Brereton Noeleen, McGee Mark, Beltman Marijke, Byrne Colin J, Meredith David, Earley Bernadette
Teagasc, Grange, Animal & Grassland Research and Innovation Centre, Dunsany, Co. Meath, Ireland.
School of Veterinary Medicine, University College Dublin, Belfield, Dublin 4, Co. Dublin, Ireland.
Ir Vet J. 2024 Jul 5;77(1):13. doi: 10.1186/s13620-024-00276-x.
Development of the cow-calf bond post-partum and passive immunity of calves from spring-calving beef × beef (B×B) and beef × dairy (B×D) cow genotypes was determined using primiparous and multiparous (Experiment 1), and primiparous and second-parity (Experiment 2) animals. In Experiment 1, calves either suckled colostrum naturally ('natural-suckling') (n = 126), or were fed colostrum, using an oesophageal-tube ('artificially-fed') (n = 26), from their dam within 1-h post-partum. In Experiment 2, all calves (n = 60) were artificially-fed colostrum from their dam. Prior to colostrum suckling/feeding, colostrum was sampled for IgG analysis. The cow-calf bond was assessed using CCTV recordings during the first 4-h post-partum. Calves were blood sampled at 48-h post-partum to determine IgG and total protein (TP) concentrations, and zinc sulphate turbidity (ZST) units.
There was no difference (P > 0.05) in cow licking behaviours and calf standing and suckling behaviours between the genotypes, except in Experiment 2 where B×D calves had more attempts to suckle before suckling occurred (P ≤ 0.05) compared to B×B calves. In Experiment 1, multiparous cows licked their calves sooner (P ≤ 0.05) and for longer (P < 0.01), and their calves had fewer attempts to stand (P < 0.001), stood for longer (P = 0.05), and had fewer attempts to suckle before suckling occurred (P < 0.001) than primiparous cows; there was no parity effect on cow-calf behaviour in Experiment 2. Colostrum IgG concentrations and measures of calf passive immunity did not differ (P > 0.05) between the genotypes in either Experiment. In Experiment 1, colostrum IgG concentrations were greater (P ≤ 0.05) in multiparous compared to primiparous cows and their calves had superior (P ≤ 0.05) passive immunity; no effect of parity was found in Experiment 2. Passive immunity did not differ (P > 0.05) between suckled and artificially-fed calves in Experiment 1.
Cow genotype had little effect on cow-calf behaviours, but under 'natural-suckling' conditions primiparous cows expressed maternal inexperience and their calves were less vigorous than multiparous cows. Colostrum IgG concentration and calf passive immunity measures were unaffected by genotype, but under 'natural-suckling' conditions calves from primiparous cows had lower passive immunity.
利用初产和经产（实验1）以及初产和二胎（实验2）动物，确定了春季产犊的肉牛×肉牛（B×B）和肉牛×奶牛（B×D）母牛基因型产后母牛与犊牛间的联系发展情况以及犊牛的被动免疫情况。在实验1中，犊牛要么自然吮吸初乳（“自然哺乳”）（n = 126），要么在产后1小时内通过食管管饲法从其母亲处喂食初乳（“人工喂养”）（n = 26）。在实验2中，所有犊牛（n = 60）均通过食管管饲法从其母亲处喂食初乳。在初乳吮吸/喂食前，采集初乳样本进行IgG分析。在产后的前4小时内，使用闭路电视记录评估母牛与犊牛间的联系。在产后48小时对犊牛进行采血，以测定IgG和总蛋白（TP）浓度以及硫酸锌浊度（ZST）单位。
除在实验2中，与B×B犊牛相比，B×D犊牛在开始吮吸前有更多的吮吸尝试（P≤0.05）外，不同基因型之间在母牛舔犊行为以及犊牛站立和吮吸行为方面没有差异（P>0.05）。在实验1中，经产母牛舔犊更早（P≤0.05）且时间更长（P<0.01），其犊牛站立尝试次数更少（P<0.001）、站立时间更长（P = 0.05），且在开始吮吸前的吮吸尝试次数更少（P<0.001）；在实验2中，胎次对母牛与犊牛的行为没有影响。在两个实验中，不同基因型之间初乳IgG浓度和犊牛被动免疫指标均无差异（P>0.05）。在实验1中，经产母牛的初乳IgG浓度更高（P≤0.05），其犊牛具有更好的（P≤0.05）被动免疫；在实验2中未发现胎次的影响。在实验1中，吮吸和人工喂养的犊牛之间的被动免疫没有差异（P>0.05）。
母牛基因型对母牛与犊牛间的行为影响较小，但在“自然哺乳”条件下，初产母牛表现出母性经验不足，其犊牛比经产母牛的犊牛活力更低。初乳IgG浓度和犊牛被动免疫指标不受基因型影响，但在“自然哺乳”条件下，初产母牛的犊牛被动免疫较低。
