Rumen-protected zinc–methionine dietary inclusion alters dairy cow performances, and oxidative and inflammatory status under long-term environmental heat stress

Abstract

Dairy cows are susceptible to heat stress due to the levels of milk production and feed intake. Dietary supplemental amino acids, particularly rate-limiting amino acids, for example, methionine (Met), may alleviate the potential negative consequences. Zinc (Zn) is beneficial to the immune system and mammary gland development during heat stress. We investigated the impact of a source of a rumen-protected Zn-Met complex (Loprotin, Kaesler Nutrition GmbH, Cuxhaven, Germany) in high-producing Holstein cows during a long-term environmental heat stress period. A total of 62 multiparous lactating Holstein cows were allocated in a completely randomized design to two dietary treatments, namely, basal diet without (control) and basal diet with the supplemental Zn-Met complex (RPZM) at 0.131% of diet DM. Cows in the RPZM group had higher energy-corrected milk (46.71 vs. 52.85 ± 1.72 kg/d for control and RPZM groups, respectively) as well as milk fat and protein concentration (27.28 vs. 32.80 ± 1.82 and 30.13 vs. 31.03 ± 0.25 g/kg for control and RPZM groups, respectively). The Zn-Met complex supplemented cows had lower haptoglobin and IL-1B concentration than the control (267 vs. 240 ± 10.53 mcg/mL and 76.8 vs. 60.0 ± 3.4 ng/L for control and RPZM groups, respectively). RPZM supplementation resulted in better oxidative status, indicated by higher total antioxidant status and lower malondialdehyde concentrations (0.62 vs. 0.68 ± 0.02 mmol/L and 2.01 vs. 1.76 ± 0.15 nmol/L for control and RPZM groups, respectively). Overall, the results from this study showed that RPZM dietary inclusion could maintain milk production and milk composition of animals during periods of heat stress. Enhanced performance of animals upon Zn-Met complex supplementation could be partly due to improved oxidative and immune status.

Impact of close-up dry period heat stress on performance, fertility, and immunometabolic blood indices of dairy cows – prospective cohort study

“…However, most published studies on this issue have primarily focused on its effects on lactating cows [21], calves, and heifers [22]. They have also explored the effectiveness of feed additives in mitigating the negative consequences of HS [23,24], as well as changes in farm management, including the implementation of cooling systems like a combination of ventilation and water spraying, especially during lactation [25]. Additionally, limited scienti c data are available on the carry-over effects of HS occurrence de ned by the THI during the close-up period, which is a critical time for highyielding dairy cows during the transition period, on productive performance, fertility, and immunometabolic status during the subsequent lactation.…”

A Review on the Effects of Micronutrients in Heat Stress Alleviation in Dairy Animals

“…Overall, the findings of this study demonstrated that feeding rumen-protected zincmethionine to animals during times of heat stress could maintain their ability to produce milk and the composition of their milk. Animals' improved performance after taking Zn-Met complex supplements may have improved oxidative and immune status [33]. Supplementing multiparous lactating Holstein with 35 mg of Zn/kg of DM from Zn hydroxy chloride and 40 mg of Zn/kg of DM from Zn-Met complex had a significant impact on mammary cell turnover [34].…”

Effect of supplementing lysins and methionine to low-protein diets on growth performance, hepatic antioxidant capacity, immune status, and glycolytic activity of tibetan sheep

“…It was involved in various physiological processes, such as DNA methylation, protein synthesis, and antioxidant balance [ 10 ]. Previous studies conducted in dairy cow observed that supply of Met altered the synthesis of low-density lipoproteins (VLDL), thereby inhibiting the accumulation of triacylglycerol in the liver [ 11 ]. Thus, to maintain a protein-amino acid balance, essential amino acids should be supplemented when decreasing the levels of dietary protein while diminishing dietary protein [ 12 ].…”