Effects of probiotic-supplemented milk replacer on growth, blood biochemistry, fermentation, digestibility, and carcass traits in lambs.

The objective of this study was to investigate the effects of feeding cow's milk replacer and probiotic supplementation on growth performance, blood metabolites, ruminal fermentation parameters, and nutrient digestibility in male lambs, with ewe's milk serving as the control treatment. Eighteen male lambs with an average initial body weight of 5.0 ± 1.2 kg and age of 15 ± 4 days were randomly assigned to three experimental groups: ewe's milk, cow's milk replacer, and cow's milk replacer with probiotic supplementation. The experiment was conducted using a completely randomized design. Lambs fed ewe's milk showed significantly higher average daily gain (218.4 g/day) compared to those fed cow's milk replacer (183.7 g/day) or cow's milk replacer with probiotic (209.1 g/day). Similarly, dry matter intake was highest in the ewe's milk group (585.6 g/day) compared to the cow's milk replacer (435.9 g/day) and cow's milk replacer with probiotic (510.5 g/day) groups. Blood glucose levels were higher in the ewe's milk group (75.3 mg/dL) compared to the cow's milk replacer (70.3 mg/dL) and cow's milk replacer with probiotic (72.1 mg/dL) groups. Probiotic supplementation resulted in increased blood urea nitrogen (15.6 mg/dL) and total protein (7.3 g/dL) levels compared to the other groups. Furthermore, the ewe's milk group showed higher apparent dry matter (76.1%) and crude protein (68.5%) digestibility compared to the other treatments. The fecal score on day 30 was higher in the cow's milk replacer group (2.34) compared to the ewe's milk (1.24) and cow's milk replacer with probiotic (1.45) groups. There were no significant differences in the carcass traits of the experimental lambs. In conclusion, based on the results of this study, it seems that feeding cow's milk + probiotic as a replacement for ewe's milk did not significantly affect the performance, carcass traits, and blood and fermentation parameters in infant lambs.

Effects of monensin supplementation on rumen fermentation, methane emissions, nitrogen balance, and metabolic responses of dairy cows: A systematic review and dose-response meta-analysis.

To investigate the effects of supplemental monensin administration on the metabolic responses of dairy cows, a systematic review and dose-response meta-analysis were conducted. Initially, 604 studies were identified through comprehensive database searches, including Google Scholar, Scopus, Science Direct, and PubMed, using key words related to dairy cows, monensin, and metabolic outcomes. After a 2-stage screening process, 51 articles with a total of 60 experiments were selected for meta-analysis based on criteria such as study implementation date between 2001 and 2022, presence of a control group that did not receive monensin supplementation, reporting of at least 1 outcome variable, and presentation of means and corresponding errors. The meta-analysis used the 1-stage random-effects method, and sensitivity analyses were performed to assess the robustness of the results. The results showed that the administration of monensin at a dosage of 19 to 26 mg/kg was inversely related to methane emissions and that the administration of monensin at a dosage of 18 to 50 mg/kg resulted in a significant decrease in dry matter intake. Administration of monensin at doses of 13 to 28 and 15 to 24 mg/kg also resulted in a significant decrease in ruminal acetate proportion and an increase in propionate proportion, respectively, with no effects on ruminal butyrate, NH3, or pH levels. We found no effects on blood parameters or nitrogen retention, but a significant negative correlation was observed between monensin supplementation and fecal nitrogen excretion. Based on the analysis of all variables evaluated, the optimal dose range of monensin was estimated to be 19 to 24 mg/kg.

The Effect of Different Zinc Sources on Biochemical Parameters, Intestinal Morphology, Carcass Characteristics and Performance in Finishing Lambs.

To investigate the effect of different sources of zinc supplements on blood serum parameters, nutrient digestibility, growth performance, carcass characteristics, and intestinal morphology, 18 male Zandi lambs (with initial body weight of 31 ± 1.2 kg and 120 ± 8 days old) were divided into three groups, six animals each in a completely random design. Experimental treatments include (1) control treatment of basal diet without zinc supplementation, (2) basal diet with 40 mg/kg of zinc supplementation from zinc sulfate source, and (3) basal diet with 40 mg/kg of zinc supplementation with origin it was organic (Zn-peptide). All lambs were kept in individual pens with cemented floor and provision of individual feeding and watering. Mean daily weight gain increased with zinc supplementation (P < 0.05), but feed intake and feed conversion ratio were not affected by zinc supplementation in the diet. Zinc supplementation increased the apparent digestibility of the dry matter (P < 0.05), but the digestibility of dietary fat, neutral detergent fiber (NDF), and acid detergent fiber (ADF) were not affected by zinc supplementation. In this experiment, the addition of organic and inorganic supplements to the diet of fattening lambs had no significant effect on serum triglyceride, cholesterol, low-density lipoprotein (LDL), high-density lipoprotein (HDL) and glucose concentrations, and carcass traits. The concentration of aspartate aminotransferase (AST) enzyme in the zinc sulfate group was significantly higher than the control and organic zinc groups (P < 0.05). Concentrations of blood urea nitrogen were lower in zinc fed lambs, compared to control (P ≤ 0.05). The villi width in the duodenum was higher in the zinc supplementation treatments (P < 0.05). Also, in the ileum section, the height of the villi in the treatment of zinc sulfate supplement was higher, compared to the complement and control (P < 0.05). The results of this study showed that Zn supplementation, regardless of its source, improved growth performance in fattening lambs. However, no effect was observed on feed intake and efficiency, carcass traits, and blood parameters.

Comprehensive review of resveratrol as a feed additive in dairy cows: exploring its potential diverse effects and implications.

Heat stress and growing demand for dairy products in tropical regions exert metabolic pressure on dairy cows, leading to metabolic diseases and economic losses. Resveratrol (RSV) is known for its numerous beneficial health effects and can be used as a barrier against metabolic abnormalities and prevent economic losses. Several studies have investigated the effects of RSV in humans and various animal species. In this review, we attempted to investigate the effects of RSV from different aspects so that we could have a practical proposal for its utilization in dairy cows. RSV was found to have potential antioxidant, anti-inflammatory, anti-obesity, and antimicrobial effects, leading to improved reproductive performance. It is interesting that the effect of RSV on the microbial population leads to a significant decrease in methane emissions. However, high doses of RSV have been associated with possible adverse effects, underscoring the dose dependence of its efficacy. In conclusion, RSV polyphenol at optimal doses is a promising agent for the prevention and treatment of metabolic abnormalities in dairy cows, based on our literature review and study results.

Effects of monensin supplementation on lactation performance of dairy cows: a systematic review and dose-response meta­analysis.

The aim of this study was to conduct a comprehensive review with meta-analysis to determine the effects of the dose-response relationship between monensin supplementation and dairy cow performance and milk composition. Results from 566 full-text articles and 48 articles with 52 studies were meta-analyzed for pooled estimates. Monensin supplementation up to 23 ppm increased milk production, with the optimal dose being 12.6 ppm. Monensin supplementation at doses ranging from 16 to 96 ppm increased milk production in the prepartum phase (- 28 to 0 day relative to calving). From 60 to 150 DIM, monensin supplementation up to 21 ppm had a significant positive effect on this outcome, while supplementation in the 37 to 96 ppm range caused a decrease in this variable. At 0 to 60 and > 150 DIM, monensin supplementation had no effect on milk yield. At dosages of 22 to 96 ppm, 12 to 36 ppm, and below 58 ppm and 35 ppm, respectively, monensin supplementation resulted in significant decreases in dry matter intake (DMI), milk protein percentage, milk fat percentage, and milk fat yield. Overall, based on the results of this meta-analysis and considering all variables, the recommended optimal dose of monensin could be about 16 ppm.

Effects of wheat straw particle size as a free-choice provision on growth performance and feeding behaviors of dairy calves.

In the dairy calf feeding, supplementation of forage to the starter feed is commonly practiced. However, data are insufficient about how changes in particle size (PS) of forage affect calf performance and behavior in a free-choice forage provision system. This study aimed to assess the effects of supplementing wheat straw varying in PS on performance, skeletal growth characteristics, ruminal pH, nutritional behaviors, and blood metabolites of dairy calves. Forty-eight Holstein calves (43.8 ±â€¯3.2 kg of BW) from d 15 of age were randomly assigned to one of the four treatments (n = 12/treatment; six males and six females): (1) starter without wheat straw supplementation (CON), (2) CON supplemented with wheat straw chopped at 1 mm geometrical mean particle length (GMPL) (fine PS), (3) CON supplemented with wheat straw at 4 mm GMPL (medium PS), and (4) CON supplemented with wheat straw at 7 mm GMPL (long PS). The calves were given ad libitum access to feed and water throughout the study. All calves were weaned on d 56 of age and continued the experiment until d 90. The starter, wheat straw, and total solid feed intakes were not affected by GMPL of wheat straw; however, CON calves had a lower solid feed-, total DM- and NDF-intake than calves offered wheat straw. Further, ADG, weaning, and final BWs as well as feed efficiency were similar between treatments. No difference was observed in growth rate of hip height, hip width, body barrel, wither height, and heart girth among treatments, however, wheat straw supplemented calves tended to have greater body length at weaning. Blood concentration of serum ß-hydroxy butyrate was greater in wheat straw supplemented calves compared with CON calves on d 56 and 90. Calves supplemented with wheat straw spent more time eating starter and forage, lying and ruminating and less time for standing and non-nutritional behaviors compared with the CON calves on d 49 and 63 of the study. Moreover, calves offered wheat straw had greater ruminal pH than CON calves at 4 and 8 h after offering starter feed on d 35. In conclusion, supplementing wheat straw as a free-choice increased solid feed intake, rumen pH, and calves' welfare, however, PS of wheat straw had no effect.

Effect of potassium iodide supplementation and teat-dipping on iodine status in dairy cows and milk iodine levels.

Two experiments were designed to determine the effects of dietary iodine and teat-dipping on the iodine status of dairy cows and their milk. Eight mid-lactation Holstein dairy cows with an initial body weight of 642 ± 62 kg and 145 ± 21 d in milk were studied for 2 periods over 44 d. In period 1, all cows were fed a basal diet supplemented with potassium iodide (KI) (10 mg I/Kg DM) for 8 d with no teat-dipping. In period 2, a pre-milking teat-dipping was applied for 10 d followed by no teat-dipping before milking (udder wash without iodine) and then post-dipping treatment was applied for 5 d. Feeding KI increased concentrations of iodine in serum, urine, and milk (P < 0.05). Switching from the KI supplementation to no iodine addition resulted in an immediate decrease of iodine in serum, urine, and milk (P < 0.05). Post teat-dipping resulted in increased iodine levels in serum, urine, and milk (P < 0.05). However, pre-milking teat-dipping did not affect iodine concentration compared to post-dipping. A 250 mL cup of milk from the control and KI-supplemented diets would provide 29.4% and 68.4%, respectively, of the adult-recommended dietary allowance for iodine. In conclusion, milk iodine concentration could be effectively enhanced by KI supplementation and teat-dipping practices.

Metabolic and molecular responses to calcium soap of fish oil fed to ewes during peripartal period.

It has been shown that n-3 long chain fatty acids (n-3 LCFA) are involved in energy/lipid metabolisms, reproductive parameters, and molecular regulations leading to maintained homeostasis. We hypothesized that supplementation of peripartal diets with fish oil (FO), as a source of n-3 LCFA, could improve energy balance and modulate metabolic pressure in a sheep model. Prepartum ewes (n = 24) were fed control (CON) or calcium soap of fish oil (FO) supplemented-diet from four weeks before until three weeks after parturation. Feed intake, body weight (BW) change, plasma metabolites, colostrums/milk composition, and fatty acids profile of milk along with the expression of core microRNAs in glucose and lipid metabolism were evaluated. Prepartal feed intake decreased in FO group (1674 ± 33.26 vs. 1812 ± 35.56) though post-partal intake was similar. Differences in BW were not also significant (55.47 ± 2.07 in CON vs. 53.69 ± 1.94 in FO). No differences were observed in plasma metabolites except for cholesterol that was lower in FO group (56.25 ± 0.71 vs. 53.09 ± 0.61). Milk fat percentage was reduced (8.82 ± 0.49 vs. 7.03 ± 0.45) while the percentage of milk total n-3 LCFA increased in FO group. In accordance, the relative transcript abundance of miR-101 (0.215 ± 0.08) and miR-103 (0.37 ± 0.15) decreased by FO supplementation. Results showed that FO supplementation during peripartal period decreased milk fat, feed intake, plasma cholesterol, milk n-6:n-3 ratio and the expression of miR-101. Although the trend indicated that FO could alter lipid metabolism during transition period, further studies are needed to fully address its effect on energy balance and homeorhetic processes.

Bentonite supplementation can improve performance and fermentation parameters of chronic lead-exposed lambs.

Two experiments were conducted to investigate the effect of supplemental bentonite on performance, blood, and fermentation characteristics in Zandi lambs. In experiment 1, 20 Zandi male lambs (initial BW, 17.5 ± 1.6 kg and 110 ± 5 days old) were randomly assigned into four groups of five animals in each. The experimental treatments were (1) control (no Pb and bentonite), (2) 15 mg/kg DM Pb as Pb acetate and no bentonite, (3) 15 mg/kg DM Pb as Pb acetate and 1.5% bentonite, and (4) 15 mg/kg DM Pb as Pb acetate and 3% bentonite. The dietary treatments had no significant effect on dry matter intake of experimental lambs. Feed required per unit of weight gain was more (P < 0.05) in lead-exposed lambs in group 2 compared to the control and bentonite supplemented groups. Serum glucose, urea nitrogen, cholesterol, HDL, and LDL concentrations was similar among the treatments. In experiment 2, an in vitro gas production technique was used to evaluate the effects of bentonite supplementation on the gas production parameters of lead-polluted diets. The rate and amount of gas production was higher for bentonite supplemented groups (P < 0.01). Asymptotic gas production (b), metabolizable energy, and concentration of short chain fatty acids were lower (P < 0.05) for lead-polluted non-supplemented diet (group 2) as compared to the bentonite supplemented and control groups. It was concluded that bentonite supplementation favorably modified ruminal fermentation pattern and improved feed conversion ratio in growing lead-exposed lambs.

Source of copper may have regressive effects on serum cholesterol and urea nitrogen among male fattening lambs.

An experiment was conducted to determine the effect of dietary copper (Cu) on mineral profile, hematological parameters, and lipid metabolism in lambs. Eighteen Zandi male lambs (approximately 3 months of age; 17.53±1.6 kg of body weight) were housed in individual pens and were assigned randomly to one of three treatments. Treatments consisted of (1) control (no supplemental Cu), (2) 10 mg Cu/kg dry matter (DM) from copper sulfate (CuS), and (3) 10 mg Cu/kg DM from Cu proteinate (CuP). The Cu concentration was 8.2 mg/kg DM in the basal diet. Blood was sampled from the jugular vein at the beginning of the study (enrollment, before feeding Cu supplement) and at days 25, 50, and 70 of experiment. The amounts of total serum glucose, urea nitrogen, calcium, phosphorus, iron, copper, zinc, and lipids and hematological parameters were measured. Average daily gain and feed efficiency were improved (P<0.05) with Cu supplementation and were better for the lambs fed diet supplemented with CuP. The concentrations of serum Ca, P, and Zn were not affected by source of Cu in the diet. However, Fe concentration was lower (P<0.01) in the Cu-supplemented groups. Experimental treatment had no significant effects on the hematological parameters. The serum glucose concentration was not affected by treatments. However, the urea nitrogen concentrations were significantly affected (P<0.05) by added Cu and was lower for CuP group as compared to the lambs in the CuS and control groups. Addition of Cu had no influence (P>0.05) on the serum triglyceride concentration, but lambs fed with CuP supplement had lower (P<0.05) serum cholesterol than the CuS and control animals. These results indicated that CuP supplemented at 10 mg/kg DM improved gain and enhanced the efficiency of nitrogen in male lambs.

Changes in blood metals, hematology and hepatic enzyme activities in lactating cows reared in the vicinity of a lead-zinc smelter.

The present study examines blood metals levels and health parameters in dairy cows reared in areas around a Pb-Zn industrial complex located near the city of Zanjan-Iran. Blood samples (n = 27) were collected from cows reared around the smelter. Blood samples (n = 25) were also collected from cows reared in areas where chances of Pb contamination of soil, water and fodder do not exist, to serve as reference. The mean blood Pb level in cows around the smelter (1.09 ± 0.26 µg/mL) was higher than the cows from the reference area (0.72 ± 0.25 µg/mL). Hematocrit (PCV) levels decreased in cows reared in the near of smelter (24.37 % ± 2.22 %) compared to the reference site (27.54 % ± 2.87 %). Hemoglobin (Hb) concentration and mean corpuscular Hb concentration value in cows from the area around the smelter were statistically lower than the cows reared in reference area. Activities of alanine transaminase and aspartate aminotransferase (IU/l) were significantly higher in cows around the smelter as compared to reference animals.

Effect of forage inclusion and particle size in diets of neonatal lambs on performance and rumen development.

A slaughter experiment was conducted to determine the effects of alfalfa particle size on rumen morphology and performance of lambs. Twenty-four Balouchi lambs aged 21 days (9.1 ± 1.1 kg) were randomly fed control (diet without alfalfa hay; CON) and mixed rations containing 15% finely ground (FINE; 2 mm) and 15% coarsely chopped alfalfa hay (LONG; 3 to 4 cm). After a 63 days feeding period, nine animals (three per treatment) were slaughtered to obtain ruminal tissue samples for morphological analyses. Alfalfa particle size did not affect (p > 0.05) papillae density, height, width, epithelium depth and surface area. Coarse alfalfa decreased the stratum corneum and increased (p < 0.05) muscle depth compared with fine and control diets. Neither DNA content and nor RNA concentration of rumen tissue was affected by feeding different diets. Forage particle size did not affect the blood concentration of glucose, urea nitrogen (BUN), beta-hydroxybutyric acid (BHBA) and non-esterified fatty acids (NEFA). Dry matter intake and feed conversion ratio were higher for control diet; however, there were no significant differences between treatments for average daily gain. These data suggest that coarse alfalfa significantly reduces the stratum corneum and increases muscularity of rumen wall and tended to better feed conversion ratio.

Carcass performance and meat mineral content in Balouchi lamb fed pistachio by-products.

This experiment investigated the effect of pistachio by-products (PB) in the feed of weaned Balouchi lambs on their daily gain, carcass traits and on the levels of Ca, Zn, Fe and Cu of Longissimus dorsi muscle. Twenty eight male lambs were divided into four groups with 7 lambs each and fed separately for 90days. The first group (control) was fed a commercial concentrate, and the second, third and fourth (test) groups received diets in which 10, 20 and 30% PB was used in partial replacement of alfalfa hay and beet pulp. The results showed that the high level of PB had no effect on performance and carcass traits. There were no significant differences between groups in mineral content in Longissimus dorsi muscle. These results suggested that PB can be use in diet of fattening lambs up to 30% without any adverse effects on carcass performance and mineral content of lamb meat.

Iodine in raw and pasteurized milk of dairy cows fed different amounts of potassium iodide.

Relation between iodine (I) intake by lactating Holstein cows and iodine concentrations in raw and pasteurized milk were investigated. Four treatment groups with eight cows assigned to each treatment were fed a basal diet containing 0.534 mg I/kg alone or supplemented with potassium iodide at 2.5, 5 or 7.5 mg/kg in 7-week period. Iodine concentrations in raw milk increased with each increase in dietary I from 162.2 ng/ml for basal diet to 534.5, 559.8 and 607.5 ng/ml when 2.5, 5 and 7.5 mg/kg was fed as potassium iodide (P < 0.05). This trend was found for blood plasma and urine iodine concentration. Iodine supplementation had no significant effect on thyroidal hormones. high-temperature short-time (HTST) pasteurization process reduced I concentration. The mean iodine content found in the milk prior to heating processing was 466.0 ± 205.0 ng/ml, whereas for the processed milk this level was 349.5 ± 172.8 ng/ml. It was concluded that iodine supplementation above of NRC recommendation (0.5 mg/kg diet DM) resulted in significant increases in iodine concentrations in milk, although the effect of heating in HTST pasteurization process on iodine concentration was not negligible.

Parenteral selenium and vitamin E supplementation to lambs: hematology, serum biochemistry, performance, and relationship with other trace elements.

Most regions in Iran are generally selenium (Se) deficient and all mineral premixes which used in farm animals contain Se in the form of sodium selenite. The objective of this study was to evaluate the effects of injected Se and vitamin E (vit E) on hematology, serum proteins, and performance of lambs during the period which the animals are at risk of Se and/or vit E deficiency. The study also aims to determine the relationship between selenium injection and the levels of other trace elements in blood serum of lambs. A total of 16 lambs of Baloochi breed (age, 70 ± 7 days and weight, 15.2 ± 1.4) were enrolled in the study. The animals were divided into two groups. In the test group, vit E and Se injected at a dose of 0.2 ml/kg BW (Vetoquinol, Selepherol®, Lure Cedex, France, α-tocopherol acetate 3.82 g/100 ml plus sodium selenite 0.023 g/100 ml) at the enrollment. Control lambs were received equal amounts of normal saline as placebo. Blood was sampled from the jugular vein at the beginning of the study (enrollment, before injection of vit E and selenium and saline) and at days 7, 14, 21, and 28 of experiment. The amounts of total serum protein, albumin, glucose, iron, copper, zinc, creatine kinase (CK), and aspartate aminotransferase (AST) and Se were measured. The concentration of globulin was calculated as the difference between total serum protein and albumin. For evaluation of growth and health, body weight of all the lambs was measured at day 0 of the experiment and the sampling times and days of treatment for each lamb were recorded. Treatment with Se and vit E decreased the activities of CK and AST compared to the controls (p < 0.05). Age (sampling time) had significant effects on the values of Se, iron, zinc, AST, hemoglobin, total protein, glucose, weight, height, and length (p < 0.05). Significant interactions between sampling time and group were seen for CK, AST, iron, glucose, weight, and length. No significant differences were seen for total weight gain (control, 3.48 ± 0.75 kg; test, 3.85 ± 0.9 kg), and average daily gain (control, 0.12 ± 0.03 kg; test, 0.14 ± 0.03 kg) between trial groups.

The effects of feeding clinoptilolite on hematology, performance, and health of newborn lambs.

The effects of feeding clinoptilolite on hematology, performance, and health of newborn Balouchi lambs were evaluated in this experiment. In a completely randomized design, 30 newborn lambs were allocated to three groups and fed by basal diet (C0; without clinoptilolite) and C1 and C2 (the basal diet plus 1.5% and 3% clinoptilolite, respectively, for 6 weeks (3 weeks before and 3 weeks after weaning)). Blood samples were taken from all lambs, at the time when the animals were allocated to the experimental diet and at the end of each week of experiment, and analyzed for hematology, plasma fibrinogen, and total protein. Performance and health of all lambs were measured. Fecal consistency score and diarrhea severity were evaluated. There was no difference between lambs in case of hematological parameters. Lambs fecal consistency score and severity of diarrhea were lowest (P < 0.05) for lambs on C1 and C2 and highest for lambs on C0. Dry matter intake and feed conservation ratio were similar between the groups of lambs fed by different diets, but daily gain of lambs differed significantly (P < 0.05) and was higher in C2. It was concluded that addition of 3% clinoptilolite to starter diet of newborn lamb can reduce incidence and severity of diarrhea, although its effect on hematology and performance was negligible.