Nutrient intake and apparent digestibility coefficient of lambs fed with coffee husk in replacement of oat hay

This study aimed to evaluate the effects of replacing oat hay with coffee husk in the diet of lambs on the intake and apparent digestibility of dry matter (DM), organic matter (OM), crude protein (CP), ether extract (EE), non-fiber carbohydrate (NFC), neutral detergent fiber (NDF), and acid detergent fiber (ADF). The experimental design was 4×4 Latin square with four levels of replacement of oat hay with coffee husk (0, 7.5, 15, and 22.5%) with four individually housed Texel sheep. Intake and apparent digestibility coefficients were measured at four periods of 12 days. All orts and feces were collected, weighed, homogenized, and sampled. The use of coffee husk at up to 22.5% of the total DM in the diet of lambs improved the intake of nutrients. Except for NDF, no significant differences were observed for the apparent digestibility of other parameters (DM, OM, CP, EE, NFC, and the ADF). Coffee husk can be included at up to 22.5% of total dry matter in diets with 30% roughage and 70% concentrate, being a good alternative to reduce feed costs in lamb production.

each other, depending on diet quality, and are commonly referred to as associative effects (CRUZ et al., 2011).
In this study, we evaluated the effect of substituting oat hay with coffee husk in the diet of lambs on the intake and apparent digestibility of dry matter (DM), organic matter (OM), crude protein (CP), ether extract (EE), neutral detergent fiber (NDF), and acid detergent fiber (ADF).
The experiment was performed from May to December, 2013, at the University of North Paraná (UNOPAR) in Arapongas (23°S, 51°W, elevation 816m), Paraná, Brazil.This city presents a predominantly humid subtropical climate.The present study is in accordance with the ethical principles of animal experimentation of the Ethics Committee for Animal Use (CEA) of UNOPAR.The laboratory trials were performed in the Animal Nutrition Laboratory, Arapongas Campus (UNOPAR).
Four mature Texel sheep (mean body weight 15.3kg with a standard deviation of 3.48) were used, housed in individual, cemented, and partially covered bays equipped with troughs for food and water.Diets were formulated according to the nutritional requirements described by the NRC (2007) as isonitrogenous, and were composed of 300g/kg roughage (oat hay) and 700g/kg concentrate as DM (Table 1).The experimental design was 4×4 Latin square with four treatments and four replicates.The treatments consisted of four levels of substitution of oat hay with coffee husk: 0, 7.5, 15, and 22.5%.
Animals were fed twice daily at 08:00 and 17:00 h.Feed intake was monitored daily, and the food supply was set at 15% above the voluntary intake, adjusted according to the consumption during the previous day.Water was provided ad libitum.Representative samples of the total diet (concentrate and roughage) and the leftovers were collected in each experimental period for chemical analysis (Table 1).Samples were pre-dried in a forced-air oven at 55°C for 72h to determine the partial DM, milled in a Wiley mill with a 1-mm screen, and then stored for further analysis.The following variables were determined: DM, ash, OM, CP, EE, NDF, ADF, lignin (LIG), neutral detergent insoluble protein (NDIP), and acid detergent insoluble protein (ADIP), according to MIZUBUTI et al. (2009).Total digestible nutrients (TDN) were estimated in accordance with NRC (2001).Non-fiber carbohydrate (NFC) was estimated by NFC=100 − (NDF+CP+EE+ash).
Intake and apparent digestibility coefficients were measured within five experimental periods, with 62 days in total.The first period lasted for 14 days and was used for animal adaptation.The others periods comprised 12 days each, divided into diet adjustments (7 d) and digestibility trials (5 d).All orts and feces were collected from the 8th to the 12th day of each experimental period, and then weighed, homogenized, and sampled.Samples were dried at 55°C to constant weight, sieved (sieve with a 1-mm pore), and stored for further analysis.The DM, OM, NDF, ADF, NFC, CP, and EE apparent digestibility coefficients were determined by the difference between the dietary component consumed, and that excreted in feces.
Statistical analyses were carried out in the MIXED procedure of the statistical package SAS ® , version 9.2 (SAS Institute Inc., Cary, NC).Results were considered significant at 5% probability.
The intake of CP, NDF, and ADF showed an increasing linear response as a function of the levels of coffee husk in diet (Table 2).The intake of DM and OM were similar for the different treatments studied, whereas nutrient intake increased, indicating that coffee husk did not negatively affect intake and animal performance, and that coffee husk can be used in ruminant feed.Moreover, the higher the level of coffee husk in the diet, the greater was the intake of nutrients.
A positive quadratic effect was observed for the variables EE and NFC intake (Table 2), and the highest mean values recorded were 21.07 and 450.53g, respectively, obtained for the diet with 7.5% coffee husk inclusion; a decrease in the intake of these nutrients was observed for the diets with 15 and 22.5% coffee husk in replacement of oat hay.Thus, inclusion of coffee husk at up to 7.5% of the total DM of the diet resulted in increased nutrient intake without affecting DM intake.
No significant differences in the apparent digestibility of DM, OM, CP, ADF, NFC, and EE were observed (Table 2); however, NDF responded in a linear and quadratic manner as a function of coffee husk levels.Although, we expected that DM and fiber would have lower digestibility, this was not reported with the increasing inclusion levels of coffee husk in the diets.
A possible explanation for the linear effect observed for NDF is that the inclusion of coffee husk in the diet had a positive effect on nutrient intake (Table 2); this shows that the inclusion did not limit consumption by the animals; and therefore, did not reduce digestibility.For each unit of oat hay replaced by coffee husk, there were increases in NDF intake, ADF intake, and NDF digestibility of 3.08, 1.05, and 0.57%, respectively.The digestibility of the ADF was not altered with the substitution of hay with the coffee husk, possibly due to the higher levels of hemicellulose in the diets containing the coffee husk compared to the control diet, indicating that the NDF of the coffee husk has a fraction of hemicellulose with good digestibility.
According to VAN SOEST (1994), roughage-based diets are important for ruminants in confinement.Fiber helps to stimulate chewing and rumination, positively affecting digestibility since the digestibility of NDF improved with increased levels of coffee husk in the diet.
SALINA-RIOS et al. ( 2015) evaluated sheep diets supplemented with ensiled coffee pulp with 5% molasses (control, 8%, and 16% coffee pulp), and reported that food intake was not affected by the supplementation levels studied.Thus, up to 16% coffee pulp with 5% molasses can be added to lamb diets without affecting animal performance.SOUZA et al. (2004) studied the effects on feed intake and apparent digestibility of replacing corn meal with different levels (0, 6.25, 12.5, 18.75, and 25% DM) of coffee husk in a concentrate diet for lambs, and observed a linear effect of coffee husk levels on EE intake, estimating a reduction of 0.528g per gram of husk added.In addition, no changes were observed in apparent digestibility for DM, OM, CP, and NDF.BERNARDINO et al. (2009) reported no difference in EE digestibility coefficients for different coffee husk levels in diet, reporting an average of 79.1%, similar to that observed in this study (average of 83.7%).
Coffee husk can be included in diets of lambs at up to 7.5% of total DM in diets with 30% roughage and 70% concentrate, since it can improve Table 1.Ingredient composition and chemical composition of diets containing different inclusion levels of coffee husk to replace oat hay.

Table 2 -
Nutrient intake and apparent digestibility coefficient of Texel lambs fed diets containing different levels of coffee husk in substitution to oat hay.