Evaluation of Clinical and Biochemical Traits in Egyptian Barki Sheep with Different Growth Performances

Abstract

The Barki sheep industry is becoming increasingly important in Egypt because of the high quality of their meat and wool. This sheep breed is also commonly known for its resistance to arid and harsh environmental conditions. Such characteristics can be exploited in solving the problematic situation of inadequate animal protein for human consumption, particularly under climatic changes. However, very few studies have investigated aspects of breeding, nutrition, and susceptibility to infectious or non-infectious diseases in Barki sheep. Herein, we propose to unravel the differences in the clinical and biochemical profiles among Barki sheep of different growth rates. We measured clinical and biochemical parameters in stunted (n = 10; test group) and in good body condition (n = 9; control group) Barki sheep. Animals subjected to this experiment were of the same sex (female), age (12 months old), and housed in the same farm with similar conditions of feeding, management practice, and vaccination and deworming regimens. Regarding clinical examination, stunted/tested sheep showed a significantly higher pulse and respiratory rate compared to sheep with a good body condition/control group. The appetite, body temperature, and digestion processes were the same in both groups. In biochemical investigations, nutritional biomarkers were reduced markedly in stunted sheep compared with the control sheep, including total protein (p = 0.0445), albumin (p = 0.0087), cholesterol (p = 0.0007), and triglycerides (p = 0.0059). In addition, the Barki sheep test group suffered from higher levels of urea and blood urea nitrogen than the control group. Consistently, growth and thyroid hormone levels were lower in stunted sheep than the control sheep, although the differences were not statistically significant (p > 0.05). No significant differences were detected in both groups for serum levels of calcium, phosphorus, magnesium, iron, and zinc (p > 0.05). To detect the reasons for emaciation, certain debilitating infections were tested. All tested sheep showed negative coprological tests for gastrointestinal parasites, and had no obvious seropositivity to brucellosis, toxoplasmosis, neosporosis, or Q fever. This study demonstrates the useful biochemical markers for monitoring growth performance in Egyptian Barki sheep and unravels the usefulness of this breed in nationwide breeding and farming.

Keywords: Barki sheep; biochemical; clinical; mineral; parasite; protein.

Figure 1

Illustration diagram showing the observational and experimental approaches in this study. Our sheep were purchased from the Beheira governorate in September 2021 at the age of 4 months with an approximate body weight of 11–13 kg. They were subjected to experimental procedures at 12 months old. During that time, all sheep were subjected to the same conditions of housing, feeding, vaccination, and deworming regimens. All sheep in this experiment received a primary (at 4 months old) and a booster dose (at 5.5 months old), and were treated with a broad spectrum anti-parasitic oral suspension at 7 and 10 months old. At the age of 12 months, despite expose to similar conditions, a remarkable difference in body weight was observed in some animals (herein referred as stunted/test animals, n = 10) compared to others (referred as good condition/control animals, n = 9). The 2 arrows above refer to the drenching of animals with anthelmintic drugs 2 times at 3-week intervals, according to the manufacturer’s instructions.

Figure 2

Clinical findings of examined Barki sheep. Body weight, body condition, and systemic parameters were investigated in stunted and good body condition sheep. Each bar represents the mean ± SD with the p-value comparing the two groups using an unpaired Student’s t-test. Significance at p ≤ 0.05.

Figure 3

Biochemical analysis of Barki sheep serum. Values of various serum biochemical variables in Barki sheep of stunted and good body condition. Each bar represents the mean ± SD with p-value comparing the two groups using an unpaired Student’s t-test. Significance at p ≤ 0.05.

Figure 4

Mineral analysis of Barki sheep serum. Values of various serum variables in Barki sheep of stunted and good body condition. Each bar represents the mean ± SD with p-value comparing the two groups using an unpaired Student’s t-test. Significance at p ≤ 0.05.

Figure 5

Serum levels of thyroid-stimulating hormone and growth hormone in stunted and good body condition Barki sheep. Serum level of TSH and growth hormone between stunted Barki sheep (n = 10) and good body condition sheep or control group (n = 9). Each bar represents the mean ± SD with p-value comparing the two groups using an unpaired Student’s t-test. Significance at p ≤ 0.05.

Figure 6

Correlation between different clinical and biochemical parameters against the body weight of all examined sheep. Scatter graphs show the correlation between body weight and different parameters including body condition score (A), cholesterol (B), triglycerides (C), total proteins (D), albumin (E), and growth hormone (F) from stunted (n = 10) and good body condition sheep (n = 9). The equation represents the approximation formula. The break line represents the calculated line of best fit. Correlation coefficients were calculated using Pearson’s correlation coefficient: |r| = 0.70 strong correlation; 0.5 < |r| < 0.7 moderately strong correlation; and |r| = 0.3–0.5 weak-to-moderate correlation.

Figure 7

Different ELISAs for examined Barki sheep. Sera from stunted (n = 10) and good body condition (n = 9) Barki sheep were tested using a commercial ELISA for detection of specific antibodies against Brucella species, Coxiella burnetii, Toxoplasma gondii, and Neospora caninum and for significant differences in different sera against the same tested antigen. Each bar represents the mean ± standard deviation. The different letters above the bars in the graphs indicate statistically significant differences of other groups (one-way ANOVA with Tukey–Kramer post hoc analysis, p < 0.05). Red dots refer to positive samples either from the control or test samples. NC; negative control, PC; positive control.