Influence of boron supplementation on performance, immunity and antioxidant status of lambs fed diets with or without adequate level of calcium

<div><p>Little is known about biological significance of effects of dietary Boron (B) and Calcium (Ca) interaction on health and production of farm animals. This is a preliminary investigation to evaluate the effects of B supplementation in lambs fed diets with (normal) or without adequate (low) levels of Ca. Twenty-four crossbred ram lambs were randomly distributed into four groups with six animals each in a 2x2 factorial design namely, normal-Ca diet (NCa) and low-Ca diet (LCa) fed without or with 40 ppm B (NCaB-40 and LCaB-40). The lambs were fed paddy straw and hybrid napier hay-based total mixed ration (60 roughage: 40 concentrate) during 180 days experimental period. Compared to control, the LCa diet lowered (P<0.01) average daily gain of lambs, but B-supplementation (LCaB-40) of the same nullified the effect. The lowered (P<0.05) total antioxidant activity and humoral immune response in lambs fed LCa diet were restored (P>0.05) to become at par with the control (NCa) upon supplementation of B (LCaB-40). The mRNA expression of SOD1 was lowered (P<0.05) due to LCa diet feeding which too was normalized on B-supplementation to become at par (P>0.05) with the control (NCa). Further, B-supplementation restored lowered (P<0.05) SOD1 gene expression on LCa diet, but enhanced (P<0.05) that in NCaB-40 group, when compared to the control (NCa) diet fed animals. However, these variations were not reflected in the SOD activity in the erythrocytes. The cell-mediated immune response was higher (P<0.05) in lambs fed LCa and LCaB-40 groups and there was no significant interaction between the levels of either Ca or B in diets with the period of immune response measurement. B- supplementation of LCa diet ameliorated tissue degenerative changes in liver and kidney. It was concluded that feeding LCa diet to lambs resulted in reduced growth rate, total antioxidant activity, humoral immune response along with degenerative changes in liver and kidney tissues, but B-supplementation of such diet restored most of these changes and ameliorated histopathological alterations.</p></div

Gene primer sequence of SOD1 and reference gene.

<p>Gene primer sequence of SOD1 and reference gene.</p

Pictomicrograph showing spleen tissue in ram lambs fed experimental rations.

<p>Haematoxylin and Eosin staining, scale bar = 100μm. Ca deficiency induced histological alterations are restored/ameliorated by Boron.</p

Ingredient and chemical composition of experimental diets.

<p>Ingredient and chemical composition of experimental diets.</p

Pictomicrograph showing liver tissue in ram lambs fed experimental rations.

<p>Haematoxylin and Eosin staining, scale bar = 100μm. Ca deficiency induced histological alterations are restored/ameliorated by Boron. Arrows in the LC group indicate vacuole degeneration and nuclear condensation.</p

Pictomicrograph showing kidney tissue in ram lambs fed experimental rations.

<p>Haematoxylin and Eosin staining, scale bar = 100μm. Ca deficiency induced histological alterations are restored/ameliorated by Boron. Arrows in the LC group indicate protein casts.</p

Growth performance of lambs fed experimental diets.

<p>Growth performance of lambs fed experimental diets.</p

Serum SOD activity in ram lambs fed on experimental rations.

<p>Serum SOD activity in ram lambs fed on experimental rations.</p

Composition of mineral mixtures (100g).

<p>Composition of mineral mixtures (100g).</p

Influence of boron supplementation on total antioxidant activity, relative mRNA abundance of SOD1, humoral and cellular immune responses of lambs fed diets with or without adequate level of calcium.

<p>Note: lowered total antioxidant capacity(A), relative mRNA abundance of SOD1(B) and humoral immune responses (C) on low Ca diets are restored and cellular immune response (D) is ameliorated by Boron supplementation.</p