Heat stress (HS) greatly affects sustainable livestock production, thereby affecting the productive performance and welfare of animals. The effect of summer heat on lactating Holstein cows at different lactation, pregnancy phases, and blood metabolism were investigated in this study. Eighteen Holstein cows were selected randomly and housed in the cow farm. Climatic reads and blood parameters were measured. The temperature-humidity index has been designed as a measure of animal comfort and is a simple combination of temperature and humidity. The study showed that heat stress has a significant effect (P ≤ 0.01) on hematological and biochemical parameters. Mean platelet volume (MPV) and red blood cell distribution width (RDW) were reduced significantly (P ≤ 0.01) during lactation. There was a significant increase in creatinine level at 45 days in milk. A significant inverse correlation between HS with milk production and feed intake. So far, it was concluded that certain hematological and biochemical parameters were substantially altered by HS. A negative effect of HS on milk production and feed intake was observed.

This study investigated the effect of different levels of corn supplementation as energy source into palm kernel cake–urea-treated rice straw basal diet on urinary excretion of purine derivatives, nitrogen utilization, rumen fermentation, and rumen microorganism populations. Twenty-seven Dorper lambs were randomly assigned to three treatment groups and kept in individual pens for a 120-day period. The animals were subjected to the dietary treatments as follows: T1: 75.3% PKC + 0% corn, T2: 70.3% PKC + 5% corn, and T3: 65.3% PKC + 10% corn. Hypoxanthine and uric acid excretion level were recorded similarly in lambs supplemented with corn. The microbial N yield and butyrate level was higher in corn-supplemented group, but fecal N excretion, T3 has the lowest level than other groups. Lambs fed T3 had a greater rumen protozoa population while the number of R. flavefaciens was recorded highest in T2. No significant differences were observed for total bacteria, F. succinogenes, R. albus, and methanogen population among all treatment. Based on these results, T3 could be fed to lambs without deleterious effect on the VFA and N balance.

Simple SummaryIn Malaysia, livestock farms have used palm kernel cake as the main source of feed for livestock. The low cost and good content of crude protein in palm kernel cake makes it an appropriate food for sheep, but feeding huge amounts of palm kernel cakes (PKC) for a long period may expose them to copper toxicity. This study suggests supplementing a certain amount of corn as a source of energy into PKC basal diets estranged of toxicity to maintain the health status of lambs compared with other treatments, in terms of the hematological and biochemical parameters of lambs.AbstractTwenty-seven Dorper lambs were used to determine the effect of supplementing corn as a source of energy into the palm kernel cake (PKC) urea-treated rice straw basal diet on the blood metabolic profile and metals in lambs. The lambs were randomly allotted to three experimental treatments according to their initial body weight for a 120 day trial. Dietary treatments were: T1 (control diet) = 75.3% of PKC + 0% corn, T2 = 70.3% of PKC + 5% corn, and T3 = 65.3% of PKC + 10% corn. The results of this study indicated that copper (Cu), selenium (Se), zinc (Zn), and iron (Fe) concentration intake, retention, and its absorption from the gut and apparent mineral digestibility were highly significant for the levels of corn supplementation. The biochemical and hematological parameters remained within normal levels with the treatments, but the white blood cell, eosinophil count, cholesterol, and low-density lipoprotein cholesterol (LDL) were significantly higher in T3. Treatment 3 significantly increased the concentration of Se and Fe, while Zn was reduced in the blood serum of lambs on day 120. The result shows that the inclusion of corn has no effect on the hematological and biochemical parameters of lambs after incorporating corn into the PKC-based diet at 5% and 10%.