Effects of hypertonic dextrose and paraffin solution as non‐antibiotic treatments of clinical endometritis on reproductive performance of high producing dairy cows

The objective of this study was to compare the reproductive performance of cows affected by clinical endometritis (CE) following treatment with an intrauterine infusion of 50% dextrose solutions (DEX) and liquid paraffin (LP) as alternative therapies with routine treatments including PGF_2α injection and intrauterine infusion of oxytetracycline (OTC). Moreover, the reproductive indices of cows treated with endometritis were compared with those of healthy ones. At postpartum reproductive tract examination (28–35 DIM) in one Iranian dairy farm, cows with CE without any selection were assigned to four groups: (a) OTC, a common treatment in Iran, was administered (5 g) to 396 cows, (b) PGF₂α (PG) was injected to 496 cows, (c) dextrose solution (DEX): intrauterine infusion of 50% dextrose solution (200 ml) was done in 427 cows, and (d) liquid paraffin (LP) was administered (100 ml) to 423 cows via intrauterine route. We further assigned 2,233 clinically healthy cows to the control group. The incidence of endometritis was 41.6% in this study. Based on the results of reproductive indices including median days to first AI, days open (DO), first service conception rate, conception rate in 2nd and 3rd services, conception rate in all three services, pregnancy rate < 100 days and pregnancy rate < 200 days, except for median days to first AI in other reproductive indexes, reproductive performance was significantly lower in LP group compared with the healthy cows and other treatment groups (p < 0.05). Except for the first service conception rate and proportion of cows pregnant before 100 days in milk (DIM), there existed no significant difference between the DEX group and the control as far as reproductive performance is concerned (p ≥ 0.05). The first service conception rate was recognizably lower in DEX group compared with OTC and PG (p < 0.05). In conclusion, the use of a non‐antibiotic special solution of dextrose 50% is a good alternative to antibiotic agents concerning the treatment of CE in dairy cows.     

Relationships between insulin-like growth factor-I,milk yield,body condition score,and postpartum luteal activity in high-producing dairy cows

The relations between body condition score (BCS), milk yield, serum insulin-like growth factor-I (IGF-I) profile, and luteal activity were investigated in postpartum dairy cows. Seventy-one healthy high-producing multiparous Holstein cows were subjected to transrectal ultrasound scanning twice weekly from the first to the eighth week postpartum. Blood samples were collected twice weekly to measure serum progesterone (P4) and every 2 weeks to detect serum IGF-I concentrations. BCS was monitored weekly after calving. Cows with serum P4 concentrations ≥1 ng/ml on at least two consecutive samplings were considered to have commenced luteal activity. Commencement of luteal activity (C-LA) was observed earlier than 45 days postpartum in 71.8% of cows while 28.2% showed C-LA later than 45 days. Prolonged luteal phase was the most common abnormal pattern of luteal activity observed. Cows with a C-LA earlier than 45 days postpartum had higher (P ≤ 0.05) mean serum concentrations of IGF-I than those with later C-LA. In addition, cows which showed C-LA earlier than 45 days postpartum had more optimal productive indices including shorter calving to conception interval and calving to first service interval (P ≤ 0.05), and fewer services per conception (P = 0.07). C-LA was significantly later in cows that lost more than 0.5 BCS units within 3 weeks postpartum than in those that lost less than 0.5 units BCS during the same interval (P = 0.02). We conclude that high-producing dairy cows with higher postpartum serum IGF-I concentrations have earlier commencement and normal luteal activity, and better reproductive performance. Severity and duration of BCS loss adversely affect commencement of luteal activity.     

Mercury and methyl mercury concentration in sediment,benthic, Barbus Grypus and pelagic,Barbus esocinus fish species,from Musa estuary,Iran

The concentrations of mercury (Hg) and methyl mercury (MeHg) in sediment and tissues of Barbus grypus and Barbus esocinus fish species from Musa estuary, north part of the Persian Gulf, were measured. The order of Hg and MeHg concentrations in the sediment and tissues of the fish species was as follows: liver > gill > muscle > sediment. In the tissues of two fish species, the Hg and MeHg concentrations were highest in liver whereas lowest in the muscle. In the sediment, mean concentrations of Hg and MeHg were 0.83 and 0.437 µg g^?1. Mean concentrations of Hg and MeHg in B. grypus were 1.2–0.624 µg g^?1 and in all tissues of B. esocinus were 0.75 and 0.421 µg g^?1. Significant correlation between heavy metal concentration in sediment and fish may be related to high variability of heavy metal in the sediment.     

Effects of first postpartum progesterone rise,metabolites, milk yield,and body condition score on the subsequent ovarian activity and fertility in lactating Holstein dairy cows

Seventy multiparous healthy lactating Holstein cows (fat-corrected milk yield = 7,561.8 kg) were monitored from 14 days before to 70 days after calving. Transrectal ultrasound scanning was performed twice weekly from 7 to 65 days postpartum. Blood samples were also collected twice weekly to measure serum P₄ and biweekly to detect serum β-hydroxybutyrate (βHB) and nonesterified fatty acid (NEFA) concentrations. Body condition score (BCS) was taken biweekly after calving. Based on the serum P₄ profile of 59 cows (11 cows were excluded due to the occurrence of postpartum diseases) studied, 27 (45.8%) had normal ovarian activity, while 21 (35.6%), six (10.1%), three (5.1%), and two (3.4%) had delayed ovulation (DOV), prolonged luteal phase (PLP), short luteal phase (SLP), and cessation of ovarian activity, respectively. Cows with PLP had an earlier ovulation compared to that of cows with normal ovarian activity (23.16 ± 4.02 vs 31.9 ± 8.35 days; P < 0.05). PLP cows also had a greater mean ± standard deviation peak milk yield (44.2 ± 5.8 vs 37.2 ± 5.7 kg/day, 75 days postpartum; P < 0.05) than cows with normal postpartum ovarian activity. The PLP group also had greater milk production in the previous lactation period. Logistic regression analysis indicated that cows with P₄ concentration ≥1 ng/ml on day 24 after calving were more at risk for PLP by 1.1 for each 1 kg increase in mean peak milk yield during 75 days after calving. BCS was lower in cows with DOV compared to that of cows with normal ovarian activity at any time after calving (P < 0.05). Serum βHB concentrations in DOV cows were significantly higher than that of normal cows on day 42 after calving (0.69 ± 0.29 vs 0.54 ± 0.12 mmol/L, P < 0.05). No significant difference was found in the mean concentrations of NEFA between cows in different groups at any time after calving (P > 0.05). The concentrations of P₄ on days 28 and 31 were negatively correlated with βHB concentration on day 42 after calving in cows with normal ovarian activity (R = −0.44, P = 0.02). In conclusion, these findings suggest that early ovulation and hence early postpartum P₄ rise in addition to the high milk production could partly be responsible for the occurrence of PLP in dairy cows.