BackgroundTotal serum protein (TSP) within the first few days of life in the neonatal calf has predictive value for subsequent growth and production in calves before and after weaning.IntroductionThe objective of this study was to evaluate the effect of TSP concentration 24‐h after birth (24‐h) on the performance and health of Holstein dairy calves.MethodsA total of 152 female calves were enrolled in this study. Blood samples were collected at 24‐h, and TSP concentration was measured with a refractometer. Calves based on TSP concentration at 24‐h were allocated into three groups: 1 – TSP ≤6.5 g/dL, 2 – TSP between 6.6 and 6.9 g/dL and 3 – TSP ≥7 g/dL. The weighing was done at birth and at days 30 and 60. Starter feed intake was recorded from day 3 to weaning, and body structures were measured at birth and weaning day.ResultsCalves with TSP >6.5 g/dL had greater body weight at days 30 and 60 than calves with TSP ≤6.5 g/dL. Average daily gain during 1–30 and 1–60 days of life increased as TSP increased. Furthermore, starter feed intake during the first 60 days of life was greater in calves with TSP ≥7 g/dL than calves with TSP <7 g/dL. The TSP concentration influenced structural growth, and >6.5 g/dL calves had greater heart girth, hip width and body length than ≤6.5 g/dL calves. Moreover, odds ratio for pneumonia decreased as TSP increased, whereas diarrhoea was unaffected.ConclusionThe TSP at 24‐h is an important contributing factor for the variation in growth performance and health of preweaning calves, and strategies to improve calf immunity and increase TSP lead to better animal health during preweaning period.ImplicationsThese results indicated that TSP ≥6.5 g/dL possibly was associated with greater performance, and this concentration could be considered a baseline for future analyses.

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IntroductionAromatic and herbal plants usage as feed additives have become a new tendency in dairy cows’ nutrition to enhance animal performance. This experiment was performed to study the effects of supplementing fennel seed powder (FSP) to diets during early lactation on performance, milk fatty acid (FA) profile, and rumen fermentation of Holstein dairy cows.MethodsTwenty-four primiparous Holstein dairy cows (10 ± 3 d in milk, 30 ± 2.1 Kg of milk/d, 610 ± 31 Kg body weight; mean ± SE) were balanced for actual milk yield and calving date (n = 8 per treatment) in a complete randomized design. Animals were allocated randomly to diets containing 0 g/d (0FSP), 25 g/d (25FSP), or 50 g/d (50FSP) FSP, individually top-dressed over the total mixed ration. The experimental period was 45 d consisting of the first 15 d for adaptation and the final 30 d for data collection and sampling.Results and discussionDry matter intake responded quadratically to FSP feeding, and cows fed 25FP treatment had greater DMI than 0FSP treatment. The average ruminal pH value decreased linearly as FSP increased in diets. Ruminal valerate and isovalerate proportion increased linearly as FSP inclusion in diets increased, while acetate proportion decreased and acetate:propionate ratio tended to decrease linearly. Increasing FSP in diets linearly increased serum glucose, globulin, and total protein concentrations. Milk yield increased linearly as FSP inclusion in diets increased, whereas milk composition was unaffected. Increasing FSP in diets linearly increased de novo and mixed FA and decreased preformed FA in milk. Dietary treatments did not affect saturated FA, whereas unsaturated FA, mono and poly unsaturated FA linearly decreased with increasing FSP inclusion in diets. Moreover, the content of C18:0 tended to decrease, and C18:1 cis-9 decreased linearly as FSP inclusion increased. Also, increasing the FSP level in diets decreased linearly non-esterified fatty acids and acetone concentrations in the milk. It could be concluded that FSP addition at 50 g/d could enhance performance of early lactating cows.

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