تاثیر استفاده از عصاره گیاهان دارویی آویشن شیرازی و اُکالیپتوس در آغوز بر نرخ مرگ و میر، رشد و فراسنجه‌های خونی بزغاله‌های نژاد مورسیا

Introduction:
Mortality in newborn goat kids represents a significant economic and welfare challenge for small ruminant production systems worldwide. This issue has become increasingly concerning for breeders in recent years, particularly in intensive production systems where early separation from mothers and artificial feeding methods are common practices. In Iran, the dairy goat industry has experienced considerable expansion, yet kid mortality rates remain problematically high, creating substantial obstacles for producers and limiting the sector's profitability and sustainability.
Current research on small ruminant mortality in Iran has predominantly concentrated on pathogenic factors, including bacterial, viral, and parasitic infections. While these investigations have provided valuable insights into disease transmission and prevention, there has been a notable gap in research focused on nutritional interventions as preventive measures against early mortality. This oversight is particularly significant considering that nutrition during the critical first days of life plays a fundamental role in developing immunity and establishing gastrointestinal health in newborn ruminants.
The Morciano Granadina goat breed, valued for its high milk yield and adaptability to various climatic conditions, has been introduced to Iranian production systems. However, these animals have exhibited concerning mortality rates of approximately 35% in newborn kids, substantially higher than what is considered acceptable in sustainable production systems. This alarming statistic necessitates the development and implementation of effective preventive strategies.
In recent years, global interest in natural alternatives to synthetic pharmaceuticals has grown significantly. Medicinal plants and their derivatives have gained attention as potential replacements for antibiotics and other conventional treatments. Among these, Shirazi thyme (Zataria multiflora) and Eucalyptus (Eucalyptus globulus) have demonstrated promising antimicrobial, anti-inflammatory, and immunomodulatory properties in various studies. These plants contain bioactive compounds including thymol, carvacrol, and eucalyptol, which have been documented to exhibit beneficial effects on gastrointestinal health and immune function.
Given these considerations, this study was designed to investigate the potential of Shirazi thyme and eucalyptus medicinal plant extracts administered through colostrum as a preventive measure against early mortality in Morciano Granadina goat kids. Additionally, the study monitored growth performance and blood parameters to evaluate the overall impact of these botanical interventions on kid development and health status.
Materials and Methods:
The experiment was conducted at a commercial dairy goat farm in Maksal farm, Qazvin, Iran during the kidding season. A total of sixty newborn Morciano Granadina goat kids with an average birth weight of 2.5 ± 0.15 kg were utilized in this study. The research employed a completely randomized design with six treatments and ten replications (individual goat kids) per treatment.
The experimental treatments were as follows: Con treatment: Control (colostrum only, without additives), ST12 treatment: Colostrum containing 12 mg Shirazi thyme extract, ST18 treatment: Colostrum containing 18 mg Shirazi thyme extract, EU12 treatment: Colostrum containing 12 mg eucalyptus extract, EU18 treatment: Colostrum containing 18 mg eucalyptus extract, Anti treatment: Colostrum containing Colistin pump antibiotic (standard farm protocol). The plant extracts were prepared using hydro-alcoholic extraction methods from dried Shirazi thyme leaves and Eucalyptus leaves, with active compound concentrations standardized through HPLC analysis. The extracts were administered by mixing with colostrum immediately before feeding.
Following standard farm protocol for artificially raised kids, newborns were separated from their mothers immediately after birth. Each kid was weighed, identified with numbered ear tags, and allocated to one of the six treatment groups. Colostrum was collected from the respective mothers using a milking machine and tested for quality using a Brix refractometer. Only colostrum with Brix values ≥22% was utilized in the study. Colostrum composition (fat, protein, lactose, dry matter, and non-fat dry matter) was analyzed using Fourier Transform Infrared (FTIR) spectroscopy.
Kids received colostrum at 25% of their birth body weight, divided into three feedings within the first 24 hours post-birth. The respective treatment additives were included in each colostrum feeding during the first 72 hours of life. Following the colostrum period, all kids were managed according to standard farm protocols, receiving milk replacer until weaning at two months of age.
Data collection included body weight measurements at birth and at monthly intervals until weaning. Health parameters, including incidence and duration of diarrhea, respiratory diseases, and other health conditions, were diagnosed and documented by the farm veterinarian. Blood samples were collected at 14 and 28 days of age for analysis of hematological and biochemical parameters, including complete blood count, liver enzymes, total protein, albumin, and globulin levels.
Results and Discussion:
Mortality rates showed significant differences (P<0.05) among treatments, with the highest mortality observed in the control group (50%) and the lowest in the ST18 (10%), EU18 (10%), and Anti (10%) groups. The ST12 and EU12 treatments showed intermediate mortality rates (40% each), suggesting a dose-dependent effect of the plant extracts.
Post-mortem examinations and clinical records identified diarrhea as the primary cause of death during the early postnatal period, accounting for approximately 75% of total mortality. This finding aligns with previous research indicating that enteric diseases represent the most significant threat to newborn ruminant survival. The remaining mortality was attributed to respiratory infections and other miscellaneous causes.
Growth performance analysis revealed that kids receiving the ST18, EU18, and Anti treatments exhibited numerically higher average daily gain during the first month compared to the control group, although these differences did not reach statistical significance (P>0.05). No significant differences were observed in body weights at weaning across the treatment groups, suggesting that while the plant extracts may provide protection during the critical early period, their effects on long-term growth performance may be limited.
Blood parameter analysis revealed no significant differences between treatments in hematological values or liver enzymes. This finding is particularly important as it indicates that the plant extracts at various concentrations had no adverse effects on liver function or body metabolism, confirming their safety for use in newborn goat kids.
The comparable efficacy of the 18 mg extracts of both Shirazi thyme and Eucalyptus plants to the Colistin Pump antibiotic represents a promising finding, suggesting potential for these botanical alternatives in situations where antibiotic use is restricted or undesirable.
Conclusions:
This study demonstrates that Shirazi thyme and Eucalyptus medicinal plant extracts administered at 18 mg for 72 hours after birth through colostrum can effectively reduce mortality rates in Morciano Granadina goat kids, with efficacy comparable to that of the conventional antibiotic treatment. These botanical alternatives represent promising tools for sustainable goat production systems, particularly in contexts where antimicrobial resistance concerns or consumer demand for antibiotic-free production exists. Future research should explore optimized dosages, combinations of plant extracts, and potential long-term benefits on productivity and health.