A 431-d experiment was conducted to determine the effects of whole cottonseed containing gossypol (7400 mg/kg) on growth and development from weaning until pregnancy in Holstein heifers. Treatment diets (n = 5) contained 0, 15, or 30% whole cottonseed. The basal diet included alfalfa hay, corn grain, soybean meal, molasses, and dicalcium phosphate. Gossypol content of the treatment diets was 0, 1300, and 2000 mg/kg, and gossypol content in feces was 0, 290, and 1170 mg/kg, respectively, for treatments containing 0, 15, and 30% whole cottonseed. Estimated ingestion of gossypol (accumulated) was 0, 8, and 12 g/kg of BW, respectively, for treatments containing 0, 15, and 30% whole cottonseed during the 431-d experiment. Erythrocyte fragility was similar among treatment groups on d -3; on d 228, erythrocyte fragility was similar for heifers fed treatments containing 0 and 15% whole cottonseed, but was lower than that for heifers fed the 30% whole cottonseed diet. However, on d 430, fragility of erythrocytes increased linearly as the percentage of whole cottonseed increased. Clinical profiles of serum suggest possible impairment of liver and kidney function on d 144 and 430. Age and BW at onset of puberty and pregnancy rates were similar among treatments. One heifer fed the 30% whole cottonseed died on d 396, possibly from gossypol toxicosis. Long-term dietary supplementation at 15 to 30% whole cottonseed for long periods should be examined further for gossypol content and toxicity response of heifers and for effects on growth and development.

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Two trials were conducted to evaluate effects of dietary potassium (K) concentration and lasalocid (L) in lamb finishing diets. Treatments were arranged in a 2 X 2 factorial and consisted of a 65% concentrate diet with 1.1% K (C), .9% K + 21.3 mg L/kg (CL), 2.1% K (P) and 2.5% K + 20 mg L/kg (PL). In trial 1, 64 fine-wool lambs (initial wt 35.3 kg) were randomly assigned to the four treatments (two pens of four wethers and four ewes/treatment) for a 56-d feeding trial. Average daily gain was not affected by K, but was increased (P less than .10) by L (.23 vs .26 kg/d). Lasalocid tended (P less than .20) to improve feed:gain ratio (5.6 vs 6.3). A K X L interaction (P less than .06) was noted for feed intake, with values of 1.37, 1.45, 1.49 and 1.51 kg X head-1 X d-1 for the C, CL, P and PL groups, respectively. In trial 2, 16 wether lambs (four/treatment fed at 2% of body weight) were used in a site and extent of digestion and nitrogen (N) balance trial, using the same four diets as in trial 1. Site of digestion was estimated from abomasal samples taken at slaughter, with indigestible acid detergent fiber as a marker. Total tract organic matter digestibility was increased (P less than .05) with added K (80.1 vs 76.4%) and L (80 vs 76.4%). Ruminal starch digestibility was not affected by added K, but was decreased (P less than .10) by added L (71.8 vs 88.2%).(ABSTRACT TRUNCATED AT 250 WORDS)

Bacterial lipopolysaccharide endotoxins (LPS) elicit inflammatory responses reflective of acute bacterial infection. We determine if feeding ewes high (15.5 %) or low (8.5 %) CP diets for 10 d altered inflammatory responses to an i.v. bolus of 0 (control), 0.75 (L75), or 1.50 (L150) μg LPS/kg BW in a 2 × 3 factorial (n = 5/treatment). Rectal temperatures, heart and respiratory rates, blood leukocyte concentrations, and serum cortisol, insulin, and glucose concentrations were measured for 24 h after an LPS bolus (bolus = 0 h). In general, rectal temperatures were greater (P ≤ 0.05) in control ewes fed high CP, but LPS increased (P ≤ 0.05) rectal temperature in a dose-dependent manner at most times between 2 and 24 h after bolus. Peak rectal temperature in L75 and L150 occurred 4 h after bolus. A monophasic, dose-independent rise (P ≤ 0.023) in serum cortisol occurred from 0.5 to 24 h after bolus, with peak cortisol at 4 h. Serum insulin was increased (P ≤ 0.016) by LPS in a dose-dependent manner from 4 to 24 h after bolus. Insulin did not differ between control ewes fed high and low CP diets but was greater (P < 0.001) in L75 ewes fed low compared with high CP and in L150 ewes fed high compared with low CP. Elevated insulin was not preceded by elevated serum glucose. Total white blood cell concentrations were not affected (P ≥ 0.135) by LPS, but neutrophil and monocyte fractions of white blood cells were increased (P ≤ 0.047) by LPS at 12 and 24 h and at 24 h after bolus, respectively, and lymphocyte fraction was increased (P = 0.037) at 2 h and decreased (P ≤ 0.006) at 12 and 24 h after bolus. Red blood cell and hemoglobin concentrations and hematocrit (%) were elevated (P ≤ 0.022) by LPS at 2 and 4 h after bolus. Rectal temperatures and serum glucose were greater (P ≤ 0.033) in ewes fed a high CP diet before LPS injection, but these effects were lost at and within 2.5 h of bolus, respectively. Feeding high CP diets for 10 d did not reduce inflammation in ewes during the first 24 h after LPS exposure but may benefit livestock by preventing acute insulin resistance when endotoxin exposure is mild.

Early gestation is a critical period when implantation and placental vascularization are established, processes influenced by progesterone (P 4 ). Although human chorionic gonadotropin (hCG) is not endogenously synthesized by livestock, it binds the LH receptor, stimulating P 4 synthesis. We hypothesized treating pregnant ewes with hCG would increase serum P 4 , number of corpora lutea (CLs) and concepti, augment steroidogenic enzymes, and increase membrane P 4 receptors (PAQRs) and angiogenic factors in reproductive tissues. The objective was to determine molecular alterations induced by hCG in pregnant sheep that may promote pregnancy. Ewes received either 600 IU of hCG or saline i.m. on day 4 post mating. Blood samples were collected daily from day 0 until tissue collection for serum P 4 analysis. Reproductive tissues were collected on either day 13 or 25 of gestation and analyzed for PAQRs, CXCR4, proangiogenic factors and steroidogenic enzymes. Ewes receiving hCG had more CL and greater serum P 4 , which remained elevated. On day 25, StAR protein production decreased in CL from hCG-treated ewes while HSD3B1 was unchanged; further, expression of CXCR4 significantly increased and KDR tended to increase. PAQR7 and CXCR4 protein was increased in caruncle tissue from hCG-treated ewes. Maternal hCG exposure influenced fetal extraembryonic tissues, as VEGFA, VEGFB, FLT1, and ANGPT1 expression increased. Our results indicate hCG increases serum P 4 due to augmented CL number per ewe. hCG treatment resulted in greater PAQR7 and CXCR4 in maternal endometrium and promoted expression of proangiogenic factors in fetal extraembryonic membranes. Supplementing livestock with hCG may boost P 4 levels and improve reproductive efficiency.Reproduction (2015) 150 43-52