Growth performance, nutrient digestibility, and slaughter traits of male fattening lambs under different feeding standards

Abstract

This study compared the growth performance, nutrient utilization, and slaughter traits of Dorper crossbred male lambs fed as per the established nutrition recommendations for sheep, with an aim to verify the efficacy of different feeding standards. A total of 576 lambs (4 months of age, 28.3 ± 0.86 kg BW) were randomly allotted to 3 treatments with 12 replicates per treatment (16 lambs per replicate). The lambs were fed diets formulated according to the following 3 nutritional systems: the nutrient requirements of Dorper crossbred lambs established by Chinese Academy of Agricultural Sciences (CAAS), NRC (National Research Council), (2007), and AFRC (Agricultural and Food Research Council) (1993). The experiment lasted for 81 d. Feed intake was recorded every 3 days, and lambs were weighed every 20 days. Digestibility trials were conducted with 6 lambs each group from d 42 to 53 and d 70 to 81. At the end of the experiment, 10 lambs randomly chosen from each group were sacrificed to determine the carcass traits and meat quality. The results indicated that the lambs in the NRC group had the highest dry matter intake (DMI), followed by those in the AFRC and CAAS groups ( P < 0.05). The average daily gain, carcass weight, and dressing percentage were higher for lambs in the CAAS group than those in the NRC group ( P < 0.05). The lambs in the CAAS group had the lowest feed conversion ratio, followed by those in the AFRC and NRC groups ( P < 0.05). The apparent digestibility of DM was higher for the lambs in the CAAS group than those in the NRC group ( P < 0.05). Water losing rate, as well as the lightness (L*), redness (a*), and yellowness (b*) values of the longissimus thoracis were not different among groups ( P > 0.05). In conclusion, Dorper crossbred lambs fed diets formulated according to the CAAS recommendations exhibited superior growth performance than those fed diets formulated according to the American or British feeding standards.

Inclusion of Yerba Mate (Ilex paraguariensis) Extract in the Diet of Growing Lambs: Effects on Blood Parameters, Animal Performance, and Carcass Traits

“…Animal performance data presented in this study showed positive results and is similar to results reported in the literature using Dorper breed and its cross-breeds [ 57 , 58 , 59 ]. The effect of high levels of yerba mate extract (4%) resulted in a reduction in dry matter intake and, consequently, a reduction in the general performance of the lambs; on the other hand, inclusions of up to 2% caused an increase in dry matter intake, total weight gain, and daily weight gain.…”

Use of Tithonia diversifolia (hemsl.) A. Gray in the diet of growing lambs

“…To this respect, Costa et al (2018) while investigating the requirements of energy and protein for weight gain and carcass quality of lambs (Santa Inés and Morada Nova, 28 to 31 kg BW), reported a FI of 1 kg day -1 , a value lower than that found in this study (FI>1, for both diets, every week). Furthermore, Ma et al (2019) evaluating the growth and nutrient utilization of Dorper lambs and their crosses (average initial BW of 28.3 kg), found a FI of 1.2 to 1.3 kg day -1 , values similar to those obtained in the present study (Table 3). Forbes (2007) affirmed that the sheep's ability to select among parts of forages is very important to regulate the voluntary FI.…”

A Field Trial on the Effect of Propylene Glycol on Dairy Nanny Goats Welfare During Critical Transition Stages

“…The impact of using PG on DMI is inconsistent with the current study; according to Lien et al (2010) who reported a higher in DM intake in cows treated with 500 ml PG (19.72 kg /head/ day) than 18.25kg /head/ day in control caws during early lactation. In general, the lowest DMI observed in PG groups compared with PG0 group could be explained by the difference in energy density of diets formulated (Ma et al, 2019) energy sources plays an important role in establishing nutrient requirements for animals, they were mainly based on the minimum nutrient requirement of animals.…”