Effect of feeding complete diets containing graded levels of Prosopis cineraria leaves on feed intake,nutrient utilization and rumen fermentation in lambs and kids

A study was conducted to assess the effect of feeding graded levels of tannin-containing Prosopis cineraria leaves in a complete feed mixture (CFM) on the performance of lambs and kids. Eighteen lambs and 18 kids of Malpura and Marwari breed, respectively of similar age (90 days) and body weight (11.0 kg), were randomly distributed in to three groups of six each. Each group was offered complete feed mixtures ad libitum in feeding troughs under group feeding system for 90 days. The concentrate component of CFM was from the commercial feed in mash form containing corn, soybean meal, wheat bran and de-oiled rice bran. Prosopis leaves were ground to pass through a 4 mm sieve before being thoroughly mixed with required quantity of concentrate mash. CFMs contained graded levels of P. cineraria leaves. In, CFM-1, ratio of P. cineraria to concentrate mixture was 25: 75 (T₁), whereas in CFM-2 and CFM-3, it was 50:50 (T₂) and 75:25 (T₃), respectively. The lambs in L₁, L₂ and L₃ and kids in K₁, K₂ and K₃, groups received CFM-1, CFM-2 and CFM-3, respectively. CP (g kg⁻¹) was 182 in CFM-1, 162 in CFM-2 and 140 in CFM-3. P. cineraria leaves contained (g kg⁻¹) CP 159, neutral detergent fibre (NDF) 567, acid detergent fibre (ADF) 360 and acid detergent lignin (ADL) 189 on dry matter (DM) basis. The extractable condensed tannin (CT; leucocyanidin equivalent), hydrolysable tannin (HT) and protein precipitation capacity (PPC) of the leaves (g kg⁻¹) were 90.7, 3.4 and 111.5, respectively. DMI in L₁ and L₂ lambs were higher than their corresponding groups in kids, whereas it was reverse in L₃ (more in kids than lambs). Significant difference in digestible crude protein (DCP) intake was recorded among the groups in both lambs and kids. In lambs, highest DCPI (g day⁻¹) was recorded in L₁ (93.3), as compared to L₂ (82.2) and L₃ (37.2), whereas in kids it was K₂ (73.4), followed by K₁ (69.2) and K₃ (43.8). Significant difference in the digestibility of DM, CP and NDF were recorded among three groups in both species. Maximum nutrient digestibility was recorded in T₁ followed by T2 and T₃ in both lambs and kids. However, digestibility of all the nutrients was more in kids than that of lambs. Maximum ammonia-N, total N and trichloro acetic acid (TCA) precipitable N was recorded in T₁ followed by T₂ and T₃ in both the species. However, there was no typical trend between the two species in rumen parameters. Blood haemoglobin (Hb) and blood urea nitrogen (BUN) values were highest in T₁ followed by T₂ and T₃ in both lambs and kids. After 90 days of intensive feeding, maximum weight gain was recorded in T₂ as compared to that of T₁ and T₃ in both lambs and kids. Although L₁ lambs performed better under high concentrate diet compared to K₁ kids, weight gain in K₂ and K₃ kids were significantly higher compared to their counter part lambs. Similar was the trend in ADG also. It was concluded that performance of lambs and kids differed with the level of CT in their diet and kids performed better on high tannin diet as compared to that of lambs.