV neutralizing antibodies during the first 4 mo of life. The levels of antibodies to BRSV, BHV-1, and BPIV-3 were similar in the 2 groups. The mean time to seronegativity was similar for each virus in the 2 groups; however, greater variation was observed in the antibody levels and in the duration of detection of immunity in the MC group than in the CR group. Thus, the CR product provided calves with more uniform levels and duration of antibodies to common bovine respiratory viruses.

Les produits de remplacement du colostrum sont une alternative pour fournir une immunité passive aux veaux nouveau-nés; toutefois, leur capacité à fournir des niveaux adéquats d'anticorps reconnaissant les virus respiratoires n'a pas été décrite. L'objectif de la présente étude était de comparer les niveaux d'IgG sériques à 2 jours d'âge et la durée de détection des anticorps contre le virus de la diarrhée virale bovine de type 1 (BVDV-1), le virus de la diarrhée virale bovine de type 2 (BVDV-2), le virus respiratoire syncitial bovin (BRSV), l'herpesvirus bovin de type 1 (BHV-1), et le virus parainfluenza bovin de type 3 (BPIV-3) chez des veaux nourris avec du colostrum maternel (MC) ou du colostrum de remplacement (CR) à la naissance. Quarante veaux nouveau-nés mâles de race Holstein ont été assignés soit au groupe CR ou MC. Les animaux du groupe CR (n = 20) ont reçu deux paquets de substitut de colostrum (100 g d'IgG par paquet de 470 g), alors que les animaux du groupe MC (n = 20) ont reçu 3,8 L de colostrum maternel. Des échantillons sanguins pour la détection d'IgG et d'anticorps contre les virus ont été prélevés de chaque veau à la naissance, à 2 et 7 j d'âge, et à chaque mois jusqu'à ce que les veaux deviennent séronégatifs. Les veaux dans le groupe MC avaient des concentrations d'IgG plus élevées à 2 j d'âge. L'efficacité d'absorption apparente d'IgG était plus grande dans le groupe MC que dans le groupe CR, bien que la différence ne fût pas significative. Les veaux dans le groupe CR avaient des concentrations plus élevées d'anticorps neutralisants envers BVDV durant les 4 premiers mois de vie. Les niveaux d'anticorps contre BRSV, BHV-1, et BPIV-3 étaient similaires dans les deux groupes. Le temps moyen pour atteindre la séronégativité était similaire pour chaque virus dans les deux groupes; toutefois, de plus grandes variations étaient observées dans les niveaux d'anticorps et la durée de détection de l'immunité dans le groupe MC comparativement au groupe CR. Ainsi, le produit CR a fourni des veaux avec des niveaux d'anticorps contre les virus respiratoires bovins communs plus uniformes et de plus longue durée.(Traduit par Docteur Serge Messier).

Intake of specific fatty acids and fat alters growth, health, and titers following vaccination in dairy calves.

Typical fatty acid profiles of milk and milk replacer (MR) differ. Calf MR in the United States are made from animal fat, which are low in short- and medium-chain fatty acids and linolenic acid. Two 56-d trials compared a control MR containing 27% crude protein and formulated with 3 fat and fatty acid compositions. The 3 MR treatments were (1) only animal fat totaling 17% fat (CON), (2) animal fat supplemented with butyrate, medium-chain fatty acids, and linolenic acid using a commercial product (1.25% NeoTec4 MR; Provimi North America, Brookville, OH) totaling 17% fat (fatty acid-supplemented; FA-S), and (3) milk fat totaling 33% fat (MF). The MR were fed at 660 g of dry matter from d 0 to 42 and weaned. Starter (20% crude protein) and water were fed ad libitum for 56 d. Trial 1 utilized Holstein calves (24 female, 24 male) during summer months and trial 2 utilized Holstein calves (48 male) during fall months. Calves (41±1 kg of initial body weight; 2 to 3d of age) were sourced from a single farm and housed in a naturally ventilated nursery without added heat. Calves were in individual pens with straw bedding. Calf was the experimental unit. Data for each trial were analyzed as a completely randomized design with a 3 (MR treatment) × 2 (sex) factorial arrangement of treatments in trial 1 with repeated measures and as a completely randomized design with 3 MR treatments in trial 2 with repeated measures. Preplanned contrast statements of treatments CON versus FA-S and CON versus MF were used to separate means. We found no interactions of MR treatment by sex. Calf average daily gain, hip width change, and feed efficiency differed (CONFA-S). Titers to bovine respiratory parainfluenza-3 and bovine virus diarrhea type 1 (vaccinations to these pathogens were on d 7 and 28) in serum samples taken on d 49 and 56 differed (CONFA-S; CONFA-S; CON>MF). Calves fed FA-S and MF had improved growth and feed efficiency compared with calves fed CON, whereas calves fed FA-S also had improved measurements related to health and immunity.

Evaluation of attenuation, immunogenicity and efficacy of a bovine parainfluenza virus type 3 (PIV-3) vaccine and a recombinant chimeric bovine/human PIV-3 vaccine vector in rhesus monkeys.

Restricted replication in the respiratory tract of rhesus monkeys is an intrinsic property of bovine parainfluenza virus type 3 (bPIV-3) strains. This host range phenotype of bPIV-3 has been utilized as a marker to evaluate the attenuation of bPIV-3 vaccines for human use. Two safety, immunogenicity and efficacy studies in primates evaluated and compared three human parainfluenza virus type 3 (hPIV-3) vaccine candidates: biologically derived bPIV-3, a plasmid-derived bPIV-3 (r-bPIV-3) and a chimeric bovine/human PIV-3 (b/hPIV-3). These studies also examined the feasibility of substituting Vero cells, cultured in the presence or absence of foetal bovine serum, for foetal rhesus lung-2 (FRhL-2) cells as the tissue culture substrate for the production of bPIV-3 vaccine. The results demonstrated that (i) Vero cell-produced bPIV-3 was as attenuated, immunogenic and efficacious as bPIV-3 vaccine grown in FRhL-2 cells, (ii) plasmid-derived bPIV-3 was as attenuated, immunogenic and efficacious as the biologically derived bPIV-3 and (iii) the b/hPIV-3 chimera displayed an intermediate attenuation phenotype and protected animals completely from hPIV-3 challenge. These results support the use of bPIV-3 vaccines propagated in Vero cells in human clinical trials and the use of b/hPIV-3 as a virus vaccine vector to express foreign viral antigens.