Goats significantly contribute to Indian economy and play a vital role in lively hood security of marginal and landless farmers. They provide household nutritional security and family income through meat, milk and manure with little or no feed supplementation. Mostly these animals are reared under free range system and termed as anytime money (ATM) for the rural house hold. Ruminal lactic acidosis is a carbohydrate fermentation disorder of the rumen that can affect any ruminant species including goats. Acidosis is caused by the feeding of highly fermentable carbohydrates, feeding of low fiber diet, poor management practices or a combination of these. Manifestations of acidosis vary from a slight drop in feed intake (mild) to death (severe). Acute form of the disease in goats is characterized by indigestion, rumen stasis, dehydration, toxaemia, acidosis in coordination, collapse and frequently death in untreated cases.

Ruminal lactoacidosis is one of the most important clinical emergencies of small ruminants (sheep and goats) resulting in high mortality (Radostits et al., 2007). Lactic acid is known to increase in the rumen from 1 to 1500 mg/100 mL (Uhart and Carroll, 1967) and in the blood from 4.5 to 90 mg/100 mL (Heuter et al., 1956; Dunlop and Hammond, 1965) following consumption of large quantity of fermentable carbohydrates. Systemic changes occurring during lactic acidosis require greater understanding for proper treatment and preventive measures to reduce the risk of grain engorgement in ruminants. Changes in blood gas parameters like VpH, H+, HCO3-, and base deficit in ruminal acidosis are important to assess the severity of disease along with the changes in rumen liquor and biochemical parameters.

Materials and Methods                                                                               

Six clinical cases of acute ruminal acidosis were selected for the present study. Six healthy goats from the herd of small farmers nearby Veterinary College, Bidar were used for studying normal parameters and kept as control group. Ruminalotilityas observed manually with stethoscope, for other investigations 40-50 mL rumen liquor was collected with the help of “stomach tube aspiration”.

Samples were strained with the help of four fold muslin cloth and samples were kept at 4 degree centigrade in refrigerator till analysis of the following parameter. Blood samples were collected in NaEDTA vials and stored at 4 degree Celsius in refrigerator and pH of rumen liquor was estimated immediately after the collection with the help of digital pH meter and was expressed in single decimal (viz. 7.1, 7.2). Gram positive bacterial count was done by taking ten drops of strained rumen liquor and evenly spread on a clean glass slide and heat fixed. The smear was stained with grams staining solution and around 100 bacteria were counted and gram positive to gram negative ratio was noted (Rogosa, 1964) and it was expressed in % values. Total protozoan count wasstimated as per the method described by the Moir (1951). Total protozoa were counted by taking 5 mL of strained rumen liquor and was diluted with 10 per cent formal saline to make total volume 20 mL from this 10 mL of mixed rumen liquor was taken and 10 drops of 2 per cent eosin was added to colour the protozoa.  The diluted rumen liquor was then charged in a Neubauer-hemocytometer. The total protozoan count was expressed as counts per mL (nx10⁵).

Glucose was estimated by glucose oxidase paraoxidase (op) method as described by Henry (1963) and was expressed in mg/dL. AST levelsere estimated by modified IFCC method as described by Reitman and Frankel (1957) and was expressed in IU/L. Statistical analysis of data was carried out by employing paid‘t’ test and ANOVA as per Snedecor and Cochran (1994).

Results and Discussions

The pH of healthyontrol group was 6.67 ± 0.05 compared to affected goats which was significantly decreased to 5.13 ± 0.14. Similar changes were observed by Tanwar and Mathur (1983), Braun et al. (1992), Basak et al. (1993) and Shah et al. (2018) in goats. The gram positive bacterial count was 27 ± 1.15 ercent (%) in health group which was significantly increased to 72.67± 4.19 % in affected goats this was in agreements with reports of Choudhary et al. (2011), Padmaja and Praveena (2011), Tufani et al. (2013) and Ullaht al. (2013). The decrease in pH of the ruminal fluid may be due to increase production of volatile fatty acids like acetic, proprionic and butyric acid. The decrease in pH of the rumen favours the growth of streptococci with decline in the number of normal Gram negative bacteria and protozoa which further aggravates the process of lactic acid production.

The TPC (Total protozoan count) was 2.67 ± 0.2110⁵/ml of rumen liquor in healthy groups whereas in case of acidotic goats it was observed nil.  The absence of protozoan ruminal fluid of  pH < 5.5 may be due to increased acid produced in rumen, which has been also reported by earlier workers  Choudhary et al. (2011), Padmaja and Praveena (2011), Rahima et al. (2012), Tufani et al. (2013) and Ullah et al. (2013).

Table 1: Comparison of healthy control with acidotic goats

The values bearing same superscript do not differ significantly within the each row

The blood gas analysis of healthy goats showed the values of VpH 7.39 ±0.02 which was significantly decreased to 7.14±0.01 in affected goats. This was in agreement with Angelov et al. (1996) and Ullah et al. (2013). The decrease in the pH may be due to over-distention of rumen which impedes venous return to heart. This factor impairs hepatic perfusion and poorer lactic acid utilization which in turns leads to systemic lactic acidosis, manifesting decrease blood pH (Ullah et al., 2013). The values of VpCO₂and VpO₂ of healthy animals showed significant difference compared to the values of affected goats but bothhe values were within the normal physiological limits (Rahima et al., 2012).The HCO₃ levelf healthy goats was 24.85 ±0.21mol/L which was significantly decreased to 11.43±0.47mmol/L in affected goats this was in accordance with Rahima et al. (2012). The H+f healthy goat was 45.62 ± 0.66mol/L which showed significant increase to 110.62±2.18nmol/L in affected goats as it was also observed by Rahima et al. (2012). Base deficit of healthy goats was 4.12 ± 0.13mmol/L which was significantly increased to 13.97±0.31mmol/L in affected goats. Increase in the base deficit, H+ level and reduction in the level of HCO3- re suggestive of metabolic acidosis.

Serum levelf glucose in healthy goats was 51.95± 2.93mg/dl which showed significant increase to 112.03±3.14 mg/dl in affected goats. AST (Aspartate transaminase) of healthy goats was 21.62 ± 0.93 IU/L which was significantly increased to 99.51±2.45 IU/L in affected goats. These elevated levels of serum glucose and AST in acidotic goats might be due to hepatocellular damage as a result of toxic product like alcohol, histamine, thiaminase and other endotoxins produced in the rumen epitheliumnd thus entering the portal circulation or due to dehydration resulting in to liver damage.

Conclusion

Ruminal acidosis hampers the fermentative capacity of rumen by inhibiting the microflora and fauna. Blood gas analyzer assisted parameters like blood pH, bicarbonate, H⁺ concentration and base deficit showed significant change in affected goats which was suggestive of metabolic acidosis.

Acknowledgment

The authors are very much thankful to the support extended by the Institute for providing necessary facilities to carry out this study.

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