Effects of different starters with different neutral detergent fiber sources on growth performance and gastrointestinal tract development of Hu lambs

The aim of this study was to investigate the effects of different types of starters with various NDF sources on growth performance and gastrointestinal development of Hu lambs. Sixty healthy Hu lambs, each with initial body weight of (3.47 ± 0.69) kg, were selected, and the single-factor experimental design was adopted. The lambs were divided into four treatments and fed different starters with different neutral detergent fiber (NDF) sources, which included alfalfa hay (AH), soybean hull (SH), oat hay (OH), and beet pulp (BP). The results showed that the final body weight, carcass weight, average daily gain, and average daily feed intake were significantly higher in AH-fed lambs than in the other lambs (P < 0.05). The kidney index and gall bladder index of SH-fed lambs were significantly lower than those of lambs feeding on OH and BP (P < 0.05), while the ratio of rumen content weight to whole stomach content and the whole gastrointestinal tract content weight were significantly higher compared with those in OH- and BP-fed lambs (P < 0.05). The ratio of reticulum content weight to whole stomach content, the whole gastrointestinal tract content, and body weight of SH-fed lambs were significantly lower compared with those in other lambs (P < 0.05). The ratio of rumen weight to whole stomach weight and the whole gastrointestinal tract weight of AH- and OH-fed lambs were significantly higher than those of BP-fed lambs (P < 0.05). The ratio of rumen weight to body weight was significantly higher in SH-fed lambs than in AH-fed lambs (P < 0.05). The ratio of rumen volume to whole stomach volume of SH-fed lambs was significantly higher than that of OH-fed lambs (P < 0.05). The ratio of rumen volume to whole gastrointestinal tract volume was significantly higher in AH- and SH-fed lambs than in BP-fed lambs (P < 0.05). The ratio of abomasum weight to whole stomach weight of BP-fed lambs was significantly higher than that of SH-fed lambs (P < 0.05). The ratio of jejunum weight and volume to whole gastrointestinal tract weight and volume of OH-fed lambs was significantly higher than that of SH-fed lambs (P < 0.05). In conclusion, because of the different structure of the fiber in different starters with different NDF sources, apparent differences were observed among different treatments in growth performance and gastrointestinal tract development of Hu lambs.