Effect of sustained-release antioxidant bolus on body condition score, blood parameters, uterine health, and some reproductive parameters in transition dairy cows under heat stress condition.

The transition period for dairy cows is stressful, and if this occurs during heat stress conditions, it will become more challenging for them. This study aimed to evaluate the effect of sustained-release bolus (Each bolus consisted of a mixture of mineral salts including copper sulfate (8 g), sodium selenite (0.17 g), manganese sulfate (3.9 g), zinc sulfate (2.4 g), and vitamin A (0.47 g) on body condition score (BCS) change, serum metabolites, uterine health, and some reproductive parameters in transition cows with moderate or high pre-calving BCS. Four experimental treatments were (1) moderate BCS without bolus consumption (MB-Bo, n = 35), (2) moderate BCS with bolus consumption (MB + Bo, n = 35), (3) high BCS without bolus consumption (HB-Bo, n = 35), and (4) high BCS with bolus consumption (HB + Bo, n = 35). Results showed that after calving, negative energy balance occurred in all experimental groups. However, cows with high BCS (HB-Bo and HB + Bo) had greater (P = 0.02) BCS change during the postpartum period (0-40 days). Bolus administration decreased white blood cells count 14 days after calving (P = 0.02). Cows with moderate BCS (MB-BO and MB + Bo) had higher (P < 0.01) red blood cell count than cows with high BCS (HB-Bo and HB + Bo) on 14 days after calving. The cows in MB + Bo group had higher (P < 0.05) serum glucose and albumin and lower (P < 0.01) non-esterified fatty acids and beta-hydroxybutyrate. Moreover, this group of cows had higher (P < 0.05) serum total antioxidant capacity, glutathione peroxidase and superoxide dismutase, and lower malondialdehyde (P = 0.03) than other groups. In this regard, the increase in antioxidant capacity with the consumption of blues caused the HB-Bo group to have more incidence of metritis (P = 0.08) and endometritis (P = 0.08). The HB-Bo group had about 12 days longer (P < 0.01) days open than MB + Bo group. It was concluded that consumption of slow-release bolus containing antioxidant elements had positive effect on the metabolic and reproductive status of high-producing dairy cows under heat stress condition.

Effect of sustained release bolus oral administration on body condition change, blood parameters, and uterine health in primiparous cows under heat stress.

The transition period is very stressful for primiparous cows due to their first calving experience and will be more challenging if it occurs under heat stress conditions. Heat stress reduces the feed intake of dairy cows. Therefore, it reduces the consumption of minerals and vitamins. Oral administration of boluses through the provision of mineral-vitamin compounds can reduce metabolic abnormalities after calving. The present study aimed to evaluate effect of sustained-release bolus on body condition score (BCS) change, serum metabolites, uterine health, and reproductive status in primiparous cows. Heifers were selected at the beginning of the close-up period (n = 60, BCS = 3.35 ± 0.12). There were 2 experimental treatments at the time of calving: (1) heifers without bolus oral administration (H - Bo, n = 30); (2) heifers with bolus oral administration (H + Bo, n = 30). The results showed that although the rate of BCS loss was lower in the group receiving bolus, the effect of bolus was not significant. The effect of bolus on blood level of glucose, non-esterified fatty acids (NEFA), and beta-hydroxybutyrate (BHBA) was not significant; however, the highest concentration of albumin (P = 0.05) was observed in the H + Bo group on day 42 after calving. The concentration of aspartate transaminase (AST) tended to increase (P = 0.06) on day 14 after calving and entire the study. Total antioxidant capacity (TAC) was affected (P < 0.05) by bolus throughout the period of study, and the highest (P < 0.05) concentration of glutathione peroxidase (GPX) and superoxide dismutase (SOD) was observed in H + Bo group on day 42 after calving. The H + Bo group had the lowest (P < 0.05) vaginal discharge score (VDS). In general, oral administration of the sustained-release bolus in heifers significantly affected the antioxidant factors and uterine health, as well as had positive effects on liver function, body condition, and reproduction status.

Effect of shortening the dry period on colostrum and milk quality, blood parameters and some reproductive parameters in high-producing Holstein cows of different body condition score.

This study aimed to evaluate the effect of shortening the dry period in high-yielding cows of different body condition scores (BCS). We report colostrum and milk quality, some serum metabolites, BCS changes, and some reproductive parameters with measurements being made over the first two months of lactation. Cows were grouped based on the length of the dry period (normal: about 50 d and short: about 28 d) and BCS (moderate: 2.75 to 3.5 and high ≥ 3.5). Short dry period decreased colostrum volume and, in combination with high BCS only, caused a decrease in milk production. Short dry period moderate BCS cows had the highest serum insulin concentration on day 14 after calving and highest glucose concentration on day 28, but neither differed significantly when measured over the whole period. By contrast, short dry period cows had significantly lower concentrations of non-esterified fatty acids and beta-hydroxybutyrate measured over the whole period. Post-partum loss of BCS was less in short and especially so in the short, moderate BCS group. Following a synchronization protocol at 35 d postpartum. The cows with a short dry period and moderate BCS had lower open days, days to first postpartum estrus and services per conception. It was concluded that short dry periods and moderate BCS had a positive influence on serum metabolites, BCS changes and reproductive parameters.

Effect of pomegranate by-product silage on feed intake, blood metabolites, inflammatory responses, and prostaglandin F2α metabolites in Holstein dairy cows.

Dairy cows often suffer metabolic disorders due to the challenges of the transition period. The aim of study was to determine the effects of feeding pomegranate by-product silage (PBS) on feed intake and some blood parameters, such as non-esterified fatty acids (NEFA) and beta hydroxy butyric acid (BHBA), interleukin-1 (IL-1), serum amyloid-A (SAA), prostaglandin F2α metabolites (PGFM), and progesterone (P4) in fresh Holstein cows. The experimental groups were as follows: CON (0 g PBS of DM) and PBS (120 g PBS of DM). Results showed that replacing corn silage with PBS had no effect on dry matter intake (DMI) throughout the study. The CON group had highest (p < .05) NEFA at 14 d postpartum and serum BHBA was decreased by feeding PBS, especially on days 21 (p < .05) and 28 (p < .05) and the entire study (p < .01). Cows fed PBS had lower (p < .05) serum Malondialdehyde (MDA) than CON cows at different times. Feeding PBS decreased (p < .01) serum IL-1 compared to CON group (216.7 versus. 515.5 Pg/ml) at 28 d postpartum, and also cows fed 120 g PBS had higher (p < .01) serum P4. It was concluded that feeding PBS had no adverse effect on feed intake, milk production, and some reproductive parameters. Moreover, PBS positively affected serum metabolites in fresh dairy cows.